Sören Verstraete, Sascha C Verbruggen, José A Hordijk, Ilse Vanhorebeek, Karolijn Dulfer, Fabian Güiza, Esther van Puffelen, An Jacobs, Sandra Leys, Astrid Durt, Hanna Van Cleemput, Renate D Eveleens, Gonzalo Garcia Guerra, Pieter J Wouters, Koen F Joosten, Greet Van den Berghe

Withholding early parenteral nutrition for 1 week in the PICU did not negatively affect survival, anthropometrics, health status, and neurocognitive development, and improved inhibitory control 2 years after PICU admission.

Bartholomew, T. L., Kidd, T. J., Sa Pessoa, J., Conde Alvarez, R., Bengoechea, J. A.

Acinetobacter baumannii causes a wide range of nosocomial infections. This pathogen is considered a threat to human health due to the increasing isolation of multidrug resistant strains. There is a major gap in knowledge on the infection biology of A. baumannii, and only few virulence factors have been characterized including the lipopolysaccharide. The lipid A expressed by A. baumannii is hepta-acylated and contains 2-hydroxylaurate. The late acyltransferases controlling the acylation of the lipid A have been already characterized. Here we report the characterization of A. baumannii LpxO, which encodes the enzyme responsible for the 2-hydroxylation of the lipid A. By genetic methods and mass spectrometry, we demonstrate that LpxO catalyses the 2-hydroxylation of the laurate transferred by A. baumannii LpxL. LpxO-dependent lipid A 2-hydroxylation protects A. baumannii from polymyxin B, colistin, and human β-defensin 3. LpxO contributes to survival of A. baumannii in human whole blood, and is required for pathogen survival in the waxmoth Galleria mellonella. LpxO also protects Acinetobacter from G. mellonella antimicrobial peptides and limits the expression of them. Further demonstrating the importance of LpxO-dependent modification in immune evasion, 2-hydroxylation of the lipid A limits the activation of MAPK JNK to attenuate inflammatory responses. In addition, LpxO-controlled lipid A modification mediates the production of the anti-inflammatory cytokine IL-10 via the activation of the transcriptional factor CREB. IL-10, in turn, limits the production of inflammatory cytokines following A. baumannii infection. Altogether, our studies suggest that LpxO is a candidate to develop anti A. baumannii drugs.…

Soentjens P, De Koninck K, Tsoumanis A, et al.

AbstractBACKGROUNDEffective and safe single-visit rabies vaccination for pre- and post-exposure prophylaxis (PrEP and PEP) could substantially simplify rabies prevention and therefore increase compliance.METHODSIn a comparative trial, 303 healthy adults received a primary vaccination consisting of two intradermal (ID) doses of 0.1mL of the purified chicken embryo cell vaccine (PCEV) during a single visit. One year later, subjects were randomly assigned to receive either four or two ID PEP booster doses of 0.1mL of PCEV during a single visit.The primary endpoint for immunogenicity was the percentage of subjects with an adequate antibody level (>0.5 IU/mL) seven days after the booster doses. The safety endpoint was the proportion of participants developing adverse events (AE) following primary and/or booster vaccination.RESULTSll subjects, except one (99.3%) in each study group, had a rabies antibody titer >0.5 IU/mL on day 7 following the booster schedules.Subjects exposed to the four-dose PEP schedule had a geometric mean titer of 20 IU/mL versus 14 IU/mL for the two-dose PEP schedule (p=0.0228).Local reactions at the injection site following PrEP and PEP were mild and transient and only seen in 14.9% and 49.6 to 53% of the participants respectively. No serious AE were reported.CONCLUSIONIn healthy adults, a two-dose (2x 0.1mL) single-visit intradermal post-exposure prophylaxis schedule was as immunologically adequate and safe as a four-dose (4x 0.1mL) single-visit PEP schedule, seven to twenty-eight months following a two-dose (2x 0.1mL) single-visit intradermal pre-exposure prophylaxis.

Heidar Ali Panahi, Azam Bolhassani, Gholamreza Javadi, Zahra Noormohammadi

by Heidar Ali Panahi, Azam Bolhassani, Gholamreza Javadi, Zahra Noormohammadi Human papillomaviruses (HPVs) are a group of circular double-stranded DNA viruses, showing severe tropism to mucosal tissues. A subset of HPVs, especially HPV16 and 18, are the primary etiological cause for several epithelial cell malignancies, causing about 5.2% of all cancers worldwide. Due to the high prevalence and mortality, HPV-associated cancers have remained as a significant health problem in human society, making an urgent need to develop an effective therapeutic vaccine against them. Achieving this goal is primarily dependent on the identification of efficient tumor-associated epitopes, inducing a robust cell-mediated immune response. Previous information has shown that E5, E6, and E7 early proteins are responsible for the induction and maintenance of HPV-associated cancers. Therefore, the prediction of major histocompatibility complex (MHC) class I T cell epitopes of HPV16, 18, 31 and 45 oncoproteins was targeted in this study. For this purpose, a two-step plan was designed to identify the most probable CD8+ T cell epitopes. In the first step, MHC-I and II binding, MHC-I processing, MHC-I population coverage and MHC-I immunogenicity prediction analyses, and in the second step, MHC-I and II protein-peptide docking, epitope conservation, and cross-reactivity with host antigens’ analyses were carried out successively by different tools. Finally, we introduced five probable CD8+ T cell epitopes for each oncoprotein of the HPV genotypes (60 epitopes in total), which obtained better scores by an integrated approach. These predicted epitopes are valuable candidates for in vitro or in vivo therapeutic vaccine studies against the HPV-associated cancers. Additionally, this two-step plan that each step includes several analyses to find appropriate epitopes provides a rational basis for DNA- or peptide-based vaccine development.

Sally Peprah, Constance Tenge, Isaiah O. Genga, Mediatrix Mumia, Pamela A. Were, Robert T. Kuremu, Walter N. Wekesa, Peter O. Sumba, Tobias Kinyera, Isaac Otim, Ismail D. Legason, Joshua Biddle, Steven J. Reynolds, Ambrose O. Talisuna, Robert J. Biggar, Kishor Bhatia, James J. Goedert, Ruth M. Pfeiffer and Sam M. Mbulaiteye

Abstract. The burden of Plasmodium falciparum (Pf) malaria in Kenya is decreasing; however, it is still one of the top 10 causes of morbidity, particularly in regions of western Kenya. Between April 2015 and June 2016, we enrolled 965 apparently healthy children aged 0–15 years in former Nyanza and Western Provinces in Kenya to characterize the demographic, geographic, and household risk factors of asymptomatic malaria as part of an epidemiologic study to investigate the risk factors for endemic Burkitt lymphoma. The children were sampled using a stratified, multistage cluster sampling survey design. Malaria was assessed by rapid diagnostic test (RDT) and thick-film microscopy (TFM). Primary analyses of Pf malaria prevalence (pfPR) are based on RDT. Associations between weighted pfPR and potential risk factors were evaluated using logistic regression, accounting for the survey design. Plasmodium falciparum malaria prevalence was 36.0% (27.5%, 44.5%) by RDT and 22.3% (16.0%, 28.6%) by TFM. Plasmodium falciparum malaria prevalence was positively associated with living in the lake-endemic area (adjusted odds ratio [aOR] 3.46; 95% confidence interval [95% CI] 1.63, 7.37), paternal occupation as peasant farmer (aOR 1.87; 1.08, 3.26) or manual laborer (aOR 1.83; 1.00, 3.37), and keeping dogs (aOR 1.62; 0.98–2.69) or cows (aOR 1.52; 0.96–2.40) inside or near the household. Plasmodium falciparum malaria prevalence was inversely associated with indoor residual insecticide spraying (IRS) (aOR 0.44; 0.19, 1.01), having a household connected to electricity (aOR 0.47; 0.22, 0.98), and a household with two (aOR 0.45; 0.22, 0.93) or ≥ three rooms (aOR 0.41; 0.18, 0.93). We report high but geographically heterogeneous pfPR in children in western Kenya and significant associations with IRS and household-level socioeconomic factors.…

Lauren Zebertavage, Shelly Bambina, Jessica Shugart, Alejandro Alice, Kyra D. Zens, Peter Lauer, Bill Hanson, Michael J. Gough, Marka R. Crittenden, Keith S. Bahjat

by Lauren Zebertavage, Shelly Bambina, Jessica Shugart, Alejandro Alice, Kyra D. Zens, Peter Lauer, Bill Hanson, Michael J. Gough, Marka R. Crittenden, Keith S. Bahjat Dysregulated signaling via the epidermal growth factor receptor (EGFR)-family is believed to contribute to the progression of a diverse array of cancers. The most common variant of EGFR is EGFRvIII, which results from a consistent and tumor-specific in-frame deletion of exons 2–7 of the EGFR gene. This deletion generates a novel glycine at the junction and leads to constitutive ligand-independent activity. This junction forms a novel shared tumor neo-antigen with demonstrated immunogenicity in both mice and humans. A 21-amino acid peptide spanning the junctional region was selected, and then one or five copies of this 21-AA neo-peptide were incorporated into live-attenuated Listeria monocytogenes-based vaccine vector. These vaccine candidates demonstrated efficient secretion of the recombinant protein and potent induction of EGFRvIII-specific CD8+ T cells, which prevented growth of an EGFRvIII-expressing squamous cell carcinoma. These data demonstrate the potency of a novel cancer-specific vaccine candidate that can elicit EGFRvIII-specific cellular immunity, for the purpose of targeting EGFRvIII positive cancers that are resistant to conventional therapies.

Hsu C, Chang I, Hsieh P, et al.

AbstractKlebsiella pneumoniae is an important human pathogen causing hospital-acquired and community-acquired infections. Systemic K. pneumoniae infections may be preceded by gastrointestinal colonization, but the basis of this bacterium’s interaction with the intestinal epithelium remains unclear. Here, we report that the K. pneumoniae Sap (sensitivity to antimicrobial peptides) transporter contributes to bacterial–host cell interactions and in vivo virulence. Gene deletion showed that sapA is required for the adherence of a K. pneumoniae blood isolate to intestinal epithelial, lung epithelial, urinary bladder epithelial, and liver cells. The ΔsapA mutant was deficient for translocation across intestinal epithelial monolayers, macrophage interactions, and induction of proinflammatory cytokines. In a mouse gastrointestinal infection model, ΔsapA yielded significantly decreased bacterial loads in liver, spleen and intestine, reduced liver abscess generation, and decreased mortality. These findings offer new insights into the pathogenic interaction of K. pneumoniae with the host gastrointestinal tract to cause systemic infection.

Ortega, Sterling B.; Pandiyan, Poornima; Windsor, Jana; Torres, Vanessa O.; Selvaraj, Uma M.; Lee, Amy; Morriss, Michael; Tian, Fenghua; Raman, Lakshmi; Stowe, Ann M.

Objectives: Extracorporeal membrane oxygenation provides short-term cardiopulmonary life support, but is associated with peripheral innate inflammation, disruptions in cerebral autoregulation, and acquired brain injury. We tested the hypothesis that extracorporeal membrane oxygenation also induces CNS-directed adaptive immune responses which may exacerbate extracorporeal membrane oxygenation-associated brain injury. Design: A single center prospective observational study. Setting: Pediatric and cardiac ICUs at a single tertiary care, academic center. Patients: Twenty pediatric extracorporeal membrane oxygenation patients (0–14 yr; 13 females, 7 males) and five nonextracorporeal membrane oxygenation Pediatric Logistic Organ Dysfunction score matched patients Interventions: None. Measurements and Main Results: Venous blood samples were collected from the extracorporeal membrane oxygenation circuit at day 1 (10–23 hr), day 3, and day 7 of extracorporeal membrane oxygenation. Flow cytometry quantified circulating innate and adaptive immune cells, and CNS-directed autoreactivity was detected using an in vitro recall response assay. Disruption of cerebral autoregulation was determined using continuous bedside near-infrared spectroscopy and acquired brain injury confirmed by MRI. Extracorporeal membrane oxygenation patients with acquired brain injury (n = 9) presented with a 10-fold increase in interleukin-8 over extracorporeal membrane oxygenation patients without brain injury (p < 0.01). Furthermore, brain injury within extracorporeal membrane oxygenation patients potentiated an inflammatory phenotype in adaptive immune cells and selective autoreactivity to brain peptides in circulating B cell and cytotoxic T cell populations. Correlation analysis revealed a significant relationship between adaptive immune responses of extracorporeal membrane oxygenation patients with acquired brain injury and loss of cerebral autoregulation. Conclusions: We show that pediatric extracorporeal membrane oxygenation patients with acquired brain injury exhibit an induction of pro-inflammatory cell signaling, a robust activation of adaptive immune cells, and CNS-targeting adaptive immune responses. As these patients experience developmental delays for years after extracorporeal membrane oxygenation, it is critical to identify and characterize adaptive immune cell mechanisms that target the developing CNS. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Drs. Ortega, Pandiyan, Raman, and Stowe contributed equally. Drs. Ortega and Pandiyan designed, performed, and analyzed the immunology-based assays and co-wrote the article. Dr. Pandiyan performed and analyzed the immunology-based assays as well as recruited patients and co-wrote the article. Ms. Windsor and Dr. Lee recruited patients and Ms. Windsor, Ms. Torres, Ms. Selvaraj, and Dr. Stowe processed samples. Dr. Tian quantified autoregulation disruption based on wavelength transform coherence. Dr. Morriss scored all neuroimaging. Drs. Raman and Stowe designed and supervised the study and co-wrote the article. All authors read, edited, and approved of the article. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (http://journals.lww.com/ccmjournal). Drs. Tian and Raman were supported, in part by, American Heart Association (AHA) Beginning-Grant-in Aid (15BGIA25860045). Drs. Pandiyan and Raman were funded by Extracorporeal Life Support Organization research grant and UT Southwestern Center for Translational Medicine award. Research reported in this publication was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health under award number UL1TR001105. Dr. Stowe was supported from the AHA (14SDG 18410020), National Institutes of Health/National Institute of Neurological Disorders and Stroke (NS088555), Dr. Ortega (14POST20480373) and Ms. Selvaraj (17PRE33660147) from the AHA. Drs. Ortega’s, Pandiyan’s, Windsor’s, and Stowe’s institutions received funding from Extracorporeal Life Support Organization and National Center for Advancing Translational Sciences of the National Institutes of Health (NIH) under award number UL1TR001105. Drs. Ortega, Pandiyan, Windsor, Torres, Raman, and Stowe received support for article research from the NIH. Dr. Tian’s institution received funding from the American Heart Association, and he disclosed work for hire. The remaining authors have disclosed that they do not have any potential conflicts of interest. Address requests for reprints to: Ann M. Stowe, PhD, Department of Neurology, University of Kentucky College of Medicine, 741 S. Limestone St., BBSRB 363, Lexington, KY, 40536. E-mail: Ann.Stowe@uky.edu Copyright © by 2019 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.

Dubé M, Chan E, Lake J, et al.

AbstractBackgroundDipeptidyl peptidase-4 (DPP-4) inhibitors have pleotropic anti-inflammatory and immune regulatory effects in addition to their glucoregulatory actions. We evaluated inflammation and immune markers in suppressed HIV infection during treatment with the DPP-4 inhibitor sitagliptin.MethodsVirologically suppressed adults with HIV without diabetes mellitus on stable ART with ≥100/mm 3 CD4 cells were randomized to 16 weeks of sitagliptin 100 mg/d vs. placebo in a multicenter trial. The primary endpoint was the change in plasma soluble CD14 (sCD14) from baseline to week 15/16. Additional soluble biomarkers, and lymphocyte and monocyte activation were assessed.ResultsNinety participants were randomized, and 42 from each arm were included in per-protocol analyses. Evaluable participants were 45% non-Hispanic white, 38% non-Hispanic black, 15% Hispanic, median age of 51 years, 83% male, with median CD4 count 602 cells/mm 3. At week 15/16, there was no difference in sCD14 change between the two arms (p=0.69). Relative to placebo, the sitagliptin arm had 47% greater decline in CXCL10 (95% CI:-57,-35) at week 15 (p

Huang, Y., Alumasa, J. N., Callaghan, L. T., Baugh, S., Rae, C., Keiler, K. C., McGillivray, S. M.

Staphylococcus aureus is a leading cause of infection in the US and, due to the rapid development of resistance, new antibiotics are constantly needed. Trans-translation is a particularly promising antibiotic target because it is conserved in many bacterial species, is critical to bacterial survival, and is unique among prokaryotes. We have investigated the potential of KKL-40, a small molecule inhibitor of trans-translation, and find that it inhibits both methicillin-susceptible and methicillin-resistant strains of S. aureus. KKL-40 is also effective against Gram-positive pathogens including a vancomycin-resistant strain of Enterococcus faecalis, Bacillus subtilis and Streptococcus pyogenes, although its performance with Gram-negatives is mixed. KKL-40 synergistically interacts with the human antimicrobial peptide LL-37, a member of the cathelicidin family, to inhibit S. aureus but not other antibiotics tested including daptomycin, kanamycin or erythromycin. KKL-40 is not cytotoxic to HeLa cells at concentrations that are 100-fold greater than the effective MIC. We also find that S. aureus develops minimal resistance to KKL-40 even after multi-day passage in sub-lethal concentrations. Therefore, trans-translation inhibitors could be a particularly promising drug target against S. aureus, not only because of their ability to inhibit bacterial growth, but also because of their potential to simultaneously render S. aureus more susceptible to host antimicrobial peptides.…

Ling-juan Zhang, Stella Xiang Chen, Christian F. Guerrero-Juarez, Fengwu Li, Yun Tong, Yuqiong Liang, Marc Liggins, Xu Chen, Hao Chen, Min Li, Tissa Hata, Ye Zheng, Maksim V. Plikus, Richard L. Gallo

Dermal immature adipocytes fight against Staphylococcus aureus infection by secreting antimicrobial peptides during adipogenesis. Zhang et al. demonstrate that activation of the TGF-β pathway suppresses the adipogenic potential of dermal fibroblasts and therefore leads to an age-dependent loss of antimicrobial protection from dermal fat.

Abstract The ongoing transmission of Mycobacterium (M.) leprae reflected in a very slow decline in leprosy incidence, forces us to be innovative and conduct cutting-edge research. Single dose rifampicin (SDR) as post-exposure prophylaxis (PEP) for contacts of leprosy patients, reduces their risk to develop leprosy by 60%. This is a promising new preventive measure that can be integrated into routine leprosy control programmes, as is being demonstrated in the Leprosy Post-Exposure Programme that is currently ongoing in eight countries. The limited (60%) effectiveness of SDR is likely due to the fact that some contacts have a preclinical infection beyond the early stages for which SDR is not sufficient to prevent the development of clinical signs and symptoms of leprosy. An enhanced regimen, more potent against a higher load of leprosy bacteria, would increase the effectiveness of this preventive measure significantly. The Netherlands Leprosy Relief (NLR) is developing a multi-country study aiming to show that breaking the chain of transmission of M. leprae is possible, evidenced by a dramatic reduction in incidence. In this study the assessment of the effectiveness of an enhanced prophylactic regimen for leprosy is an important component. To define the so called PEP++ regimen for this intervention study, NLR convened an Expert Meeting that was attended by clinical leprologists, public health experts, pharmacologists, dermatologists and microbiologists. The Expert Meeting advised on combinations of available drugs, with known efficacy against leprosy, as well as on the duration of the intake, aiming at a risk reduction of 80–90%. To come to a conclusion the Expert Meeting considered the bactericidal, sterilising and bacteriostatic activity of the potential drugs. The criteria used to determine an optimal enhanced regimen were: effectiveness, safety, acceptability, availability, affordability, feasibility and not inducing drug resistance. The Expert Meeting concluded that the enhanced regimen for the PEP++ study should comprise three standard doses of rifampicin 600 mg (weight adjusted when given to children) plus moxifloxacin 400 mg given at four-weekly intervals. For children and for adults with contraindications for moxifloxacin, moxifloxacin should be replaced by clarithromycin 300 mg (weight adjusted).…

Andreoni, F., Toyofuku, M., Menzi, C., Kalawong, R., Mairpady Shambat, S., Francois, P., Zinkernagel, A. S., Eberl, L.

Bacterial membrane vesicles research has so far mainly focussed on Gram-negative bacteria. Only recently Gram-positive bacteria have been demonstrated to produce and release extracellular membrane vesicles (MVs) that contribute to bacterial virulence. Although treatment of bacteria with antibiotics is a well-established trigger of bacterial MVs formation, the underlying mechanisms are poorly understood. In this study we show that antibiotics can induce MVs through different routes in the important human pathogen Staphylococcus aureus. DNA damaging agents and antibiotics inducing the SOS response triggered vesicle formation in lysogenic strains of S. aureus but not in their phage-devoid counterparts. β-lactam antibiotics flucloxacillin and ceftaroline increased vesicle formation in a prophage-independent manner by weakening the peptidoglycan layer. We present evidence that the amount of DNA associated with MVs formed by phage lysis is higher than that of MVs formed by β-lactam antibiotics-induced blebbing. The purified MVs derived from S. aureus protected the bacteria from challenge with daptomycin, a membrane-targeting antibiotic, both in vitro and ex vivo in whole blood. In addition, the MVs protected S. aureus from killing in whole blood, indicating that antibiotic-induced MVs function as a decoy and thereby contribute to the survival of the bacterium.…

McLean, K., Holmes, E. A., Penewit, K., Lee, D. K., Hardy, S. R., Ren, M., Krist, M. P., Huang, K., Waalkes, A., Salipante, S. J.

Adaptation of Staphylococcus aureus to host microenvironments during chronic infection involves spontaneous mutations, yet changes underlying adaptive phenotypes remain incompletely explored. Here we employed artificial selection and whole genome sequencing to better characterize spontaneous chromosomal mutations that alter two pathogenicity phenotypes relevant to chronic infection in S. aureus: intracellular invasiveness and intracellular cytotoxicity. We identified 23 genes whose alteration coincided with enhanced virulence, 11 that were previously known and 12 of which (52%) had no previously described role in S. aureus pathogenicity. Using precision genome editing, transposon mutants, and gene complementation, we empirically assessed the contributions of individual genes to the two virulence phenotypes. We functionally validated 14 of 21 genes tested as measurably influencing invasion and/or cytotoxicity, including 8 newly implicated by this study. We identified inactivating mutations (murA, ndhC, and a hypothetical membrane protein) and gain-of-function mutations (aroE Thr182Ile, yhcF Thr74Ile, and Asp486Glu in a hypothetical peptidase) in previously unrecognized S. aureus virulence genes that enhance pathogenesis when introduced into a clean genetic background, as well as a novel activating mutation in known virulence regulator saeS (Ala106Thr). Investigation of potentially epistatic interactions identified a tufA mutation (Ala271Val) that enhances virulence only in the context of purine operon repressor (purR) inactivation. This project reveals a functionally diverse range of genes affected by gain- or loss-of-function mutations that contribute to S. aureus adaptive virulence phenotypes. More generally, the work establishes artificial selection as a means to determine the genetic mechanisms underlying complex bacterial phenotypes relevant to adaptation during infection.…

Carlos Iniesta, Débora Álvarez-del Arco, Luis Miguel García-Sousa, Belén Alejos, Asunción Díaz, Nieves Sanz, Jorge Garrido, Michael Meulbroek, Ferran Pujol, Santiago Moreno, María José Fuster-Ruiz de Apocada, Pep Coll, Antonio Antela, Jorge del Romero, Oskar Ayerdi, Melchor Riera, Juanse Hernández, Julia del Amo

by Carlos Iniesta, Débora Álvarez-del Arco, Luis Miguel García-Sousa, Belén Alejos, Asunción Díaz, Nieves Sanz, Jorge Garrido, Michael Meulbroek, Ferran Pujol, Santiago Moreno, María José Fuster-Ruiz de Apocada, Pep Coll, Antonio Antela, Jorge del Romero, Oskar Ayerdi, Melchor Riera, Juanse Hernández, Julia del Amo Objective To assess the awareness, knowledge, use, and willingness to use and need of PrEP among men who have sex with men (MSM) and transgender women (TW) who attended World Gay Pride (WGP) 2017 in Madrid. Design and methods Online survey. Participants were recruited through gay-oriented dating apps and HIV Non-Governmental Organizations´ social media. Inclusion criteria included being MSM or TW, age 18 years old or above, and having attended WGP in Madrid. Information regarding the participant’s awareness and knowledge, use or willingness to use, and need for PrEP was collected, as well as sociodemographic characteristics. Participants were considered to be in need of PrEP if they met one of the following indication criteria: having practiced unprotected anal intercourse with more than 2 partners, having practiced chemsex, or having engaged in commercial sex—all in the preceding 6 months. Descriptive and multivariable analyses with logistic regression were conducted. Results 472 participants met the inclusion criteria and completed the questionnaire. The mean age was 38, 97.7% were MSM, 77% had a university education, and 85% were living in Spain, mostly in big cities. Overall, 64% of participants were aware of PrEP, but only 33% knew correctly what PrEP was. 67% of HIV-negative participants were willing to take PrEP, although only 5% were taking it during WGP, mostly due to lack of access. 43% of HIV-negative respondents met at least one PrEP indication criteria. For HIV-negative men living in Spain, university education and living in big cities was associated with PrEP awareness. Lower education level and meeting PrEP criteria was associated with willingness to use PrEP. Conclusions Our study shows that among MSM attending WGP 2017 in Madrid, there was limited PrEP awareness, low accuracy of PrEP knowledge, and a high need and willingness to use PrEP. Health authorities should strengthen existing preventive strategies and implement PrEP.…

Patrick Ebner, Friedrich Götz

The excretion of cytoplasmic and signal-peptide-less proteins (ECP) by microorganisms and eukaryotes remains a fascinating topic. In principle, it appears to be a waste of energy. However, it turns out that – extracellularly – some cytoplasmic proteins (CPs) exert a completely different function such as contributing to pathogenicity or evasion of the immune system. Such CPs have been referred to as ‘moonlighting’ proteins. ECP is boosted by many endogenous or external factors that impair the membrane or cell wall structure.

Helene Botella, Julien Vaubourgeix

Fluorescent amino acid analogs have proven to be useful tools for studying the dynamics of peptidoglycan metabolism. García-Heredia and colleagues showed that their route of incorporation differs depending on the adjunct fluorophore and applied this property to investigate mycobacterial peptidoglycan synthesis and remodeling with heightened granularity.

Derek B. Laskar, Michael Rose, Raavi Gupta, Herbert B. Tanowitz and M. A. Haseeb

Abstract. A 63-year-old woman who migrated from Nigeria to the United States was found to have an elevated total serum protein, anemia, and eosinophilia. Serum protein electrophoresis (SPEP) and serum protein immunofixation electrophoresis (SPIFE) demonstrated monoclonal immunoglobulin G (IgG) κ restricted bands (IgG 3,820 mg/dL; κ/λ ratio 4.47), indicative of monoclonal gammopathy of unknown significance (MGUS). A rapid diagnostic test (RDT) for malaria was positive for Plasmodium falciparum (BinaxNOW®; Alere Scarborough Inc., Scarborough, ME). Giemsa-stained blood smears were negative for malarial parasites, however, Loa loa microfilariae were identified. Reverse transcription polymerase chain reaction for P. falciparum, Plasmodium ovale, Plasmodium malariae, and Plasmodium vivax yielded a negative result. She was treated for loiasis with diethylcarbamazine and received no malaria medication. Treatment resulted in a resolution of the microfilaremia and eosinophilia, a negative RDT for malaria, and marked reduction in the monoclonal gammopathy. This is the first reported human case of MGUS associated with loiasis and its resolution after antiparasitic treatment.…

Wuerth, K., Lee, A. H. Y., Falsafi, R., Gill, E. E., Hancock, R. E. W.

Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial pneumonia and infects patients with cystic fibrosis. P. aeruginosa lung infections are difficult to treat due to bacterial resistance to antibiotics, and strains with multi-drug resistance are becoming more prevalent. Here we examined the use of a small host defense peptide, innate defense regulator 1002 (IDR-1002), in an acute P. aeruginosa lung infection in vivo. IDR-1002 significantly reduced the bacterial burden in the bronchoalveolar lavage fluid (BALF) as well as MCP-1 in the BALF and serum, KC in the serum, and IL-6 in the BALF. RNA-Seq was conducted on lungs and whole blood and the effects of P. aeruginosa, IDR-1002, or the combination of P. aeruginosa and IDR-1002 were evaluated. Differential gene expression analysis showed that P. aeruginosa increased multiple inflammatory and innate immune pathways as well as affected hemostasis, matrix metalloproteinases, collagen biosynthesis, and various metabolism pathways in the lungs and/or blood. Infected mice treated with IDR-1002 had significant changes in gene expression compared to untreated infected mice, with fewer differentially expressed genes associated with the inflammatory and innate immune responses to microbial infection, and treatment also affected morphogenesis, certain metabolic pathways, and lymphocyte activation. Overall, these results show that IDR-1002 was effective in treating P. aeruginosa acute lung infections and associated inflammation.…

Brynildsen, Jon; Petäjä, Liisa; Myhre, Peder L.; Lyngbakken, Magnus N.; Nygård, Ståle; Stridsberg, Mats; Christensen, Geir; Ottesen, Anett H.; Pettilä, Ville; Omland, Torbjørn; Røsjø, Helge

Objectives: Secretoneurin is associated with cardiomyocyte Ca2+ handling and improves risk prediction in patients with acute myocardial dysfunction. Whether secretoneurin improves risk assessment on top of established cardiac biomarkers and European System for Cardiac Operative Risk Evaluation II in patients undergoing cardiac surgery is not known. Design: Prospective, observational, single-center sub-study of a multicenter study. Setting: Prospective observational study of survival in patients undergoing cardiac surgery. Patients: A total of 619 patients undergoing cardiac surgery. Interventions: Patients underwent either isolated coronary artery bypass graft surgery, single noncoronary artery bypass graft surgery, two procedures, or three or more procedures. Procedures other than coronary artery bypass graft were valve surgery, surgery on thoracic aorta, and other cardiac surgery. Measurements and Main Results: We measured preoperative and postoperative secretoneurin concentrations and adjusted for European System for Cardiac Operative Risk Evaluation II, N-terminal pro-B-type natriuretic peptide, and cardiac troponin T concentrations in multivariate analyses. During 961 days of follow-up, 59 patients died (9.5%). Secretoneurin concentrations were higher among nonsurvivors compared with survivors, both before (168 pmol/L [quartile 1–3, 147–206 pmol/L] vs 160 pmol/L [131–193 pmol/L]; p = 0.039) and after cardiac surgery (173 pmol/L [129–217 pmol/L] vs 143 pmol/L [111–173 pmol/L]; p < 0.001). Secretoneurin concentrations decreased from preoperative to postoperative measurements in survivors, whereas we observed no significant decrease in secretoneurin concentrations among nonsurvivors. Secretoneurin concentrations were weakly correlated with established risk indices. Patients with the highest postoperative secretoneurin concentrations had worse outcome compared with patients with lower secretoneurin concentrations (p < 0.001 by the log-rank test) and postoperative secretoneurin concentrations were associated with time to death in multivariate Cox regression analysis: hazard ratio lnsecretoneurin 2.96 (95% CI, 1.46–5.99; p = 0.003). Adding postoperative secretoneurin concentrations to European System for Cardiac Operative Risk Evaluation II improved patient risk stratification, as assessed by the integrated discrimination index: 0.023 (95% CI, 0.0043–0.041; p = 0.016). Conclusions: Circulating postoperative secretoneurin concentrations provide incremental prognostic information to established risk indices in patients undergoing cardiac surgery. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (http://journals.lww.com/ccmjournal). Akershus University Hospital and the Research Council of Norway supported this study. The FINNish Acute Kidney Injury Study got the special state subsidy (EVO) grants from Helsinki University (TYH 2013343, TYH 2013106, and T102010070), from Academy of Finland. Dr. Petäjä’s institutions received funding from EVO grants from Helsinki University (TYH 2013343, TYH 2013106, and T102010070), and they disclosed that the Academy of Finland supported FINNish Acute Kidney Injury Study. Drs. Christensen, Omland, and Røsjø disclosed that they are partners in a patent (PCT/GB0818650.4) filed by the University of Oslo regarding the use of secretoneurin as a biomarker in patients with cardiovascular disease and patients with critical illness, and they have financial interests in CardiNor AS, which holds the license to commercialize secretoneurin. They have also received personal fees from CardiNor AS. Drs. Myhre, Omland, and Røsjø have also received personal fees from Novartis. Dr. Omland received funding as a member of the editorial board of the journal Circulation, and from Abbott, Bayer, Roche, and Novartis. He has also received research funding from Abbott, Roche, Singulex, and AstraZeneca. Dr. Omland has served on advisory boards and received speaker´s honoraria and travel funding from Roche Diagnostics and Roche Diagnostics provided high-sensitivity troponin T and N-terminal pro-B-type natriuretic peptide kits at a reduced price via Akershus University Hospital. Drs. Omland and Rosjo disclosed that Akershus University Hospital and the Research Council of Norway supported this study. The remaining authors have disclosed that they do not have any potential conflicts of interest. Address requests for reprints to: Helge Røsjø, MD, PhD, Division of Medicine, Akershus University Hospital, Sykehusveien 25, 1478 Lørenskog, Norway. E-mail: helge.rosjo@medisin.uio.no Copyright © by 2019 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.

Yang, H., Gong, Y., Zhang, H., Etobayeva, I., Miernikiewicz, P., Luo, D., Li, X., Zhang, X., Dabrowska, K., Nelson, D. C., He, J., Wei, H.

Streptococcus pneumoniae is one of the leading pathogens that cause a variety of mucosal and invasive infections. With the increased emergence of multidrug-resistant S. pneumoniae, new antimicrobials with mechanisms of action different from conventional antibiotics are urgently needed. In this study, we identified a putative lysin (gp20) encoded by the Streptococcus phage SPSL1 using the LytA autolysin as a template. Molecular dissection of gp20 revealed a binding domain (GPB) containing choline-binding repeats (CBRs) that are high specificity for S. pneumoniae. By fusing GPB to the CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) catalytic domain of the PlyC lysin, we constructed a novel chimeric lysin, ClyJ, with improved activity to the pneumococcal Cpl-1 lysin. No resistance was observed in S. pneumoniae strains after exposure to incrementally doubling concentrations of ClyJ for 8 continuous days in vitro. In a mouse bacteremia model using penicillin G as a control, a single intraperitoneal injection of ClyJ improved the survival rate of lethal S. pneumoniae infected mice in a dose-dependent manner. Giving its high lytic activity and safety profile, ClyJ may represent a promising alternative to combat pneumococcal infections.…

Habib Hasan Farooqui, Sakthivel Selvaraj, Aashna Mehta, David L. Heymann

by Habib Hasan Farooqui, Sakthivel Selvaraj, Aashna Mehta, David L. Heymann India was the largest consumer of antibiotics in 2010 in the world. Evidence suggests that countries with high per-capita antibiotic consumption have higher rates of antibiotic resistance. To control antibiotic resistance, not only reduction in antibiotic consumption is required, socio-economic factors like access to clean water and sanitation, regulation of private healthcare sector and better governance are equally important. The key objective of this research was to investigate the five year trends in consumption of major antibiotic classes in India and compare them with European Surveillance of Antimicrobial Consumption Network (ESAC-Net) countries. We used Intercontinental Marketing Statistics (IMS) Health (now IQVIA) medicine sales audit data of antibiotic sales in the retail private sector (excluding the hospitals sector) in India. We then standardized dosage trends and assigned defined daily dose (DDD) to all formulations based on the ATC/DDD index. We expressed our data in standardized matrices of DDD per 1000 inhabitants’ per day (DID) to compare antibiotic use in India with ESAC-Net countries. The antibiotic use was plotted and reported by year and antibiotic class. Our main findings are—per capita antibiotic consumption in the retail sector in India has increased from 13.1 DID in 2008 to 16.0 DID in 2012—an increase of ~22%; use of newer class of antibiotics like carbapenems (J01DH), lincosamides (J01FF), glycopeptides (J01XA), 3rd generation cephalosporins (J01DD) and penicillin’s with beta-lactamase inhibitors has risen; and antibiotic consumption rates in India are still low as compared to ESAC-Net countries (16.0 DID vs. 21.54 DID). To conclude our study has provided the first reliable estimates of antibiotic use in the retail sector in India vis-à-vis ESAC-Net countries. In addition, our study could provide a reference point to measure the impact of interventions directed towards reducing antibiotic use.

Lucy Mackenzie-Impoinvil, Gareth D. Weedall, Juan C. Lol, Jesús Pinto, Lucrecia Vizcaino, Nicole Dzuris, Jacob Riveron, Norma Padilla, Charles Wondji, Audrey Lenhart

by Lucy Mackenzie-Impoinvil, Gareth D. Weedall, Juan C. Lol, Jesús Pinto, Lucrecia Vizcaino, Nicole Dzuris, Jacob Riveron, Norma Padilla, Charles Wondji, Audrey Lenhart Decades of unmanaged insecticide use and routine exposure to agrochemicals have left many populations of malaria vectors in the Americas resistant to multiple classes of insecticides, including pyrethroids. The molecular basis of pyrethroid resistance is relatively uncharacterised in American malaria vectors, preventing the design of suitable resistance management strategies. Using whole transcriptome sequencing, we characterized the mechanisms of pyrethroid resistance in Anopheles albimanus from Peru and Guatemala. An. albimanus were phenotyped as either deltamethrin or alpha-cypermethrin resistant. RNA from 1) resistant, 2) unexposed, and 3) a susceptible laboratory strain of An. albimanus was sequenced and analyzed using RNA-Seq. Expression profiles of the three groups were compared based on the current annotation of the An. albimanus reference genome. Several candidate genes associated with pyrethroid resistance in other malaria vectors were found to be overexpressed in resistant An. albimanus. In addition, gene ontology terms related to serine-type endopeptidase activity, extracellular activity and chitin metabolic process were also commonly overexpressed in the field caught resistant and unexposed samples from both Peru and Guatemala when compared to the susceptible strain. The cytochrome P450 CYP9K1 was overexpressed 14x in deltamethrin and 8x in alpha-cypermethrin-resistant samples from Peru and 2x in deltamethrin-resistant samples from Guatemala, relative to the susceptible laboratory strain. CYP6P5 was overexpressed 68x in deltamethrin-resistant samples from Peru but not in deltamethrin-resistant samples from Guatemala. When comparing overexpressed genes between deltamethrin-resistant and alpha-cypermethrin-resistant samples from Peru, a single P450 gene, CYP4C26, was overexpressed 9.8x (p

To the Editor: In their study of the value of copeptin for diagnosing diabetes insipidus, Fenske et al. (Aug. 2 issue) overlook two possible methodologic flaws. First, some of their patients appear to have had an element of a solute diuresis. For example, among patients with primary polydipsia, the……

Hiroshi Wada, Atsushi Shimizu, Toshihiro Osada, Yuki Tanaka, Satoshi Fukaya, Eiji Sasaki

by Hiroshi Wada, Atsushi Shimizu, Toshihiro Osada, Yuki Tanaka, Satoshi Fukaya, Eiji Sasaki…

Righi, Elda; Carnelutti, Alessia; Bassetti, Matteo

Purpose of review An increase of skin and soft tissue infections involving Staphylococcus aureus has been reported in community and hospital settings. Methicillin resistance in S. aureus is associated with treatment failure and increased mortality. Recently, new antimicrobials with enhanced activity against methicillin-resistant Staph. aureus have been approved for the treatment of skin and soft tissue infections. Among these, novel oxazolidinones and lipoglycopeptides represent options with favorable pharmacokinetic characteristics and safety profiles. Recent findings Newly approved compounds include tedizolid, characterized by the availability of both oral and intravenous formulation and once daily administration and dalbavancin, a long-acting antimicrobial allowing for weekly administration. These new molecules present advantages, such as enhanced activity against multidrug-resistant Gram-positive bacteria and favorable safety profiles. Summary We have reviewed the pharmacokinetic characteristics and the implications for use in skin and soft tissue infections of tedizolid and dalbavancin. Advantages associated with the use of these compounds include the possibility for early patient discharge, reduced hospital length of stay, and outpatient treatment, with potential impact on morbidity, mortality, and overall health-care costs. Correspondence to Elda Righi, Infectious Diseases Clinic, Azienda Sanitaria Universitaria Integrata, Piazzale Misericordia 15, 33100 Udine, Italy. Tel: +39 0432 559354; fax: +39 0432 559360; e-mail: elda.righi@libero.it Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Kebriaei, R., Rice, S. A., Stamper, K. C., Rybak, M. J.

Glycopeptides such as vancomycin have been used as the first line therapy against MRSA infections for over half a century. Reduced susceptibility and emergence of resistance to first generation glycopeptides has led to development of second generation lipoglycopeptide derivatives such as dalbavancin which hold broader ranges of activity and enhanced pharmacokinetic properties. We evaluated the MIC values for a total of 100 isolates including 25 MRSA, 25 hVISA, 25 daptomycin non-susceptible (DNS) MRSA and 25 VISA strains against dalbavancin, ceftaroline and vancomycin alone and in combination. Dalbavancin was highly active against hVISA, DNS and MRSA strains achieving 96-100% susceptibility and 72% susceptibility against VISA strains. The combination of dalbavancin plus ceftaroline reduced dalbavancin MICs 62.5-fold and demonstrated enhanced killing against all four phenotypes in PK/PD models. Four strains of the aforementioned phenotypes were randomly chosen for pharmacodynamics/pharmacokinetic simulation models. Of interest, while both dalbavancin and vancomycin in combination with ceftaroline demonstrated significant improvement in glycopeptide fAUC/MIC values against these four phenotypes, the dalbavancin-ceftaroline combinations exhibited a 44-11270-fold higher fAUC/MIC value in comparison to vancomycin-ceftaroline combinations. In addition, the time to detection limit was reduced for this combination (24-32h) vs. the vancomycin-ceftaroline combination (24-72h). To our knowledge, this is the first comprehensive study of dalbavancin and vancomycin combinations with ceftaroline. This data provides a novel approach for combating recalcitrant MRSA infections.…

Seydlova, G., Sokol, A., Liskova, P., Konopasek, I., Fiser, R.

Daptomycin is a calcium-dependent lipodepsipeptide antibiotic clinically used to treat serious infections caused by Gram-positive pathogens. Its precise mode of action is somewhat controversial; the biggest issue is daptomycin pore formation, which we directly investigated here. We first performed a screening experiment using propidium iodide (PI) entry to Bacillus subtilis cells and chose the optimum and therapeutically relevant conditions (10 µg/mL daptomycin and 1.25 mM CaCl2) for the subsequent analyses. Using conductance measurements on planar lipid bilayers, we show that daptomycin forms non-uniform oligomeric pores with conductance ranging from 120 pS up to 14 nS. The smallest conductance unit is probably a dimer, however tetramers and pentamers occur in the membrane most frequently. Moreover, daptomycin pore-forming activity is exponentially dependent on the applied membrane voltage. We further analyzed the membrane permeabilizing activity in B. subtilis cells using fluorescence methods (PI, DiSC3(5)). Daptomycin most rapidly permeabilizes cells with high initial membrane potential and dissipates it within a few minutes. Low initial membrane potential hinders daptomycin pore formation.…

Barros, E. M., Martin, M. J., Selleck, E. M., Lebreton, F., Sampaio, J. L. M., Gilmore, M. S.

Lipopeptide daptomycin is a last line cell membrane-targeting antibiotic to treat multidrug-resistant Staphylococcus aureus. Alarmingly, daptomycin-resistant S. aureus isolates have emerged. The mechanisms underlying daptomycin resistance are diverse, share similarities with resistance to cationic antimicrobial peptides and other lipopeptides, but remain to be fully elucidated. We selected mutants with increased resistance to daptomycin from a library of transposon insertions in ST8 S. aureus HG003. Insertions in conferring increased daptomycin resistance were localized to two genes, one coding for a hypothetical lipoprotein (SAOUHSC_00362, Dsp1), and the other for an alkaline shock protein (SAOUHSC_02441, Asp23). Markerless loss of function mutants were then generated for comparison. All transposon mutants and knockout strains exhibited increased daptomycin resistance compared to wild type and complemented strains. Null and transposon insertion mutants also exhibited increased resistance to cationic antimicrobial peptides. Interestingly, dsp1 also showed increased resistance to vancomycin, a cell wall targeting drug with a different mode of action. Null mutations in both dsp1 and asp23 displayed increased tolerance as reflected by reduced killing to both daptomycin and vancomycin, as well as an increased tolerance to surfactant (Triton X-100). Neither mutant exhibited increased resistance to lysostaphin, a cell wall targeting endopeptidase. These findings identified two genes core to the S. aureus species, that make previously uncharacterized contributions to antimicrobial resistance and tolerance in S. aureus.…

Phillips, Tamsin K; Wilson, Ira B; Brittain, Kirsty; Zerbe, Allison; Mellins, Claude A; Remien, Robert H; Orrell, Catherine; Abrams, Elaine J; Myer, Landon

Introduction: Routine HIV viral load (VL) monitoring is recommended for patients on antiretroviral therapy (ART) but frequent VL testing, required in pregnant and postpartum women, is often not feasible. Self-reported adherence can be valuable, but little is known about its longitudinal characteristics. Methods: We followed women living with HIV from ART initiation in pregnancy through 18 months postpartum in Cape Town, South Africa, with repeated measurement of VL and self-reported adherence using a three-item scale. We used generalized estimating equations (with results presented as odds ratios [OR] with 95% confidence intervals [CI]) to investigate the association between viremia and change in adherence over pairs of consecutive visits. Results: Among 2085 visit pairs from 433 women, a decrease in self-reported adherence relative to the previous visit on any of three self-report items, or the combined scale, was associated with VL >50 and >1000 copies/mL. The best performing thresholds to predict VL >50 copies/mL were a single level decrease on the Likert response item “how good a job did you do at taking your HIV medicines in the way that you were supposed to?” (OR 2.08 95% CI 1.48-2.91), and a decrease equivalent to ≥5 missed doses or a one level decrease in score on either of two Likert items (OR 1.34 95% CI 1.06-1.69). Conclusion: Longitudinal changes in self-reported adherence can help identify patients with viremia. This approach warrants consideration in settings where frequent viral load monitoring or other objective adherence measures are not possible. Corresponding author: Tamsin K Phillips, Level 5 Falmouth Building, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa, Tel: +27 21 650 1646, Email: tk.phillips@uct.ac.za Conflicts of interest and sources of funding: This research was supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through the National Institute of Child Health and Human Development (NICHD), grant number 1R01HD074558. Additional funding comes from the Elizabeth Glaser Pediatric AIDS Foundation. Dr. Wilson is partially supported by the Providence/Boston Center for AIDS Research (P30AI042853) and by Institutional Development Award Number U54GM115677 from the National Institute of General Medical Sciences of the National Institutes of Health, which funds Advance Clinical and Translational Research (Advance-CTR) from the Rhode Island IDeA-CTR award (U54GM115677). Dr Orrell is partially supported through DAIDS grants (1R01AI122300 – 01, 1R34MH108393-01 and 2UM1AI0695-08). Drs. Mellins and Remien are partially supported by NIMH Center Grant (P30-MH43520). For the remaining authors none were declared. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

Kayana Suryadi, Nancy Shine

by Kayana Suryadi, Nancy Shine Bacillus anthracis is a major biological warfare threat. The inhalation form of infection can kill quickly. While antibiotic treatment is effective, if diagnosis is delayed, the rapidly produced toxin may already be present in lethal amounts. This report describes a fast, sensitive, specific and accurate method for detection of active infection by Bacillus anthracis in plasma. One of the virulence factors, anthrax lethal factor, is an endopeptidase present in blood early in the infection. However, the use of peptidic substrates to detect endopetidases is problematic in plasma due to the presence of other proteases and the likelihood of nonspecific cleavage of the substrate. The fluorescently labeled peptide substrate MAPKKide Plus designed in this study is not cleaved by plasma proteases and thus is specific for lethal factor. Three detection strategies are described. Two include enrichment by capture from plasma using lethal factor antibody-coated microtiter plates or similarly coated immuno-tubes. The captured lethal factor is exposed to the MAPKKide Plus, and the amount of cleavage is determined either by HPLC or microplate reader. Concentration of lethal factor using the antibody-coated plates aplnd HPLC allows for detection of less than 5 pg lethal factor/ml of neat plasma after 2 hours of incubation. Using antibody-coated immuno-tubes, 20 pg lethal factor/ml plasma can be detected in 5 hours by a simple end point read of fluorescence in a microplate reader. For a third strategy, the substrate is added directly to diluted plasma, and cleavage is monitored by the increase in fluorescence as a function of time. The limit of detection by this simple method is 25 ng lethal factor/ml of plasma in 15 minutes, 5 ng/ml after 45 minutes, and…

Pepper, Dominique J.; Demirkale, Cumhur Y.; Sun, Junfeng; Rhee, Chanu; Fram, David; Eichacker, Peter; Klompas, Michael; Suffredini, Anthony F.; Kadri, Sameer S.

Objectives: Observational studies suggest obesity is associated with sepsis survival, but these studies are small, fail to adjust for key confounders, measure body mass index at inconsistent time points, and/or use administrative data to define sepsis. To estimate the relationship between body mass index and sepsis mortality using detailed clinical data for case detection and risk adjustment. Design: Retrospective cohort analysis of a large clinical data repository. Setting: One-hundred thirty-nine hospitals in the United States. Patients: Adult inpatients with sepsis meeting Sepsis-3 criteria. Exposure: Body mass index in six categories: underweight (body mass index < 18.5 kg/m2), normal weight (body mass index = 18.5–24.9 kg/m2), overweight (body mass index = 25.0–29.9 kg/m2), obese class I (body mass index = 30.0–34.9 kg/m2), obese class II (body mass index = 35.0–39.9 kg/m2), and obese class III (body mass index ≥ 40 kg/m2). Measurements: Multivariate logistic regression with generalized estimating equations to estimate the effect of body mass index category on short-term mortality (in-hospital death or discharge to hospice) adjusting for patient, infection, and hospital-level factors. Sensitivity analyses were conducted in subgroups of age, gender, Elixhauser comorbidity index, Sequential Organ Failure Assessment quartiles, bacteremic sepsis, and ICU admission. Main Results: From 2009 to 2015, we identified 55,038 adults with sepsis and assessable body mass index measurements: 6% underweight, 33% normal weight, 28% overweight, and 33% obese. Crude mortality was inversely proportional to body mass index category: underweight (31%), normal weight (24%), overweight (19%), obese class I (16%), obese class II (16%), and obese class III (14%). Compared with normal weight, the adjusted odds ratio (95% CI) of mortality was 1.62 (1.50–1.74) for underweight, 0.73 (0.70–0.77) for overweight, 0.61 (0.57–0.66) for obese class I, 0.61 (0.55–0.67) for obese class II, and 0.65 (0.59–0.71) for obese class III. Results were consistent in sensitivity analyses. Conclusions: In adults with clinically defined sepsis, we demonstrate lower short-term mortality in patients with higher body mass indices compared with those with normal body mass indices (both unadjusted and adjusted analyses) and higher short-term mortality in those with low body mass indices. Understanding how obesity improves survival in sepsis would inform prognostic and therapeutic strategies. The findings and conclusions in this study are those of the authors and do not necessarily represent the official position of the National Institutes of Health. Drs. Pepper, Demirkale, Sun, and Kadri had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis, including and especially any adverse effects. Drs. Pepper, Demirkale, Sun, Rhee, Fram, Eichacker, Klompas, Suffredini, and Kadri contributed substantially to the study design, data analysis, and interpretation. Drs. Pepper and Kadri drafted the article. Drs. Demirkale, Sun, Rhee, Fram, Eichacker, Klompas, and Suffredini revised it critically for important intellectual content. Drs. Pepper, Demirkale, Sun, Rhee, Fram, Eichacker, Klompas, Suffredini, and Kadri approve the final version to be published. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (http://journals.lww.com/ccmjournal). Supported, in part, by the National Institutes of Health Intramural Research Program, Clinical Center. Dr. Pepper received other support from intramural funding from the National Institutes of Health (NIH). Drs. Pepper, Demirkale, Sun, Fram, Eichacker, Suffredini, and Kadri received support for article research from the NIH. Drs. Pepper, Demirkale, Sun, Suffredini, and Kadri disclosed government support. Dr. Rhee’s institution received support for article research from Agency for Healthcare Research and Quality (AHRQ) (grant number K08HS025008), and he received support for article research from AHRQ. Dr. Fram’s institution received funding from the NIH; he received funding from Commonwealth Informatics (stockholder); and he disclosed work for hire. Dr. Klompas’ institution received funding from the Centers for Disease Control and Prevention. Address requests for reprints to: Dominique J. Pepper, MD, MBChB, Critical Care Medicine Department, National Institutes of Health, Building 10, Room 2C145 Bethesda, MD 20892. E-mail: dominiquepepper@gmail.com Copyright © by 2019 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.

Slomski A.

Treatment with LY3298176, a novel dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide 1 (GLP-1) receptor agonist, resulted in better glucose control than dulaglutide, a GLP-1 receptor agonist, reported a phase 2 trial in the Lancet.

Rosenstock J, Perkovic V, Johansen O, et al.

This randomized clinical trial compares the effects of the dipeptidyl peptidase 4 inhibitor linagliptin vs placebo plus usual care on cardiovascular (CV) and renal outcomes in adults with type 2 diabetes and high CV and renal risk.

Q. Wu, J. Liu, Y. Wang, Q. Zhou, X. Wang, Z. Xuan, L. Zhang, Y. Gao, B. Chen, Y. Hu

Although administration of a second dose of varicella vaccine (2nd-dose VarV) to individuals who have previously received one-dose VarV has been recommended as a post-exposure prophylaxis (PEP) strategy for outbreak control, the effectiveness of this strategy remains unclear. We evaluated the vaccination effectiveness (VE) of 2nd-dose VarV as PEP among students involved in 129 varicella outbreaks in Shanghai, China from 2013 to 2016.

Kavanagh, A., Ramu, S., Gong, Y., Cooper, M. A., Blaskovich, M. A. T.

The determination of antibiotic potency against bacterial strains by assessment of their minimum inhibitory concentration normally uses a standardized broth microdilution assay procedure developed more than 50 years ago. However, certain antibiotics require modified assay conditions in order to observe optimal activity. For example, daptomycin requires media supplemented with Ca2+ and the lipoglycopeptides dalbavancin and oritavancin require Tween-80 to be added to the growth media to prevent depletion of free drug via adsorption to the plastic microplate. In this report we examine systematically the effects of several different plate types on microdilution broth MIC values for a set of antibiotics against Gram-positive and Gram-negative bacteria, both in media alone and in media supplemented with commonly used additives Tween-80, lysed horse blood, and 50% human serum. We observe very significant differences in measured MICs (up to 100-fold) for some lipophilic antibiotics, such as the Gram-positive lipoglycopeptide dalbavancin and the Gram-negative lipopeptide polymyxins, and find that non-specific binding plates can replace the need for surfactant additives. Microtitre plate types and any additives should be specified when reporting broth dilution MIC values as results can vary dramatically for some classes of antibiotics.…

Menard, Chantalle E.; Kumar, Anand; Houston, Donald S.; Turgeon, Alexis F.; Rimmer, Emily; Houston, Brett L.; Doucette, Steven; Zarychanski, Ryan

Objectives: To characterize the prevalence, incidence, and temporal evolution of thrombocytopenia (platelets < 100 × 109/L) in septic shock and to investigate the independent association of thrombocytopenia on clinical outcomes. Design: Retrospective, propensity-matched, cohort study. Setting: Two academic ICUs in Winnipeg, Canada. Patients: Nine-hundred eighty adult patients diagnosed with septic shock between 2007 and 2012. Interventions: Propensity-matched cohort analysis and Cox proportional hazard model evaluating thrombocytopenia over time. Measurements and Main Results: Of 980 adults, 165 patients (16.8%) had thrombocytopenia at ICU admission (prevalent), whereas 271 (27.7%) developed thrombocytopenia during ICU admission (incident). Among patients with incident thrombocytopenia, the median time from ICU admission to thrombocytopenia was 2 days (interquartile range, 1–3 d). Among survivors, the median time from incident thrombocytopenia to platelet recovery was 6 days (interquartile range, 4–8 d). The median time from liberation of vasopressors to recovery of platelets concentration (≥ 100 × 109/L) was 2 days (interquartile range, 0–4 d). In a propensity-matched analysis, thrombocytopenia was associated with increased durations of ICU length of stay (9 vs 6 d; p < 0.01), mechanical ventilation (7 vs 4 d; p < 0.01), and vasopressor use (4 vs 3 d; p < 0.01), as well as increased major bleeding events (41% vs 18%; p < 0.01). In an adjusted Cox proportional hazards model, thrombocytopenia was significantly associated with both increased ICU mortality (hazard ratio, 1.99; 95% CI, 1.51–2.63) and hospital mortality (hazard ratio, 1.93; 95% CI, 1.48–2.51). Conclusions: Both the prevalence and incidence of thrombocytopenia are high in septic shock. Incident thrombocytopenia occurs early in septic shock, and platelet recovery lags behind clinical recovery. In septic shock, thrombocytopenia is associated with increased length of stay, longer duration of organ support, major bleeding events, and mortality. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (http://journals.lww.com/ccmjournal). Supported, in part, with funds obtained from the Lyonel G Israel’s Professorship in Haematology, University of Manitoba. Dr. Turgeon receives salary support from the Canadian Institutes of Health Research (CIHR) (Canada Research Chair in Critical Care Neurology and Trauma). Dr. Houston disclosed off-label product use of hepcidin-binding peptide (anticalin, PRS-080), hepcidin-binding L-RNA spiegelmer (lexaptepid pegol or NOX-H94), monoclonal antibody to hepcidin (LY2787106) (14), antihemojuvelin antibodies, soluble hemojuvelin/Fc construct, and bone morphogenetic protein receptor inhibitor (unrelated to this work). All are indicated as inhibitors of the hepcidin pathway in development for treatment of anemia. Mr. Doucette received funding from Winnipeg Regional Health Authority, and he disclosed work for hire. Dr. Zarychanski receives salary and operating grant support from the CIHR. The remaining authors have disclosed that they do not have any potential conflicts of interest. This work was performed at the University of Manitoba in Winnipeg, MB, Canada. For information regarding this article, E-mail: rzarychanski@cancercare.mb.ca Copyright © by 2019 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.

Abstract Background Almost half the world’s population is infected with Helicobacter pylori (H. pylori) with the highest reported prevalence from Africa. This infection is associated with several morbid gastrointestinal conditions. Understanding the trends in seroprevalence and the factors associated with H. pylori seropositivity in dyspeptic persons can provide a guide for public health policies. Methods This was a retrospective study, carried out with outpatient records of Wum District Hospital (WDH) from January 2012 to December 2016. We reviewed records of all patients for whom a H. pylori serology test was requested. The Cochran-Armitage trend test and multiple regression models were used to explore seroprevalence trends and predictors of seropositivity respectively. Results We included 451 records, 63.6% (n = 287) were female. The mean age of the study population was 40.7 years, and the overall H. pylori seroprevalence was 51.5% (95% CI: 47–56%). The use of recommended eradication regimen appears to be low and declining. On average, H. pylori seroprevalence declined by 6.8% annually (p 

Anne-Laure Flamar, Henri Bonnabau, Sandra Zurawski, Christine Lacabaratz, Monica Montes, Laura Richert, Aurelie Wiedemann, Lindsey Galmin, Deborah Weiss, Anthony Cristillo, Lauren Hudacik, Andres Salazar, Cécile Peltekian, Rodolphe Thiebaut, Gerard Zurawski, Yves Levy

by Anne-Laure Flamar, Henri Bonnabau, Sandra Zurawski, Christine Lacabaratz, Monica Montes, Laura Richert, Aurelie Wiedemann, Lindsey Galmin, Deborah Weiss, Anthony Cristillo, Lauren Hudacik, Andres Salazar, Cécile Peltekian, Rodolphe Thiebaut, Gerard Zurawski, Yves Levy HIV-1 infection can be controlled by anti-retroviral drug therapy, but this is a lifetime treatment and the virus remains latent and rapidly rebounds if therapy is stopped. HIV-1-infected individuals under this drug regimen have increased rates of cancers, cardiovascular diseases, and autoimmunity due to compromised immunity. A therapeutic vaccine boosting cellular immunity against HIV-1 is therefore desirable and, possibly combined with other immune modulating agents, could obviate the need for long-term drug therapies. An approach to elicit strong T cell-based immunity is to direct virus protein antigens specifically to dendritic cells (DCs), which are the key cell type for controlling immune responses. For eliciting therapeutic cellular immunity in HIV-1-infected individuals, we developed vaccines comprised of five T cell epitope-rich regions of HIV-1 Gag, Nef, and Pol (HIV5pep) fused to monoclonal antibodies that bind either, the antigen presenting cell activating receptor CD40, or the endocytic dendritic cell immunoreceptor DCIR. The study aimed to demonstrate vaccine safety, establish efficacy for broad T cell responses in both primed and naïve settings, and identify one candidate vaccine for human therapeutic development. The vaccines were administered to Rhesus macaques by intradermal injection with poly-ICLC adjuvant. The animals were either i) naïve or, ii) previously primed with modified vaccinia Ankara vector (MVA) encoding HIV-1 Gag, Pol, and Nef (MVA GagPolNef). In the MVA-primed groups, both DC-targeting vaccinations boosted HIV5pep-specific blood CD4+ T cells producing multiple cytokines, but did not affect the MVA-elicited CD8+ T cell responses. In the naive groups, both DC-targeting vaccines elicited antigen-specific polyfunctional CD4+ and CD8+ T cell responses to multiple epitopes and these responses were unchanged by a subsequent MVA GagPolNef boost. In both settings, the T cell responses elicited via the CD40-targeting vaccine were more robust and were detectable in all the animals, favoring further development of the CD40-targeting vaccine for therapeutic vaccination of HIV-1-infected individuals.

Bennett M, Bombardi R, Kose N, et al.

AbstractThe nutrient metal iron plays a key role in the survival of microorganisms. The iron-regulated surface determinant (Isd) system scavenges heme-iron from the human host, enabling acquisition of iron in iron-deplete conditions in Staphylococcus aureus during infection. The cell surface receptors IsdB and IsdH bind hemoproteins and transfer heme to IsdA, the final surface protein before heme-iron is transported through the peptidoglycan. To define the human B-cell response to IsdA, we isolated human monoclonal antibodies (mAbs) specific to the surface Isd proteins and determined their mechanism of action. We describe the first isolation of fully human IsdA and IsdH mAbs, as well as cross-reactive Isd mAbs. Two of the identified IsdA mAbs worked in a murine septic model of infection to reduce bacterial burden during staphylococcal infection. Their protection was a result of both heme-blocking and Fc-mediated effector functions, underscoring the importance of targeting S. aureus using diverse mechanisms.

Jeroen Corver, Jeff Sen, Bastian V.H. Hornung, Bart J. Mertens, Eric K.L. Berssenbrugge, Céline Harmanus, Ingrid M.J.G. Sanders, Nitin Kumar, Trevor D. Lawley, Ed J. Kuijper, Paul J. Hensbergen, Simone Nicolardi

Clostridioides difficile infection (CDI) has become the main cause of nosocomial infective diarrhoea. To survey and control the spreading of different C. difficile strains, there is a need for suitable rapid tests. The aim of this study was to identify peptide/protein markers for the rapid recognition of C. difficile strains by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS).

Abstract Background For the success of the malaria control and eradication programme it is essential to reduce parasite transmission by mosquito vectors. In the midguts of mosquitoes fed with parasite-infected blood, sexual-stage parasites fertilize to develop into motile ookinetes that traverse midgut epithelial cells and reside adjacent the basal lamina. Therefore, the ookinete is a promising target of transmission-blocking vaccines to break the parasite lifecycle in mosquito vectors. However, the molecular mechanisms of ookinete formation and invasion of epithelial cells have not been fully elucidated. A unique structure called the crystalloid body has been identified in the ookinete cytoplasm by electron microscopy, but its biological functions remain unclear. Methods A recombinant protein of a novel molecule, designated as crystalloid body specific PH domain-containing protein of Plasmodium yoelii (PyCryPH), was synthesized using a wheat germ cell-free system. Specific rabbit antibodies against PyCryPH were obtained to characterize the expression and localization of PyCryPH during sexual-stage parasite development. In addition, PyCryPH knockout parasites were generated by targeted gene disruption to examine PyCryPH function in mosquito-stage parasite development. Results Western blot and immunofluorescence assays using specific antibodies showed that PyCryPH is specifically expressed in zygotes and ookinetes. By immunoelectron microscopy it was demonstrated that PyCryPH is localized within crystalloid bodies. Parasites with a disrupted PyCryPH gene developed normally into ookinetes and formed oocysts on the basal lamina of midguts. In addition, the number of sporozoites residing in salivary glands was comparable to that of wild-type parasites. Conclusions CryPH, containing a signal peptide and PH domain, is predominantly expressed in zygotes and ookinetes and is localized to crystalloid bodies in P. yoelii. CryPH accumulates in vesicle-like structures prior to the appearance of typical crystalloid bodies. Unlike other known crystalloid body localized proteins, CryPH does not appear to have a multiple domain architecture characteristic of the LAP/CCp family proteins. Although CryPH is highly conserved among Plasmodium, Babesia, Theileria, and Cryptosporidium, PyCryPH is dispensable for the development of invasive ookinetes and sporozoites in mosquito bodies.…

Bleasby, K., Fillgrove, K. L., Houle, R., Lu, B., Palamanda, J., Newton, D. J., Lin, M., Chan, G. H., Sanchez, R. I.

Doravirine is a novel non-nucleoside reverse transcriptase inhibitor for the treatment of human immunodeficiency virus type 1 infection. In vitro studies were conducted to assess the potential for drug interactions with doravirine via major drug-metabolizing enzymes and transporters. Kinetic studies confirmed that cytochrome P450 (CYP) 3A plays a major role in the metabolism of doravirine, with ~20-fold higher catalytic efficiency for CYP3A4 versus CYP3A5. Doravirine was not a substrate of breast cancer resistance protein (BCRP) and likely not a substrate of organic anion transporting polypeptide (OATP) 1B1 or 1B3. Doravirine was not a reversible inhibitor of major CYP enzymes (CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4) or of UGT1A1, nor a time-dependent inhibitor of CYP3A4. No induction of CYP1A2 or 2B6 was observed in cultured human hepatocytes; small increases in CYP3A4 mRNA (≤20%) were reported at doravirine concentrations ≥10 μM but with no corresponding increase in enzyme activity. In vitro transport studies indicated a low potential for interactions with substrates of BCRP, P-glycoprotein, OATP1B1 and OATP1B3, the bile salt extrusion pump, organic anion transporter (OAT)1 and OAT3, organic cation transporter 2, and multidrug and toxin extrusion (MATE)1 and MATE2K proteins. In summary, these in vitro findings indicate that CYP3A4 and CYP3A5 mediate the metabolism of doravirine, albeit with different catalytic efficiency. Clinical trials reported elsewhere confirm that doravirine is subject to drug-drug interactions (DDIs) via CYP3A inhibitors and inducers, but support that DDIs (either direction) are unlikely via other major drug-metabolizing enzymes and transporters.…

Wang, Y., Shen, Y., Liu, H., Yin, J., Zhang, X.-T., Gong, A.-Y., Chen, X., Chen, S., Mathy, N. W., Cao, J., Chen, X.-M.

Cryptosporidium, a protozoan parasite that infects the gastrointestinal epithelium and other mucosal surfaces in humans and animals, is an important opportunistic pathogen in AIDS patients and one of the most common enteric pathogens affecting young children in developing regions. This parasite is referred to as a "minimally invasive" mucosal pathogen and epithelial cells play a central role in activating and orchestrating host immune responses. We previously demonstrated that C. parvum infection stimulates host epithelial cells to release exosomes and these released exosomes shuttle several antimicrobial peptides to carry out anti-C. parvum activity. In this study, we detected upregulation of inflammatory genes in the liver and spleen following C. parvum intestinal infection in neonatal mice. Interestingly, exosomes released from intestinal epithelial cells following C. parvum infection could activate the nuclear factor kappa B signaling pathway and trigger inflammatory gene transcription in isolated primary splenocytes. Several epithelial cell-derived proteins and a subset of parasite RNAs were detected in the exosomes released from C. parvum-infected intestinal epithelial cells. Shuttling of these effector molecules, including the high mobility group box 1 protein, was involved in the induction of inflammatory responses in splenocytes induced by the released exosomes from infected cells. Our data indicate that exosomes released from intestinal epithelial cells upon C. parvum infection can activate immune cells through shuttling various effector molecules, a process that may be relevant to host systemic responses to Cryptosporidium infection.…

Abstract Background Plasmodium falciparum haemozoin, a detoxification product of digested haemoglobin from infected erythrocytes, is released into the bloodstream upon schizont rupture and accumulates in leukocytes. High levels of haemozoin correlate with disease severity. Some studies have shown that concentrations of the substrate of inducible nitric oxide synthase (iNOS), l-arginine, as well as nitric oxide are low in patients infected with P. falciparum malaria. The present study investigates, in vitro, the role of P. falciparum haemozoin on nitric oxide production, iNOS expression in macrophages, and the possible interaction between l-arginine and haemozoin. Methods Plasmodium falciparum haemozoin was obtained from in vitro cultures through magnetic isolation. Phagocytosis of haemozoin by immortalized bone marrow derived macrophages was detected by confocal reflection combined with fluorescence microscopy. Nitrite concentrations in the supernatants was evaluated by Griess assay as a standard indication of nitric oxide production, while iNOS expression was detected on cell extracts by western blotting. Detection of l-arginine in haemozoin-treated or untreated media was achieved by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Results Haemozoin synergizes in vitro with interferon-gamma to produce nitric oxide. However, when mouse macrophages were stimulated with haemozoin, a proportional increase of nitric oxide was observed up to 25 μM of haemozoin, followed by a decrease with doses up to 100 μM, when nitric oxide release was completely abrogated. This was not due to reactive oxygen species production, nor to an effect on iNOS activity. Interestingly, when at 24 h, haemozoin-treated macrophages were washed and incubated in fresh medium for further 24 h, the nitric oxide production was restored in a dose–response manner. Similar results were seen when l-arginine-enriched media was used in the stimulation. Moreover, muramyldipeptide, a strong nitric oxide inducer, was unable to activate macrophages to release nitric oxide in the presence of haemozoin-treated medium. By LC–MS/MS a complete depletion of l-arginine was observed in this haemozoin-treated, conditioned medium. Conclusions It is proposed that haemozoin interacts with l-arginine reducing its availability for iNOS, and thus decreasing nitric oxide production. The clinical (or pathological) implications of these results are discussed.…

Foegeding, N. J., Raghunathan, K., Campbell, A. M., Kim, S. W., Lau, K. S., Kenworthy, A. K., Cover, T. L., Ohi, M. D.

Helicobacter pylori VacA is a secreted pore-forming toxin that induces cell vacuolation in vitro and contributes to the pathogenesis of gastric cancer and peptic ulcer disease. We observed that purified VacA has relatively little effect on the viability of AGS gastric epithelial cells, but the presence of exogenous weak bases such as ammonium chloride (NH4Cl) enhances the susceptibility of these cells to VacA-induced vacuolation and cell death. Therefore, we tested the hypothesis that NH4Cl augments VacA toxicity by altering the intracellular trafficking of VacA or inhibiting intracellular VacA degradation. We observed VacA colocalization with LAMP1- and LC3-positive vesicles in both the presence and absence of NH4Cl, indicating that NH4Cl does not alter VacA trafficking to lysosomes or autophagosomes. Conversely, we found that supplemental NH4Cl significantly increases the intracellular stability of VacA. By conducting experiments using chemical inhibitors, stable ATG5 knockdown cell lines, and ATG16L1 knockout cells (generated using CRISPR/Cas9), we show that VacA degradation is independent of autophagy and proteasome activity, but dependent on lysosomal acidification. We conclude that weak bases like ammonia, potentially generated during infection by H. pylori urease and other enzymes, enhance VacA toxicity by inhibiting toxin degradation.…

Puri, S., Kumar, R., Rojas, I. G., Salvatori, O., Edgerton, M.

Candida albicans, the causative agent of mucosal infections including oropharyngeal candidiasis (OPC) as well as bloodstream infections is becoming increasingly resistant to existing treatment options. In the absence of novel drug candidates, drug repurposing aimed at using existing drugs to treat off label diseases is a promising strategy. C. albicans requires environmental iron for survival and virulence while host nutritional immunity deploys iron-binding proteins to sequester iron and reduce fungal growth. Here we evaluated the role of iron-limitation using deferasirox (an FDA approved iron chelator for treatment of patients with iron overload) during murine OPC; and assessed deferasirox-treated C. albicans for its interaction with human oral epithelial (OE), neutrophils, and antimicrobial peptides. Therapeutic deferasirox treatment significantly reduced salivary iron levels while a non-significant reduction in fungal burden was observed. Preventive treatment that allowed for two additional days of drug administration in our murine model, resulted in significant reduction of C. albicans colony forming units (CFU)/g of tongue tissue, a significant reduction in salivary iron levels, and significantly reduced neutrophil-mediated inflammation. C. albicans harvested from tongues of animals undergoing preventive treatment had differential expression of 106 genes, including those involved in iron metabolism, adhesion, and response to host innate immunity. Moreover, deferasirox-treated C. albicans cells had two-fold reduction in survival in neutrophil phagosomes (with greater susceptibility to oxidative stress); and reduced adhesion and invasion of OE cells, in vitro. Thus deferasirox treatment has the potential to alleviate OPC by affecting C. albicans gene expression and reducing virulence.…

Xinggang Wang, Junbo Ge, Ruizhen Chen

Abstract Latency associated peptide (LAP) is a protein expressed on the membrane of some regulatory T cells (Treg). LAP+ Treg have greater immunomodulatory effect than that of their negative counterparts. In this study, we presented data on the proportion of LAP+ Treg out of CD4+ cells in mice with viral myocarditis, which we believed was more sensitive and specific than that of the ratio of total Treg in CD4+ cells. Comparing with the previously recognized total Treg, LAP+ Treg was a better biomarker on myocardial inflammation. This article is protected by copyright. All rights reserved.

Igor Iatsenko, Jean-Philippe Boquete, Bruno Lemaitre

Iatsenko et al. find that flies bearing a mutation in a peptidoglycan recognition protein exhibit dysbiosis and shortened lifespan. In these flies, the unrestricted growth of a commensal bacterium generates excessive lactate, which triggers ROS production in intestinal cells and subsequent dysplasia. This ROS-producing pathway is conserved, suggesting relevance of such host-microbe metabolic crosstalk in age-related pathologies in humans.

Pan, X., Li, Z., Huang, X., Huang, G., Gao, S., Shen, H., Liu, L., Lei, J., Yan, N.

The voltage-gated sodium channel Nav1.2 is responsible for the initiation and propagation of action potentials in the central nervous system. We report the cryo–electron microscopy structure of human Nav1.2 bound to a peptidic pore blocker, the μ-conotoxin KIIIA, in the presence of an auxiliary subunit β2 to an overall resolution of 3.0 Å. The immunoglobulin (Ig) domain of β2 interacts with the shoulder of the pore domain through a disulfide bond. The 16-residue KIIIA interacts with the extracellular segments in repeats I to III, placing Lys7 at the entrance to the selectivity filter. Many interacting residues are specific to Nav1.2, revealing a molecular basis for KIIIA specificity. The structure establishes a framework for rational design of subtype-specific blockers for Nav channels.…