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Infection, 20.07.2024
Tilføjet 20.07.2024
Abstract Introduction Non-fermenting Gram-negative bacilli (NFGNB) other than Pseudomonas aeruginosa and Acinetobacter baumannii complex are pathogens of interest due to their ability to cause health-care associated infections and display complex drug resistance phenotypes. However, their clinical and microbiological landscape is still poorly characterized. Methods Observational retrospective study including all hospitalized patients presenting with a positive positive blood culture (BC) episode caused by less common NFGNB over a four-year period (January 2020–December 2023). Clinical-microbiological features and factors associated with mortality were investigated. Results Sixty-six less common NFGNB isolates other than Pseudomonas and Acinetobacter species causing 63 positive BC episodes were recovered from 60 patients. Positive BC episodes were predominantly sustained by Stenotrophomonas maltophilia (49.2%) followed by Achromobacter species (15.9%) that exhibited the most complex resistance phenotype. Positive BC episodes had bloodstream infection criteria in 95.2% of cases (60 out 63), being intravascular device (30.2%) and respiratory tract (19.1%) the main sources of infection. Fourteen-day, 30-day, and in-hospital mortality rates were 6.4%, 9.5%, and 15.9%, respectively. The longer time from admission to the positive BC episode, older age, diabetes, admission due to sepsis, and higher Charlson Comorbidity Index were identified as the main predictors of in-hospital mortality. Conclusions Positive BC episodes sustained by NFGNB other than Pseudomonas and Acinetobacter species were predominantly sustained by Stenotrophomonas maltophilia and Achromobacter species, having bloodstream infection criteria in the vast majority of cases. Factors that have emerged to be associated with mortality highlighted how these species may have more room in prolonged hospitalisation and at the end of life for patients with chronic organ diseases.
Læs mere Tjek på PubMedQ. C. Truong-BolducY. WangB. G. LawtonH. Brown HardingL. M. YonkerJ. M. VyasD. C. Hooper1Infectious Diseases Division and Medical Services, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA2Department of Pediatrics, Cystic Fibrosis Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA3Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USABenjamin P. Howden
Antimicrobial Agents And Chemotherapy, 20.07.2024
Tilføjet 20.07.2024
BMC Infectious Diseases, 17.07.2024
Tilføjet 17.07.2024
Abstract Background Aminoglycosides have been a cornerstone of the treatment of nosocomial infections caused by Pseudomonas aeruginosa for over 80 years. However, escalating emergence of resistance poses a significant challenge. Therefore, this study aimed to investigate the prevailing patterns of aminoglycoside resistance among clinical isolates of P. aeruginosa in Iran; as well as the underlying resistance mechanisms observed in patients referred to Ardabil hospitals. Methods A total of 200 isolates from five hospitals were evaluated. The resistance profiles of P. aeruginosa isolates to tobramycin, amikacin, and netilmicin were determined using the disk diffusion method. The capacity of aminoglycoside-resistant isolates to form biofilms was assessed through a phenotypic assay, and the results were confirmed using the gene amplification technique. The presence of genes associated with aminoglycoside resistance was detected using polymerase chain reaction (PCR). Quantitative reverse transcription PCR (qRT-PCR) was performed to measure the expression levels of genes encoding the MexXY-OprM efflux pump and PhoPQ two-component system (TCS). Results The prevalence of aminoglycoside-resistant P. aeruginosa isolates was 48%, with 94.7% demonstrating multidrug resistance (MDR). All aminoglycoside-resistant P. aeruginosa strains exhibited biofilm-forming capabilities and harbored all the genes associated with biofilm production. Among the nine genes encoding 16S rRNA methylase and aminoglycoside-modifying enzymes, three genes were detected in these isolates: aac(6’)-Ib (85.4%), ant(2’’)-Ia (18.7%), and aph(3’)-VI (3.1%). Additionally, all aminoglycoside-resistant P. aeruginosa isolates carried mexY and phoP genes, although the expression levels of mexY and phoP were 75% and 87.5%, respectively. Conclusion Given the considerably high prevalence of aminoglycoside-resistant P. aeruginosa strains, urgent measures are warranted to transition towards the use of novel aminoglycosides and to uphold vigilant surveillance of resistance patterns.
Læs mere Tjek på PubMedNuttawut Sutnu, Wiwat Chancharoenthana, Supitcha Kamolratanakul, Pornpimol Phuengmaung, Uthaibhorn Singkham-In, Chiratchaya Chongrak, Sirikan Montathip, Dhammika Leshan Wannigama, Tanittha Chatsuwan, Puey Ounjai, Marcus J. Schultz, Asada Leelahavanichkul
PLoS One Infectious Diseases, 17.07.2024
Tilføjet 17.07.2024
by Nuttawut Sutnu, Wiwat Chancharoenthana, Supitcha Kamolratanakul, Pornpimol Phuengmaung, Uthaibhorn Singkham-In, Chiratchaya Chongrak, Sirikan Montathip, Dhammika Leshan Wannigama, Tanittha Chatsuwan, Puey Ounjai, Marcus J. Schultz, Asada Leelahavanichkul Background Most of the current bacteriophages (phages) are mostly isolated from environments. However, phages isolated from feces might be more specific to the bacteria that are harmful to the host. Meanwhile, some phages from the environment might affect non-pathogenic bacteria for the host. Methods Here, bacteriophages isolated from mouse feces were intratracheally (IT) or intravenously (IV) administered in pneumonia mice caused by Pseudomonas aeruginosa at 2 hours post-intratracheal bacterial administration. As such, the mice with phage treatment, using either IT or IV administration, demonstrated less severe pneumonia as indicated by mortality, serum cytokines, bacteremia, bacterial abundance in bronchoalveolar lavage fluid (BALF), and neutrophil extracellular traps (NETs) in lung tissue (immunofluorescence of neutrophil elastase and myeloperoxidase). Results Interestingly, the abundance of phages in BALF from the IT and IV injections was similar, supporting a flexible route of phage administration. With the incubation of bacteria with neutrophils, the presence of bacteriophages significantly improved bactericidal activity, but not NETs formation, with the elevated supernatant IL-6 and TNF-α, but not IL-1β. In conclusion, our findings suggest that bacteriophages against Pseudomonas aeruginosa can be discovered from feces of the host. Conclusions The phages attenuate pneumonia partly through an enhanced neutrophil bactericidal activity, but not via inducing NETs formation. The isolation of phages from the infected hosts themselves might be practically useful for future treatment. More studies are warranted.
Læs mere Tjek på PubMedMicaela Mossop, Jonathan Ish-Horowicz, Dominic Hughes, Rebecca Dobra, Alessandra G. Cunanan, Mark Rosenthal, Siobhán B. Carr, Newara Ramadan, Laura M. Nolan, Jane C. Davies
American Journal of Respiratory and Critical Care Medicine , 16.07.2024
Tilføjet 16.07.2024
American Journal of Respiratory and Critical Care Medicine, Volume 210, Issue 2, Page 240-242, July 15, 2024.
Læs mere Tjek på PubMedInfection, 12.07.2024
Tilføjet 12.07.2024
Abstract Introduction Non-fermenting Gram-negative bacilli (NFGNB) other than Pseudomonas aeruginosa and Acinetobacter baumannii complex are pathogens of interest due to their ability to cause health-care associated infections and display complex drug resistance phenotypes. However, their clinical and microbiological landscape is still poorly characterized. Methods Observational retrospective study including all hospitalized patients presenting with a positive positive blood culture (BC) episode caused by less common NFGNB over a four-year period (January 2020–December 2023). Clinical-microbiological features and factors associated with mortality were investigated. Results Sixty-six less common NFGNB isolates other than Pseudomonas and Acinetobacter species causing 63 positive BC episodes were recovered from 60 patients. Positive BC episodes were predominantly sustained by Stenotrophomonas maltophilia (49.2%) followed by Achromobacter species (15.9%) that exhibited the most complex resistance phenotype. Positive BC episodes had bloodstream infection criteria in 95.2% of cases (60 out 63), being intravascular device (30.2%) and respiratory tract (19.1%) the main sources of infection. Fourteen-day, 30-day, and in-hospital mortality rates were 6.4%, 9.5%, and 15.9%, respectively. The longer time from admission to the positive BC episode, older age, diabetes, admission due to sepsis, and higher Charlson Comorbidity Index were identified as the main predictors of in-hospital mortality. Conclusions Positive BC episodes sustained by NFGNB other than Pseudomonas and Acinetobacter species were predominantly sustained by Stenotrophomonas maltophilia and Achromobacter species, having bloodstream infection criteria in the vast majority of cases. Factors that have emerged to be associated with mortality highlighted how these species may have more room in prolonged hospitalisation and at the end of life for patients with chronic organ diseases.
Læs mere Tjek på PubMedInfection, 10.07.2024
Tilføjet 10.07.2024
Abstract Pseudomonas aeruginosa is one of the most common nosocomial pathogens and part of the top emergent species associated with antimicrobial resistance that has become one of the greatest threat to public health in the twenty-first century. This bacterium is provided with a wide set of virulence factors that contribute to pathogenesis in acute and chronic infections. This review aims to summarize the impact of multidrug resistance on the virulence and fitness of P. aeruginosa. Although it is generally assumed that acquisition of resistant determinants is associated with a fitness cost, several studies support that resistance mutations may not be associated with a decrease in virulence and/or that certain compensatory mutations may allow multidrug resistance strains to recover their initial fitness. We discuss the interplay between resistance profiles and virulence from a microbiological perspective but also the clinical consequences in outcomes and the economic impact.
Læs mere Tjek på PubMedBMC Infectious Diseases, 10.07.2024
Tilføjet 10.07.2024
Abstract Background Aminoglycosides have been a cornerstone of the treatment of nosocomial infections caused by Pseudomonas aeruginosa for over 80 years. However, escalating emergence of resistance poses a significant challenge. Therefore, this study aimed to investigate the prevailing patterns of aminoglycoside resistance among clinical isolates of P. aeruginosa in Iran; as well as the underlying resistance mechanisms observed in patients referred to Ardabil hospitals. Methods A total of 200 isolates from five hospitals were evaluated. The resistance profiles of P. aeruginosa isolates to tobramycin, amikacin, and netilmicin were determined using the disk diffusion method. The capacity of aminoglycoside-resistant isolates to form biofilms was assessed through a phenotypic assay, and the results were confirmed using the gene amplification technique. The presence of genes associated with aminoglycoside resistance was detected using polymerase chain reaction (PCR). Quantitative reverse transcription PCR (qRT-PCR) was performed to measure the expression levels of genes encoding the MexXY-OprM efflux pump and PhoPQ two-component system (TCS). Results The prevalence of aminoglycoside-resistant P. aeruginosa isolates was 48%, with 94.7% demonstrating multidrug resistance (MDR). All aminoglycoside-resistant P. aeruginosa strains exhibited biofilm-forming capabilities and harbored all the genes associated with biofilm production. Among the nine genes encoding 16S rRNA methylase and aminoglycoside-modifying enzymes, three genes were detected in these isolates: aac(6’)-Ib (85.4%), ant(2’’)-Ia (18.7%), and aph(3’)-VI (3.1%). Additionally, all aminoglycoside-resistant P. aeruginosa isolates carried mexY and phoP genes, although the expression levels of mexY and phoP were 75% and 87.5%, respectively. Conclusion Given the considerably high prevalence of aminoglycoside-resistant P. aeruginosa strains, urgent measures are warranted to transition towards the use of novel aminoglycosides and to uphold vigilant surveillance of resistance patterns.
Læs mere Tjek på PubMedJi, M., Park, J. H., Ha, A., Jeong, J.
BMJ Open, 5.07.2024
Tilføjet 5.07.2024
ObjectivesTo investigate the epidemiological characteristics and clinical outcomes of culture-proven bacterial and fungal keratitis at a single tertiary referral centre on Jeju Island, South Korea. DesignA retrospective study design. SettingData from a solitary referral centre on Jeju Island spanning January 2011 to December 2022. ParticipantsAmong the 245 patients clinically diagnosed with infectious microbial keratitis, 110 individuals had culture-positive results. Primary and secondary outcome measuresThe primary outcome was the identification of causative microbial profiles and epidemiological characteristics, while the secondary outcome was the correlation of these factors with treatment outcomes. ResultsOf 245 patients, 110 (44.9%) had culture-positive infectious keratitis, showing 69 bacterial, 32 fungal, 4 superimposed bacterial and 5 cases with coinfection by bacteria and fungus. The most common pathogen was Pseudomonas species in 14.4% of the bacterial keratitis cases, followed by Staphylococcus epidermidis (9%), Staphylococcus aureus (8%) and Moraxella species (7%). The total treatment success rate for bacterial keratitis was 67.5%. The frequency of methicillin-resistant Staphylococcus on Jeju Island did increase during the study period. Fusarium species had the highest incidence at 22.2%, followed by Candida (16.7%) and Colletotrichum species (11.1%). 56.7% of fungal keratitis patients were successfully treated. An initial large corneal lesion (>3 mm) showed a statistically significant association with treatment failure. ConclusionThe incidence of Moraxella and Colletotrichum species in our study was higher than that reported in other districts with different climates and environments. The results reported here reflect the unique environmental features of Jeju Island, characterised by high humidity and temperatures.
Læs mere Tjek på PubMedInfection, 3.07.2024
Tilføjet 3.07.2024
Abstract Pseudomonas aeruginosa is one of the most common nosocomial pathogens and part of the top emergent species associated with antimicrobial resistance that has become one of the greatest threat to public health in the twenty-first century. This bacterium is provided with a wide set of virulence factors that contribute to pathogenesis in acute and chronic infections. This review aims to summarize the impact of multidrug resistance on the virulence and fitness of P. aeruginosa. Although it is generally assumed that acquisition of resistant determinants is associated with a fitness cost, several studies support that resistance mutations may not be associated with a decrease in virulence and/or that certain compensatory mutations may allow multidrug resistance strains to recover their initial fitness. We discuss the interplay between resistance profiles and virulence from a microbiological perspective but also the clinical consequences in outcomes and the economic impact.
Læs mere Tjek på PubMedAurélie Crabbé
American Journal of Respiratory and Critical Care Medicine , 1.07.2024
Tilføjet 1.07.2024
American Journal of Respiratory and Critical Care Medicine, Volume 210, Issue 1, Page 8-9, July 1, 2024.
Læs mere Tjek på PubMedRhiannon E. Cecil, Deborah R. Yoder-Himes
PLoS One Infectious Diseases, 24.06.2024
Tilføjet 24.06.2024
by Rhiannon E. Cecil, Deborah R. Yoder-Himes Exploration of interspecies interactions between microorganisms can have taxonomic, ecological, evolutionary, or medical applications. To better explore interactions between microorganisms it is important to establish the ideal conditions that ensure survival of all species involved. In this study, we sought to identify the ideal biotic and abiotic factors that would result in high co-culture viability of two interkingdom species, Pseudomonas aeruginosa and Acanthamoeba castellanii, two soil dwelling microbes. There have been limited studies showing long-term interactions between these two organisms as co-culture can result in high mortality for one or both organisms suggesting a predator-predator interaction may exist between them. In this study, we identified biotic and abiotic conditions that resulted in a high viability for both organisms in long-term co-culture, including optimizing temperature, nutrient concentration, choice of bacterial strains, and the initial ratio of interacting partners. These two species represent ideal partners for studying microbial interactions because amoebae act similarly to mammalian immune cells in many respects, and this can allow researchers to study host-pathogen interactions in vitro. Therefore, long-term interaction studies between these microbes might reveal the evolutionary steps that occur in bacteria when subjected to intense predation, like what occurs when pathogens enter the human body. The culture conditions characterized here resulted in high viability for both organisms for at least 14-days in co-culture suggesting that long-term experimental studies between these species can be achieved using these culture conditions.
Læs mere Tjek på PubMedInfection, 24.06.2024
Tilføjet 24.06.2024
Abstract Purpose To determine predictors of mortality among patients with Pseudomonas aeruginosa bacteraemia. Methods Retrospective study. Setting This study conducted at the Lausanne University Hospital, Switzerland included adult patients with P. aeruginosa bacteraemia from 2015 to 2021. Results During the study period, 278 episodes of P. aeruginosa bacteraemia were included. Twenty (7%) isolates were multidrug-resistant. The most common type of infection was low respiratory tract infection (58 episodes; 21%). Sepsis was present in the majority of episodes (152; 55%). Infectious diseases consultation within 48 h of bacteraemia onset was performed in 203 (73%) episodes. Appropriate antimicrobial treatment was administered within 48 h in 257 (92%) episodes. For most episodes (145; 52%), source control was considered necessary, with 93 (64%) of them undergoing such interventions within 48 h. The 14-day mortality was 15% (42 episodes). The Cox multivariable regression model showed that 14-day mortality was associated with sepsis (P 0.002; aHR 6.58, CI 1.95–22.16), and lower respiratory tract infection (P
Læs mere Tjek på PubMedInfection, 21.06.2024
Tilføjet 21.06.2024
Abstract Purpose To determine predictors of mortality among patients with Pseudomonas aeruginosa bacteraemia. Methods Retrospective study. Setting This study conducted at the Lausanne University Hospital, Switzerland included adult patients with P. aeruginosa bacteraemia from 2015 to 2021. Results During the study period, 278 episodes of P. aeruginosa bacteraemia were included. Twenty (7%) isolates were multidrug-resistant. The most common type of infection was low respiratory tract infection (58 episodes; 21%). Sepsis was present in the majority of episodes (152; 55%). Infectious diseases consultation within 48 h of bacteraemia onset was performed in 203 (73%) episodes. Appropriate antimicrobial treatment was administered within 48 h in 257 (92%) episodes. For most episodes (145; 52%), source control was considered necessary, with 93 (64%) of them undergoing such interventions within 48 h. The 14-day mortality was 15% (42 episodes). The Cox multivariable regression model showed that 14-day mortality was associated with sepsis (P 0.002; aHR 6.58, CI 1.95–22.16), and lower respiratory tract infection (P
Læs mere Tjek på PubMedInfection, 14.06.2024
Tilføjet 14.06.2024
Abstract Background The landscape of Pseudomonas infective endocarditis (IE) is evolving with the widespread use of cardiac implantable devices and hospital-acquired infections. This systematic review aimed to evaluate the emerging risk factors and outcomes in Pseudomonas IE. Methods A literature search was performed in major electronic databases (PubMed, Scopus, and Google Scholar) with appropriate keywords and combinations till November 2023. We recorded data for risk factors, diagnostic and treatment modalities. This study is registered with PROSPERO, CRD42023442807. Results A total of 218 cases (131 articles) were included. Intravenous drug use (IDUs) and prosthetic valve endocarditis (PVE) were major risk factors for IE (37.6% and 22%). However, the prosthetic valve was the predominant risk factor in the last two decades (23.5%). Paravalvular complications (paravalvular leak, abscess, or pseudoaneurysm) were described in 40 cases (18%), and the vast majority belonged to the aortic valve (70%). The mean time from symptom onset to presentation was 14 days. The incidence of difficult-to-treat resistant (DTR) pseudomonas was 7.4%. Valve replacement was performed in 57.3% of cases. Combination antibiotics were used in most cases (77%), with the aminoglycosides-based combination being the most frequently used (66%). The overall mortality rate was 26.1%. The recurrence rate was 11.2%. Almost half of these patients were IDUs (47%), and most had aortic valve endocarditis (76%). Conclusions This review highlights the changing epidemiology of Pseudomonas endocarditis with the emergence of prosthetic valve infections. Acute presentation and associated high mortality are characteristic of Pseudomonas IE and require aggressive diagnostic and therapeutic approach.
Læs mere Tjek på PubMedInfection, 10.06.2024
Tilføjet 10.06.2024
Abstract Background The landscape of Pseudomonas infective endocarditis (IE) is evolving with the widespread use of cardiac implantable devices and hospital-acquired infections. This systematic review aimed to evaluate the emerging risk factors and outcomes in Pseudomonas IE. Methods A literature search was performed in major electronic databases (PubMed, Scopus, and Google Scholar) with appropriate keywords and combinations till November 2023. We recorded data for risk factors, diagnostic and treatment modalities. This study is registered with PROSPERO, CRD42023442807. Results A total of 218 cases (131 articles) were included. Intravenous drug use (IDUs) and prosthetic valve endocarditis (PVE) were major risk factors for IE (37.6% and 22%). However, the prosthetic valve was the predominant risk factor in the last two decades (23.5%). Paravalvular complications (paravalvular leak, abscess, or pseudoaneurysm) were described in 40 cases (18%), and the vast majority belonged to the aortic valve (70%). The mean time from symptom onset to presentation was 14 days. The incidence of difficult-to-treat resistant (DTR) pseudomonas was 7.4%. Valve replacement was performed in 57.3% of cases. Combination antibiotics were used in most cases (77%), with the aminoglycosides-based combination being the most frequently used (66%). The overall mortality rate was 26.1%. The recurrence rate was 11.2%. Almost half of these patients were IDUs (47%), and most had aortic valve endocarditis (76%). Conclusions This review highlights the changing epidemiology of Pseudomonas endocarditis with the emergence of prosthetic valve infections. Acute presentation and associated high mortality are characteristic of Pseudomonas IE and require aggressive diagnostic and therapeutic approach.
Læs mere Tjek på PubMedInfection, 4.06.2024
Tilføjet 4.06.2024
Abstract Background Antimicrobial resistance among Pseudomonas aeruginosa (P. aeruginosa), a leading cause of nosocomial infections worldwide, is escalating. This study investigated the prevalence of extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs) among 104 P. aeruginosa clinical isolates from Alexandria Main University Hospital, Alexandria, Egypt. Methods Antimicrobial susceptibility testing was performed using agar dilution technique, or broth microdilution method in case of colistin. ESBL and MBL prevalence was assessed phenotypically and genotypically using polymerase chain reaction (PCR). The role of plasmids in mediating resistance to extended-spectrum β-lactams was studied via transformation technique using plasmids isolated from ceftazidime-resistant isolates. Results Antimicrobial susceptibility testing revealed alarming resistance rates to carbapenems, cephalosporins, and fluoroquinolones. Using PCR as the gold standard, phenotypic methods underestimated ESBL production while overestimating MBL production. Eighty-five isolates (81.7%) possessed only ESBL encoding genes, among which 69 isolates harbored a single ESBL gene [blaOXA-10 (n = 67) and blaPER (n = 2)]. Four ESBL-genotype combinations were detected: blaPER + blaOXA-10 (n = 8), blaVEB-1 + blaOXA-10 (n = 6), blaPSE + blaOXA-10 (n = 1), and blaPER + blaVEB-1 + blaOXA-10 (n = 1). Three isolates (2.9%) possessed only the MBL encoding gene blaVIM. Three ESBL + MBL- genotype combinations: blaOXA-10 + blaAIM, blaOXA-10 + blaVIM, and blaPER + blaOXA-10 + blaAIM were detected in 2, 1 and 1 isolate(s), respectively. Five plasmid preparations harboring blaVEB-1 and blaOXA-10 were successfully transformed into chemically competent Escherichia coli DH5α with transformation efficiencies ranging between 6.8 × 10 3 and 3.7 × 10 4 CFU/μg DNA plasmid. Selected tested transformants were ceftazidime-resistant and harbored plasmids carrying blaOXA-10. Conclusions The study highlights the importance of the expeditious characterization of ESBLs and MBLs using genotypic methods among P. aeruginosa clinical isolates to hinder the development and dissemination of multidrug resistant strains.
Læs mere Tjek på PubMedInfection, 3.06.2024
Tilføjet 3.06.2024
Abstract Background Antimicrobial resistance among Pseudomonas aeruginosa (P. aeruginosa), a leading cause of nosocomial infections worldwide, is escalating. This study investigated the prevalence of extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs) among 104 P. aeruginosa clinical isolates from Alexandria Main University Hospital, Alexandria, Egypt. Methods Antimicrobial susceptibility testing was performed using agar dilution technique, or broth microdilution method in case of colistin. ESBL and MBL prevalence was assessed phenotypically and genotypically using polymerase chain reaction (PCR). The role of plasmids in mediating resistance to extended-spectrum β-lactams was studied via transformation technique using plasmids isolated from ceftazidime-resistant isolates. Results Antimicrobial susceptibility testing revealed alarming resistance rates to carbapenems, cephalosporins, and fluoroquinolones. Using PCR as the gold standard, phenotypic methods underestimated ESBL production while overestimating MBL production. Eighty-five isolates (81.7%) possessed only ESBL encoding genes, among which 69 isolates harbored a single ESBL gene [blaOXA-10 (n = 67) and blaPER (n = 2)]. Four ESBL-genotype combinations were detected: blaPER + blaOXA-10 (n = 8), blaVEB-1 + blaOXA-10 (n = 6), blaPSE + blaOXA-10 (n = 1), and blaPER + blaVEB-1 + blaOXA-10 (n = 1). Three isolates (2.9%) possessed only the MBL encoding gene blaVIM. Three ESBL + MBL- genotype combinations: blaOXA-10 + blaAIM, blaOXA-10 + blaVIM, and blaPER + blaOXA-10 + blaAIM were detected in 2, 1 and 1 isolate(s), respectively. Five plasmid preparations harboring blaVEB-1 and blaOXA-10 were successfully transformed into chemically competent Escherichia coli DH5α with transformation efficiencies ranging between 6.8 × 10 3 and 3.7 × 10 4 CFU/μg DNA plasmid. Selected tested transformants were ceftazidime-resistant and harbored plasmids carrying blaOXA-10. Conclusions The study highlights the importance of the expeditious characterization of ESBLs and MBLs using genotypic methods among P. aeruginosa clinical isolates to hinder the development and dissemination of multidrug resistant strains.
Læs mere Tjek på PubMedQiong Xu, Zhoufang Mei, Qiongfang Cha, Jiajun Chen, Hui Qin, Bin Liu, Zhijun Jie, Xueling Wu
International Journal of Infectious Diseases, 30.05.2024
Tilføjet 30.05.2024
Recurrent bronchiectasis exacerbations are associated with increased airways inflammation, progressive lung damage, impaired lung function and even increased mortality [1]. Bacterial infections are key pathological features during bronchiectasis exacerbations. Along with Pseudomonas aeruginosa and Haemophilus influenzae, NTM is commonly isolated in bronchiectasis by bacterial culture. However, NTM treatment requires species-specific regimens tailored to patients. mNGS demonstrates higher accuracy (74.9%) and sensitivity (72.5%) in detecting pathogens in bronchoalveolar lavage fluid (BALF) compared to conventional microbiological tests [2].
Læs mere Tjek på PubMedClinical Infectious Diseases, 30.05.2024
Tilføjet 30.05.2024
BMC Infectious Diseases, 29.05.2024
Tilføjet 29.05.2024
Abstract Background Carbapenem-resistant Gram-negative bacteria (CR-GNB) are a critical public health threat globally; however, there are inadequate surveillance data, especially in intensive care units (ICU), to inform infection prevention and control in many resource-constrained settings. Here, we assessed the prevalence of CR-GNB infections and risk factors for acquisition in a Kenyan ICU. Methods A hospital-based cross-sectional study design was adopted, recruiting 162 patients clinically presenting with bacterial infection after 48 h of ICU admission, from January to October 2022 at the Nairobi West Hospital, Kenya. Demographics and clinical data were collected by case report form. The type of sample collected, including blood, tracheal aspirate, ascitic tap, urine, stool, and sputum depended on the patient’s clinical presentation and were transported to the hospital Microbiology laboratory in a cool box for processing within 2 h. The samples were analyzed by cultured and BD Phoenix system used for isolates’ identity and antimicrobial susceptibility. Results CR-GNB infections prevalence was 25.9% (42/162), with Klebsiella pneumoniae (35.7%, 15/42) and Pseudomonas aeruginosa (26.2%, 11/42) predominating. All isolates were multidrug-resistant (MDR). P. aeruginosa and A. baumannii were 100% colistin-resistant, while K. pneumoniae (33.3%) was tigecycline-resistant. History of antibiotics (aOR = 3.40, p = 0.005) and nasogastric tube (NGT) use (aOR = 5.84, p =
Læs mere Tjek på PubMedBMC Infectious Diseases, 29.05.2024
Tilføjet 29.05.2024
Abstract Background Carbapenem-resistant Gram-negative bacteria (CR-GNB) are a critical public health threat globally; however, there are inadequate surveillance data, especially in intensive care units (ICU), to inform infection prevention and control in many resource-constrained settings. Here, we assessed the prevalence of CR-GNB infections and risk factors for acquisition in a Kenyan ICU. Methods A hospital-based cross-sectional study design was adopted, recruiting 162 patients clinically presenting with bacterial infection after 48 h of ICU admission, from January to October 2022 at the Nairobi West Hospital, Kenya. Demographics and clinical data were collected by case report form. The type of sample collected, including blood, tracheal aspirate, ascitic tap, urine, stool, and sputum depended on the patient’s clinical presentation and were transported to the hospital Microbiology laboratory in a cool box for processing within 2 h. The samples were analyzed by cultured and BD Phoenix system used for isolates’ identity and antimicrobial susceptibility. Results CR-GNB infections prevalence was 25.9% (42/162), with Klebsiella pneumoniae (35.7%, 15/42) and Pseudomonas aeruginosa (26.2%, 11/42) predominating. All isolates were multidrug-resistant (MDR). P. aeruginosa and A. baumannii were 100% colistin-resistant, while K. pneumoniae (33.3%) was tigecycline-resistant. History of antibiotics (aOR = 3.40, p = 0.005) and nasogastric tube (NGT) use (aOR = 5.84, p =
Læs mere Tjek på PubMedPia Katharina Vestweber, Jana Wächter, Viktoria Planz, Nathalie Jung, Maike Windbergs
PLoS One Infectious Diseases, 29.05.2024
Tilføjet 29.05.2024
by Pia Katharina Vestweber, Jana Wächter, Viktoria Planz, Nathalie Jung, Maike Windbergs Due to high tolerance to antibiotics and pronounced virulence, bacterial biofilms are considered a key factor and major clinical challenge in persistent wound infections. They are typically composed of multiple species, whose interactions determine the biofilm’s structural development, functional properties and thus the progression of wound infections. However, most attempts to study bacterial biofilms in vitro solely rely on mono-species populations, since cultivating multi-species biofilms, especially for prolonged periods of time, poses significant challenges. To address this, the present study examined the influence of bacterial composition on structural biofilm development, morphology and spatial organization, as well as antibiotic tolerance and virulence on human skin cells in the context of persistent wound infections. By creating a wound-mimetic microenvironment, the successful cultivation of dual-species biofilms of two of the most prevalent wound pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, was realized over a period of 72 h. Combining quantitative analysis with electron microscopy and label-free imaging enabled a comprehensive evaluation of the dynamics of biofilm formation and matrix secretion, revealing a twofold increased maturation of dual-species biofilms. Antibiotic tolerance was comparable for both mono-species cultures, however, dual-species communities showed a 50% increase in tolerance, mediated by a significantly reduced penetration of the applied antibiotic into the biofilm matrix. Further synergistic effects were observed, where dual-species biofilms exacerbated wound healing beyond the effects observed from either Pseudomonas or Staphylococcus. Consequently, predicting biofilm development, antimicrobial tolerance and virulence for multi-species biofilms based solely on the results from mono-species biofilms is unreliable. This study underscores the substantial impact of a multi-species composition on biofilm functional properties and emphasizes the need to tailor future studies reflecting the bacterial composition of the respective in vivo situation, leading to a more comprehensive understanding of microbial communities in the context of basic microbiology and the development of effective treatments.
Læs mere Tjek på PubMedBMC Infectious Diseases, 25.05.2024
Tilføjet 25.05.2024
Abstract Background Carbapenem-resistant Gram-negative bacteria (CR-GNB) are a critical public health threat globally; however, there are inadequate surveillance data, especially in intensive care units (ICU), to inform infection prevention and control in many resource-constrained settings. Here, we assessed the prevalence of CR-GNB infections and risk factors for acquisition in a Kenyan ICU. Methods A hospital-based cross-sectional study design was adopted, recruiting 162 patients clinically presenting with bacterial infection after 48 h of ICU admission, from January to October 2022 at the Nairobi West Hospital, Kenya. Demographics and clinical data were collected by case report form. The type of sample collected, including blood, tracheal aspirate, ascitic tap, urine, stool, and sputum depended on the patient’s clinical presentation and were transported to the hospital Microbiology laboratory in a cool box for processing within 2 h. The samples were analyzed by cultured and BD Phoenix system used for isolates’ identity and antimicrobial susceptibility. Results CR-GNB infections prevalence was 25.9% (42/162), with Klebsiella pneumoniae (35.7%, 15/42) and Pseudomonas aeruginosa (26.2%, 11/42) predominating. All isolates were multidrug-resistant (MDR). P. aeruginosa and A. baumannii were 100% colistin-resistant, while K. pneumoniae (33.3%) was tigecycline-resistant. History of antibiotics (aOR = 3.40, p = 0.005) and nasogastric tube (NGT) use (aOR = 5.84, p =
Læs mere Tjek på PubMedBMC Infectious Diseases, 18.05.2024
Tilføjet 18.05.2024
Abstract Background The study aims were to evaluate the species distribution and antimicrobial resistance profile of Gram-negative pathogens isolated from specimens of intra-abdominal infections (IAI), urinary tract infections (UTI), respiratory tract infections (RTI), and blood stream infections (BSI) in emergency departments (EDs) in China. Methods From 2016 to 2019, 656 isolates were collected from 18 hospitals across China. Minimum inhibitory concentrations were determined by CLSI broth microdilution and interpreted according to CLSI M100 (2021) guidelines. In addition, organ-specific weighted incidence antibiograms (OSWIAs) were constructed. Results Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) were the most common pathogens isolated from BSI, IAI and UTI, accounting for 80% of the Gram-negative clinical isolates, while Pseudomonas aeruginosa (P. aeruginosa) was mainly isolated from RTI. E. coli showed
Læs mere Tjek på PubMedJournal of Infectious Diseases, 11.05.2024
Tilføjet 11.05.2024
Abstract Targeted therapy is an attractive approach for treating infectious diseases. Affibody molecules have similar capability to antibodies that facilitate molecular recognition in both diagnostic and therapeutic applications. Targeting major outer membrane protein (MOMP) for treating infection of Chlamydia trachomatis, one of the most common sexually transmitted pathogens, is a promising therapeutic approach. Previously, we have reported a MOMP-specific affibody (ZMOMP:461) from phage display library. Here, we first fused it with modified Pseudomonas Exotoxin (PE38KDEL) and a cell-penetrating peptide (CPP) to develop an affitoxin, Z461X-CPP. We then verified the addition of both toxin and CPPs that did not affect the affinitive capability of ZMOMP:461 to MOMP. Upon uptake by C.trachomatis-infected cells, Z461X-CPP induced cell apoptosis in vitro. In animal model, Z461X significantly shortened the duration of C. trachomatis infection and prevented pathological damage in mouse reproductive system. These findings provide compelling evidence that the MOMP-specific affitoxin has great potential for targeting therapy of C. trachomatis infection.
Læs mere Tjek på PubMedChristophe Le TerrierSamanta FreireClément ViguierJacqueline FindlayPatrice NordmannLaurent Poirel1Emerging Antibiotic Resistance, Medical and Molecular Microbiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland2Division of Intensive care unit, University hospitals of Geneva, Geneva, Switzerland3Infectious Disease Department, University hospital of Toulouse, Toulouse, France4Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), Fribourg, Switzerland, Alessandra Carattoli
Antimicrobial Agents And Chemotherapy, 10.05.2024
Tilføjet 10.05.2024
Louise Dahl HultqvistJens Bo AndersenCarl Martin NilssonCharlotte Uldahl JansenMorten RybtkeTim Holm JakobsenThomas Eiland NielsenKlaus QvortrupClaus MoserMichael GrazKatrine QvortrupTim Tolker-NielsenMichael Givskov1Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark2Department of Chemistry, Technical University of Denmark, Lyngby, Denmark3Department of Biomedical Sciences, CFIM, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark4Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark, Anne-Catrin Uhlemann
Antimicrobial Agents And Chemotherapy, 9.05.2024
Tilføjet 9.05.2024
BMC Infectious Diseases, 2.05.2024
Tilføjet 2.05.2024
Abstract Background Pseudomonas aeruginosa (P. aeruginosa) is a life-threatening bacterium known for its rapid development of antibiotic resistance, posing significant challenges in clinical treatment, biosecurity, food safety, and environmental monitoring. Early and accurate identification of P. aeruginosa is crucial for effective intervention. Methods The lasB gene of P. aeruginosa was selected as the target for the detection. RPA primers for recombinase polymerase amplification (RPA) and crRNA for CRISPR/Cas12a detection were meticulously designed to target specific regions within the lasB gene. The specificity of the RPA/CRISPR/Cas12a detection platform was assessed using 15 strains. The detection limit of RPA/CRISPR/Cas12a detection platform was determined by utilizing a pseudo-dilution series of the P. aeruginosa DNA. The practical applicability of the RPA/CRISPR/Cas12a detection platform was validated by comparing it with qPCR on 150 samples (35 processed meat product samples, 55 cold seasoned vegetable dishes, 60 bottled water samples). Results The RPA/CRISPR/Cas12a detection platform demonstrates high specificity, with no cross-reactivity with non-P. aeruginosa strains. This assay exhibits remarkable sensitivity, with a limit of detection (LOD) of 100 copies/µL for fluorescence assay and 101 copies/µL for the LFTS method. Furthermore, the performance of the RPA/CRISPR/Cas12a detection platform is comparable to that of the well-established qPCR method, while offering advantages such as shorter reaction time, simplified operation, and reduced equipment requirements. Conclusions The RPA/CRISPR/Cas12a detection platform presents a straightforward, accurate, and sensitive approach for early P. aeruginosa detection and holds great promise for diverse applications requiring rapid and reliable identification.
Læs mere Tjek på PubMedVidmantas PetraitisRuta PetraitienePovilas KavaliauskasEthan NaingAndrew GarciaVilma ZigmantaiteRamune GrigaleviciuteAudrius KucinskasAlius PockeviciusRimantas StakauskasThomas J. Walsh1Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine of Cornell University, New York, New York, USA2The Biological Research Center, Lithuanian University of Health Sciences, Kaunas, Lithuania3Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania4Department of Veterinary Pathobiology, Veterinary Academy, Pathology Center, Lithuanian University of Health Sciences, Kaunas, Lithuania5Center for Innovative Therapeutics and Diagnostics, Richmond, Virginia, USA, Anne-Catrin Uhlemann
Antimicrobial Agents And Chemotherapy, 30.04.2024
Tilføjet 30.04.2024
Daniel E. Jacobsen, Makaela M. Montoya, Trent R. Llewellyn, Kaitlyn Martinez, Kristen M. Wilding, Kiersten D. Lenz, Carrie A. Manore, Jessica Z. Kubicek-Sutherland, Harshini Mukundan
PLoS One Infectious Diseases, 23.04.2024
Tilføjet 23.04.2024
by Daniel E. Jacobsen, Makaela M. Montoya, Trent R. Llewellyn, Kaitlyn Martinez, Kristen M. Wilding, Kiersten D. Lenz, Carrie A. Manore, Jessica Z. Kubicek-Sutherland, Harshini Mukundan Universal and early recognition of pathogens occurs through recognition of evolutionarily conserved pathogen associated molecular patterns (PAMPs) by innate immune receptors and the consequent secretion of cytokines and chemokines. The intrinsic complexity of innate immune signaling and associated signal transduction challenges our ability to obtain physiologically relevant, reproducible and accurate data from experimental systems. One of the reasons for the discrepancy in observed data is the choice of measurement strategy. Immune signaling is regulated by the interplay between pathogen-derived molecules with host cells resulting in cellular expression changes. However, these cellular processes are often studied by the independent assessment of either the transcriptome or the proteome. Correlation between transcription and protein analysis is lacking in a variety of studies. In order to methodically evaluate the correlation between transcription and protein expression profiles associated with innate immune signaling, we measured cytokine and chemokine levels following exposure of human cells to the PAMP lipopolysaccharide (LPS) from the Gram-negative pathogen Pseudomonas aeruginosa. Expression of 84 messenger RNA (mRNA) transcripts and 69 proteins, including 35 overlapping targets, were measured in human lung epithelial cells. We evaluated 50 biological replicates to determine reproducibility of outcomes. Following pairwise normalization, 16 mRNA transcripts and 6 proteins were significantly upregulated following LPS exposure, while only five (CCL2, CSF3, CXCL5, CXCL8/IL8, and IL6) were upregulated in both transcriptomic and proteomic analysis. This lack of correlation between transcription and protein expression data may contribute to the discrepancy in the immune profiles reported in various studies. The use of multiomic assessments to achieve a systems-level understanding of immune signaling processes can result in the identification of host biomarker profiles for a variety of infectious diseases and facilitate countermeasure design and development.
Læs mere Tjek på PubMedAna D. VegaKailynn DeRondeAdriana JimenezMichael PiazzaChristine VuOctavio MartinezLaura J. RojasSteven MarshallMohamad YasminRobert A. BonomoLilian M. Abbo1Department of Pharmacy, Jackson Health System, Miami, Florida, USA2Department of Epidemiology, Florida International University, Miami, Florida, USA3Department of Medicine, Virtua Medical Group, Medford, New Jersey, USA4Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA5Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA6CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, Ohio, USA7Department of Medicine, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA8Departments of Proteomics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA9Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA10Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA, Pranita D. Tamma
Antimicrobial Agents And Chemotherapy, 11.04.2024
Tilføjet 11.04.2024
Bryan K. Lynn, Patrick De Leenheer, Martin Schuster
PLoS One Infectious Diseases, 10.04.2024
Tilføjet 10.04.2024
by Bryan K. Lynn, Patrick De Leenheer, Martin Schuster Cooperation via shared public goods is ubiquitous in nature, however, noncontributing social cheaters can exploit the public goods provided by cooperating individuals to gain a fitness advantage. Theory predicts that this dynamic can cause a Tragedy of the Commons, and in particular, a ‘Collapsing’ Tragedy defined as the extinction of the entire population if the public good is essential. However, there is little empirical evidence of the Collapsing Tragedy in evolutionary biology. Here, we experimentally demonstrate this outcome in a microbial model system, the public good-producing bacterium Pseudomonas aeruginosa grown in a continuous-culture chemostat. In a growth medium that requires extracellular protein digestion, we find that P. aeruginosa populations maintain a high density when entirely composed of cooperating, protease-producing cells but completely collapse when non-producing cheater cells are introduced. We formulate a mechanistic mathematical model that recapitulates experimental observations and suggests key parameters, such as the dilution rate and the cost of public good production, that define the stability of cooperative behavior. We combine model prediction with experimental validation to explain striking differences in the long-term cheater trajectories of replicate cocultures through mutational events that increase cheater fitness. Taken together, our integrated empirical and theoretical approach validates and parametrizes the Collapsing Tragedy in a microbial population, and provides a quantitative, mechanistic framework for generating testable predictions of social behavior.
Læs mere Tjek på PubMedInfection, 10.04.2024
Tilføjet 10.04.2024
Abstract Purpose Bronchoalveolar lavage is commonly used in clinical practice for unresolved pneumonia. However, bronchoalveolar lavage is not suitable for all patients as it is an invasive procedure and can worsen oxygenation. The diagnostic value of bronchial wash and sputum has been debated extensively over the years. In this study, we aim to compare the diagnostic value in several pathogens of bronchoalveolar lavage and bronchial wash, and secondarily bronchoalveolar lavage and sputum. Methods We retrospectively included all adult patients in our hospital who underwent bronchoalveolar lavage, bronchial wash, and where sputum sampling was done between January 1st of 2018 and December 31st of 2021. The intraclass correlation coefficient was computed for the three tests. Results In total, 308 patients were included. We found a level of correlation of 0.819 and 0.865, respectively, between bronchoalveolar lavage and bronchial wash for two pathogens: Staphylococcus aureus and Pseudomonas aeruginosa. For Stenotrophomonas maltophilia and Aspergillus fumigatus, we found an intraclass correlation coefficient of 0.568 and 0.624, respectively. Between bronchoalveolar lavage and sputum, we found varying levels of agreement. Conclusion Our study shows reasonably well agreement levels between bronchoalveolar lavage and bronchial wash, suggesting that bronchial wash could potentially be an alternative to bronchoalveolar lavage.
Læs mere Tjek på PubMedBMC Infectious Diseases, 10.04.2024
Tilføjet 10.04.2024
Abstract Introduction Carbapenem-resistant gram-negative bacilli are a worldwide concern because of high morbidity and mortality rates. Additionally, the increasing prevalence of these bacteria is dangerous. To investigate the extent of antimicrobial resistance and prioritize the utility of novel drugs, we evaluated the molecular characteristics and antimicrobial susceptibility profiles of carbapenem-resistant Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii in Ecuador in 2022. Methods Ninety-five clinical isolates of carbapenem non-susceptible gram-negative bacilli were collected from six hospitals in Ecuador. Carbapenem resistance was confirmed with meropenem disk diffusion assays following Clinical Laboratory Standard Institute guidelines. Carbapenemase production was tested using a modified carbapenemase inactivation method. Antimicrobial susceptibility was tested with a disk diffusion assay, the Vitek 2 System, and gradient diffusion strips. Broth microdilution assays were used to assess colistin susceptibility. All the isolates were screened for the blaKPC, blaNDM, blaOXA-48, blaVIM and blaIMP genes. In addition, A. baumannii isolates were screened for the blaOXA-23, blaOXA-58 and blaOXA-24/40 genes. Results Carbapenemase production was observed in 96.84% of the isolates. The blaKPC, blaNDM and blaOXA-48 genes were detected in Enterobacterales, with blaKPC being predominant. The blaVIM gene was detected in P. aeruginosa, and blaOXA-24/40 predominated in A. baumannii. Most of the isolates showed co-resistance to aminoglycosides, fluoroquinolones, and trimethoprim/sulfamethoxazole. Both ceftazidime/avibactam and meropenem/vaborbactam were active against carbapenem-resistant gram-negative bacilli that produce serin-carbapenemases. Conclusion The epidemiology of carbapenem resistance in Ecuador is dominated by carbapenemase-producing K. pneumoniae harbouring blaKPC. Extensively drug resistant (XDR) P. aeruginosa and A. baumannii were identified, and their identification revealed the urgent need to implement strategies to reduce the dissemination of these strains.
Læs mere Tjek på PubMedInfection, 9.04.2024
Tilføjet 9.04.2024
Abstract Purpose Bronchoalveolar lavage is commonly used in clinical practice for unresolved pneumonia. However, bronchoalveolar lavage is not suitable for all patients as it is an invasive procedure and can worsen oxygenation. The diagnostic value of bronchial wash and sputum has been debated extensively over the years. In this study, we aim to compare the diagnostic value in several pathogens of bronchoalveolar lavage and bronchial wash, and secondarily bronchoalveolar lavage and sputum. Methods We retrospectively included all adult patients in our hospital who underwent bronchoalveolar lavage, bronchial wash, and where sputum sampling was done between January 1st of 2018 and December 31st of 2021. The intraclass correlation coefficient was computed for the three tests. Results In total, 308 patients were included. We found a level of correlation of 0.819 and 0.865, respectively, between bronchoalveolar lavage and bronchial wash for two pathogens: Staphylococcus aureus and Pseudomonas aeruginosa. For Stenotrophomonas maltophilia and Aspergillus fumigatus, we found an intraclass correlation coefficient of 0.568 and 0.624, respectively. Between bronchoalveolar lavage and sputum, we found varying levels of agreement. Conclusion Our study shows reasonably well agreement levels between bronchoalveolar lavage and bronchial wash, suggesting that bronchial wash could potentially be an alternative to bronchoalveolar lavage.
Læs mere Tjek på PubMedBMC Infectious Diseases, 7.04.2024
Tilføjet 7.04.2024
Abstract Introduction Carbapenem-resistant gram-negative bacilli are a worldwide concern because of high morbidity and mortality rates. Additionally, the increasing prevalence of these bacteria is dangerous. To investigate the extent of antimicrobial resistance and prioritize the utility of novel drugs, we evaluated the molecular characteristics and antimicrobial susceptibility profiles of carbapenem-resistant Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii in Ecuador in 2022. Methods Ninety-five clinical isolates of carbapenem non-susceptible gram-negative bacilli were collected from six hospitals in Ecuador. Carbapenem resistance was confirmed with meropenem disk diffusion assays following Clinical Laboratory Standard Institute guidelines. Carbapenemase production was tested using a modified carbapenemase inactivation method. Antimicrobial susceptibility was tested with a disk diffusion assay, the Vitek 2 System, and gradient diffusion strips. Broth microdilution assays were used to assess colistin susceptibility. All the isolates were screened for the blaKPC, blaNDM, blaOXA-48, blaVIM and blaIMP genes. In addition, A. baumannii isolates were screened for the blaOXA-23, blaOXA-58 and blaOXA-24/40 genes. Results Carbapenemase production was observed in 96.84% of the isolates. The blaKPC, blaNDM and blaOXA-48 genes were detected in Enterobacterales, with blaKPC being predominant. The blaVIM gene was detected in P. aeruginosa, and blaOXA-24/40 predominated in A. baumannii. Most of the isolates showed co-resistance to aminoglycosides, fluoroquinolones, and trimethoprim/sulfamethoxazole. Both ceftazidime/avibactam and meropenem/vaborbactam were active against carbapenem-resistant gram-negative bacilli that produce serin-carbapenemases. Conclusion The epidemiology of carbapenem resistance in Ecuador is dominated by carbapenemase-producing K. pneumoniae harbouring blaKPC. Extensively drug resistant (XDR) P. aeruginosa and A. baumannii were identified, and their identification revealed the urgent need to implement strategies to reduce the dissemination of these strains.
Læs mere Tjek på PubMedBMC Infectious Diseases, 6.04.2024
Tilføjet 6.04.2024
Abstract Background Bloodstream infections (BSI) are the major cause of morbidity and mortality in children in developing countries. The purpose of the current study was to establish the antimicrobial susceptibility pattern of bacterial isolates from bloodstream infections at Children’s Medical Center Hospital (CMC), Tehran, Iran. Methods We retrospectively recorded all positive blood cultures and antimicrobial susceptibility of all bloodstream isolates among children admitted to CMC, during 5 years. Specimen culture, bacterial identification, and antimicrobial susceptibility testing were performed according to standard laboratory methods. Results From 3,179 pathogens isolated from the blood cultures 2,824 bacteria were cultured, with 1,312 cases being identified as Gram-positive bacteria (46%) and 1,512 cases as Gram-negative bacteria (54%). The most common Gram-negative bacteria isolated were as follows: Pseudomonas spp. (n = 266, 17.6%), Klebsiella pneumoniae (n = 242, 16%), Stenotrophomonas maltophilia (n = 204, 13.5%), Enterobacter spp. (n = 164, 10.8%), Escherichia coli (n = 159, 10.5%), Pseudomonas aeruginosa (n = 126, 8.3%), Serratia marcescens (n = 121, 8%), and Acinetobacter baumannii (n = 73, 4.8%). The most common Gram-positive bacteria isolated were coagulase-negative staphylococci (CONS) (n = 697, 53%), Streptococcus spp. (n = 237, 18%), Staphylococcus aureus (n = 202, 15%) and Enterococcus spp. (n = 167, 12.7%). 34% of bacterial strains were isolated from ICUs. The rates of methicillin resistance in S. aureus and CONS were 34% and 91%, respectively. E. coli isolates showed high resistance to cefotaxime (84%). All isolates of K. pneumoniae were susceptible to colistin and 56% were susceptible to imipenem. P. aeruginosa isolates showed high susceptibility to all antibiotics. Conclusions Our findings emphasize the need of clinicians having access to up-to-date bacterial susceptibility data for routinely prescribed drugs. Continuous monitoring of changes in bacterial resistance will aid in the establishment of national priorities for local intervention initiatives in Iran. The increased risk of BSI caused by antibiotic-resistant organisms, emphasizes the significance of implementing appropriate antibiotic prescribing regulations and developing innovative vaccination techniques in Iran.
Læs mere Tjek på PubMedJirapat Thongchol, Zihao Yu, Laith Harb, Yiruo Lin, Matthias Koch, Matthew Theodore, Utkarsh Narsaria, Joshua Shaevitz, Zemer Gitai, Yinghao Wu, Junjie Zhang, Lanying Zeng
Science, 5.04.2024
Tilføjet 5.04.2024
BMC Infectious Diseases, 4.04.2024
Tilføjet 4.04.2024
Abstract Background Bloodstream infections (BSI) are the major cause of morbidity and mortality in children in developing countries. The purpose of the current study was to establish the antimicrobial susceptibility pattern of bacterial isolates from bloodstream infections at Children’s Medical Center Hospital (CMC), Tehran, Iran. Methods We retrospectively recorded all positive blood cultures and antimicrobial susceptibility of all bloodstream isolates among children admitted to CMC, during 5 years. Specimen culture, bacterial identification, and antimicrobial susceptibility testing were performed according to standard laboratory methods. Results From 3,179 pathogens isolated from the blood cultures 2,824 bacteria were cultured, with 1,312 cases being identified as Gram-positive bacteria (46%) and 1,512 cases as Gram-negative bacteria (54%). The most common Gram-negative bacteria isolated were as follows: Pseudomonas spp. (n = 266, 17.6%), Klebsiella pneumoniae (n = 242, 16%), Stenotrophomonas maltophilia (n = 204, 13.5%), Enterobacter spp. (n = 164, 10.8%), Escherichia coli (n = 159, 10.5%), Pseudomonas aeruginosa (n = 126, 8.3%), Serratia marcescens (n = 121, 8%), and Acinetobacter baumannii (n = 73, 4.8%). The most common Gram-positive bacteria isolated were coagulase-negative staphylococci (CONS) (n = 697, 53%), Streptococcus spp. (n = 237, 18%), Staphylococcus aureus (n = 202, 15%) and Enterococcus spp. (n = 167, 12.7%). 34% of bacterial strains were isolated from ICUs. The rates of methicillin resistance in S. aureus and CONS were 34% and 91%, respectively. E. coli isolates showed high resistance to cefotaxime (84%). All isolates of K. pneumoniae were susceptible to colistin and 56% were susceptible to imipenem. P. aeruginosa isolates showed high susceptibility to all antibiotics. Conclusions Our findings emphasize the need of clinicians having access to up-to-date bacterial susceptibility data for routinely prescribed drugs. Continuous monitoring of changes in bacterial resistance will aid in the establishment of national priorities for local intervention initiatives in Iran. The increased risk of BSI caused by antibiotic-resistant organisms, emphasizes the significance of implementing appropriate antibiotic prescribing regulations and developing innovative vaccination techniques in Iran.
Læs mere Tjek på PubMedHirokazu YanoWataru HayashiSayoko KawakamiSadao AokiEiko AnzaiHui ZuoNorikazu KitamuraAki HirabayashiToshiki KajiharaShizuo KayamaYo SugawaraKoji YaharaMotoyuki Sugai1Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan, Pranita D. Tamma
Antimicrobial Agents And Chemotherapy, 3.04.2024
Tilføjet 3.04.2024
Jiaren LiYouyou LiLiang ZhouHongming LiTengfei WanJin TangLei ZhouHui XieLong Wanga Department of Urology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, Chinab Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan, China
Virulence, 3.04.2024
Tilføjet 3.04.2024
BMC Infectious Diseases, 30.03.2024
Tilføjet 30.03.2024
Abstract Background Vagococcal infections are extremely rare in humans. There are limited studies on the optimal methods for identification, antimicrobial susceptibility testing, and clinical manifestations of vagococcal infections. Herein, we report a patient with a urinary tract infection who had Vagococcus fluvialis in the urine. Case presentation An 84-year-old man presented to our urology department with a fever that had persisted for several days. He previously worked as a zoo clerk. The patient underwent a left nephroureterectomy for ureteral cancer 5 years ago, and total cystectomy and right cutaneous ureterostomy for muscle-invasive bladder cancer 1 year prior. He was empirically treated with 500 mg of levofloxacin intravenously every 24 h for the urinary tract infection. V. fluvialis was detected in his urine samples and Pseudomonas aeruginosa was detected in his urine and blood samples. Two bacterial species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. He was administered intravenous levofloxacin for approximately 1 week, followed by oral levofloxacin for another week, after which the infections were eradicated. Conclusions To the best of our knowledge, this is the first report of V. fluvialis detected in human urine in Japan. Vagococcus spp. is commonly isolated from fish or animals, and based on the patient’s work history, it is possible that the patient was a carrier because of transmission from animals.
Læs mere Tjek på PubMedAmruta A. KarbelkarMaria FontT. Jarrod SmithHolger SondermannGeorge A. O’TooleaDepartment of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755bCSSB Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg, Germany
Proceedings of the National Academy of Sciences, 28.03.2024
Tilføjet 28.03.2024
Proceedings of the National Academy of Sciences, Volume 121, Issue 13, March 2024.
Læs mere Tjek på PubMedPaulina Guzmán-Guzmán, Eduardo Valencia-Cantero, Gustavo Santoyo
PLoS One Infectious Diseases, 22.03.2024
Tilføjet 22.03.2024
by Paulina Guzmán-Guzmán, Eduardo Valencia-Cantero, Gustavo Santoyo Trichoderma uses different molecules to establish communication during its interactions with other organisms, such as effector proteins. Effectors modulate plant physiology to colonize plant roots or improve Trichoderma’s mycoparasitic capacity. In the soil, these fungi can establish relationships with plant growth–promoting bacteria (PGPBs), thus affecting their overall benefits on the plant or its fungal prey, and possibly, the role of effector proteins. The aim of this study was to determine the induction of Trichoderma atroviride gene expression coding for effector proteins during the interaction with different PGPBs, Arabidopsis or the phytopathogen Fusarium brachygibbosum, and to determine whether PGPBs potentiates the beneficial effects of T. atroviride. During the interaction with F. brachygibbosum and PGPBs, the effector coding genes epl1, tatrx2 and tacfem1 increased their expression, especially during the consortia with the bacteria. During the interaction of T. atroviride with the plant and PGPBs, the expression of epl1 and tatrx2 increased, mainly with the consortium formed with Pseudomonas fluorescens UM270, Bacillus velezensis AF12, or B. halotolerans AF23. Additionally, the consortium formed by T. atroviride and R. badensis SER3 stimulated A. thaliana PR1:GUS and LOX2:GUS for SA- and JA-mediated defence responses. Finally, the consortium of T. atroviride with SER3 was better at inhibiting pathogen growth, but the consortium of T. atroviride with UM270 was better at promoting Arabidopsis growth. These results showed that the biocontrol capacity and plant growth-promoting traits of Trichoderma spp. can be potentiated by PGPBs by stimulating its effector functions.
Læs mere Tjek på PubMedBMC Infectious Diseases, 22.03.2024
Tilføjet 22.03.2024
Abstract Background Vagococcal infections are extremely rare in humans. There are limited studies on the optimal methods for identification, antimicrobial susceptibility testing, and clinical manifestations of vagococcal infections. Herein, we report a patient with a urinary tract infection who had Vagococcus fluvialis in the urine. Case presentation An 84-year-old man presented to our urology department with a fever that had persisted for several days. He previously worked as a zoo clerk. The patient underwent a left nephroureterectomy for ureteral cancer 5 years ago, and total cystectomy and right cutaneous ureterostomy for muscle-invasive bladder cancer 1 year prior. He was empirically treated with 500 mg of levofloxacin intravenously every 24 h for the urinary tract infection. V. fluvialis was detected in his urine samples and Pseudomonas aeruginosa was detected in his urine and blood samples. Two bacterial species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. He was administered intravenous levofloxacin for approximately 1 week, followed by oral levofloxacin for another week, after which the infections were eradicated. Conclusions To the best of our knowledge, this is the first report of V. fluvialis detected in human urine in Japan. Vagococcus spp. is commonly isolated from fish or animals, and based on the patient’s work history, it is possible that the patient was a carrier because of transmission from animals.
Læs mere Tjek på PubMedClinical Infectious Diseases, 21.03.2024
Tilføjet 21.03.2024
Saima AslamDwayne RoachMikeljon P. NikolichBiswajit BiswasRobert T. SchooleyKimberley A. Lilly-BishopGregory K. RiceRegina Z. CerTheron HamiltonMatthew HenryTiffany LuongAnn-Charlott SalabarriaLaura Sisk-HackworthAndrey A. FilippovFrancois LebretonLindsey HallRan Nir-PazHadil OnallahGilat LivniEran ShostakAnat Wieder-FinesodDafna YahavOrtal YerushalmySivan Alkalay-OrenRon BraunsteinLeron KhalifaAmit RimonDaniel GelmanRonen Hazan1Division of Infectious Diseases and Global Public Health and the Center for Innovative Phage Applications and Therapeutics, University of California San Diego, La Jolla, California, USA2Department of Biology, San Diego State University, San Diego, California, USA3Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA4Naval Medical Research Command – Frederick, Fort Detrick, Maryland, USA5Leidos, Inc, Reston, Virginia, USA6The Geneva Foundation, Tacoma, Washington, USA7Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel8Schneider Children’s Medical Center, Petah Tikva, Israel9The Infectious Diseases Unit, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel10Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, Hebrew University of Jerusalem, Jerusalem, Israel, Cesar A. Arias
Antimicrobial Agents And Chemotherapy, 13.03.2024
Tilføjet 13.03.2024
Xiaoya WeiJiacong GaoDandan ZhouCongjuan XuPing ChenShuiping ChenYanhong ZhangXuehua LiuGuanxian LiGuangbo ZhuHuimin LiuJinjin LiBin GengLinlin GaoZhihui ChengIain L. LamontDaniel PletzerYongxin JinShouguang JinWeihui Wu1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China2Department of Laboratory Medicine, 5th Medical Center of PLA General Hospital, Beijing, China3Nankai University Affiliated Hospital (Tianjin Forth Hospital), Tianjin, China4Tianjin Union Medical Center, Nankai University Affiliated Hospital, Tianjin, China5Department of Biochemistry, University of Otago, Dunedin, New Zealand6Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand, Laurent Poirel
Antimicrobial Agents And Chemotherapy, 13.03.2024
Tilføjet 13.03.2024
Journal of Infectious Diseases, 6.03.2024
Tilføjet 6.03.2024
Abstract Background Pseudomonas aeruginosa is a multidrug-resistant pathogen causing recalcitrant pulmonary infections in people with cystic fibrosis (pwCF). Cystic fibrosis transmembrane conductance regulator (CFTR) modulators have been developed that partially correct the defective chloride channel driving disease. Despite the many clinical benefits, studies in adults have demonstrated that while P. aeruginosa sputum load decreases, chronic infection persists. Here, we investigate how P. aeruginosa in pwCF may change in the altered lung environment after CFTR modulation.Methods P. aeruginosa strains (n = 105) were isolated from the sputum of 11 chronically colonized pwCF at baseline and up to 21 months posttreatment with elexacaftor-tezacaftor-ivacaftor or tezacaftor-ivacaftor. Phenotypic characterization and comparative genomics were performed.Results Clonal lineages of P. aeruginosa persisted after therapy, with no evidence of displacement by alternative strains. We identified commonly mutated genes among patient isolates that may be positively selected for in the CFTR-modulated lung. However, classic chronic P. aeruginosa phenotypes such as mucoid morphology were sustained, and isolates remained just as resistant to clinically relevant antibiotics.Conclusions Despite the clinical benefits of CFTR modulators, clonal lineages of P. aeruginosa persist that may prove just as difficult to manage in the future, especially in pwCF with advanced lung disease.
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