Abstract Background Vancomycin-induced bleeding has been reported, attributed to the mechanism of immune thrombocytopenia. A rare case of vancomycin-induced gastrointestinal hemorrhage in a young patient with no underlying disease, receiving intravenous vancomycin for methicillin-resistant Staphylococcus aureus (MRSA) infection, is presented. This occurrence occurred without thrombocytopenia. Relevant cases reported in the literature were also reviewed. Case presentation A 34-year-old male patient presented with maxillofacial multiple spaces infection accompanying left temporal abscess, bilateral lung abscesses. Culture results from both blood and secretion indicated that the infection was caused by MRSA. The patient received standard-dose vancomycin (1 g q12h intravenously guttae) for treatment. On the 5th day of therapy, he presented with bright red blood in his stool; however, vancomycin treatment was continued. By the 9th day, a decrease in hemoglobin level to 76 g/L and a platelet (PLT) count of 424 × 109/L raised concerns about gastrointestinal hemorrhage. The hemoglobin level decreased to 62 g/L on day 12. Due to the high tissue concentration of linezolid, administration of linezolid at a dose of 600 mg q12h intravenously guttae commenced on the 13th day as an alternative to vancomycin(D13-D17). Subsequently, on the 17th day, there was an improvement in hemoglobin level to 78 g/L. However, despite treatment with linezolid, the patient’s fever showed no significant improvement, prompting a switch back to vancomycin at a dosage of 1 g q12h intravenously guttae(D18-D22). On the 21st day, there was a recurrence of gastrointestinal hemorrhage, accompanied by a hemoglobin level of 42 g/L and a PLT count of 224 × 109/L. Gastroscopy revealed the presence of a gastroduodenal ulcer. The patient had no prior history of hemorrhoids, gastrointestinal ulcers, liver cirrhosis, or purpura. Prior to admission, he had not been administered non-steroidal anti-inflammatory drugs (NSAIDs) or steroids. During hospitalization, the only medications given were vancomycin, ambroxol and lidocaine. Additional tests ruled out immunological disorders as the cause of gastrointestinal ulcers, and a positive vancomycin rechallenge test indicated an association between vancomycin and bleeding. After discontinuation of vancomycin, no further bleeding occurred. This case highlights a rare occurrence of vancomycin-induced bleeding without thrombocytopenia, classified as “Certain” according to the World Health Organization-Uppsala Monitoring Centre (WHO-UMC) scale for standardized case causality assessment. Conclusion This case represents the first documented instance of vancomycin-induced bleeding without thrombocytopenia, as confirmed by a positive rechallenge test. This discovery will aid in the early detection of this rare adverse reaction in future cases. …

Abstract Background and rationale Methicillin resistant Staphylococcus aureus (MRSA) colonization increases the risk of MRSA infection. Detecting MRSA colonization can influence postoperative outcomes and prolong hospital stay. The conventional standard culture method for detecting MRSA colonization has limitations in terms of sensitivity and turnaround time. Hence, we sought out use of Xpert PCR kit for prompt evaluation of MRSA colonization to support MRSA prevention in a tertiary care hospital in Karachi, Pakistan. Materials and methods During 1st April-31st December 2022, 290 nasal and skin swab samples were collected from 257 patients and processed using routine culture (as gold standard method) and PCR-based MRSA detection assay (MRSA Xpert). Results A total of two hundred and ninety (290) swab samples from 257 patients were obtained, 33 of which were paired. The overall prevalence of MRSA colonization was 12% by both methods, with 90% of cases classified as community-associated (CA-MRSA) whereas 10% as hospital-acquired (HA-MRSA). The colonized group showed a higher subsequent MRSA infection rate (11% vs. 3.5%) compared to the noncolonized group. Culture identified 11% of screening samples as MRSA positive, Xpert MRSA assay showed 100% sensitivity and 95% specificity. The cost of a single MRSA Xpert assay was $50 while MRSA culture cost around $7.50. Conclusion Our study findings suggest that the presence of MRSA colonization in our cohort of patients is consistent with the existing trends in hospital epidemiology. Both conventional culture and Xpert MRSA methods showed comparable efficacy for detection of MRSA colonization. Larger-scale studies are recommended to validate these findings conclusively. …

Abstract Background and rationale Methicillin resistant Staphylococcus aureus (MRSA) colonization increases the risk of MRSA infection. Detecting MRSA colonization can influence postoperative outcomes and prolong hospital stay. The conventional standard culture method for detecting MRSA colonization has limitations in terms of sensitivity and turnaround time. Hence, we sought out use of Xpert PCR kit for prompt evaluation of MRSA colonization to support MRSA prevention in a tertiary care hospital in Karachi, Pakistan. Materials and methods During 1st April-31st December 2022, 290 nasal and skin swab samples were collected from 257 patients and processed using routine culture (as gold standard method) and PCR-based MRSA detection assay (MRSA Xpert). Results A total of two hundred and ninety (290) swab samples from 257 patients were obtained, 33 of which were paired. The overall prevalence of MRSA colonization was 12% by both methods, with 90% of cases classified as community-associated (CA-MRSA) whereas 10% as hospital-acquired (HA-MRSA). The colonized group showed a higher subsequent MRSA infection rate (11% vs. 3.5%) compared to the noncolonized group. Culture identified 11% of screening samples as MRSA positive, Xpert MRSA assay showed 100% sensitivity and 95% specificity. The cost of a single MRSA Xpert assay was $50 while MRSA culture cost around $7.50. Conclusion Our study findings suggest that the presence of MRSA colonization in our cohort of patients is consistent with the existing trends in hospital epidemiology. Both conventional culture and Xpert MRSA methods showed comparable efficacy for detection of MRSA colonization. Larger-scale studies are recommended to validate these findings conclusively. …

Abstract Background In the pediatric population, Staphylococcus aureus infections are responsible for increased morbidity and mortality, length of hospitalization and the cost of inpatient treatment. The aim of this study is to describe the antimicrobial resistance profile of S. aureus isolated in clinical specimens from pediatric patients admitted to a tertiary hospital in Rio de Janeiro, Brazil. Methods Culture reports and medical records of hospitalized patients under 18 years of age with S. aureus infections between January 2015 and December 2022 were retrospectively analyzed. Information was collected on recent antibiotic use, previous hospital admission, inpatient unit, clinical specimen, time of infection (community or nosocomial), classification according to susceptibility to methicillin (methicillin sensitive - MSSA or methicillin resistant - MRSA) and sensitivity to other antimicrobials. We analyzed the distribution of the sensitivity profile of S. aureus infections over the 7 years evaluated in the study. Results Were included 255 unique clinical episodes, among which the frequencies of MSSA and MRSA were 164 (64%) and 91 (36%), respectively. Over the 7 years evaluated, there was stability in the prevalence percentage, with a predominance of MSSA in the range of 60 to 73.3%, except in 2020, when there was a drop in the prevalence of MSSA (from 73.3% in 2019 to 52.5%) with an increase in MRSA (from 26.7% in 2019 to 47.5%). Ninety-seven (38%) infections were community-acquired and 158 (62%) were healthcare-associated. The main clinical specimens collected were blood cultures (35.2%) and wound secretions (17%). The MRSA isolates presented percentages of sensitivity to trimethoprim-sulfamethoxazole from 90.4 to 100%, and to clindamycin from 77 to 89.8% in MRSA healthcare associated and MRSA community respectively. Conclusion There was a constant predominance in the prevalence of MSSA with percentage values ​​maintained from 2015 to 2022, except in 2020, in which there was a specific drop in the prevalence of MSSA with an increase in MRSA. MSSA infections are still predominant in the pediatric population, but MRSA rates also present significant values, including in community infections, and should be considered in initial empiric therapy. …

by Mohammed S. Almuhayawi, Mohammed H. Alruhaili, Mohamed K. Y. Soliman, Muyassar K. Tarabulsi, Ruba A. Ashy, Amna A. Saddiq, Samy Selim, Yasir Alruwaili, Salem S. Salem It is thought to be risk-free, environmentally benign, and safe for biological processes to produce zinc oxide nanoparticles from renewable resources. This study examined Cassia javanica’s ability to create ZnONPs. The generated ZnONPs were analyzed using a variety of techniques, such as TEM, FTIR spectroscopy, UV-Vis spectroscopy, and XRD analysis. The antibacterial potential of ZnONPs has been investigated using both Agar well diffusion and microtitreplate (MTP) methods. One method used to evaluate ZnONPs’ capacity to scavenge free radicals at different concentrations was the DPPH method. The permanent zinc oxide (ZnO) shape and the naturally occurring crystal structure of ZnONPs were validated by the XRD data. ZnONPs showed antibacterial activity with MICs of 31.7 μg/mL toward Bacillus subtilis, 62.5 μg/mL for Salmonella typhimurium, Escherichia coli while Clostridium sporogenes and Bacillus pumilus was 125μg/mL. Furthermore, ZnONPs demonstrated a range of antibiofilm activities toward Staphylococcus aureus (MRSA). ZnONPs showed an intriguing antioxidant capacity, achieving IC50 of 109.3 μg/ml μg/mL. Additionally, ZnONPs demonstrated low toxic effect on Vero cell with IC50 154.01 μg/mL as well as possible anticancer action when applied to the carcinoma cell lines HepG2 with IC50 of 47.48 μg/mL. Furthermore, ZnONPs at 62.5 μg/mL had a promising antiviral impact against HSV1 and COX B4, with antiviral activities of 75.4% and 65.8%, respectively.

Abstract Background In the pediatric population, Staphylococcus aureus infections are responsible for increased morbidity and mortality, length of hospitalization and the cost of inpatient treatment. The aim of this study is to describe the antimicrobial resistance profile of S. aureus isolated in clinical specimens from pediatric patients admitted to a tertiary hospital in Rio de Janeiro, Brazil. Methods Culture reports and medical records of hospitalized patients under 18 years of age with S. aureus infections between January 2015 and December 2022 were retrospectively analyzed. Information was collected on recent antibiotic use, previous hospital admission, inpatient unit, clinical specimen, time of infection (community or nosocomial), classification according to susceptibility to methicillin (methicillin sensitive - MSSA or methicillin resistant - MRSA) and sensitivity to other antimicrobials. We analyzed the distribution of the sensitivity profile of S. aureus infections over the 7 years evaluated in the study. Results Were included 255 unique clinical episodes, among which the frequencies of MSSA and MRSA were 164 (64%) and 91 (36%), respectively. Over the 7 years evaluated, there was stability in the prevalence percentage, with a predominance of MSSA in the range of 60 to 73.3%, except in 2020, when there was a drop in the prevalence of MSSA (from 73.3% in 2019 to 52.5%) with an increase in MRSA (from 26.7% in 2019 to 47.5%). Ninety-seven (38%) infections were community-acquired and 158 (62%) were healthcare-associated. The main clinical specimens collected were blood cultures (35.2%) and wound secretions (17%). The MRSA isolates presented percentages of sensitivity to trimethoprim-sulfamethoxazole from 90.4 to 100%, and to clindamycin from 77 to 89.8% in MRSA healthcare associated and MRSA community respectively. Conclusion There was a constant predominance in the prevalence of MSSA with percentage values ​​maintained from 2015 to 2022, except in 2020, in which there was a specific drop in the prevalence of MSSA with an increase in MRSA. MSSA infections are still predominant in the pediatric population, but MRSA rates also present significant values, including in community infections, and should be considered in initial empiric therapy. …

Abstract Background Corynebacterium striatum (C. striatum), a common skin and mucosal colonizer, is increasingly considered as an opportunistic pathogen causing bloodstream infections (BSIs). This study aims to investigate the clinical features and outcomes of C. striatum-BSI. Methods We included hospitalized cases with C. striatum-positive blood cultures from January 2014 to June 2022 and classified them into C. striatum-BSI group and contamination group; Clinical characteristics, treatments, and outcomes were compared between the C. striatum-BSI group and contamination group, Methicillin-resistant Staphylococcus aureus (MRSA)-BSI and Methicillin-resistant Staphylococcus epidermidis (MRSE)-BSI. Results Fifty-three patients with positive C. striatum blood cultures were identified. Among them, 25 patients were classified as C. striatum-BSI, with 21 as contamination cases. And 62 cases of MRSA-BSI and 44 cases of MRSE-BSI were identified. Compared to the contaminated group, the C. striatum-BSI group had a shorter time to positivity of blood cultures (27.0 h vs. 42.5 h, P = 0.011). C. striatum-BSI group had a longer time to positivity (27 h) when compared to both the MRSA (20 h) and MRSE groups (19 h) (p 

by Zhaolei Wang, Haixia Du, Haofang Wan, Jiehong Yang, Haitong Wan Methicillin-resistant Staphylococcus aureus (MRSA) is an opportunistic pathogen that can cause severe bacterial pneumonia. Amygdalin is the main active pharmaceutical ingredient of bitter almond, which has broad-spectrum antibacterial, anti-inflammatory, anti-oxidation and immunomodulatory effects. It is also the main ingredient of Yinhua Pinggan granule, which is commonly used to moisten the lung and relieve cough. However, little is known about the effects of amygdalin on MRSA. In this study, we found that amygdalin exhibited good antimicrobial activity in vitro against MRSA. Amygdalin has a protective effect on MRSA infected cells, and the effect is better when combined with levofloxacin. It also can reduce the adhesion and invasion of MRSA to cells. Amygdalin has anti-inflammatory and antioxidant effects, which can significantly reduce the increase of inflammatory factors and the production of ROS caused by infection. The protective mechanism of amygdalin on cells may be related to inhibiting the expression of NLRP3, ASC and IL-1β pyroptosis pathways. Taken together, our study suggests that amygdalin exerts antibacterial effects by affecting biofilm formation, the expression of virulence factors, and drug resistance genes. Amygdalin combined with levofloxacin has a protective effect on A549 cells infected with MRSA, and the mechanism may be related to the inhibition of inflammatory response, oxidative damage and pyroptosis.

Abstract Background The increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains resistant to non-beta-lactam antimicrobials poses a significant challenge in treating severe MRSA bloodstream infections. This study explores resistance development and mechanisms in MRSA isolates, especially after the first dalbavancin-resistant MRSA strain in our hospital in 2016. Methods This study investigated 55 MRSA bloodstream isolates (02/2015–02/2021) from the University Hospital of the Medical University of Vienna, Austria. The MICs of dalbavancin, linezolid, and daptomycin were assessed. Two isolates (16–33 and 19–362) resistant to dalbavancin were analyzed via whole-genome sequencing, with morphology evaluated using transmission electron microscopy (TEM). Results S.aureus BSI strain 19–362 had two novel missense mutations (p.I515M and p.A606D) in the pbp2 gene. Isolate 16–33 had a 534 bp deletion in the DHH domain of GdpP and a SNV in pbp2 (p.G146R). Both strains had mutations in the rpoB gene, but at different positions. TEM revealed significantly thicker cell walls in 16–33 (p 

Abstract Background The increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) strains resistant to non-beta-lactam antimicrobials poses a significant challenge in treating severe MRSA bloodstream infections. This study explores resistance development and mechanisms in MRSA isolates, especially after the first dalbavancin-resistant MRSA strain in our hospital in 2016. Methods This study investigated 55 MRSA bloodstream isolates (02/2015–02/2021) from the University Hospital of the Medical University of Vienna, Austria. The MICs of dalbavancin, linezolid, and daptomycin were assessed. Two isolates (16–33 and 19–362) resistant to dalbavancin were analyzed via whole-genome sequencing, with morphology evaluated using transmission electron microscopy (TEM). Results S.aureus BSI strain 19–362 had two novel missense mutations (p.I515M and p.A606D) in the pbp2 gene. Isolate 16–33 had a 534 bp deletion in the DHH domain of GdpP and a SNV in pbp2 (p.G146R). Both strains had mutations in the rpoB gene, but at different positions. TEM revealed significantly thicker cell walls in 16–33 (p