Community-acquired Methicillin-resistant Staphylococcus Aureus Research Articles

Preventing MRSA Infections in Sports: Effective Strategies and Approaches

Introduction: Infections caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are a growing concern, particularly among asymptomatic individuals. CA-MRSA can lead to various conditions such as skin infections, septic arthritis, pyomyositis, endocarditis, and pubic osteomyelitis, with athletes being especially vulnerable due to shared equipment, close contact, and skin trauma. Prolonged colonization of the anterior nares and persistence on shared surfaces contribute to its spread. Purpose of work: This study aims to review MRSA prevalence in sports and provide effective strategies for prevention and management.The purpose of this paper is to evaluate MRSA prevalence in sports and provide effective strategies for prevention and management. Materials and methods: A comprehensive analysis of research papers available on PubMed, Google Scholar and Scopus was undertaken using the search terms encompassing the following keywords: Community- acquired MRSA / MRSA and Sport / MRSA and athletes / MRSA Prevention Strategies in Sports / MRSA Infection Risks in Athletes / MRSA Colonization and Sports Participation. Results: A meta-analysis found that about 6% of asymptomatic athletes are colonized with MRSA, though rates vary by sport and country. Decolonization methods may reduce infection risk, but their effects are often temporary. This study examines MRSA colonization and infections in athletes, stressing the importance of preventive measures.

Beyond the Usual Suspects: Unmasking a Rare Pulmonary Co-Infection

This case report presents a 33-year-old male farmer with community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) pneumonia complicated by Leptospirosis. The patient presented with a 2.5-month history of high-grade fever, chest pain, and weight loss. Investigations revealed multiple cavitary lesions in bilateral lungs. Blood cultures were positive for MRSA, and ELISA for leptospira was positive. The patient was successfully treated with vancomycin and anticoagulation therapy and discharged.

Genomic characterization of methicillin-resistant Staphylococcus aureus isolated from patients attending regional referral hospitals in Tanzania

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) colonization increases the risk of subsequent infection by MRSA strain complex interlinking between hospital and community-acquired MRSA which increases the chance of drug resistance and severity of the disease.ObjectiveGenomic characterization of Staphylococcus aures strains isolated from patients attending regional referral hospitals in Tanzania.MethodologyA laboratory-based cross-sectional study using short read-based sequencing technology, (Nextseq550,Illumina, Inc. San diego, California, USA). The samples used were collected from patients attending selected regional referral hospitals in Tanzania under the SeqAfrica project. Sequences were analyzed using tools available in the center for genomic and epidemiology server, and visualization of the phylogenetic tree was performed in ITOL 6.0. SPSS 28.0 was used for statistical analysis.ResultsAmong 103 sequences of S. aureus, 48.5% (50/103) carry the mecA gene for MRSA. High proportions of MRSA were observed among participants aged between 18 and 34 years (52.4%), in females (54.3%), and among outpatients (60.5%). The majority of observed MRSA carried plasmids rep5a (92.0%), rep16 (90.0%), rep7c (90.0%), rep15 (82.0%), rep19 (80.0%) and rep10 (72.0%). Among all plasmids observed rep5a, rep16, rep20, and repUS70 carried the blaZ gene, rep10 carried the erm(C) gene and rep7a carried the tet(K) gene. MLST and phylogeny analysis reveal high diversity among MRSA. Six different clones were observed circulating at selected regional hospitals and MRSA with ST8 was dominant.ConclusionThe study reveals a significant presence of MRSA in Staphylococcus aureus strains from Tanzanian regional hospitals, with nearly half carrying the mecA gene. MRSA is notably prevalent among young adults, females, and outpatients, showing high genetic diversity and dominance of ST8. Various plasmids carrying resistance genes indicate a complex resistance profile, highlighting the need for targeted interventions to manage MRSA infections in Tanzania.

Dynamical analysis of methicillin-resistant Staphylococcus aureus infection in North Cyprus with optimal control: prevalence and awareness

The number of Methicillin-resistant Staphylococcus aureus (MRSA) cases in communities and hospitals is on the rise worldwide. In this work, a nonlinear deterministic model for the dynamics of MRSA infection in society was developed to visualize the significance of awareness in interventions that could be applied in the prevention of transmission with and without optimal control. Positivity and uniqueness were verified for the proposed corruption model to identify the level of resolution of infection factors in society. Furthermore, how various parameters affect the reproductive number R0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${R}_{0}$$\\end{document} and sensitivity analysis of the proposed model was explored through mathematical techniques and figures. The global stability of model equilibria analysis was established by using Lyapunov functions with the first derivative test. A total of seven years of data gathered from a private hospital consisting of inpatients and outpatients of MRSA were used in this model for numerical simulations and for observing the dynamics of infection by using a non-standard finite difference (NSFD) scheme. When optimal control was applied as a second model, it was determined that increasing awareness of hand hygiene and wearing a mask were the key controlling measures to prevent the spread of community-acquired MRSA (CA-MRSA) and hospital-acquired MRSA (HA-MRSA). Lastly, it was concluded that both CA-MRSA and HA-MRSA cases are on the rise in the community, and increasing awareness concerning transmission is extremely significant in preventing further spread.

Virulence and resistance profiling of Staphylococcus aureus isolated from subclinical bovine mastitis in the Pakistani Pothohar region

Mastitis is considered one of the most widespread infectious disease of cattle and buffaloes, affecting dairy herds. The current study aimed to characterize the Staphylococcus aureus isolates recovered from subclinical mastitis animals in Pothohar region of the country. A total of 278 milk samples from 17 different dairy farms around two districts of the Pothohar region, Islamabad and Rawalpindi, were collected and screened for sub clinical mastitis using California Mastitis Test. Positive milk samples were processed for isolation of Staphylococcus aureus using mannitol salt agar. The recovered isolates were analyzed for their antimicrobial susceptibility and virulence genes using disc diffusion and PCR respectively. 62.2% samples were positive for subclinical mastitis and in total 70 Staphylococcus aureus isolates were recovered. 21% of these isolates were determined to be methicillin resistant, carrying the mecA gene. S. aureus isolates recovered during the study were resistant to all first line therapeutic antibiotics and in total 52% isolates were multidrug resistant. SCCmec typing revealed MRSA SCCmec types IV and V, indicating potential community-acquired MRSA (CA-MRSA) transmission. Virulence profiling revealed high prevalence of key genes associated with adhesion, toxin production, and immune evasion, such as hla, hlb, clfA, clfB and cap5. Furthermore, the Panton-Valentine leukocidin (PVL) toxin, that is often associated with recurrent skin and soft tissue infections, was present in 5.7% of isolates. In conclusion, the increased prevalence of MRSA in bovine mastitis is highlighted by this study, which also reveals a variety of virulence factors in S. aureus and emphasizes the significance of appropriate antibiotic therapy in combating this economically burdensome disease.

Synergistic bactericidal activity of a novel dual β-lactam combination against methicillin-resistant Staphylococcus aureus.

MRSA is a major cause of hospital-acquired and community-acquired infections. Treatment options for MRSA are limited because of the rapid development of β-lactam resistance. Combining antibiotics offers an affordable, time-saving, viable and efficient approach for developing novel antimicrobial therapies. Both amoxicillin and cefdinir are oral β-lactams with indications for a wide range of bacterial infections and mild side effects. This study aimed to investigate the in vitro and in vivo efficacy of combining these two β-lactams against MRSA strains. Fourteen representative prevalent MRSA strains with diverse sequence types (STs) were tested with a combination of amoxicillin and cefdinir, using chequerboard and time-kill assays. The Galleria mellonella larvae infection model was used to evaluate the in vivo efficacy of this dual combination against the community-acquired MRSA (CA-MRSA) strain USA300 and the hospital-acquired MRSA (HA-MRSA) strain COL. The chequerboard assay revealed a synergistic activity of the dual amoxicillin/cefdinir combination against all tested MRSA strains, with fractional inhibitory concentration index (FICI) values below 0.5 and at least a 4-fold reduction in the MICs of both antibiotics. Time-kill assays demonstrated synergistic bactericidal activity of this dual combination against the MRSA strain USA300 and strain COL. Moreover, in vivo studies showed that the administration of amoxicillin/cefdinir combination to G. mellonella larvae infected with MRSA strains significantly improved the survival rate up to 82%, which was comparable to the efficacy of vancomycin. In vitro and in vivo studies indicate that the dual combination of amoxicillin/cefdinir demonstrates a synergistic bactericidal efficacy against MRSA strains of various STs. Further research is needed to explore its potential as a treatment option for MRSA infections.

Effects of sub-inhibitory concentrations of nafcillin, vancomycin, ciprofloxacin, and rifampin on biofilm formation of clinical methicillin-resistant Staphylococcus aureus.

Bacteria can be exposed to sub-MICs of antibiotics at the beginning and end of a dosing regimen, between doses, or during low-dose therapies. Growing evidence suggests that sub-MICs of antimicrobials can stimulate MRSA biofilm formation and alter the composition of the biofilm matrix. Pevious studies have found that sub-MICs of oxacillin, methicillin, and amoxicillin promote biofilm formation in some community-acquired MRSA (CA-MRSA). We evaluated biofilm induction by sub-MICs of four different classes of antibiotics in 44 CA-MRSA and 63 healthcare-associated MRSA (HA-MRSA) strains. Our study indicated that sub-MICs of nafcillin, vancomycin, ciprofloxacin, and rifampin frequently promote biofilm induction in clinical MRSA isolates. Strong biofilm induction in sub-MICs of nafcillin, ciprofloxacin, and rifampin was more frequent in HA-MRSA than in CA-MRSA. Antibiotic-induced biofilm formation depends on the antibiotic class, MRSA strain, and antibiotic resistance. Our results emphasize the importance of maintaining effective bactericidal concentrations of antibiotics to treat biofilm-related infections.

Herbal Bioactive Compounds for Skin Infections and Inflammatory Conditions

Skin microbiota is an integral part of the human immune system. Staphylococcus aureus is one of the essential components of the normal flora. Approximately 20–30% of healthy individuals are persistently colonized with S. aureus, whereas the remainders are considered low-level intermittent carriers. Despite these natural aspects of existence, S. aureus can be a major opportunistic human pathogen. This versatile microorganism can infect a variety of anatomical sites, causing a broad spectrum of pathologies ranging from superficial to invasive infections. It developed a variety of strategies to adopt to a changing microenvironment. This attributed to the emergence of resistance to antibiotics of different classes during the past six decades. Methicillin-resistant S. aureus (MRSA) was originally confined to health-care settings (health-care-associated MRSA). Later on, community-acquired MRSA was identified as another source of infections. Recent figures indicate that MRSA strains have been associated with approximately 75% of all S. aureus infections worldwide. Several guidelines have been published to establish an adequate treatment of skin and soft tissue infections (SSTIs) caused by MRSA strains. In the first part of this review, we focus on current treatment guidelines with a focus on medical drug therapy, but drug therapy has its own limitations. Recently, the interest in herbal remedies has greatly increased. There is growing evidence of antimicrobial activity of medicinal plants and their extracts. The second part of this review is dedicated to herbal compounds to circumvent antibiotic resistance. Herbal compounds may potentiate the action of antibiotics and restore the activities of antibacterial agents against which S. aureus has developed a drug resistance. Part 2 focuses on the role of S. aureus in pathology of the two major inflammatory skin diseases, i.e., atopic dermatitis (AD) and psoriasis. Finally, Part 3 provides an overview on natural compounds with antimicrobial activity against S. aureus and possible use in the treatment of SSTIs,

Prominent Classes of Antibiotics and their Mechanism of Resistance against Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a prominent pathogenic, antibiotic-resistant microorganism that contains a variety of virulent characteristics having the capacity to develop tolerance to several major classes of antibiotics. The ongoing creation of clones enhances this potential, transforming S. aureus into an “Anti-Infective.” MRSA has started to rise as a Hospital-Acquired MRSA, but due to evolution, new strains of MRSA have been discovered throughout the past several years. The new strains of MRSA as Community-Acquired MRSA, and Livestock-Associated MRSA are infecting the patients despite preexisting medical conditions, being as susceptible to any treatment. The continuous expansion of MRSA is still ongoing. The main goal of this article is to improve reading comprehension of MRSA by studying the prominent classes of antibiotics and their mechanism of resistance which are now susceptible or getting susceptible to the MRSA.

Staphylococcal scalded skin syndrome in neonate: Another face of CA-MRSA.

Staphylococcal scalded skin syndrome (SSSS), also known as Ritter's disease, in its severe form occurs predominantly in infants and children. It is caused by infection with group II (often phage group 71) Staphylococcus aureus. The foci of infection include nasopharynx, less commonly umbilicus, urinary tract, superficial abrasion, conjunctivae, and blood. Staphylococci are non-motile, non-spore-forming, catalase-positive, gram-positive cocci that appear predominantly as grape-like clusters. Although this organism is frequently a part of normal human microbial flora, it can cause significant opportunistic infections under certain conditions such as when extremes of age groups are involved, the presence of indwelling medical devices, and intravenous (iv) drug abuse. Staphylococcus aureus may cause a variety of infectious manifestations ranging from relatively benign skin infections to life-threatening systemic illnesses. SSSS caused by S. aureus strains produces exfoliative toxins which result in the development of blisters, erythema, and desquamation. Here, we present a case of an 11-day-old neonate who was diagnosed with SSSS. The causative agent responsible for this syndrome was identified as methicillin-resistant Staphylococcus aureus (MRSA). The molecular characterization of the gene Panton-Valentine leukocidin (PVL) was done by polymerase chain reaction (PCR) and was detected positive for PVL which is a distinctive virulence factor seen almost in all of the community-acquired MRSA strains. The patient was discharged after parenteral clindamycin therapy with almost complete resolution of symptoms.

Microbiological analysis of skin and soft tissue infections in children presenting to a paediatric tertiary care centre in Sri Lanka

Introduction: Skin and soft tissue infections (SSTIs) are a common cause of hospitalisation in children. They are diverse in spectrum, ranging from impetigo and abscesses to life threatening necrotising infections. The main pathogens associated with SSTIs are Staphylococccus aureus and Streptococcus pyogenes. Emergence of community acquired methicillin resistant S. aureus (CA-MRSA) is of major concern when antibiotics are required, and it is important to know the prevalence of these pathogens in different geographic locations. This study was done with the aim of identifying and characterising the common bacterial pathogens implicated in SSTIs in children presenting to Sirimavo Bandaranaike Children’s Hospital (SBSCH), Peradeniya, Sri Lanka, which is one of the two paediatric referral hospitals in Sri Lanka.Method: A retrospective, descriptive study analysed data gathered from request forms accompanying pus and tissue sent for culture from patients with SSTIs to the SBSCH microbiology laboratory during a period of 13 months from January 2021 to January 2022.Results: Two hundred and ninety samples were received from suspected SSTIs of which 197 (67.9%) were positive for bacterial growth, with S. aureus present in 163 (83%). Methicillin resistant S. aureus (MRSA) was isolated from 113 (57%) and methicillin sensitive S. aureus (MSSA) from 50 (25%). The frequency of coliforms, Pseudomonas spp., and Group A streptococcus were 31 (16%), 3 (1.5%) and 4 (2%) respectively. Sensitivity of MRSA isolates to cotrimoxazole, clindamycin, ciprofloxacin and erythromycin were 97%, 86%,72% and 29% respectively. Among MSSA isolates, 94% were sensitive to cotrimoxazole, while sensitivity to clindamycin, ciprofloxacin and erythromycin were 74%, 67% and 40% respectively.Conclusion: MRSA was the most frequent pathogen associated with purulent SSTIs in children, followed by MSSA. One fourth of MSSA were resistant to ciprofloxacin and clindamycin. Ciprofloxacin and clindamycin resistance in MRSA was 15% and 28% respectively.

Staphylococcus aureus Panton-Valentine Leukocidin worsens acute implant-associated osteomyelitis in humanized BRGSF mice.

Staphylococcus aureus is the most common pathogen that causes implant-associated osteomyelitis, a clinically incurable disease. Immune evasion of S. aureus relies on various mechanisms to survive within the bone niche, including the secretion of leukotoxins such as Panton-Valentine leukocidin (PVL). PVL is a pore-forming toxin exhibiting selective human tropism for C5a receptors (C5aR1 and C5aR2) and CD45 on neutrophils, monocytes, and macrophages. PVL is an important virulence determinant in lung, skin and soft tissue infections. The involvement of PVL in S. aureus pathogenesis during bone infections has not been studied extensively yet. To investigate this, humanized BALB/c Rag2-/-Il2rg-/-SirpaNODFlk2-/- (huBRGSF) mice were subjected to transtibial implant-associated osteomyelitis with community-acquired methicillin-resistant S. aureus (CA-MRSA) USA300 wild type strain (WT), an isogenic mutant lacking lukF/S-PV (Δpvl), or complemented mutant (Δpvl+pvl). Three days post-surgery, Δpvl-infected huBRGSF mice had a less severe infection compared to WT-infected animals as characterized by 1) improved clinical outcomes, 2) lower ex vivo bacterial bone burden, 3) absence of staphylococcal abscess communities (SACs) in their bone marrow, and 4) compromised MRSA dissemination to internal organs (liver, kidney, spleen, heart). Interestingly, Δpvl-infected huBRGSF mice had fewer human myeloid cells, neutrophils, and HLA-DR+ monocytes in the bone niche compared to WT-infected animals. Expectedly, a smaller fraction of human myeloid cells were apoptotic in the Δpvl-infected huBRGSF animals. Taken together, our study highlights the pivotal role of PVL during acute implant-associated osteomyelitis in humanized mice.

A meta-analysis of the Prevalence and Risk Factors of Community-acquired MRSA among Students at Abasyn University in Peshawar, Pakistan

Staphylococcus aureus is the most pathogenic species in the genus, having been linked to nosocomial infections as well as community-acquired infections. In healthy people, it frequently colonises the skin and mucous membranes asymptomatically, especially the anterior nares. These days, community-acquired MRSA is a significant issue. The goal of the current investigation was to determine MRSA's detrimental consequences in Khyber Pakhtunkhwa. Fifty samples were gathered from Abasyn University students in Peshawar for this purpose. The samples were taken using sterile nasal swabs, and they were inoculated on nutritional agar medium within eight hours. Catalase and coagulase tests revealed the presence of Staphylococcus aureus. Thirty of the fifty samples tested positive for Staphylococcus aureus. The following antibiotics were used: vincomycin, oxyacillin, augmentin, ampicillin, and foxittin. MRSA prevalence was 76.66%.

The Challenges of The Diagnostic and Therapeutic Approach of Patients with Infectious Pathology in Emergency Medicine.

A retrospective observational study was performed on 657 patients, from whom clinical samples (urine, purulent secretions, blood cultures, etc.) were collected for microbiological diagnosis in the first 3 days after presentation in the ED. The identification of pathogens and the antimicrobial susceptibility testing with minimum inhibitory concentration determination were carried out according to the laboratory protocols. From the 767 biological samples analyzed, 903 microbial isolates were identified. E. coli was most frequently isolated (24.25%), followed by Klebsiella spp., S. aureus (SA), and non-fermentative Gram-negative bacilli. E. coli strains maintained their natural susceptibility to most antibiotics tested. In the case of Pseudomonas spp. and Acinetobacter spp., increased rates of AMR were identified. Also, 32.3% of SA strains were community-acquired MRSA. The introduction of rapid microbiological diagnostic methods in emergency medicine is imperative in order to timely identify AMR strains and improve therapeutic protocols.

Genomic Analysis of a Community-Acquired Methicillin-Resistant Staphylococcus aureus Sequence Type 1 Associated with Caprine Mastitis.

This study aimed to investigate the genomic and epidemiological features of a methicillin-resistant Staphylococcus aureus sequence type 1 (MRSA ST1) strain associated with caprine subclinical mastitis. An S. aureus strain was isolated from goat's milk with subclinical mastitis in Paraiba, Northeastern Brazil, by means of aseptic procedures and tested for antimicrobial susceptibility using the disk-diffusion method. Whole genome sequencing was performed using the Illumina MiSeq platform. After genome assembly and annotation, in silico analyses, including multilocus sequence typing (MLST), antimicrobial resistance and stress-response genes, virulence factors, and plasmids detection were performed. A comparative SNP-based phylogenetic analysis was performed using publicly available MRSA genomes. The strain showed phenotypic resistance to cefoxitin, penicillin, and tetracycline and was identified as sequence type 1 (ST1) and spa type 128 (t128). It harbored the SCCmec type IVa (2B), as well as the lukF-PV and lukS-PV genes. The strain was phylogenetically related to six community-acquired MRSA isolates (CA-MRSA) strains associated with human clinical disease in North America, Europe, and Australia. This is the first report of a CA-MRSA strain associated with milk in the Americas. The structural and epidemiologic features reported in the MRSA ST1 carrying a mecA-SCCmec type IVa suggest highly complex mechanisms of horizontal gene transfer in MRSA. The SNP-based phylogenetic analysis suggests a zooanthroponotic transmission, i.e., a strain of human origin.

2177. Characterization of community-acquired methicillin-resistant Staphylococcus aureus isolated from patients with skin and soft tissue infections in selected health facilities, in Kenya

Abstract Background Colonization of the skin, mucus membrane, and nose of humans by Staphylococcus aureus (S. aureus) is more common than infection. The lack of proper microbiological surveillance systems in Africa may underestimate the burden of Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), while little is known about its incidence. In Kenya, there is a paucity of data on prevalence and circulating CA-MRSA strains. Methods Cross-sectional study design was employed with a sample size of 228 wound swabs from community-acquired skin and soft tissue infections, collected from 5 AMR surveillance sites in Kenya. S. aureus isolation, identification, and antimicrobial susceptibility tests were carried out according to standard bacteriology methods. Molecular characterization for MRSA isolates was performed by whole genome sequencing. Results Descriptive and inferential statistics were computed using the R program. Total S. aureus isolated was 29.38 % while MRSA isolation varied within study sites, with a CA-MRSA prevalence of 1.8 %. Phenotypic resistance observed did not match genotypic resistance for some isolates. Resistance mostly reported in nosocomial infections and resistance to reserved antibiotics was observed, which raises concern. Mutations within resistance genes, Inducible-Macrolide-Lincosamide-Streptogramin b resistance (MLSBi), 23S ribosome resistance and also erythromycin resistance by efflux pump was observed. Staphylococcal chromosomal cassette mec (SCCmec) type IV was the most prevalent while the sequence types (STs) obtained were ST 30, 8 and the novel STs 7460 and 7635. Only one isolate had intact mecA and its regulatory genes, but still conferred methicillin resistance. IS 1272 was detected in mecA regulatory genes. Conclusion The resistance patterns observed in this study further highlight the burden of antimicrobial resistance in community isolates of S. aureus. There is need for more research on CA-MRSA within Antimicrobial resistance (AMR) surveillance in Kenya in order to better understand the molecular epidemiology as well as the drivers of resistance Disclosures All Authors: No reported disclosures

No Changes in the Occurrence of Methicillin-Resistant Staphylococcus aureus (MRSA) in South-East Austria during the COVID-19 Pandemic.

Methicillin-resistant Staphylococcus aureus (MRSA) is a universal threat. Once being well established in the healthcare setting, MRSA has undergone various epidemiological changes. This includes the emergence of more aggressive community-acquired MRSA (CA-MRSA) and the occurrence of MRSA which have their origin in animal breeding, called livestock-associated MRSA (LA-MRSA). Emergence of new clones as well as changes in the occurrence of some clonal lineages also describes the fluctuating dynamic within the MRSA family. There is paucity of data describing the possible impact of the COVID-19 pandemic on the MRSA dynamics. The aim of the study was the analysis of MRSA isolates in a three-year time period, including the pre-COVID-19 years 2018 and 2019 and the first year of the pandemic 2020. The analysis includes prevalence determination, antibiotic susceptibility testing, spa typing, and detection of genes encoding the PVL toxin. The MRSA rate remained constant throughout the study period. In terms of a dynamic within the MRSA family, only a few significant changes could be observed, but all except one occurred before the start of the COVID-19 pandemic. In summary, there was no significant impact of the COVID-19 pandemic on MRSA in Austria.

Panton-Valentine Leukocidin (PVL) genes may not be a reliable marker for community-acquired MRSA in the Dakahlia Governorate, Egypt

BackgroundMethicillin-resistant Staphylococcus aureus is linked to both nosocomial and community infections. One of the key virulence factors of S. aureus is Panton-Valentine leukocidin (PVL). The PVL genes are mostly associated with community-acquired MRSA (CA-MRSA). This study evaluates the prevalence of PVL genes as a marker for CA-MRSA at tertiary hospitals in Mansoura, Dakahlia, Egypt. S. aureus was isolated from clinical specimens obtained from different departments of tertiary hospitals, outpatient clinics, and hospital healthcare workers (HCWs). PCR was used to detect the mecA, PVL, and SCCmec genes among the recovered isolates. Standard broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) of nine antibiotics against S. aureus.ResultsTwo hundred S. aureus isolates were recovered and identified out of the total isolates (n = 320). The mecA gene was detected in 103 S. aureus isolates (51.5%). Among the MRSA isolates, 46.60% were PVL-positive. The incidence of the PVL genes of MRSA in nosocomial (HA), outpatient clinics (CA), and HCWs was 46.66%, 56.52%, and 42%, respectively. All MRSA isolates showed resistance to cefoxitin. The percentage of resistance to most tested antibiotics was high, except for ciprofloxacin (6.85%). Both antibiotic resistance and multidrug resistance among MRSA isolates were generally higher in PVL-positive isolates than in PVL-negative isolates in HA- and CA-MRSA isolates. While SCCmec type V was the most prevalent in PVL-positive MRSA stains, type I was the most prevalent in PVL-negative isolates.ConclusionThis study revealed that PVL genes are generally highly prevalent among mecA-positive MRSA isolates, whether they are CA-MRSA, HA-MRSA, or HCW isolates. Therefore, PVL is not a valid marker for CA-MRSA in Mansoura, Dakahlia Governorate, Egypt, as has been reported in other countries. Further epidemiologic studies are required to track the incidence of PVL in HA-MRSA, CA-MRSA, and HCW isolates in other Egyptian governorates.

A Bayesian multilevel analysis exploring population-level effects mediating the relationship between area-level poverty and community-acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) infection across California communities.

Poverty is an often-cited driver of health disparities, and associations between poverty and community-acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) infection are well documented. However, the pathways through which poverty influences infection have not been thoroughly examined. This project aims to identify mediating variables, or mechanisms, explaining why area-level poverty is associated with CA-MRSA infection in Californians. Bayesian multilevel models accounting for spatial confounding were developed to test whether the association between area-level poverty and CA-MRSA infection is mediated by living in a primary care shortage area (HCSA), living near an adult correctional facility, and residential environmental degradation. The association between area-level poverty and CA-MRSA infection can be partially explained by spatial autocorrelation, living in an HCSA, and environmental degradation in the neighborhood. Combined, the mediators explain approximately 6% of the odds of CA-MRSA infection for individuals living in neighborhoods with high poverty rates and 50% of the statistical association between area-level poverty and CA-MRSA infection. The statistical association between area-level poverty and infection was completely explained by the mediators for individuals living in neighborhoods with low poverty rates.

An oral caspase inhibitor as monotherapy or with antibiotics eradicates MRSA skin infections in mice.

Staphylococcus aureus is the leading cause of skin and soft tissue infections. With the emergence of antibiotic-resistant bacteria, there is an unmet clinical need to develop immune-based therapies to treat skin infections. Previously, we have shown pan-caspase inhibition as a potential host-directed immunotherapy against community-acquired methicillin-resistant S aureus (CA-MRSA) and other bacterial skin infections. Here, we evaluated the role of irreversible pan-caspase inhibitor emricasan as a monotherapy and an adjunctive with a standard-of-care antibiotic, doxycycline, as potential host-directed immunotherapies against S. aureus skin infections in vivo. We used the established CA-MRSA strain USA300 on the dorsum of WT C57BL/6J mice and monitored lesion size and bacterial burden noninvasively, and longitudinally over 14 days with in vivo bioluminescence imaging (BLI). Mice in four groups placebo (0.5% carboxymethyl cellulose [CMC] solution), placebo plus doxycycline (100 mg/kg), emricasan (40 mg/kg) plus doxycycline, and emricasan only were treated orally twice daily by oral gavage for 7 days, starting at 4 h after injection of S aureus. When compared with placebo, all three groups, placebo plus doxycycline, emricasan plus doxycycline, and emricasan treated group, exhibited biological effect, with reduction of both the lesion size (*p = .0277, ****p < .0001, ****p < .0001, respectively) and bacterial burden (***p = .003, ****p < .0001, ****p < .0001, respectively). Importantly, the efficacy of emricasan against S. aureus was not due to direct antibacterial activity. Collectively, pan-caspase inhibitor emricasan and emricasan plus doxycycline reduced both the lesion size and bacterial burden in vivo, and emricasan is a potential host-directed immunotherapy against MRSA skin infections in a preclinical mouse model.