Prevalence and Risk Factors Associated with Vancomycin-Resistant Staphylococcus aureus Precursor Organism Colonization among Patients with Chronic Lower-Extremity Wounds in Southeastern Michigan (original) (raw)
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Infection and Drug Resistance, 2023
Background: Wound infection is a prevalent concern in the medical field, being is a multi-step process involving several biological processes. Methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) infections often occur in areas of damaged skin, such as abrasions and open wounds. Methods: This research aims to light the incidence of MRSA and VRSA in wound swabs, the antimicrobial susceptibility configuration of isolated S. aureus patterns in pus/wound samples collected from Saudi Arabian tertiary hospital. The cross section study, β-lactamase detection, VRSA genotyping, MAR index, D-test and VRSA genotyping are methods, which used for completed this research. Results: Patients of several ages and genders delivered specimens from two hospitals in the Al jouf area, in the northern province of Saudi Arabia. S. aureus was found in 188 (34.7%) of the 542 wounds. The traumatized wounds provided 71 isolates (38.8%), surgical wound provided 49 isolates (26.8%) and abscess were represented 16 by isolates (8.7%). In the study, 123 (65.4%) out of 188 were MRSA, 60 (31.9%) were MSSA, and five (2.7%) were VRSA. Linezolid and rifampin were found to be the most effective antimicrobials with 100% in vitro antibacterial activity against S. aureus isolates. The Multiple antimicrobials resistance (MAR) index revealed 73 isolates (38.9%) with a MAR index greater than 0.2, and 115 (61.1%) less than 0.2. The D-test showed that of MLS b phenotypes among S. aureus, 22 (11.7%) strains were D-test positive (MLSb i phenotype), 53 (28.2%) strains were constitutive MLS c phenotypes, and 17 (9%) strains were shown to have MSb phenotypes. All VRSA isolates (n=5) were found to be positive for vanA, and no vanB positive isolates were detected in the study. Conclusion: Regular monitoring and an antimicrobials stewardship program should be in place to provide critical information that can be utilized for empirical therapy and future prevention strategies.
Frequency of S. Aureus in Septic Wound Infections at a Tertiary Care Unit
2019
Background: Skin plays a pivotal role in protecting against micro-organisms. Damage to skin through cut, surgical incision, burn and road traffic accident etc. make it susceptible for micro-organism to invade our body. Septic wounds further put stress on immune system of already injured person, hence increase morbidity and mortality. Approximately 30% of the human population is colonized with Staphylococcus aureus. It is a leading cause of wound complication, soft tissue and skin infections, infective endocarditis, bacteremia and sepsis etc. Objective: Aim of this study is to determine frequency of Staphylococcus aureus in septic wound infections. Methodology: It was a cross sectional study done at surgical wards, burn center, orthopedic department and intensive care unit of Nishtar Hospital Multan from September 2017 to November 2017. We obtained 150 consecutive pus samples from wounded patients presenting with clinical symptoms of septic wound. The collected samples were transport...
Journal of Antimicrobial Chemotherapy, 2008
The aim of this study was to describe the rates of antimicrobial susceptibility of Staphylococcus aureus from skin and wound infections reported from nine regions of the USA during 2005-07 and to identify the regional variation in patterns of resistance. Methods: The Surveillance Network (TSN) comprises 296 laboratories across the nine census regions of the USA. TSN laboratories reported the susceptibility data for six antimicrobials by isolate with source and other relevant data. Antimicrobial susceptibility data were analysed by individual drug resistance, multidrug resistance and geographical distribution of resistance phenotypes. Results: There were over 380 000 isolates of S. aureus tested and reported for the period 2005-07. Methicillin resistance was observed in 57.8% in 2007, with little change from 2005. There was little difference in rates of methicillin resistance between community and hospital strains, although strains from intensive care units (ICUs) tended to be slightly more resistant overall. Resistance to other antimicrobials was also reported. A regional variation in resistance rates was noted with the highest rates in the Central states and lowest in the New England and Mid-Atlantic regions. There was high activity observed with trimethoprim/sulfamethoxazole and gentamicin. Linezolid resistance was rare. Oxacillin resistance was similar among paediatric and elderly cohorts, whereas ciprofloxacin and clindamycin resistance was significantly (P < 0.01) more common in elderly patients when compared with both paediatric and adult populations. Less than a third of all isolates showed no resistance mechanism, 30.3%. Three distinct resistance phenotypes accounted for 46% of all resistant strains. Overall, there were more highly drug-resistant isolates from the ICU with four, five or six drug-resistant phenotypes accounting for over a third of all strains. Conclusions: S. aureus has become methicillin-resistant in both the community and hospital settings; however, little change has been seen in the past 3 years. Multiresistant strains now are seen in all settings, but due to regional variation, empirical therapy should be guided by local susceptibility patterns. Currently, among the agents studied, only trimethoprim/sulfamethoxazole, gentamicin and linezolid exhibit susceptibility rates of >95%.
Critical care (London, England), 2011
Introduction: Harboring sensitive strains may prevent acquisition of resistant pathogens by competing for colonization of ecological niches. Competition may be relevant to decolonization strategies that eliminate sensitive strains and may predispose to acquiring resistant strains in high-endemic settings. We evaluated the impact of colonization with methicillin-sensitive Staphylococcus aureus (MSSA) and vancomycin-sensitive enterococci (VSE) on acquisition of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), respectively, when controlling for other risk factors. Methods: We conducted a nested case-control study of patients admitted to eight ICUs performing admission and weekly bilateral nares and rectal screening for MRSA and VRE, respectively. Analyses were identical for both pathogens. For MRSA, patients were identified who had a negative nares screen and no prior history of MRSA. We evaluated predictors of MRSA acquisition, defined as a subsequent MRSA-positive clinical or screening culture, compared to those with a subsequent MRSA-negative nares screen within the same hospitalization. Medical records were reviewed for the presence of MSSA on the initial MRSA-negative nares screen, demographic and comorbidity information, medical devices, procedures, antibiotic utilization, and daily exposure to MRSA-positive patients in the same ward. Generalized linear mixed models were used to assess predictors of acquisition. Results: In multivariate models, MSSA carriage protected against subsequent MRSA acquisition (OR = 0.52, CI: 0.29, 0.95), even when controlling for other risk factors. MRSA predictors included intubation (OR = 4.65, CI: 1.77, 12.26), fluoroquinolone exposure (OR = 1.91, CI: 1.20, 3.04), and increased time from ICU admission to initial negative swab (OR = 15.59, CI: 8.40, 28.94). In contrast, VSE carriage did not protect against VRE acquisition (OR = 1.37, CI: 0.54, 3.48), whereas hemodialysis (OR = 2.60, CI: 1.19, 5.70), low albumin (OR = 2.07, CI: 1.12, 3.83), fluoroquinolones (OR = 1.90, CI: 1.14, 3.17), third-generation cephalosporins (OR = 1.89, CI: 1.15, 3.10), and increased time from ICU admission to initial negative swab (OR = 15.13, CI: 7.86,.14) were predictive. Conclusions: MSSA carriage reduced the odds of MRSA acquisition by 50% in ICUs. In contrast, VSE colonization was not protective against VRE acquisition. Studies are needed to evaluate whether decolonization of MSSA ICU carriers increases the risk of acquiring MRSA when discharging patients to high-endemic MRSA healthcare settings. This may be particularly important for populations in whom MRSA infection may be more frequent and severe than MSSA infections, such as ICU patients.
Clinical Infectious Diseases, 2011
Background. Methicillin-resistant Staphylococcus aureus (MRSA) remains sensitive to vancomycin; when vancomycin-resistant S. aureus (VRSA) emerges, treatment becomes more complex. VRSA emergence is attributed to conjugative transfer of the vancomycin-resistance gene cluster from vancomycin-resistant enterococci (VRE) to MRSA. Because cocolonization with MRSA and VRE precedes VRSA development, this study investigates the epidemiology of cocolonization in skilled nursing facility (SNF) residents at high risk for MRSA or VRE colonization. Methods. A prospective observational study conducted at 15 SNFs in southeast Michigan. Overall, 178 residents (90 with indwelling urinary catheters and/or feeding tubes and 88 device-free) were cultured monthly for MRSA and VRE, and clinical data were recorded. Results. The incidence of MRSA/VRE cocolonization among residents with indwelling devices was 6.5 per 100 resident-months; 5.2 (95% confidence interval [CI]: 1.49-18.1) times that among those without devices. MRSA/ VRE cocolonization in the device group occurred most frequently in wounds (4.1 per 100 resident-months). In a logistic regression analysis limited to residents with devices, functional disability (rate ratio [RR], 1.3; 95% CI: 1.1-1.4) and wound presence (RR, 3.4; 95% CI: 1.4-8.6) were independent risk factors of cocolonization. Conclusions. In a population of SNF residents, individuals with indwelling devices who also had functional disability or wounds were at greatest risk of MRSA/VRE cocolonization. These individuals should be routinely monitored for the presence of VRSA colonization.
Annals of Internal Medicine, 2006
Background: Studies have shown that community-acquired methicillin-resistant Staphylococcus aureus (MRSA) causes S. aureus skin and soft-tissue infection in selected populations. Objective: To determine the proportion of infections caused by community-acquired MRSA, the clinical characteristics associated with community-acquired MRSA, and the molecular epidemiology of community-acquired MRSA among persons with communityonset S. aureus skin and soft-tissue infection. Design: Active, prospective laboratory surveillance to identify S. aureus recovered from skin and soft-tissue sources. Setting: 1000-bed urban hospital and its affiliated outpatient clinics in Atlanta, Georgia. Patients: 384 persons with microbiologically confirmed communityonset S. aureus skin and soft-tissue infection. Measurements: Proportion of infections caused by and clinical factors associated with community-acquired MRSA among persons with community-onset S. aureus skin and soft-tissue infection. Pulsed-field gel electrophoresis and antimicrobial susceptibility patterns were used to epidemiologically classify community-onset S. aureus infections. Community-acquired MRSA was defined by MRSA isolates that either demonstrated a USA 300 or USA 400 pulsed-field type or had a susceptibility pattern showing resistance only to -lactams and erythromycin (for isolates not available for pulsed-field gel electrophoresis). Results: Community-onset skin and soft-tissue infection due to S. aureus was identified in 389 episodes, with MRSA accounting for 72% (279 of 389 episodes). Among all S. aureus isolates, 63% (244 of 389 isolates) were community-acquired MRSA. Among MRSA isolates, 87% (244 of 279 isolates) were community-acquired MRSA. When analysis was restricted only to MRSA isolates that were available for pulsed-field gel electrophoresis, 91% (159 of 175 isolates) had a pulsed-field type consistent with communityacquired MRSA; of these, 99% (157 of 159 isolates) were the MRSA USA 300 clone. Factors independently associated with community-acquired MRSA infection were black race (prevalence ratio, 1.53 [95% CI, 1.16 to 2.02]), female sex (prevalence ratio, 1.16 [CI, 1.02 to 1.32]), and hospitalization within the previous 12 months (prevalence ratio, 0.80 [CI, 0.66 to 0.97]). Inadequate initial antibiotic therapy was statistically significantly more common among those with community-acquired MRSA (65%) than among those with methicillin-susceptible S. aureus skin and soft-tissue infection (1%). Limitations: Some MRSA isolates were not available for molecular typing. Conclusions: The community-acquired MRSA USA 300 clone was the predominant cause of community-onset S. aureus skin and soft-tissue infection. Empirical use of agents active against community-acquired MRSA is warranted for patients presenting with serious skin and soft-tissue infections.
New Microbes and New Infections, 2016
We have previously shown that secondary infections of Buruli ulcer wounds were frequently caused by Staphylococcus aureus. To gain understanding into possible routes of secondary infection, we characterized S. aureus isolates from patient lesions and surrounding environments across two Ghanaian health centres. One hundred and one S. aureus isolates were isolated from wounds (n = 93, 92.1%) and the hospital environment (n = 8, 7.9%) and characterized by the spa gene, mecA and the Panton-Valentine leucocidin toxin followed by spa sequencing and whole genome sequencing of a subset of 49 isolates. Spa typing and sequencing of the spa gene from 91 isolates identified 29 different spa types with t355 (ST152), t186 (ST88), and t346 dominating. Although many distinct strains were isolated from both health centres, genotype clustering was identified within centres. In addition, we identified a cluster consisting of isolates from a healthcare worker, patients dressed that same day and forceps used for dressing, pointing to possible healthcare-associated transmission. These clusters were confirmed by phylogenomic analysis. Twenty-four (22.8%) isolates were identified as methicillin-resistant S. aureus and lukFS genes encoding Panton-Valentine leucocidin were identified in 67 (63.8%) of the isolates. Phenotype screening showed widespread resistance to tetracycline, erythromycin, rifampicin, amikacin and streptomycin. Genomics confirmed the widespread presence of antibiotic resistance genes to β-lactams, chloramphenicol, trimethoprim, quinolone, streptomycin and tetracycline. Our findings indicate that the healthcare environment probably contributes to the superinfection of Buruli ulcer wounds and calls for improved training in wound management and infection control techniques.