Methicillin-resistant Staphylococcus Aureus Skin And Soft Tissue Infections Research Articles

Hiding in Plain Sight: Benefit of Abrasion and Laceration Swabs in Identification of Panton-Valentine Leucocidin (PVL)-Meticillin Resistant Staphylococcus aureus (MRSA) Colonisation in Military Personnel.

Background Outbreaks of Panton-Valentine Leucocidin (PVL)-producing methicillin-resistantStaphylococcus aureus(MRSA) skin and soft tissue infections (SSTIs) are a recurrent challenge for the Royal Marines at the Commando Training Centre (CTCRM). The intensity of commando training, its impact on skin integrity, and persistent colonisation reservoirs within the training centre have thwarted attempts to prevent these outbreaks. Aim To present an outbreak of PVL-producing MRSA SSTIs at a military training centre, demonstrating the benefit of additional abrasion and laceration swabs on the identification of colonised personnel and showing the effectiveness of a 10-day decolonisation regime. Method Following the identification of the outbreak of PVL-producing MRSA, all 36 members of the Recruit Troop underwent nasal MRSA screening to identify MRSA carriers. The screening was repeated on day 16 after completing an enhanced 10-day decolonisation regime. A third screening was conducted on the 110th day after a second peak of infection was identified. Various infection control measures, such as enhanced cleaning, restriction of movement and adjustments to the military training serials, were introduced to prevent further spread through the training centre. Results In this outbreak, two-thirds (eighteen) of the Recruit Troop suffered MRSA-PVL skin infections requiring antibiotic therapy and three required hospital admission for surgical management of their abscesses. The outbreak lasted 130 days, with two spikes in infections 10 weeks apart. The outbreak was successfully confined to one troop. Conclusion With concerns about low identification rates of carriers using nasal screening for MRSA, in this outbreak, we improved the identification of asymptomatic carriage with the simple step of additional culture swabs for all cuts and abrasions. Improved identification of colonised recruits, along with an enhanced decolonisation regime and rigid infection control practices, prevented the further spread of the clone through the training centre. In a population with constant ongoing skin trauma, such as the military, contact sport athletes and iIV drug users, our results show that a culture of suitable abrasions/lacerations will improve the identification of MRSA colonisation compared with nasal swabs alone. Despite ongoing skin trauma and the logistical difficulties in delivering effective decolonisation during military training, decolonisation was successful in 79% of recruits after one decolonisation and 87% after the second 10-day decolonisation.

Prevalence and clinical characteristics of methicillin-resistant Staphylococcus aureus infections among dermatology inpatients: A 7-year retrospective study at a tertiary care center in southwest China.

Increased rates of methicillin-resistant Staphylococcus aureus (MRSA) antibiotic resistance and the associated morbidity have increased dermatologists' attention to skin and soft tissue MRSA infections. However, the clinical characterization of MRSA skin and soft tissue infections (SSTIs) in Southwest China is lacking, which precludes optimal prevention and treatment of these infections. This study was conducted to characterize the prevalence, clinical comorbidities and antibiotic susceptibility of MRSA isolates from SSTIs, including community-associated (CA) and healthcare-associated (HA) isolates. In the Dermatology Inpatient Department of the First Affiliated Hospital of Guangxi Medical University, a retrospective study was conducted on data, including patient demographics and clinical information, from culture-confirmed S. aureus isolated from skin and soft tissue between January 1, 2015, and December 31, 2021. Isolate susceptibility to 13 antibiotics was determined using the Vitek 2 system. From among 864 S. aureus strains, we identified 283 MRSA (32.75%) isolates comprising 203 CA-MRSA and 80 HA-MRSA isolates. The average rate of CA-MRSA isolation for MRSA SSTIs was 71.73%. The HA-MRSA isolation rate for MRSA SSTIs increased significantly. HA-MRSA-infected patients were older. The most common dermatological presentation of CA-MRSA infection was staphylococcal scalded skin syndrome, while the comorbidity severe drug eruption was significantly associated with HA-MRSA infection. One CA-MRSA strain was resistant to linezolid, and one HA-MRSA strain had an intermediate phenotype for vancomycin; both strains had low sensitivity to clindamycin and erythromycin (3.70%~19.40%). However, HA-MRSA isolates were more susceptible to trimethoprim/sulfamethoxazole. CA-MRSA is a predominant pathogen causing SSTIs, and HA-MRSA infection incidence is increasing gradually. Both strains showed increasing antibiotic resistance. Our data on MRSA susceptibility may guide dermatologist antibiotic treatment decisions. Dermatologists should consider these identified comorbidities of MRSA SSTIs when patients are admitted and initiate early prevention and treatment of MRSA.

Does a Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Screen Predict the Risk for MRSA Skin and Soft Tissue Infection?

Skin and soft tissue infections (SSTIs) are often caused by gram-positive bacteria that colonize the skin. Given the overuse of antibiotics, SSTIs are increasingly caused by resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Guidance on the utility of MRSA nasal screening for MRSA SSTI is limited. To determine whether MRSA nasal screening predicts the risk of MRSA SSTIs. This was a single-center, retrospective cohort study of adult patients with an SSTI diagnosis that had MRSA nasal screening and wound cultures obtained within 48 hours of starting antibiotics. Sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratios were calculated using VassarStats. Pretest and posttest probabilities were estimated with Microsoft Excel. A total of 884 patient encounters were reviewed between December 1, 2018, and October 31, 2021, and 300 patient encounters were included. The prevalence of MRSA SSTI was 18.3%. The MRSA nasal colonization had a sensitivity of 63.6%, specificity of 93.9%, positive predictive value of 70.0% (95% CI = 55.2%-81.7%), negative predictive value of 92.0% (95% CI = 87.7%-94.9%), positive likelihood ratio of 10.39 (95% CI = 6.12-17.65), negative likelihood ratio of 0.39 (95% CI = 0.27-0.55), positive posttest probability of 70.0%, and negative posttest probability of 8.0%. Given the high positive likelihood ratio, a positive MRSA nasal screen was associated with a large increase in the probability of MRSA SSTI at our institution, and a negative MRSA nasal screen was associated with a small but potentially significant decrease in the probability of MRSA SSTI.

Retrospective analysis of methicillin-resistant Staphylococcus aureus skin and soft tissue infection among patients admitted at an Academic University Hospital from 2011 to 2015: a five-year review

The emergence of methicillin resistant Staphylococcus aureus (MRSA) is a challenge in the management of skin and soft tissue infections (SSTIs). The objective is to describe the epidemiology of MRSA SSTIs among admitted patients at the University of Santo Tomas Hospital (USTH).

Genomic epidemiology of MRSA infection and colonization isolates among military trainees with skin and soft tissue infection.

Individuals with methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infection (SSTI) can be simultaneously colonized with MRSA on multiple body sites. Using whole genome sequencing (WGS), the intrahost relatedness of MRSA colonization and infection isolates was investigated. In the context of a prospective case-control study of SSTI, we analyzed colonization and infection isolates from US Army Infantry trainees with purulent infection due to MRSA. At the time of clinical presentation for SSTI, culture swabs were obtained from the infection site, as well as from the patient's nasal, oral, inguinal, and perianal regions. S. aureus culture and susceptibility was performed by standard methods. DNA from MRSA isolates was extracted and libraries were produced. Sequences were generated on an Illumina MiSeq, sequence reads were assembled, and single nucleotide variant (SNV) data were analyzed. Of 74 trainees with MRSA SSTI, 19 (25.7%) were colonized with MRSA. Ten (52.6%) were colonized on more than one body site. Colonization frequency by anatomic site was as follows: inguinal region (33%), nasal region (30%), perianal region (22%), and oral region (14%). A total of 36 MRSA colonization isolates were characterized. The intrahost median number of SNVs between infection and colonization isolates was 17. Among trainees with recurrent MRSA SSTI, limited intrahost diversity suggests that persistent colonization is a major contributor to recurrence risk. Among military trainees with MRSA SSTI, genomic characterization of infection and colonization isolates revealed a high degree of strain relatedness. Single acquisition events may account for MRSA colonization and infection in this population.

Methicillin-resistant Staphylococcus aureus skin and soft tissue infections in young people in custody in New South Wales.

Methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) are problematic for incarcerated adolescents but have not been previously researched. This was a 2-year prospective study of all New South Wales Juvenile Custodial Centres involving incarcerated youth aged 12-20 years. The main outcomes measured were MRSA SSTIs, MRSA molecular subtypes and associations with MRSA infection. Variables included age, gender, SSTI site and type, Indigenous status, incarceration time, lifetime incarcerations, intravenous drug use, overweight/obesity, recent antibiotic use and health centre presentations. From February 2013 to January 2015, there were 77 SSTIs (92.2% male, 59.2% Indigenous, mean age 16.9 years). The majority (77.9%) were collections, mostly on the lower limb (44.2%), and 33 (42.9%) isolates were MRSA; 94% were Panton-Valentine leukocidin positive. This represents 11 SSTIs per 1000 custodial admissions, and 4.7 MRSA SSTIs per 1000 custodial admissions. Independent associations with MRSA SSTI (vs. non-MRSA SSTI) were Indigenous status (adjusted odds ratio (AOR) 5.92, P < 0.001), presenting with a collection (AOR 18.29, P < 0.001) and recent antibiotic use (AOR 3.62, P < 0.05). Incarcerated Australian youth have high rates of MRSA SSTIs, comparable to rates in US adult inmates, but with different molecular subtypes. At particular risk of MRSA infection are Indigenous youth, those with recent antibiotic use and those presenting with a collection. Many MRSA infections present at custodial admission, making surveillance and containment important, along with avoidance of unnecessary antibiotics and hand hygiene. Panton-Valentine leukocidin-positive MRSA predominates and is known for causing flu-associated necrotising pneumonia. Albeit a rare outcome, the seasonal influenza vaccination should be mandatory for youth in custody and custodial staff.

Infection Control Practices and Methicillin-Resistant Staphylococcus aureus Skin Infections: A Survey of Students in US Chiropractic Programs

ObjectiveThe purpose of this study was to assess the incidence of self-reported history of physician-diagnosed methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infection (SSTI) among chiropractic students and any association with infection control behaviors (hand and table hygiene, sharing gowns, and sharing lotion) and initiation of patient care. MethodsQuestionnaires were obtained from 312 students attending half (9/18) of US chiropractic campuses. The questionnaire was derived from earlier studies led by Bearman in 2010 and Evans in 2007. Associations were assessed with Fisher exact test. Crude odds ratios were calculated for each of the variables. Two logistic regression models were produced. ResultsAttendance at 1 campus was associated with postmatriculation MRSA SSTI in univariate analysis (P = .010). The logistic regression model was significant (P < .05), but the composing variables were not. ConclusionsFewer than 5 cases of MRSA SSTI were detected overall, revealing a low rate of reported postmatriculation MRSA SSTI among these students. There was a univariate association with postmatriculation MRSA SSTI at 1 chiropractic college.

Methicillin-Resistant Staphylococcus aureus: The Effects Are More Than Skin Deep

To assess the psychosocial effects of a methicillin-resistant Staphylococcus aureus (MRSA) diagnosis on the households of children with MRSA skin and soft tissue infection (SSTI). We constructed and administered an interview to the primary caregiver within the home of a child with a history of MRSA SSTI. Seventy-six households were enrolled. Survey responses were analyzed and grouped into 4 themes: health behavior changes, disclosure, social interactions, and knowledge/awareness. The most common theme was disclosure; 91% of participants reported sharing their child's MRSA diagnosis with someone outside of the household. Forty-two percent of respondents reported a change in the manner in which household contacts interacted as a result of the index patient's MRSA diagnosis, including isolating the index patient from other children in the household. Many households reported adopting enhanced personal hygiene behaviors and environmental cleaning routines. Thirty-eight percent of participating households reported altering how they interact with people outside of their home, largely to avoid spreading MRSA to vulnerable individuals. In addition, many participants perceived that others regarded them with caution, especially at daycare, whereas other affected households were excluded from family gatherings. Primary caregivers of children with MRSA SSTI reported changing their health behaviors, altering their interactions with people outside of their home, and feeling isolated by others in response to their child's MRSA diagnosis. The findings of our study highlight a need for community interventions and education to prevent the negative psychosocial repercussions associated with MRSA.

Prevalence and Risk Factors for Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in Custodial Populations: A Systematic Review.

early identification, isolation, and treatment of skin infections at admission; education on maintaining skin integrity and presenting early with skin infections; increasing hygiene by not sharing items and encouraging handwashing; improved handling and disinfection of communal laundering; influenza vaccination for all prisoners and staff; and population-based longitudinal studies including younger detainees.

Genomic Characterization of USA300 Methicillin-Resistant Staphylococcus aureus (MRSA) to Evaluate Intraclass Transmission and Recurrence of Skin and Soft Tissue Infection (SSTI) Among High-Risk Military Trainees.

Military trainees are at increased risk for methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infection (SSTI). Whole genome sequencing (WGS) can refine our understanding of MRSA transmission and microevolution in congregate settings. We conducted a prospective case-control study of SSTI among US Army infantry trainees at Fort Benning, Georgia, from July 2012 to December 2014. We identified clusters of USA300 MRSA SSTI within select training classes and performed WGS on clinical isolates. We then linked genomic, phylogenetic, epidemiologic, and clinical data in order to evaluate intra- and interclass disease transmission. Furthermore, among cases of recurrent MRSA SSTI, we evaluated the intrahost relatedness of infecting strains. Nine training classes with ≥5 cases of USA300 MRSA SSTI were selected. Eighty USA300 MRSA clinical isolates from 74 trainees, 6 (8.1%) of whom had recurrent infection, were subjected to WGS. We identified 2719 single nucleotide variants (SNVs). The overall median (range) SNV difference between isolates was 173 (1-339). Intraclass median SNV differences ranged from 23 to 245. Two phylogenetic clusters were suggestive of interclass MRSA transmission. One of these clusters stemmed from 2 classes that were separated by a 13-month period but housed in the same barracks. Among trainees with recurrent MRSA SSTI, the intrahost median SNV difference was 7.5 (1-48). Application of WGS revealed intra- and interclass transmission of MRSA among military trainees. An interclass cluster between 2 noncontemporaneous classes suggests a long-term reservoir for MRSA in this setting.

CA-MRSA Decolonization Strategies: Do They Reduce Recurrence Rate?

Community-associated methicillin-resistant Staphylococcus aureus commonly presents as a skin and soft tissue infection. Recurrence of the infection is common even after incision and drainage of the affected area. This Evidence-Based Report Card reviews whether decolonization strategies will reduce the rate of methicillin-resistant Staphylococcus aureus skin and soft tissue infection (MRSA-SSTI) recurrence or colonization in patients with a history of MRSA-SSTI. A systematic review of the literature was conducted from 1987 to the present day. The studies that were evaluated included individuals with recurrent skin and soft tissue infections that used decolonization procedures to decrease recurrence. The literature search generated 754 articles. Of these, 288 articles were eliminated due to duplication. Of the 466 remaining citations, 372 were not relevant. Of the remaining 94 full-text articles, 12 met the inclusion criteria. These studies were then reviewed and findings synthesized. Four studies found topical decolonization procedures were effective in reducing colonization rates. Of the studies that used combination decolonization therapy, 3 of 4 studies showed a decrease in colonization rate. Despite successful decolonization, the rate of SSTI recurrence did not decrease. Two studies that showed a decrease in SSTI recurrence utilized different study parameters. In one study, the decolonization regimen was completed monthly over 1 year. The other study treated family members in addition to the affected individual. Currently, there is insufficient evidence to support the routine use of topical or systemic decolonization regimens to decrease recurrent SSTIs in individuals with a history of MRSA-SSTI. The focus of decolonization should be focused on the prevention and spread of infection. Hygiene education should be provided to patients, household members, and close contacts to reduce infection rates.

Management of Skin and Soft Tissue Infections in a County Correctional Center: A Quality Improvement Project.

The number of antibiotic-resistant infections continues to increase. In 2005, there were nearly 11,406 deaths from methicillin-resistant Staphylococcus aureus (MRSA) infection in the United States. Since 1980, the United States has seen a 300% increase in the rate of incarceration. This is noteworthy because individuals who enter correctional facilities have an increased risk for MRSA skin and soft tissue infections (SSTIs) and the risk of colonization proportional to the length of stay. Correctional institutions have a vested interest in improving the screening and treatment of MRSA SSTIs, as it is a costly and potentially preventable problem. This article describes the process of implementing an MRSA screening and treatment policy in a county correctional center.

Risk factors for methicillin-resistant Staphylococcus aureus skin and soft tissue infection in MRSA-colonized patients discharged from a Veterans Affairs hospital.

Currently, limited studies have quantified the risk of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) for MRSA-colonized patients on discharge from hospital. Our retrospective, case-control study identified independent risk factors for the development of MRSA SSTIs among such patients detected by active MRSA nasal screening in an acute care hospital by PCR on admission, and bacteriological cultures on discharge. Cases were MRSA-colonized patients aged ⩾18 years who developed a MRSA SSTI post-discharge and controls were those who did not develop a MRSA SSTI post-discharge. Controls were matched to cases by length of follow-up (±10 days) for up to 18 months. Potential demographic and clinical risk factors for MRSA infection were identified using electronic queries and manual chart abstraction; data were compared by standard statistical tests and variables with P values ⩽0·05 in bivariable analysis were entered into a logistic regression model. Multivariable analysis demonstrated prior hospital admission within 12 months (P = 0·02), prior MRSA infection (P = 0·05), and previous myocardial infarction (P = 0·01) were independently predictive of a MRSA SSTI post-discharge. Identification of MRSA colonization upon admission and recognition of risk factors could help identify a high-risk population that could benefit from MRSA SSTI prevention strategies.

Duration of Colonization With Methicillin-Resistant Staphylococcus aureus: A Question With Many Answers

Duration of Colonization With Methicillin-Resistant Staphylococcus aureus: A Question With Many Answers

Management and outcome of adults with skin and soft tissue infection caused by methicillin-resistant Staphylococcus aureus in a tertiary hospital in central Taiwan.

Methicillin-resistant Staphylococcus aureus (MRSA) has been increasingly causing skin and soft tissue infections (SSTIs). Only limited studies have made comparisons between incision and drainage (I&D) alone and I&D with adjunctive antibiotic therapy for treatment effects, and most of the studies were conducted before the emergence of MRSA. This study was to evaluate whether antibiotics provide added benefit to I&D alone for purulent MRSA SSTIs. This retrospective study collected data on SSTI patients, including patient demographics, treatment strategies, antibiotic susceptibilities of the infecting MRSA isolates, and clinical outcomes over the course of 24 months. Antimicrobial drug susceptibility rate were 100% for vancomycin, teicoplanin, and linezolid. Among the 211 patients, 7.6% were treated solely with I&D (Group A), 62.6% were treated via I&D with adjunctive antibiotic (Group B), and 29.8% patients received only antibiotics (Group C). The cure rate was highest in Group A (93.8%), followed by Group B (90.9%) and Group C (77.8%). Combining Group B and Group C, patients who were treated appropriately demonstrated a higher cute rate (91.3% vs. 75.4%, p = 0.005). Multivariate analysis showed that Group B was more likely to be successfully treated compared to Group C (odds ratio = 2.51, 95% confidence interval = 1.01-6.25, p = 0.047), whereas no difference between Group A and Group B was found (odds ratio = 2.09, 95% confidence interval = 0.20-22.34, p = 0.542, data not shown). Surgical intervention is the definitive therapy for purulent SSTIs. Adjunctive antibiotic therapy increased the cure rate and appropriateness of prescription is influential.

Hygiene Strategies to Prevent Methicillin-Resistant Staphylococcus aureus Skin and Soft Tissue Infections: A Cluster-Randomized Controlled Trial Among High-Risk Military Trainees

Effective measures are needed to prevent methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) in high-risk community settings. The study objective was to evaluate the effect of personal hygiene-based strategies on rates of overall SSTI and MRSA SSTI. We conducted a prospective, field-based, cluster-randomized trial in US Army Infantry trainees from May 2010 through January 2012. There were 3 study groups with incrementally increased education and hygiene-based interventions: standard (S), enhanced standard (ES), and chlorhexidine (CHG). The primary endpoints were incidence of overall SSTI and MRSA SSTI. The study included 30 209 trainees constituting 540 platoons (168 S, 192 ES, and 180 CHG). A total of 1203 (4%) participants developed SSTI, 316 (26%) due to MRSA. The overall SSTI rate was 4.15 (95% confidence interval [CI], 3.77-4.58) per 100 person-cycles. SSTI rates by study group were 3.48 (95% CI, 2.87-4.22) for S, 4.18 (95% CI, 3.56-4.90) for ES, and 4.71 (95% CI, 4.03-5.50) for CHG. The MRSA SSTI rate per 100 person-cycles for all groups was 1.10 (95% CI, .91-1.32). MRSA SSTI rates by study group were 1.0 (95% CI, .70-1.42) for S, 1.29 (95% CI, .98-1.71) for ES, and 0.97 (95% CI, .70-1.36) for CHG. Personal hygiene and education measures, including once-weekly use of chlorhexidine body wash, did not prevent overall SSTI or MRSA SSTI in a high-risk population of military trainees. NCT01105767.

Economic evaluation of treatment for MRSA complicated skin and soft tissue infections in Glasgow hospitals

In the UK, methicillin-resistant Staphylococcus aureus (MRSA)-associated skin and soft tissue infections (SSTIs) are predominantly managed in the hospital using intravenous (IV) glycopeptides. We set out to explore the potential for and relative healthcare costs of earlier hospital discharge through switch to oral antibiotic therapy (linezolid or rifampicin and doxycycline) or continuation of IV therapy (teicoplanin) via an outpatient parenteral antimicrobial therapy (OPAT) service. Over 16 months, 173 patients were retrospectively identified with MRSA SSTI, of whom 82.8 % were treated with IV therapy. Thirty-seven patients were potentially suitable for earlier discharge with outpatient therapy. The model assumed 3 days of inpatient management and a maximum of 14 days of outpatient therapy. For the status quo, where patients received only inpatient care with IV therapy, hospital costs were calculated at £12,316 per patient, with 97 % of costs accounted for by direct bed day costs. The mean total cost savings achievable through OPAT or oral therapy was estimated to be £6,136 and £6,159 per patient treated, respectively. A significant proportion of patients with MRSA SSTI may be suitable for outpatient management with either oral therapy or via OPAT, with the potential for significant reduction in healthcare costs.

Marine Recruit Adherence in a Skin and Soft Tissue Infection Prevention Trial: Implications for Recruit Research and Public Health Application

A cluster-randomized trial evaluating the effectiveness of chlorhexidine gluconate-impregnated wipes against skin and soft tissue infections (SSTIs) and colonization with methicillin-resistant Staphylococcus aureus (MRSA) was conducted among military recruits attending Officer Candidate School at Marine Corps Base Quantico, Virginia. Participants were instructed to use the wipes thrice weekly and were monitored daily for SSTI. Surveys assessed frequency of wipe use as well as knowledge and attitudes regarding MRSA SSTI. Use of chlorhexidine gluconate-impregnated wipes failed to prevent SSTI; however, study adherence was moderate. Adherence with the study regimen (defined as use of > or = 50% of the wipes) was 65% at week 2 and declined to 49% by week 6. Adherence was approximately 59% in the first two classes and declined in later classes. One-third felt that use of the wipes was disruptive. Participants were knowledgeable about MRSA SSTI prevention measures. However, only 53% agreed that MRSA commonly causes skin infections in military training facilities. Understanding adherence and its determinants is needed to optimize prevention strategies that require self-administration. Future efforts should address barriers to adherence with prevention strategies in recruit training settings.

Clindamycin-resistant methicillin-resistant Staphylococcus aureus: epidemiologic and molecular characteristics and associated clinical factors

In this prospective, observational study of 618 consecutive adult patients with skin and soft tissue infections (SSTI) caused by methicillin-resistant Staphylococcus aureus (MRSA), the clinical characteristics, molecular epidemiology, and outcome of patients with clindamycin-resistant MRSA (n = 64) and clindamycin-susceptible MRSA (n = 554) were compared (including factors predictive of clindamycin-resistant MRSA SSTI). Patients with clindamycin-resistant MRSA were more likely to have had antibiotic exposure within 3 months (37.5% versus 17%, P < 0.01), surgery (25% versus 8%, P < 0.01), MRSA infection/colonization within 12 months (23% versus 7%, P < 0.01), or intravascular catheters (5% versus 0.5%, P = 0.02). On multivariate analysis, previous surgery (adjusted odds ratio [AOR] 2.97; 95% confidence interval [CI] 1.5–6.0), history of MRSA (AOR 3.4; 95% CI 1.7–7.1), and exposure to clindamycin (AOR 8.5; 95% CI 2.3–32) and to macrolides (AOR 7.2, 95% CI 1.6–31.8) were independently associated with presence of clindamycin-resistant MRSA. Clinical resolution was similar between groups (77% versus 68%; P = 0.26). Clindamycin-resistant MRSA was less often USA-300 (82% versus 98%, P = 0.004). Clindamycin resistance did not affect MRSA-SSTI clinical outcomes.

MRSA Rates and Antibiotic Susceptibilities from Skin and Soft Tissue Cultures in a Suburban ED

BackgroundPrior studies suggest that more than half of all skin and soft tissue infections (SSTIs) are caused by methicillin-resistant Staphylococcus aureus (MRSA). These data mainly represent inner-city urban centers. ObjectiveWe determined the bacteriologic etiologies and antibiotic susceptibilities from wound cultures in the emergency department (ED). We hypothesized that in a suburban ED, MRSA would not represent the major pathogen. MethodsThe study design was a retrospective, electronic medical record review in a suburban tertiary care ED with 80,000 annual visits. Subjects included ED patients of all ages who had skin or soft tissue cultures obtained in 2005–2008. Demographics and clinical data, including type of SSTI (MRSA or methicillin-sensitive S. aureus [MSSA]), culture results, and antibiotic susceptibility, were analyzed using descriptive statistics. ResultsFrom the 1246 cultures obtained during the study period, 252 (20.2%) were MSSA and 270 (21.6%) were MRSA. The rates of MRSA infections over time increased from 13.5% to 25.7% during 2005–2008. The rates of MRSA in males and females were comparable at 23.3% and 19.6%, respectively. In 2008, MRSA was 97–100% susceptible to vancomycin, linezolid, rifampin, nitrofurantoin, chloramphenicol, gentamycin, tetracycline, and trimethoprim-sulfamethoxazole (TMP-SMZ). To a lesser extent it was susceptible to clindamycin (75%), erythromycin (62%), and levofloxacin (50%). ConclusionsThere has been a significant increase in the rates of MRSA SSTIs in a suburban ED, yet only 1 in 4 SSTIs are caused by MRSA. Both MRSA and MSSA are completely susceptible to vancomycin, linezolid, rifampin, nitrofurantoin, and chloramphenicol. Gentamicin, tetracycline, and TMP-SMZ cover > 97% of both isolates.