Temporin-derived peptides promote MRSA-infected wound healing and protect mice from MRSA-induced pneumonia.

Role of Decolonization in a Comprehensive Strategy to Reduce Methicillin-Resistant Staphylococcus aureus Infections in the Neonatal Intensive Care Unit: An Observational Cohort Study - Volume 31 Issue 5

Non surgical wounds include chronic ulcers (pressure or decubitus ulcers, venous ulcers, diabetic ulcers, ischaemic ulcers), burns and traumatic wounds. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonisation (i.e. presence of MRSA in the absence of clinical features of infection such as redness or pus discharge) or infection in chronic ulcers varies between 7% and 30%. MRSA colonisation or infection of non surgical wounds can result in MRSA bacteraemia (infection of the blood) which is associated with a 30-day mortality of about 28% to 38% and a one-year mortality of about 55%. People with non surgical wounds colonised or infected with MRSA may be reservoirs of MRSA, so it is important to treat them, however, we do not know the optimal antibiotic regimen to use in these cases. To compare the benefits (such as decreased mortality and improved quality of life) and harms (such as adverse events related to antibiotic use) of all antibiotic treatments in people with non surgical wounds with established colonisation or infection caused by MRSA. We searched the following databases: The Cochrane Wounds Group Specialised Register (searched 13 March 2013); The Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2); Database of Abstracts of Reviews of Effects (2013, Issue 2); NHS Economic Evaluation Database (2013, Issue 2); Ovid MEDLINE (1946 to February Week 4 2013); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, March 12, 2013); Ovid EMBASE (1974 to 2013 Week 10); EBSCO CINAHL (1982 to 8 March 2013). We included only randomised controlled trials (RCTs) comparing antibiotic treatment with no antibiotic treatment or with another antibiotic regimen for the treatment of MRSA-infected non surgical wounds. We included all relevant RCTs in the analysis, irrespective of language, publication status, publication year, or sample size. Two review authors independently identified the trials, and extracted data from the trial reports. We calculated the risk ratio (RR) with 95% confidence intervals (CI) for comparing the binary outcomes between the groups and planned to calculate the mean difference (MD) with 95% CI for comparing the continuous outcomes. We planned to perform the meta-analysis using both fixed-effect and random-effects models. We performed intention-to-treat analysis whenever possible. We identified three trials that met the inclusion criteria for this review. In these, a total of 47 people with MRSA-positive diabetic foot infections were randomised to six different antibiotic regimens. While these trials included 925 people with multiple pathogens, they reported the information on outcomes for people with MRSA infections separately (MRSA prevalence: 5.1%). The only outcome reported for people with MRSA infection in these trials was the eradication of MRSA. The three trials did not report the review's primary outcomes (death and quality of life) and secondary outcomes (length of hospital stay, use of healthcare resources and time to complete wound healing). Two trials reported serious adverse events in people with infection due to any type of bacteria (i.e. not just MRSA infections), so the proportion of patients with serious adverse events was not available for MRSA-infected wounds. Overall, MRSA was eradicated in 31/47 (66%) of the people included in the three trials, but there were no significant differences in the proportion of people in whom MRSA was eradicated in any of the comparisons, as shown below.1. Daptomycin compared with vancomycin or semisynthetic penicillin: RR of MRSA eradication 1.13; 95% CI 0.56 to 2.25 (14 people).2. Ertapenem compared with piperacillin/tazobactam: RR of MRSA eradication 0.71; 95% CI 0.06 to 9.10 (10 people).3. Moxifloxacin compared with piperacillin/tazobactam followed by amoxycillin/clavulanate: RR of MRSA eradication 0.87; 95% CI 0.56 to 1.36 (23 people). We found no trials comparing the use of antibiotics with no antibiotic for treating MRSA-colonised non-surgical wounds and therefore can draw no conclusions for this population. In the trials that compared different antibiotics for treating MRSA-infected non surgical wounds, there was no evidence that any one antibiotic was better than the others. Further well-designed RCTs are necessary.

BackgroundAlthough there is a growing concern and policy regarding infections or colonization caused by resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), the prognosis of MRSA infections compared to that of methicillin-susceptible Staphylococcus aureus (MSSA) infections remains controversial. Moreover, there have not been any studies comparing both the burden of disease and its impact on the healthcare economy between MRSA infection and colonization while adjusting for confounding factors. These comparisons are crucial for developing effective infection control measures and healthcare policies. We aimed to compare the disease and economic burden between MRSA and MSSA infections and between MRSA infection and colonization.MethodsWe retrospectively investigated data of 496 in-patients with MRSA or MSSA infections and of 1178 in-patients with MRSA infections or MRSA colonization from a university hospital in Japan from 2016 to 2021. We compared in-hospital mortality, length of stay, and hospital charges between in-patients with MRSA and MSSA infections and those with MRSA infections and MRSA colonization using multiple regressions. We combined surveillance data, including all microbiological test results, data on patients with infections, treatment histories, and clinical outcomes, to create the datasets.ResultsThere was no statistically significant difference in in-hospital mortality rates between matched MRSA vs. MSSA infections and MRSA infection vs. colonization. On the contrary, the adjusted effects of the MRSA infection compared to those of MSSA infection on length of stay and hospital charges were 1.21-fold (95% confidence interval [CI] 1.03–1.42, P = 0.019) and 1.70-fold (95% CI 1.39–2.07, P < 0.00001), respectively. The adjusted effects of the MRSA infection compared to those of MRSA colonization on length of stay and hospital charges were 1.41-fold (95% CI 1.25–1.58, P < 0.00001) and 1.53-fold (95% CI 1.33–1.75, P < 0.00001), respectively. Regarding confounding factors, hemodialysis or hemofiltration was consistently identified and adjusted for in the multiple regression analyses comparing MRSA and MSSA infections, as well as MRSA infection and MRSA colonization.ConclusionsMRSA infection was associated with longer length of stay and higher hospital charges than both MSSA infection and MRSA colonization. Furthermore, hemodialysis or hemofiltration was identified as a common underlying factor contributing to increased length of stay and hospital charges.

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is more virulent compared with other bacteria. Data regarding outcomes after transvenous lead extraction (TLE) for device infection with various staphylococcal and non-staphylococcal species are lacking Hypothesis: We hypothesized that MRSA infection is associated with worse outcomes after TLE for device infection compared with other infections Methods: We collected data for all patients undergoing TLE for infectious indication between April 2004 and June 2015. Patients were divided into 5 groups- group 1 had MRSA infection, group 2 had methicillin-sensitive Staphylococcous aureus (MSSA), group 3 had coagulase-negative Staphylococcus (CoNS), group 4 had non-staphylococcal infection and group 5 were culture negative. Results: Out of total 700 TLE procedures for infectious indication, 134 (19.1%) had MRSA, 143 (20.4%) had MSSA, 229 (32.7%) had CoNS, 109 (15.6%) had other bacterial infections and 59 (8.4%) were culture negative. Pocket infection was more commonly associated with CoNS (40.3%) and negative cultures (18.2%). Systemic infection was unlikely to be associated with negative cultures (2.9%) and equally distributed among other 4 groups.There was no difference in procedural outcomes between the groups. Complications during hospital stay were equally common with MRSA, MSSA and CoNS infections (22.5%, 27.2%, 24.9%, respectively) and less common with other infections (16.2%) and culture negative group (9.2%). Kaplan-Meier survival curves showed worse mortality with MRSA, compared with other infections. MRSA and MSSA have similar worse mortality up to 9 months, after which curves diverge and continue to diverge up to 4 years follow up. Conclusions: MRSA and MSSA infections are associated with worse mortality up to 9 months after TLE for device infection. After 9 months, MRSA infection is associated with worse mortality and curve continues to diverge up to 4 years follow-up.

States, including Illinois, have passed legislation mandating the use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for reporting healthcare-associated infections, such as methicillin-resistant Staphylococcus aureus (MRSA). To evaluate the sensitivity of ICD-9-CM code combinations for detection of MRSA infection and to understand implications for reporting. We reviewed discharge and microbiology databases from July through August of 2005, 2006, and 2007 for ICD-9-CM codes or microbiology results suggesting MRSA infection at a tertiary care hospital near Chicago, Illinois. Medical records were reviewed to confirm MRSA infection. Time from admission to first positive MRSA culture result was evaluated to identify hospital-onset MRSA (HO-MRSA) infections. The sensitivity of MRSA code combinations for detecting confirmed MRSA infections was calculated using all codes present in the discharge record (up to 15); the effect of reviewing only 9 diagnosis codes, the number reported to the Centers for Medicare and Medicaid Services, was also evaluated. The sensitivity of the combination of diagnosis codes for detection of HO-MRSA infections was compared with that for community-onset MRSA (CO-MRSA) infections. We identified 571 potential MRSA infections with the use of screening criteria; 403 (71%) were confirmed MRSA infections, of which 61 (15%) were classified as HO-MRSA. The sensitivity of MRSA code combinations was 59% for all confirmed MRSA infections when 15 diagnoses were reviewed compared with 31% if only 9 diagnoses were reviewed (P < .001). The sensitivity of code combinations was 33% for HO-MRSA infections compared with 62% for CO-MRSA infections (P < .001). Limiting analysis to 9 diagnosis codes resulted in low sensitivity. Furthermore, code combinations were better at revealing CO-MRSA infections than HO-MRSA infections. These limitations could compromise the validity of ICD-9-CM codes for interfacility comparisons and for reporting of healthcare-associated MRSA infections.

Prevalence of and risk factors for methicillin-resistant Staphylococcus aureus colonization and infection among infants at a level III neonatal intensive care unit

Objective To evaluate the methicillin-resistant Staphylococcus aureus (MRSA) colonization in infants at neonatal intensive care unit (NICU) by active surveillance cultures (ASC) and the effects of mupirocin decolonization on MRSA infection. Methods Neonates adimitted to NICU of Ruian People's Hospital of Zhejiang Province, China between October 1, 2013 and September 30, 2014 underwent ASC within 24 hours of admission (ASC group). The samples from nasal vestibule and umbilicus were cultured for MRSA, and positive cultures were considered as MRSA colonization. These with negative cultures underwent repeated culture of MRSA by ASC at the 1st and 2nd week after NICU admission. Neonates admitted to NICU between October 1, 2014 and September 30, 2015 with MRSA colonization based on ASC were decolonized with mupirocin at both nasal vestibule and umbilicus twice daily for five consecutive days (decolonization group). Culture samples were obtained one day and one week after decolonization to repeat ASC. ASC was stopped if the subsequent culture was negative twice successively; and a second mupirocin decolonizaton was performed if the culture was positive. Chi-square test was used to compare the rates of colonization and infection between the two groups. Results (1) MRSA colonization and infection in ASC group: MRSA colonization rates within 24 hours, and in the 1st and 2nd week after NICU admission in ASC group were 2.2% (9/418), 3.7% (15/402) and 3.6% (13/361), respectively. Compared with those without MRSA colonization, neonates with MRSA colonization had a higher incidence of MRSA infection [13.5% (5/37) vs 3.7% (14/381), χ2=7.524, P=0.006]. (2) MRSA colonization and infection in decolonization group: MRSA colonization rates within 24 hours, and at the 1st and 2nd week after NICU admission in decolonization group were 2.8% (12/435), 2.9% (12/414) and 1.3% (5/373), respectively. The MRSA colonization rate at the 2nd week was significantly lower than that in ASC group (χ2=3.919, P=0.048). Twenty-nine cases had MRSA colonization, among which, 27 cases were decolonized once and two cases were decolonized twice, and all were successful. The rate of MRSA infection in decolonization group was 2.1% (9/435), which was significantly lower than in ASC group [4.5% (19/418)] (χ2=4.118, P=0.042). Conclusions Rate of MRSA colonization is high at NICU. Mupirocin can decolonize MRSA carriage and reduce MRSA infection in neonates. Key words: Intensive care units, neonatal; Methicillin-resistant staphylococcus aureus; Mupirocin; Staphylococcal infections; Watchful waiting

Multicenter Evaluation of the LightCycler MRSA Advanced Test, the Xpert MRSA Assay, and MRSASelect Directly Plated Culture with Simulated Workflow Comparison for the Detection of Methicillin-Resistant Staphylococcus aureus in Nasal Swabs

Although methicillin-resistant Staphylococcus aureus (MRSA) infection is a worldwide problem, data on its significance among vascular surgery patients remain scant and conflicting. This study was designed to evaluate the association between nosocomial MRSA infection and patient outcome following vascular surgery procedures. Outcomes among patients with MRSA infection were also compared to those infected with methicillin-sensitive Staphylococcus aureus (MSSA). All patients admitted to a tertiary care Vascular Surgery ward during the year 2002 were included in this retrospective review. In addition to information on demographic and comorbid conditions, data on surgical interventions, nosocomial infection incidence rates as defined by the Center for Disease Control guidelines, and MRSA screening results were collected. Primary outcome was in-hospital death. Secondary outcomes measures included length of hospital stay, readmissions, or repeat surgeries, and ICU admissions. Of a total of 408 subjects, 110 were documented with a nosocomial infection (27.0%). Of these, 16 patients (3.9%) were colonized with MRSA on screening at time of admission, 22 (5.4%) had acquired MRSA infection during hospitalization, and 15 (3.7%) had MSSA infection. Patients with MRSA, MSSA, and non-MRSA infection had similar baseline characteristics except for hypertension and tobacco use. Age and MRSA infection were significant risk factors for in-hospital deaths (OR 1.07, 95% CI 1.01-1.13, p = 0.01 and OR 7.44, 95% CI 1.63-33.9, p = 0.01, respectively). Adjusted for the effects of age, MRSA infection remained a significant independent risk factor associated with in-hospital deaths (OR 4.38, 95% CI 1.09-17.7, p = 0.04). After adjustment for baseline risk factors, MRSA infection was also independently associated with secondary outcome measures. Although risks of non-MRSA infections were also associated with adverse outcomes in the multivariate analyses, MRSA posed higher risks, as reflected by higher odds ratio in all instances. The 22 patients with documented MRSA infection had significantly longer hospital stays than those with MSSA infection (median 24 days vs 8 days, p = 0.02). However, no significant differences were noted between the 2 groups in terms of secondary outcome. These results show that MRSA infection is a significant risk factor for adverse clinical outcomes among patients undergoing vascular surgery procedures. Infection with MRSA results in a greater risk of these outcomes when compared with non-MRSA infection. However, despite concerns regarding the virulence of this strain of staphylococcus, patients infected with MRSA had no higher rates of morbidity or mortality except for increased length of hospital stay when compared to patients with MSSA.

New insights concerning methicillin-resistant Staphylococcus aureus disease

Background: Gaps exist in the evidence supporting the benefits of contact precautions for the prevention of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The Centers for Disease Control and Prevention allow suspending contact precautions for MRSA and VRE in cases of gown shortages, as we have seen during the COVID-19 pandemic. We evaluated the impact of discontinuing isolation precautions in hospitalized patients with MRSA and VRE infection, due to gown shortage, on the rate of hospital-acquired (HA) MRSA and VRE infections. Methods: A retrospective chart review was performed on adult patients (n = 2,200) with established MRSA or VRE infection at 5 hospitals in CommonSpirit Health, Texas Division, from March 2019 to October 2020. Data including demographics, infection site, documented symptoms, and antibiotic use were stratified based on patient location (floor vs ICU). Rates of hospital-acquired MRSA and VRE infection before and after the discontinuation of isolation (implemented in March 2020) were compared. Incidence density rate was used to assess differences in the rate of MRSA and VRE infections between pre- and postintervention groups. Results: The rate of hospital-acquired (HA) MRSA infection per 10,000 patient days before the intervention (March 19–February 20) was 12.19, compared to 10.64 after the intervention (March 20–July 20) (P = .038). The rates of HA MRSA bacteremia were 1.13 and 0.93 for the pre- and postintervention groups, respectively (P = .074). The rates of HA VRE per 10,000 patient days were 3.53 and 4.44 for the pre- and postintervention groups, respectively (P = .274). The hand hygiene rates were 0.93 before the intervention and 0.97 after the intervention (P = .028). Conclusions: Discontinuing isolation from MRSA and VRE in the hospital setting did not lead to a statistically significant increase in hospital-acquired MRSA or VRE infections. In fact, rates of hospital-acquired MRSA decreased, likely secondary to improvements in hand hygiene during this period. These results support the implementation of policies for discontinuing contact isolation for hospitalized patients with documented MRSA or VRE infection, particularly during shortages of gowns.Funding: NoDisclosures: None

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen of public health importance; MRSA prevention programs that may affect MRSA transmission and infection are increasingly common in health care settings. Whether there have been changes in MRSA infection incidence as these programs become established is unknown; however, recent data have shown that rates of MRSA bloodstream infections (BSIs) in intensive care units are decreasing. To describe changes in rates of invasive health care-associated MRSA infections from 2005 through 2008 among residents of 9 US metropolitan areas. Active, population-based surveillance for invasive MRSA in 9 metropolitan areas covering a population of approximately 15 million persons. All reports of laboratory-identified episodes of invasive (from a normally sterile body site) MRSA infections from 2005 through 2008 were evaluated and classified based on the setting of the positive culture and the presence or absence of health care exposures. Health care-associated infections (ie, hospital-onset and health care-associated community-onset), which made up 82% of the total infections, were included in this analysis. Change in incidence of invasive health care-associated MRSA infections and health care-associated MRSA BSIs using population of the catchment area as the denominator. From 2005 through 2008, there were 21,503 episodes of invasive MRSA infection; 17,508 were health care associated. Of these, 15,458 were MRSA BSIs. The incidence rate of hospital-onset invasive MRSA infections was 1.02 per 10,000 population in 2005 and decreased 9.4% per year (95% confidence interval [CI], 14.7% to 3.8%; P = .005), and the incidence of health care-associated community-onset infections was 2.20 per 10,000 population in 2005 and decreased 5.7% per year (95% CI, 9.7% to 1.6%; P = .01). The decrease was most prominent for the subset of infections with BSIs (hospital-onset: -11.2%; 95% CI -15.9% to -6.3%; health care-associated community-onset: -6.6%; 95% CI -9.5% to -3.7%). Over the 4-year period from 2005 through 2008 in 9 diverse metropolitan areas, rates of invasive health care-associated MRSA infections decreased among patients with health care-associated infections that began in the community and also decreased among those with hospital-onset invasive disease.

The rate of methicillin-resistant Staphylococcus aureus (MRSA) has increased significantly over the last decade. Previous cohort studies of patients with MRSA bacteremia have reported higher mortality rates, increased morbidity, longer hospital length of stay (LOS), and higher costs compared with patients with methicillin-susceptible S. aureus (MSSA) bacteremia. The clinical and economic impact of MRSA involving other sites of infection has not been well characterized. To determine the clinical and economic implications of MRSA compared with MSSA infections across a variety of infection sites and severity of illnesses. A retrospective, case-control analysis comparing differences in clinical and economic outcomes of patients with MRSA and MSSA infections was conducted at an academic medical center. Case patients with MRSA infection were matched (1:1 ratio) to control patients with MSSA infection according to age, site of infection, and type of care. Thirty-six matched pairs of patients with S. aureus infection were identified. Baseline characteristics of patients with MSSA and MRSA infection were similar. Patients with MRSA infections had a trend toward longer hospital LOS (15.5 vs 11 days; p = 0.05) and longer antibiotic-related LOS (10 vs 7 days; p = 0.003). Median hospital cost associated with treatment of patients with MRSA infections was higher compared with patients with MSSA infections ($16,575 vs $12,862; p = 0.11); however, this difference was not statistically significant. Treatment failure was common in patients with MRSA infection. Among patients with MSSA infections, treatment failure was associated with vancomycin use. Patients with MRSA infections had worse clinical and economic outcomes compared with patients with MSSA infections.

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen of hospital infection with multi-drug resistant characteristics. Its spread and epidemic pose great challenges to nosocomial infection control. This study was aimed to identify risk factors for hospital-acquired MRSA (HA-MRSA) infections and investigate its clinical outcome, developing infection control strategies and improving patient outcomes.MethodsA retrospective case-case-control study was conducted to compare patients in Southwest Hospital, Chongqing, People's Republic of China from January 2018 to December 2018 with control patients. In this study, 251 patients with MRSA nosocomial infection, 339 patients with methicillin-sensitive Staphylococcus aureus strains (MSSA) nosocomial infection, and 300 patients with non-Staphylococcus aureus infection were included.ResultsMultivariate analysis showed that presence of central venous catheters (odds ratio [OR], 1.932; 95% confidence interval [CI], 1.074–3.477; P=0.028), sputum suction (OR, 2.887; 95% CI, 1.591–5.240; p<0.001), and total hospital stays more than 30 days (OR, 3.067; 95% CI, 2.063–4.559; P<0.001) were independent risk factors for HA-MRSA. Renal insufficiency (OR, 2.744; 95% CI, 1.089–6.914; P=0.032) and receipt of immunosuppressors (OR, 3.140; 95% CI, 1.284–7.678; P=0.012) were independent predictors of poor prognosis of MRSA nosocomial infection. Moreover, empirical use of antibiotics (OR, 0.514; 95% CI, 0.282–0.935; P=0.029) was a protective factor for poor prognosis of MRSA nosocomial infection. In-hospital mortality in the MRSA group was not statistically significant compared with the other two groups; however, the rate of poor prognosis in the MRSA group was higher than that of the MSSA group (27.5% vs 17.1%, χ2=9.200, P=0.002) and the control group (27.5% vs 16.0%, χ2=19.190, P=0.001).ConclusionOur results have shown presence of central venous catheters, sputum suction, and total hospital stays more than 30 days were associated with nosocomial MRSA infection. Patients with renal insufficiency and immunosuppressive therapy were more likely to cause poor prognosis with MRSA infection, and the empirical use of antibiotics can effectively reduce the adverse clinical outcomes caused by MRSA infection. Based on above findings, strategies to control MRSA infection should emphasize more attention to these patients and appropriate empirical use of antibiotics.

To determine whether preoperative nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage is a significant predictor of postoperative infections, after accounting for surgical infection risk and surgical prophylaxis. Retrospective cohort study. Veterans Affairs (VA) Boston patients who had nasal MRSA polymerase chain reaction screening performed in the 31 days before clean or clean contaminated surgery in 2008-2009. Postoperative MRSA clinical cultures and infections, total surgical site infections (SSIs), and surgical prophylaxis data were abstracted from administrative databases. MRSA infections were confirmed via chart review. Multivariate analysis of risk factors for each outcome was conducted using Poisson regression. SSI risk index was calculated for a subset of 1,551 patients assessed by the VA National Surgical Quality Improvement Program. Among 4,238 eligible patients, 279 (6.6%) were positive for preoperative nasal MRSA. Postoperative MRSA clinical cultures and infections, including MRSA SSIs, were each significantly increased in patients with preoperative nasal MRSA. After adjustment for surgery type, vancomycin prophylaxis, chlorhexidine/alcohol surgical skin preparation, and SSI risk index, preoperative nasal MRSA remained significantly associated with postoperative MRSA cultures (relative risk [RR], 8.81; 95% confidence interval [CI], 3.01-25.82) and infections (RR, 8.46; 95% CI, 1.70-42.04). Vancomycin prophylaxis was associated with an increased risk of total SSI in those negative for nasal MRSA (RR, 4.34; 95% CI, 2.19-8.57) but not in patients positive for nasal MRSA. In our population, preoperative nasal MRSA colonization was independently associated with MRSA clinical cultures and infections in the postoperative period. Vancomycin prophylaxis increased the risk of total SSI in nasal MRSA-negative patients.