The Impact of MRSA Colonization on Healthcare-Associated Infections in Long-Term Care Facility Residents: A Whole-Genome Sequencing-Based Study.

Methicillin-resistant Staphylococcus aureus (MRSA) colonization has been considered a risk factor for the development of infection, however, there are no studies that have compared the colonizing and infecting strains using whole-genome sequencing (WGS). The aim of this study is to determine the prevalence of and risk factors for MRSA colonization among long-term care facilities (LTCF) residents of Tenerife (Spain), and to analyze the epidemiological relationship between the colonizing and infecting strains using WGS. A point-prevalence study was carried out at 14 LTCFs in Tenerife from October 2020 to May 2021. Nasal swabs were cultured for MRSA. Colonized residents were followed up for two years. A phylogenetic comparison between colonization and infection strains was performed using WGS. A total of 764 residents were included. The prevalence of colonization by MRSA was 28.1% (n = 215), of which 12 (5.6%) subsequently developed infection. A close genetic relationship between colonization and infection isolates was found in three of the four (75%) residents studied. Our study confirms that colonized residents can develop serious MRSA infections from the same nasal colonization strain. Given the high prevalence of MRSA colonization in these centers, it is necessary to implement strategies with preventive measures to avoid the development of infection and the transmission of MRSA.

Risk factors for colonization by carbapenemase-producing bacteria in Spanish long-term care facilities: a multicentre point-prevalence study.

BACKGROUND: The emergence of carbapenemase-producing bacteria (CPB) has become a major public health concern. Long-term care facilities (LTCF) are potential reservoirs for multidrug-resistant micro-organisms (MDRO). However, data on CPB is limited. The study aims to determine the prevalence of MDRO and risk factors for CPB colonization among residents of LTCFs. METHODS: A point-prevalence study was conducted at 14 LTCFs in Tenerife (Spain) between October 2020 and May 2021. Nasal and rectal swabs were cultured for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), carbapenemase-producing Enterobacterales, MDR Acinetobacter baumannii (MDR-Ab) and MDR Pseudomonas aeruginosa. Antimicrobial susceptibility testing and molecular detection of resistance genes were performed. Risk factors for colonization by carbapenemase-producing bacteria (CPB) were determined by univariate and multivariate analysis. RESULTS: A total of 760 LTCF residents were recruited. The prevalence of colonization by CPB was 9.3% (n = 71) with the following distribution: 35 (49.3%) K. pneumoniae, 26 (36.6%) MDR-Ab, 17 (23.9%) E. coli, and 1 (1.4%) C. koseri. In addition, the prevalence of colonization by MRSA was 28.1% (n = 215) and only one case of VRE was isolated. Multivariate analysis identified male sex (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.86-3.11; P = 0.01), having a high health requirement (OR, 6.32; 95% CI, 1.91-20.92; P = 0.003) and previous hospitalization (OR, 3.60; 95% CI, 1.59-8.15 P = 0.002) as independent risk factors for CPB rectal carriage. CONCLUSIONS: LTCFs are an important reservoir for MDRO, including CPB. We have identified some predictors of colonization by CPB, which enable a more targeted management of high-risk residents. Antimicrobial stewardship programmes and infection control preventive measures are needed to stop acquisition and transmission of MDRO.

Prediction of surgical site infection after colorectal surgery.

BACKGROUND: Surgical site infection (SSI) after colorectal surgery is a frequent complication associated with substantial morbidity. Our objective was to identify surgical predictors of SSI in patients undergoing colorectal surgery using a retrospective case-control design. MATERIAL AND METHODS: Randomly selected patients from all those undergoing colorectal surgery (2007-2013). Cases were patients who developed SSI within 30 days. Controls were patients who did not develop SSI within 30 days. Patients undergoing multiple procedures during a single surgical intervention were excluded. SSI was diagnosed according to Centers for Disease Control and Prevention definitions. The main outcome measures were SSI, surgical variables, and cumulative survival (Kaplan-Meier method). Variables considered predictors were compared using log-rank test. RESULTS: Of 911 patients undergoing colorectal surgery, 221 developed SSI (24.3%; 95% confidence interval, 24.0-24.6). On univariate analysis, significant risk factors for SSI were: female sex (P = .02), >72 hours preoperative stay (P = .04), open surgery (P = .08), incision class: contaminated and dirty (P = .001), and emergency procedures (P = .006). On multivariate analysis, significant independent predictors of SSI and survival were dirty surgery (hazard ratio [HR], 2.12; P = .015), contaminated surgery (HR, 1.74; P = .009), female sex (HR, 1.58; P = .003), open surgery, (HR, 1.51; P = .015) and >72 hours preoperative stay (HR, 1.48; P = .024). CONCLUSIONS: Dirty or contaminated surgery, female sex, open surgery, and >72 hours preoperative stay were significant predictors of SSI.