Background We conducted a longitudinal study to evaluate changes in the clinical presentation and epidemiology of Staphylococcus aureus bacteremia (SAB) in an academic, US medical center. Methods Consecutive patients with monomicrobial SAB were enrolled from January 1995 to December 2015. Each person’s initial bloodstream S. aureus isolate was genotyped using spa typing. Clonal complexes (CCs) were assigned using Ridom StaphType software. Changes over time in both the patient and bacterial characteristics were estimated with linear regression. Associations between genotypes or clinical characteristics and complications were estimated using multivariable regression models. Results Among the 2348 eligible participants, 54.2% had an implantable, foreign body of some type. This proportion increased significantly during the 21-year study period, by 0.96% annually (P = .002), as did comorbid conditions and acquisition outside of the hospital. Rates of any metastatic complication also significantly increased, by 0.94% annually (P = .019). Among the corresponding bloodstream S. aureus isolates, spa-CC012 (multi-locus sequence type [MLST] CC30), -CC004 (MLST CC45), -CC189 (MLST CC1), and -CC084 (MLST CC15) all significantly declined during the study period, while spa-CC008 (MLST CC8) significantly increased. Patients with SAB due to spa-CC008 were significantly more likely to develop metastatic complications in general, and abscesses, septic emboli, and persistent bacteremia in particular. After adjusting for demographic, racial, and clinical variables, the USA300 variant of spa-CC008 was independently associated with metastatic complications (odds ratio 1.42; 95% confidence interval 1.02–1.99). Conclusions Systematic approaches for monitoring complications of SAB and genotyping the corresponding bloodstream isolates will help identify the emergence of hypervirulent clones and likely improve clinical management of this syndrome.

objective. To determine whether antimicrobial-impregnated textiles decrease the acquisition of pathogens by healthcare provider (HCP) clothing.design. We completed a 3-arm randomized controlled trial to test the efficacy of 2 types of antimicrobial-impregnated clothing compared to standard HCP clothing. Cultures were obtained from each nurse participant, the healthcare environment, and patients during each shift. The primary outcome was the change in total contamination on nurse scrubs, measured as the sum of colony-forming units (CFU) of bacteria.participants and setting. Nurses working in medical and surgical ICUs in a 936-bed tertiary-care hospital.intervention. Nurse subjects wore standard cotton-polyester surgical scrubs (control), scrubs that contained a complex element compound with a silver-alloy embedded in its fibers (Scrub 1), or scrubs impregnated with an organosilane-based quaternary ammonium and a hydrophobic fluoroacrylate copolymer emulsion (Scrub 2). Nurse participants were blinded to scrub type and randomly participated in all 3 arms during 3 consecutive 12-hour shifts in the intensive care unit.results. In total, 40 nurses were enrolled and completed 3 shifts. Analyses of 2,919 cultures from the environment and 2,185 from HCP clothing showed that scrub type was not associated with a change in HCP clothing contamination (P = .70). Mean difference estimates were 0.118 for the Scrub 1 arm (95% confidence interval [CI], −0.206 to 0.441; P = .48) and 0.009 for the Scrub 2 rm (95% CI, −0.323 to 0.342; P = .96) compared to the control. HCP became newly contaminated with important pathogens during 19 of the 120 shifts (16%).conclusions. Antimicrobial-impregnated scrubs were not effective at reducing HCP contamination. However, the environment is an important source of HCP clothing contamination. trial registration. Clinicaltrials.gov Identifier: NCT 02645214

Background To understand the clinical, bacterial, and host characteristics associated with recurrent Staphylococcus aureus bacteremia (R-SAB), patients with R-SAB were compared to contemporaneous patients with a single episode of SAB (S-SAB). Methods All SAB isolates underwent spa genotyping. All isolates from R-SAB patients underwent pulsed-field gel electrophoresis (PFGE). PFGE-indistinguishable pairs from 40 patients underwent whole genome sequencing (WGS). Acute phase plasma from R-SAB and S-SAB patients was matched 1:1 for age, race, sex, and bacterial genotype, and underwent cytokine quantification using 25-analyte multiplex bead array. Results R-SAB occurred in 69 (9.1%) of the 756 study patients. Of the 69 patients, 30 experienced relapse (43.5%) and 39 reinfection (56.5%). Age, race, hemodialysis dependence, presence of foreign body, methicillin-resistant Staphyloccus aureus, and persistent bacteremia were individually associated with likelihood of recurrence. Multivariate risk modeling revealed that black hemodialysis patients were nearly 2 times more likely (odds ratio [OR] = 9.652 [95% confidence interval [CI], 5.402–17.418]) than white hemodialysis patients (OR = 4.53 [95% CI, 1.696–10.879]) to experience R-SAB. WGS confirmed PFGE interpretations in all cases. Median RANTES (regulated on activation, normal T cell expressed and secreted) levels in acute phase plasma from the initial episode of SAB were higher in R-SAB than in matched S-SAB controls (P = .0053, false discovery rate < 0.10). Conclusion This study identified several risk factors for R-SAB. The largest risk for R-SAB is among black hemodialysis patients. Higher RANTES levels in R-SAB compared to matched controls warrants further study.

Background Phenol-soluble modulins (PSM) are amphipathic proteins produced by Staphylococcus aureus that promote virulence, inflammatory response, and biofilm formation. We previously showed that MRSA isolates from soft tissue infection (SSTI) produced significantly higher levels of PSM than MRSA isolates from hospital-acquired pneumonia (HAP) or infective endocarditis (IE). In this investigation, we sought to validate this finding in methicillin-susceptible S. aureus (MSSA) isolates. Methods MSSA isolates (n=162) from patients with SSTI, HAP, and IE were matched 1:1:1 based on geographic origin of the infection to form 54 triplets (North America n=27, Europe n=25, Australia n=2). All isolates underwent spa-typing and were classified using eGenomics. In vitro PSM production was quantified by high performance liquid chromatography/mass spectrometry. Fischer’s Exact Test and the Kruskal-Wallis test were used for statistical analysis. Results Spa1 was more common in SSTI (14.81% SSTI, 3.70% HAP, 1.85% IE) (p<0.03). Spa2 was more common in HAP (0% SSTI, 12.96% HAP, 3.70% IE) (p<0.01). Levels of PSMα1-4 all differed significantly among the three clinical groups, with SSTI isolates producing the highest levels and IE producing the lowest levels of PSMα1-4. Spa1 isolates produced significantly more delta-toxin (p<0.03) than non-Spa1 isolates. No associations between PSM levels and clinical outcome of SSTI, HAP, or IE were identified. Conclusion Production of PSMα1-4 is highest in SSTI MSSA isolates, supporting the hypothesis that these peptides are important for SSTI pathogenesis. These findings are similar to those described in MRSA, and demonstrate that associations between PSM levels and type of infection are independent of the methicillin resistance status of the isolate.

We assessed environmental contamination of inpatient rooms housing COVID-19 patients in a dedicated COVID-19 unit. Contamination with SARS-CoV-2 was found on 5.5% (19/347) of surfaces via RT-PCR and 0.3% (1/347) of surfaces via cell culture. Environmental contamination is uncommon in hospitals rooms; RNA presence is not a specific indicator of infectious virus.