Background Previous viral pandemics have shown that secondary bacterial infections result in higher morbidity and mortality, with Staphylococcus aureus as the primary causative pathogen. The impact of secondary S. aureus bacteremia on mortality in patients infected with SARS-CoV-2 remains unknown. Methods This was a retrospective, observational case series of patients with COVID-19 disease who developed secondary S. aureus bacteremia across two New York City hospitals. The primary endpoint was to describe 14-day and 30-day hospital mortality rates of patients infected with COVID-19 and S. aureus bacteremia. Secondary endpoints included predictors of 14-day and 30-day hospital mortality in patients infected with COVID-19 and S. aureus bacteremia. Results A total of 42 hospitalized patients for COVID-19 with secondary S. aureus bacteremia were identified. Of these patients, 23 (54.8 %) and 28 (66.7%) died at 14 days and 30 days, respectively, from their first positive blood culture. Multivariate analysis identified hospital-onset bacteremia (≥4 days from date of admission) and age as significant predictors of 14-day hospital mortality, and Pitt bacteremia score as a significant predictor of 30-day hospital mortality (odds ratio [OR] 11.9 [95% confidence interval [CI] 2.03-114.7], p=0.01; (OR 1.10 [95% CI 1.03-1.20], p=0.02); and (OR 1.56 [95% CI 1.19-2.18], p=0.003), respectively. Conclusions Bacteremia with S. aureus is associated with high mortality rates in patients hospitalized with COVID-19 infection. Further investigation is warranted to understand the impact of COVID-19 and secondary S. aureus bacteremia.

OBJECTIVE To concomitantly determine the differential degrees of air and environmental contamination by Acinetobacter baumannii based on anatomic source of colonization and type of ICU layout (single-occupancy vs open layout). DESIGN Longitudinal prospective surveillance study of air and environmental surfaces in patient rooms. SETTING A 1,500-bed public teaching hospital in Miami, Florida. PATIENTS Consecutive A. baumannii-colonized patients admitted to our ICUs between October 2013 and February 2014. METHODS Air and environmental surfaces of the rooms of A. baumannii-colonized patients were sampled daily for up to 10 days. Pulsed-field gel electrophoresis (PFGE) was used to type and match the matching air, environmental, and clinical A. baumannii isolates. RESULTS A total of 25 A. baumannii-colonized patients were identified during the study period; 17 were colonized in the respiratory tract and 8 were colonized in the rectum. In rooms with rectally colonized patients, 38.3% of air samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 13.1% of air samples were positive (P=.0001). In rooms with rectally colonized patients, 15.5% of environmental samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 9.5% of environmental samples were positive (P=.02). The rates of air contamination in the open-layout and single-occupancy ICUs were 17.9% and 21.8%, respectively (P=.5). Environmental surfaces were positive in 9.5% of instances in open-layout ICUs versus 13.4% in single-occupancy ICUs (P=.09). CONCLUSIONS Air and environmental surface contaminations were significantly greater among rectally colonized patients; however, ICU layout did not influence the rate of contamination. Infect Control Hosp Epidemiol 2016;37:777-781.

Background Methicillin-resistant Staphylococcus aureus (MRSA) causes life-threatening infections in both community and hospital settings and is a leading cause of health care–associated infections (HAIs). We sought to describe the molecular epidemiological landscape of patients with MRSA bloodstream infections (BSIs) at an urban medical center by evaluating the clinical characteristics associated with the two dominant endemic clones. Methods Comprehensive clinical data from the electronic health records of 227 hospitalized patients ≥18 years old with MRSA BSI over a 33-month period in New York City were collected. The descriptive epidemiology and mortality associated with the two dominant clones were compared using logistic regression. Results Molecular analysis revealed that 91% of all single-patient MRSA BSIs were due to two equally represented genotypes, clonal complex (CC) 5 (n = 117) and CC8 (n = 110). MRSA BSIs were associated with a 90-day mortality rate of 27%. CC8 caused disease more frequently in younger age groups (56 ± 17 vs 67 ± 17 years old; P < .001) and in those of nonwhite race (odds ratio [OR], 3.45; 95% confidence interval [CI], 1.51–7.87; P = .003), with few other major distinguishing features. Morbidity and mortality also did not differ significantly between the two clones. CC8 caused BSIs more frequently in the setting of peripheral intravenous catheters (OR, 5.96; 95% CI, 1.51–23.50; P = .01). Conclusions The clinical features distinguishing dominant MRSA clones continue to converge. The association of CC8 with peripheral intravenous catheter infections underscores the importance of classical community clones causing hospital-onset infections. Ongoing monitoring and analysis of the dynamic epidemiology of this endemic pathogen are crucial to inform management and prevent disease.

Background Whole-genome sequencing (WGS) is increasingly used to map the spread of bacterial and viral pathogens in nosocomial settings. A limiting factor for more widespread adoption of WGS for hospital infection prevention practices is the availability of standardized tools for genomic epidemiology. Methods We developed the Pathogen Sequencing Phylogenomic Outbreak Toolkit (PathoSPOT) to automate integration of genomic and medical record data for rapid detection and tracing of nosocomial outbreaks. To demonstrate its capabilities, we applied PathoSPOT to complete genome surveillance data of 197 MRSA bacteremia cases from two hospitals during a 2-year period. Results PathoSPOT identified 8 clonal clusters encompassing 33 patients (16.8% of cases), none of which had been recognized by standard practices. The largest cluster corresponded to a prolonged outbreak of a hospital-associated MRSA clone among 16 adults, spanning 9 wards over a period of 21 months. Analysis of precise timeline and location data with our toolkit suggested that an initial exposure event in a single ward led to infection and long-term colonization of multiple patients, followed by transmissions to other patients during recurrent hospitalizations. Conclusions We demonstrate that PathoSPOT genomic surveillance enables the detection of complex transmission chains that are not readily apparent from epidemiological data and that contribute significantly to morbidity and mortality, enabling more effective intervention strategies.

25Background 26 Methicillin-resistant Staphylococcus aureus (MRSA) causes life-threatening infections in 27 both community and hospital settings and is a leading cause of healthcare-associated 28 infections (HAIs). We sought to describe the molecular epidemiological landscape of 29 patients with MRSA bloodstream infections (BSIs) at an urban medical center by 30 evaluating the clinical characteristics associated with the two dominant endemic clones. 31 Methods 32Comprehensive clinical data extraction from the electronic health records of 227 33 hospitalized patients ≥18 years old with MRSA BSI over a 33-month period in New York 34 City were collected. The descriptive epidemiology and mortality associated with the two 35 dominant clones was compared using logistic regression. 36 Results 37Molecular analysis revealed that 91% of all single-patient MRSA BSIs were due to two 38 equally represented genotypes, clonal complex (CC) 5 (N=117) and CC8 (N=110). 39MRSA BSIs were associated with a 90-day mortality of 27%. CC8 caused disease more 40 3 frequently in younger age groups (56 ± 17 vs 67 ± 17 years old; p<0.001) and in non- 41White race (OR=3.45 95% CI [1.51-7.87]; p=0.003), with few other major distinguishing 42 features. Morbidity and mortality also did not differ significantly between the two clones. 43CC8 caused BSIs more frequently in the setting of peripheral intravenous catheters 44 (OR=5.96; 95% CI [1.51-23.50]; p=0.01). 45 Conclusion 46 The clinical features distinguishing dominant MRSA clones continue to converge. The 47 association of CC8 with peripheral intravenous catheter infections underscores the 48 importance of classical community clones causing hospital-onset infections. Ongoing 49 monitoring and analysis of the dynamic epidemiology of this endemic pathogen is 50 crucial to inform management to prevent disease. 51 Introduction 52 Healthcare-associated infections (HAIs) pose a potentially fatal threat to patients 53 worldwide 1 and Staphylococcus aureus is one of the most common causes of HAIs in 54 the United States. 2,3 Methicillin-resistant S. aureus (MRSA) bloodstream infections 55 (BSIs) are linked with mortality up to 30% and are associated with longer hospital stays 56 and increased healthcare costs. 4,5 MRSA has long been present in healthcare settings 57 but is now well established in the community. 6 The two dominant MRSA clones in the 58 United States are clonal complex (CC) 5 and CC8. 3 Historically, CC5 has been 59 associated with older individuals with hospital or long-term care facility contact. 6 In 60contrast, CC8, predominantly the USA300 pulsotype, was first reported in the US in 61 healthy children in 1990s and raised concern for its capacity to cause severe disease in 62 majority of CC8 isolates were ST8 (N=108; 98%) with 2 (2%) additional non-ST8 clones. 132The majority (N=64; 58%) of ST8 were spa type t008, along with 20 (18%) non-t008 spa 133 types which also clustered with USA300. Additionally, CC8 included 24 (22%) spa type 134 t064, including three (3%) non-t064 spa ty...