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Shigellosis outbreaks caused by Shigella with decreased susceptibility to azithromycin (DSA-Shigella) among men who have sex with men (MSM) have been reported worldwide. We describe sexual health indicators and antimicrobial drug resistance for shigellosis cases in Minnesota, USA. We analyzed a sample of isolates received during 2012-2015 and cross-referenced cases with the Minnesota Department of Health Sexually Transmitted Disease Database to ascertain patients' HIV status and recent chlamydia, gonorrhea, and syphilis infections. Of 691 Shigella isolates, 46 (7%) were DSA-Shigella; 91% of DSA-Shigella patients were men, of whom 60% were living with HIV. Among men, those with DSA-Shigella infection had greater odds of living with HIV, identifying as MSM, or having a recent diagnosis of a sexually transmitted disease. DSA-Shigella was associated with MSM, HIV infection, and recent sexually transmitted disease. To decrease spread of DSA-Shigella, interventions targeted at communities at high risk are needed.

During August 1, 2014-July 31, 2015, in 2 counties in Minnesota, USA, incidence of invasive methicillin-susceptible Staphylococcus aureus (MSSA) (27.1 cases/100,000 persons) was twice that of invasive methicillin-resistant S. aureus (13.1 cases/100,000 persons). MSSA isolates were more genetically diverse and susceptible to more antimicrobial drugs than methicillin-resistant S. aureus isolates.

Background During the pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), policy at a Minnesota hospital changed to state that environmental services would not clean rooms of patients with confirmed or suspected SARS-CoV-2 infections, requiring nursing staff to perform these duties. Investigation of a cluster of carbapenem-resistant Enterobacterales (CRE) in patients hospitalized in the same or adjoining rooms on the medical intensive care unit (MICU) raised concern over whether SARS-CoV-2 cleaning practices and non-conventional personal protective equipment (PPE) use led to transmission of multi-drug resistant organisms (MDROs). Methods Infection Prevention conducts passive surveillance for MDRO acquisition in inpatient units. Passive surveillance of SARS-CoV-2 was performed early in the pandemic. Active surveillance SARS-CoV-2 testing on admission was initiated in July 2020 and active surveillance testing for admitted patients every 7 days was initiated in December. Incident cases of vancomycin-resistant Enterococcus (VRE), extended-spectrum-β-lactamase-producing organisms (ESBL), methicillin-resistant S. aureus (MRSA), and CRE were determined for hospitalized patients between March 1, 2020 and February 28, 2021, excluding patients with infection on admission. Rates of hospitalized patients testing positive for SARS-CoV-2 per 100 patient days were compared to rates of patients testing positive for VRE, ESBL, MRSA, and CRE per 100 patient days respectively. The same rate comparisons were completed for the MICU. Using the F-Test Two-Sample to determine variance, the Two-Sample T-test assuming unequal variances was applied to each comparison. Results Correlation was significant between rates of SARS-CoV-2 and VRE (p< 0.005), ESBL (p< 0.005), MRSA (p< 0.005), and CRE (p< 0.005) (Table 1). MICU correlation was significant between rates of SARS-CoV-2 and VRE (p< 0.005), ESBL (p< 0.005), MRSA (p< 0.005), and CRE (p< 0.005) (Table 2). Table 1: Two-sample T-test results assuming unequal variances: Hospital COVID rates per 100 patient days vs. rates of incident positive tests for VRE, ESBL, MRSA, and CRE per 100 patient days Table 2: Two-sample T-test results assuming unequal variances: MICU COVID rates per 100 patient days vs. rates of incident positive tests for VRE, ESBL, MRSA, and CRE per 100 patient days Conclusion The relationships between the rates of SARS-CoV-2 and four MDROs were statistically significant. It can be inferred from this data that changes in hospital cleaning and non-conventional PPE use may have led to an increase in transmission of MDROs in this facility. Disclosures All Authors: No reported disclosures

Carbapenemase-producing, carbapenem-resistant Enterobacteriaceae , or CP-CRE, are an emerging threat to human and animal health, because they are resistant to many of the last-line antimicrobials available for disease treatment. Carbapenemase-producing Enterobacter cloacae harboring bla KPC-3 recently was reported in the upper midwestern United States and implicated in a hospital outbreak in Fargo, North Dakota (L. M. Kiedrowski, D. M. Guerrero, F. Perez, R. A. Viau, L. J. Rojas, M. F. Mojica, S. D. Rudin, A. M. Hujer, S. H. Marshall, and R. A. Bonomo, Emerg Infect Dis 20:1583–1585, 2014, http://dx.doi.org/10.3201/eid2009.140344 ). In early 2009, the Minnesota Department of Health began collecting and screening CP-CRE from patients throughout Minnesota. Here, we analyzed a retrospective group of CP- E. cloacae isolates ( n = 34) collected between 2009 and 2013. Whole-genome sequencing and analysis revealed that 32 of the strains were clonal, belonging to the ST171 clonal complex and differing collectively by 211 single-nucleotide polymorphisms, and it revealed a dynamic clone under positive selection. The phylogeography of these strains suggests that this clone existed in eastern North Dakota and western Minnesota prior to 2009 and subsequently was identified in the Minneapolis and St. Paul metropolitan area. All strains harbored identical IncFIA-like plasmids conferring a CP-CRE phenotype and an additional IncX3 plasmid. In a single patient with multiple isolates submitted over several months, we found evidence that these plasmids had transferred from the E. cloacae clone to an Escherichia coli ST131 bacterium, rendering it as a CP-CRE. The spread of this clone throughout the upper midwestern United States is unprecedented for E. cloacae and highlights the importance of continued surveillance to identify such threats to human health.

Widespread infections with community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) have occurred in the United States with the dissemination of the USA300 strain beginning in 2000. We examined 105 isolates obtained from children treated at the University of Chicago from 1994 to 1997 (75 methicillin-susceptible S. aureus [MSSA] and 30 MRSA isolates) in order to investigate for possible evidence of USA300 during this period. Infections were defined epidemiologically based on medical record review. The isolates underwent multilocus sequence typing (MLST), as well as assays for the Panton-Valentine leukocidin (PVL) genes, the protein A gene ( spa ), and arcA and opp3 , proxy markers for the arginine catabolic mobile element (ACME), characteristic of USA300 MRSA. MRSA isolates also underwent staphylococcal cassette chromosome mec (SCC mec ) typing and pulsed-field gel electrophoresis (PFGE) subtyping. MSSA isolates belonged to 17 sequence type (ST) groups. The 12 epidemiologically defined CA-MRSA infection isolates were either ST1 ( n = 4) or ST8 ( n = 8). They belonged to 3 different PFGE types: USA100 ( n = 1), USA400 ( n = 5), and USA500 ( n = 6). Among the CA-MRSA infection isolates, 8 (67%) were PVL + . None of the MRSA or MSSA isolates contained arcA or opp3 . Only one MRSA isolate was USA300 by PFGE. This was a health care-associated (HA) MRSA isolate, negative for PVL, that carried SCC mec type II. USA300 with its characteristic features was not identified in the collection from the years 1994 to 1997.

Background Pseudomonas aeruginosa is intrinsically resistant to many commonly used antimicrobials and carbapenems are often required to treat infections. We describe the epidemiology and crude incidence of carbapenem-resistant P. aeruginosa(CRPA) in the EIP catchment area. Methods From August 1, 2016 through July 31, 2017, we conducted laboratory- and population-based surveillance for CRPA in selected metropolitan areas in Colorado, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee. We defined an incident case as the first isolate of P. aeruginosa-resistant to imipenem, meropenem, or doripenem from the lower respiratory tract, urine, wounds, or normally sterile sites identified from a resident of the EIP catchment area in a 30-day period. Patient charts were reviewed. A random sample of isolates was screened at CDC for carbapenemases using the modified carbapenem inactivation method (mCIM) and real-time PCR. Results During the 12-month period, we identified 3,042 incident cases among 2,154 patients. The crude incidence rate was 21.2 (95% CI, 20.4–21.9) per 100,000 persons and varied by site (range: 7.7 in Oregon to 31.1 in Maryland). The median age of patients was 64 years (range: Conclusion The burden of CRPA varied by EIP site. Most cases occurred in persons with healthcare exposures and underlying conditions. The majority of isolates were susceptible to at least one first-line antimicrobial. Carbapenemase producers were rare; a more specific phenotypic definition would greatly facilitate surveillance for these isolates. Disclosures All authors: No reported disclosures.

Background Pseudomonas aeruginosa is intrinsically resistant to many commonly used antimicrobials, and carbapenems are often required to treat infections. We describe the crude incidence, epidemiology, and molecular characteristics of carbapenem-resistant P. aeruginosa (CRPA) in the EIP catchment area. Methods From August 1, 2016 through July 31, 2018, we conducted laboratory- and population-based surveillance for CRPA in selected areas in eight sites. We defined a case as the first isolate of P. aeruginosa resistant to imipenem, meropenem, or doripenem from the lower respiratory tract, urine, wounds, or normally sterile sites identified from a resident of the EIP catchment area in a 30-day period. Patient charts were reviewed. Analysis excluded cystic fibrosis patients. A random sample of isolates was collected. Real-time PCR to detect carbapenemase genes and whole-genome sequencing are in progress. Results We identified 4,209 cases in 3373 patients. The annual incidence was 14.50 (95% CI, 14.07–14.94) per 100,000 persons and varied among sites from 4.89 in OR to 25.21 in NY. The median age of patients was 66 years (range: < 1–101), 42.1% were female, and nearly all (97.5%) had an underlying condition. Most cases were identified from urine (42.8%) and lower respiratory tract (35.7%) cultures. Nearly all (93.3%) occurred in patients with inpatient healthcare facility stay, surgery, chronic dialysis, or indwelling devices in the prior year; death occurred in 7.2%. Among 937 isolates tested, 847 (90.4%) underwent PCR; six (0.7%) harbored a carbapenemase, from four sites (CO, MD, NY, and OR): blaVIM (3), blaKPC (2), and blaIMP (1). Of 612 (65.3%) isolates sequenced, the most common ST types were ST235 (9.2%) and ST298 (4.9%). Conclusion Carbapenemases were rarely the cause of carbapenem resistance but were found at EIP sites with high and low CRPA incidence. The emergence of mobile carbapenemases in P. aeruginosa has the potential to increase the incidence of CRPA. Increased detection and early response to carbapenemase-producing CRPA is key to prevent further emergence. Disclosures All authors: No reported disclosures.

BACKGROUND Catheter-associated urinary tract infections (CAUTIs) are the most common healthcare-associated infection (HAI) in the United States. The Centers for Disease Control and Prevention (CDC) recommends monitoring, and documentation of auditing catheter care practices. To reduce CAUTI rates in the Neurovascular/Cardiovascular/Intensive Care Unit (ICU), a Minnesota hospital conducted audits of CAUTI bundle compliance between March 1st and October 30th, 2018 and measured the correlation between bundle compliance and incidence of CAUTI. METHODS Three audits on patients with indwelling catheters were conducted weekly in the ICU using the Joint Commission's CAUTI tracer tool. Staff on the unit floor were given verbal feedback in real time. Compliance was reported to hospital leadership weekly. ?Incidence of CAUTI was tracked monthly and reported to the National Healthcare Safety Network (NHSN) and hospital leadership. Using SAS version 9.4 a Poisson regression analysis was ?conducted to determine correlation between individual elements of the tracer and ICU infection rates. Adherence to the entire bundle was also examined. RESULTS No statistically significant correlation was found between compliance with elements of the tracer and CAUTI rates. Correlation between adherence to the full bundle and CAUTI rates was found to be approaching significance (p=0.06). The most common noncompliant elements of the tracer were missing indications for catheter placement in the order, dependent loops, and missing tamper evidence seals. CAUTI rates in the ICU increased during this time period while audit compliance remained constant. CONCLUSIONS Auditing CAUTI bundle compliance did not reduce CAUTI rates in this ICU. We were able to determine areas to focus on when educating staff on best practices to prevent CAUTI. Adhering to a CAUTI bundle is best practice, but auditing bundle compliance does not have an appreciable effect on CAUTI rates. Facilities should focus more on initial education around best practices to prevent CAUTI than on maintenance auditing.

During 2012, global detection of a new norovirus (NoV) strain, GII.4 Sydney, raised concerns about its potential effect in the United States. We analyzed data from NoV outbreaks in 5 states and emergency department visits for gastrointestinal illness in 1 state during the 2012–13 season and compared the data with those of previous seasons. During August 2012–April 2013, a total of 637 NoV outbreaks were reported compared with 536 and 432 in 2011–2012 and 2010–2011 during the same period. The proportion of outbreaks attributed to GII.4 Sydney increased from 8% in September 2012 to 82% in March 2013. The increase in emergency department visits for gastrointestinal illness during the 2012–13 season was similar to that of previous seasons. GII.4 Sydney has become the predominant US NoV outbreak strain during the 2012–13 season, but its emergence did not cause outbreak activity to substantially increase from that of previous seasons.

The surface capsular polysaccharide (CP) is a virulence factor that has been used as an antigen in several successful vaccines against bacterial pathogens. A vaccine has not yet been licensed against Staphylococcus aureus, although two multicomponent vaccines that contain CP antigens are in clinical trials. In this study, we evaluated CP production in USA300 methicillin-resistant S. aureus (MRSA) isolates that have become the predominant community-associated MRSA clones in the United States. We found that all 167 USA300 MRSA and 50 USA300 methicillin-susceptible S. aureus (MSSA) isolates were CP negative (CP−). Moreover, all 16 USA500 isolates, which have been postulated to be the progenitor lineage of USA300, were also CP−. Whole-genome sequence analysis of 146 CP− USA300 MRSA isolates revealed they all carry a cap5 locus with 4 conserved mutations compared with strain Newman. Genetic complementation experiments revealed that three of these mutations (in the cap5 promoter, cap5D nucleotide 994, and cap5E nucleotide 223) ablated CP production in USA300 and that Cap5E75 Asp, located in the coenzyme-binding domain, is essential for capsule production. All but three USA300 MSSA isolates had the same four cap5 mutations found in USA300 MRSA isolates. Most isolates with a USA500 pulsotype carried three of these four USA300-specific mutations, suggesting the fourth mutation occurred in the USA300 lineage. Phylogenetic analysis of the cap loci of our USA300 isolates as well as publicly available genomes from 41 other sequence types revealed that the USA300-specific cap5 mutations arose sequentially in S. aureus in a common ancestor of USA300 and USA500 isolates., IMPORTANCE The USA300 MRSA clone emerged as a community-associated pathogen in the United States nearly 20 years ago. Since then, it has rapidly disseminated and now causes health care-associated infections. This study shows that the CP-negative (CP−) phenotype has persisted among USA300 isolates and is a universal and characteristic trait of this highly successful MRSA lineage. It is important to note that a vaccine consisting solely of CP antigens would not likely demonstrate high efficacy in the U.S. population, where about half of MRSA isolates comprise USA300. Moreover, conversion of a USA300 strain to a CP-positive (CP+) phenotype is unlikely in vivo or in vitro since it would require the reversion of 3 mutations. We have also established that USA300 MSSA isolates and USA500 isolates are CP− and provide new insight into the evolution of the USA300 and USA500 lineages.