1369. Antibiotic Resistance in Maryland: The Statewide Antibiogram Initiative
Session: Poster Abstract Session: HAI: Epidemiologic Methods
Friday, October 28, 2016
Room: Poster Hall
Background: Antimicrobial resistance is among the greatest current threats to human health. Both the White House and the Centers for Disease Control and Prevention have recently emphasized the need for awareness of resistance trends at the local and regional levels.

Methods: In 2014 the Maryland Department of Health and Mental Hygiene requested that all acute care microbiology laboratories submit an antibiogram for calendar year 2013. 41 of 44 laboratories submitted an antibiogram. Isolate data from all units/wards and all body sites were aggregated to calculate a percent susceptible for each combination of organism and antimicrobial. Isolates were also stratified by region and hospital size to identify trends. It is unknown how closely each laboratory adhered to current Clinical Laboratory Standards Institute guidelines for antibiograms.

Results: Statewide, Acinetobacter baumannii and Pseudomonas aeruginosa were the most resistant gram negative organisms. A. baumannii was only 33-57% susceptible to the third- and fourth-generation cephalosporins, 44-51% susceptible to quinolones, and 53-57% susceptible to carbapenems. P. aeruginosa was 74% susceptible to ciprofloxacin and levofloxacin, and 87-89% susceptible to carbapenems. The Enterobacteriaceae species also showed considerable resistance to penicillins, cephalosporins and quinolones. Among gram positive organisms, methicillin-resistant Staphylococcus aureus represented 50% of the total S. aureus isolates collected in Maryland hospitals in 2013. No significant vancomycin resistance was identified in this species however. Only 26% of Enterococcus faecium isolates statewide were susceptible to vancomycin. Streptococcus pneumoniae showed significant resistance to macrolides. Differences in resistance trends by region and hospital size were also detected.

Conclusion: Maryland faces significant threats from antibiotic resistance in some of the most commonly encountered pathogens in inpatient hospital populations. Differences in testing practices and adherence to current guidelines for antibiogram creation create challenges for interpretation of aggregate data, and suggest the need for specific requirements when antibiograms are submitted for regional analyses.

Elisabeth Vaeth, MPH1, Molly Reid, M.P.H2, Katherine Richards, MPH1, Lucy Wilson, MD, ScM1 and David Blythe, MD, MPH1, (1)Maryland Department of Health and Mental Hygiene, Baltimore, MD, (2)Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD


E. Vaeth, None

M. Reid, None

K. Richards, None

L. Wilson, None

D. Blythe, None

<< Previous Abstract | Next Abstract

Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.