Work

334Emergence of OXA-23-possessing Acinetobacter baumannii in Hospitals in New York City

Year: 2014

Type: article

Abstract: Background. Acinetobacter baumannii is an established nosocomial pathogen in many medical centers worldwide. The spread of multidrug resistant strains of A. baumannii has been especially problematic. Methods. During a three month surveillance study conducted November 2013 – January 2014, all unique patient isolates of A. baumannii were gathered from 11 hospitals in New York City. Susceptibility testing was performed by CLSI methods; isolates with a meropenem MIC of ≤ 2 µg/ml were considered susceptible. All isolates were screened by PCR for the presence of carbapenemases. Select isolates underwent genetic fingerprinting using ERIC-2 primers. Findings were compared to a similar surveillance study conducted in 2009. Results. A total of 158 isolates of A. baumannii were gathered from the 11 hospitals. Overall susceptibility rates include: 72% to amikacin, 30% to ciprofloxacin, 94% to polymyxin B, 34 % to ceftazidime, and 31% to meropenem. 58 isolates possessed blaOXA23, two blaOXA24, and one blaKPC. Nine hospitals participated in a similar surveillance study conducted in 2009. For these 9 hospitals, there was a marked decline in the total number of isolates reported (from 252 in 2009 to 122 in 2013-2014; Table). However, there was a marked increase in the number of isolates carrying blaOXA-23 (from 8 to 48). For these 8 hospitals, the percentage of meropenem-resistant isolates that possessed blaOXA23 increased from 5% in 2009 to 58% in 2013-2014. Genetic fingerprinting of 15 OXA-23-carrying isolates from 8 hospitals revealed that 9 belonged to a single strain. Conclusion. Since 2009, there has been a reduction in the prevalence of carbapenem-resistant A. baumannii at hospitals in New York City. However, dissemination of strains carrying blaOXA23 has clearly increased in several medical centers. Disclosures. C. Urban, Pfizer: Speaker's Bureau, Speaker honorarium; Cubist: Speaker's Bureau, Speaker honorarium D. Landman, Tetraphase: Research Contractor, Research grant; Achaogen: Research Contractor, Research grant J. Quale, Tetraphase: Research Contractor, Research grant; Achaogen: Research Contractor, Research grant.

Source: Open Forum Infectious Diseases

DOI: 10.1093/ofid/ofu052.200