Carbapenem-resistant Acinetobacter baumannii and Klebsiella pneumoniae across a hospital system: impact of post-acute care facilities on dissemination

• Published in: Journal of antimicrobial chemotherapy 2010-08, Vol.65 (8), p.1807-1818
• Main Authors: Perez, Federico, Endimiani, Andrea, Ray, Amy J., Decker, Brooke K., Wallace, Christopher J., Hujer, Kristine M., Ecker, David J., Adams, Mark D., Toltzis, Philip, Dul, Michael J., Windau, Anne, Bajaksouzian, Saralee, Jacobs, Michael R., Salata, Robert A., Bonomo, Robert A.
• Format: Article
• Language: English
• Subjects: Acinetobacter baumannii; Acinetobacter baumannii - drug effects; Acinetobacter baumannii - isolation & purification; Acinetobacter Infections - epidemiology; Acinetobacter Infections - microbiology; Acinetobacter Infections - transmission; Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents - pharmacology; Antibiotics; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacterial Typing Techniques; beta-Lactam Resistance; Biological and medical sciences; Carbapenems - pharmacology; Child; Cross Infection - microbiology; Cross Infection - transmission; DNA Fingerprinting; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; Drug resistance; Female; Genes, Bacterial; Genotype; Hospital systems; Hospitalization; Hospitals; Humans; Klebsiella Infections - epidemiology; Klebsiella Infections - microbiology; Klebsiella Infections - transmission; Klebsiella pneumoniae; Klebsiella pneumoniae - drug effects; Klebsiella pneumoniae - isolation & purification; KPC; LTACH; LTCF; Male; Medical sciences; Microbial Sensitivity Tests; Middle Aged; MLST; Molecular Epidemiology; Molecular Sequence Data; Ohio - epidemiology; Original Research; PFGE; Pharmacology. Drug treatments; rep-PCR; Sequence Analysis, DNA; Young Adult
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkq191

Background Resistance to carbapenems among Acinetobacter baumannii and Klebsiella pneumoniae presents a serious therapeutic and infection control challenge. We describe the epidemiology and genetic basis of carbapenem resistance in A. baumannii and K. pneumoniae in a six-hospital healthcare system in Northeast Ohio. Methods Clinical isolates of A. baumannii and K. pneumoniae distributed across the healthcare system were collected from April 2007 to April 2008. Antimicrobial susceptibility testing was performed followed by molecular analysis of carbapenemase genes. Genetic relatedness of isolates was established with repetitive sequence-based PCR (rep-PCR), multilocus PCR followed by electrospray ionization mass spectrometry (PCR/ESI-MS) and PFGE. Clinical characteristics and outcomes of patients were reviewed. Results Among 39 isolates of A. baumannii, two predominant genotypes related to European clone II were found. Eighteen isolates contained blaOXA-23, and four isolates possessed blaOXA-24/40. Among 29 K. pneumoniae isolates with decreased susceptibility to carbapenems, two distinct genotypes containing blaKPC-2 or blaKPC-3 were found. Patients with carbapenem-resistant A. baumannii and K. pneumoniae were elderly, possessed multiple co-morbidities, were frequently admitted from and discharged to post-acute care facilities, and experienced prolonged hospital stays (up to 25 days) with a high mortality rate (up to 35%). Conclusion In this outbreak of carbapenem-resistant A. baumannii and K. pneumoniae across a healthcare system, we illustrate the important role post-acute care facilities play in the dissemination of multidrug-resistant phenotypes.