Outcomes and Genetic Relatedness of Carbapenem-Resistant Enterobacteriaceae at Detroit Medical Center

• Published in: Infection control and hospital epidemiology 2011-09, Vol.32 (9), p.861-871
• Main Authors: Marchaim, Dror, Chopra, Teena, Perez, Federico, Hayakawa, Kayoko, Lephart, Paul R., Bheemreddy, Suchitha, Blunden, Christopher, Hujer, Andrea M., Rudin, Susan, Shango, Maryann, Campbell, Michelle, Varkey, Jastin, Slim, Jessica, Ahmad, Farah, Patel, Diixa, Chen, Ting-Yi, Pogue, Jason M., Salimnia, Hossein, Dhar, Sorabh, Bonomo, Robert A., Kaye, Keith S.
• Format: Article
• Language: English
• Subjects: Academic Medical Centers; Acinetobacter baumannii; Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotics; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimicrobials; beta-Lactam Resistance; Biological and medical sciences; Carbapenems; Carbapenems - pharmacology; Child; Child, Preschool; Colistin - pharmacology; Disease Reservoirs - microbiology; Drug Resistance, Multiple, Bacterial; Enterobacter; Enterobacteriaceae; Enterobacteriaceae - drug effects; Enterobacteriaceae - enzymology; Enterobacteriaceae - genetics; Enterobacteriaceae Infections - drug therapy; Enterobacteriaceae Infections - epidemiology; Escherichia coli; Female; Genotype; Health outcomes; Hospital admissions; Hospital Mortality; Hospitalization; Humans; Infant; Infections; Intensive care units; Klebsiella oxytoca; Klebsiella pneumoniae; Length of Stay; Male; Medical sciences; Michigan - epidemiology; Middle Aged; Minocycline - analogs & derivatives; Minocycline - pharmacology; Miscellaneous; Mortality; Nursing; Nursing Homes; Original Article; Pharmacology. Drug treatments; Pseudomonas aeruginosa; Public health. Hygiene; Public health. Hygiene-occupational medicine; Retrospective Studies; Treatment Outcome; Young Adult
• ISSN: 0899-823X; 1559-6834
• DOI: 10.1086/661597

Background. Carbapenem-resistant Enterobacteriaceae (CRE) are rapidly emerging in hospitals in the United States and are posing a significant threat. To better understand the transmission dynamics and the acquisition of resistant strains, a thorough analysis of epidemiologic and molecular characteristics was performed. Methods. CRE isolated at Detroit Medical Center were analyzed from September 2008 to September 2009. bla KPC genes were investigated by polymerase chain reaction (PCR), and repetitive extragenic palindromic PCR (rep-PCR) was used to determine genetic similarity among strains. Epidemiologic and outcomes analyses were performed. Results. Ninety-two unique patient CRE isolates were recovered. Sixty-eight strains (74%) were Klebsiella pneumoniae, 7 were Klebsiella oxytoca, 15 were Enterobacter species, and 2 were Escherichia coli. Fifteen isolates (16%) were resistant to colistin, 14 (16%) were resistant to tigecycline, and 2 were resistant to all antimicrobials tested. The mean ± standard deviation age of patients was years. Sixty patients (68%) were admitted to the hospital from long-term care facilities. Only 70% of patients received effective antimicrobial therapy when infection was suspected, with a mean time to appropriate therapy of hours following sample culturing. The mean length of hospitalization after sample culturing was days. Of 57 inpatients, 18 (32%) died in the hospital. Independent predictors for mortality were intensive care unit stay (odds ratio [OR], 15.8; ) and co-colonization with CRE and either Acinetobacter baumannii or Pseudomonas aeruginosa (OR, 17.2; ). Among K. pneumoniae CRE, rep-PCR revealed 2 genetically related strains that comprised 70% and 20% of isolates, respectively. Conclusions. In this large U.S. cohort of patients with CRE infection, which reflects the modern continuum of medical care, co-colonization with CRE and A. baumannii or P. aeruginosa was associated with increased mortality. Two predominant clones of K. pneumoniae accounted for the majority of cases of CRE infection.