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

Abstract

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. blaKPC 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 63 ± 2 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 120 ± 23 hours following sample culturing. The mean length of hospitalization after sample culturing was 18.6 ± 2.5 days. Of 57 inpatients, 18 (32%) died in the hospital. Independent predictors for mortality were intensive care unit stay (odds ratio [OR], 15.8; P =.003) and co-colonization with CRE and either Acinetobacter baumannii or Pseudomonas aeruginosa (OR, 17.2; P =.006). 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.

Treatment Outcome of Bacteremia Due to KPC-Producing Klebsiella pneumoniae: Superiority of Combination Antimicrobial Regimens

“…KPC-producing K. pneumoniae has become a major hospital pathogen worldwide, and infections due to this organism have been associated with high mortality (2,11,15,18). The increasing prevalence and the high mortality associated with the organism underscore the importance of effective antimicrobial therapy for these serious infections.…”

“…KPC-producing K. pneumoniae is typically resistant to carbapenems as well as cephalosporins and other classes of antimicrobials, leaving few choices for treatment of infections. Mortality from infections due to KPCproducing K. pneumoniae has been reported to be at least 50% (2,11,15,18). Whereas some KPC-producing K. pneumoniae are reported as susceptible to carbapenems, especially imipenem, the clinical significance of this phenomenon is not well defined.…”

Major Variation in MICs of Tigecycline in Gram-Negative Bacilli as a Function of Testing Method

“…These infections are associated with devastating outcomes, and they place a huge burden on and threaten the general population (1,2,(5)(6)(7)(8). Tigecycline is one of the few available agents that possess antimicrobial activity against these resistant pathogens (9)(10)(11)(12)(13)(14).…”

Retrospective analysis of fosfomycin combinational therapy for sepsis caused by carbapenem-resistant Klebsiella pneumoniae

“…The increasing prevalence and the high mortality associated with the organism underscore the importance of effective antimicrobial therapy for these serious infections. However, optimal treatment for infections caused by CRKP has not yet been defined (14). The present retrospective study involved 104 unique patients with bacteremia due to CRKP with overall mortality rate of 25%, which is substantially lower than the rates reported for CRKP in previous studies (11,15,16).…”