Prevalence and Characteristics of Ertapenem-Resistant Klebsiella pneumoniae Isolates in a Taiwanese University Hospital

• Published in: Microbial drug resistance (Larchmont, N.Y.) Vol. 17; no. 2; pp. 259 - 266
• Main Authors: Wu, Jiunn-Jong, Wang, Li-Rong, Liu, Yi-Fang, Chen, Hung-Mo, Yan, Jing-Jou
• Format: Journal Article
• Language: English
• Published: United States Mary Ann Liebert, Inc 01.06.2011
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotics; Bacteria; Bacterial Typing Techniques; Beta lactamases; beta-Lactam Resistance - drug effects; beta-Lactam Resistance - genetics; beta-Lactamases - genetics; beta-Lactamases - metabolism; Disk Diffusion Antimicrobial Tests; DNA, Bacterial - genetics; Drug resistance; Drug resistance in microorganisms; Electrophoresis, Gel, Pulsed-Field; Epidemiology; Genetic aspects; Genotype; Health aspects; Hospitals; Hospitals, University; Humans; Identification and classification; Klebsiella; Klebsiella Infections - blood; Klebsiella Infections - drug therapy; Klebsiella Infections - epidemiology; Klebsiella Infections - microbiology; Klebsiella Infections - transmission; Klebsiella pneumoniae; Klebsiella pneumoniae - classification; Klebsiella pneumoniae - drug effects; Klebsiella pneumoniae - genetics; Klebsiella pneumoniae - isolation & purification; Microbial Sensitivity Tests; Mutation; Plasmids - genetics; Plasmids - metabolism; Polymerase Chain Reaction; Prevalence; Prevalence studies (Epidemiology); Sensitivity and Specificity; Taiwan; Taiwan
• ISSN: 1076-6294; 1931-8448
• DOI: 10.1089/mdr.2010.0115

This study was conducted to investigate the prevalence and characteristics of ertapenem-resistant (ETP-R) Klebsiella pneumoniae isolates at a Taiwanese hospital. The disk-diffusion tests revealed that the rate of ertapenem resistance among all isolates collected in 2008 was 13.5%, and the resistance rate among bloodstream isolates increased from 0% to 13.6% between 2001 and 2008. Eighty-two nonduplicate ETP-R isolates collected in 2008 were examined. Seventy-four (90.2%) isolates of them had extended-spectrum β-lactamases (CTX-M- and SHV-type), AmpC enzymes (DHA-1 and CMY-2), and IMP-8 metallo-β-lactamase alone or in combination, and an extremely high prevalence of fluoroquinolone resistance (95.1%) and plasmid-mediated quinolone resistance determinants (90.2%) were also observed. Eighteen ETP-R but imipenem-susceptible isolates were selected and compared with 18 imipenem-nonsusceptible isolates collected before 2008. Sequence analyses revealed genetic disruptions of OmpK36 in 11 imipenem-nonsusceptible and 6 imipenem-susceptible isolates, respectively, and OmpK35 disruptions in 10 isolates for both groups. For the isolates with intact ompK36 , sodium dodecyl sulfate–polyacrylamide gel electrophoresis suggests decreased expression of OmpK36 in 5 of 7 imipenem-nonsusceptible isolates and 3 of 12 imipenem-susceptible isolates. In conclusion, the increasing prevalence of ertapenem resistance that was predominantly attributed to noncarbapenemase-mediated resistance mechanisms in K. pneumoniae is becoming a serious treat to patients in Taiwan.