IRAZ, MeryemDuzgun, Azer OzadSANDALLI, CemalDoymaz, MEHMET ZİYAAkkoyunlu, YASEMİNSaral, AysegulPELEG, Anton Y.OZGUMUS, Osman BirolBERIS, Fatih SabanKARAOGLU, HakanCICEK, Aysegul Copur2019-10-052019-10-052015-11-01IRAZ M., Duzgun A. O. , SANDALLI C., Doymaz M. Z. , Akkoyunlu Y., Saral A., PELEG A. Y. , OZGUMUS O. B. , BERIS F. S. , KARAOGLU H., et al., -Distribution of beta-Lactamase Genes Among Carbapenem-Resistant Klebsiella pneumoniae Strains Isolated From Patients in Turkey-, ANNALS OF LABORATORY MEDICINE, cilt.35, ss.595-601, 2015https://hdl.handle.net/20.500.12645/1842Background: The emergence of carbapenem-resistant Klebsiella pneumoniae poses a serious problem to antibiotic management. We investigated the β-lactamases in a group of carbapenem-resistant K. pneumoniae clinical isolates from Turkey. Methods: Thirty-seven strains of K. pneumoniae isolated from various clinical specimens were analyzed by antimicrobial susceptibility testing, PCR for the detection of β-lactamase genes, DNA sequencing, and repetitive extragenic palindronic (REP)-PCR analysis. Results: All 37 isolates were resistant to ampicillin, ampicillin/sulbactam, piperacillin, piperacillin/tazobactam, ceftazidime, cefoperazone/sulbactam, cefepime, imipenem, and meropenem. The lowest resistance rates were observed for colistin (2.7%), tigecycline (11%), and amikacin (19%). According to PCR and sequencing results, 98% (36/37) of strains carried at least one carbapenemase gene, with 32 (86%) carrying OXA-48 and 7 (19%) carrying NDM-1. No other carbapenemase genes were identified. All strains carried a CTX-M-2-like β-lactamase, and some carried SHV- (97%), TEM- (9%), and CTX-M-1-like (62%) β-lactamases. Sequence analysis of bla(TEM) genes identified a bla(TEM-166) with an amino acid change at position 53 (Arg53Gly) from bla(TEM-1b), the first report of a mutation in this region. REP-PCR analysis revealed that there were seven different clonal groups, and temporo-spatial links were identified within these groups. Conclusions: Combinations of β-lactamases were found in all strains, with the most common being OXA-48, SHV, TEM, and CTX-M-type (76% of strains). We have reported, for the first time, a high prevalence of the NDM-1 (19%) carbapenemase in carbapenem-resistant K. pneumoniae from Turkey. These enzymes often co-exist with other β-lactamases, such as TEM, SHV, and CTX-M β-lactamases.eninfo:eu-repo/semantics/openAccessArticleWOS:0003616428000058494225182910.3343/alm.2015.35.6.59526354347