Characterization of Isolates Associated with Emergence of OXA-48-Producing Klebsiella pneumoniae in Croatia

• Published in: Microbial drug resistance (Larchmont, N.Y.) Vol. 24; no. 7; pp. 973 - 979
• Main Authors: Jelić, Marko, Škrlin, Jasenka, Bejuk, Danijela, Košćak, Iva, Butić, Iva, Gužvinec, Marija, Tambić-Andrašević, Arjana
• Format: Journal Article
• Language: English
• Published: United States Mary Ann Liebert, Inc 01.09.2018
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotics; Antimicrobial agents; Bacterial Proteins - genetics; beta-Lactamases - genetics; Carbapenemase; Carbapenems; Carbapenems - pharmacology; Cloning; Croatia; Drug resistance; E coli; Electrophoresis; Emergence; Enterobacteriaceae; Epidemics; Epidemiology; Gel electrophoresis; Gene mapping; Gene sequencing; Genes; Humans; Hybridization; Identification; Infectious diseases; Klebsiella; Klebsiella Infections - drug therapy; Klebsiella Infections - microbiology; Klebsiella pneumoniae; Klebsiella pneumoniae - drug effects; Klebsiella pneumoniae - genetics; Klebsiella pneumoniae - isolation & purification; Localization; Microbial Sensitivity Tests - methods; Molecular modelling; Multidrug resistance; Multilocus sequence typing; Multilocus Sequence Typing - methods; Nosocomial infections; Plasmids - genetics; Polymerase chain reaction; Pulsed-field gel electrophoresis; Retrospective Studies; Surveillance; Croatia; Turkey; United Kingdom > UK; France; Europe; IncL/M; 2; Tn; OXA-48; Croatia; Tn1999.2; Klebsiella pneumoniae
• ISSN: 1076-6294; 1931-8448
• DOI: 10.1089/mdr.2017.0168

Here, we report a retrospective study conducted to elucidate emergence, epidemiology, and molecular mechanisms of resistance underlying the early spread of OXA-48 carbapenemase-producing Enterobacteriaceae in Croatia. Retrospective screening for OXA-48 producers was performed on a collection of 296 nonrepetitive, carbapenem-nonsusceptible enterobacterial isolates collected from January 2011 to December 2012 from 40 participating centers in Croatia. Antimicrobial susceptibility profiles and production of carbapenemases were assessed phenotypically. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing were used for epidemiological analysis. Resistance genes were characterized by polymerase chain reaction (PCR) and sequencing. Plasmid localization of bla OXA-48 in isolates and transconjugants was investigated by S1-PFGE and Southern hybridization. PCR mapping was used for identification of genetic platform surrounding bla OXA-48 . Out of 296 carbapenem-nonsusceptible isolates, bla OXA-48 gene was detected in 12 Klebsiella pneumoniae isolates. All OXA-48-producing isolates showed varying resistance to carbapenems and 11 were multidrug resistant. All coproduced additional beta-lactamases, including CTX-M-15, which was detected in eight isolates. Isolates were delineated in five clonal types by PFGE corresponding to five sequence types (STs) assigned ST15, ST16, ST37, ST528, and ST1418. All OXA-48 isolates conjugated successfully and other resistance determinants were not cotransferred. bla OXA-48 was carried on a ∼60 kb IncL/M plasmid and was detected within Tn 1999.2 composite transposon. OXA-48, a class D carbapenemase, is emerging as a potentially significant contributor among carbapenem-resistant Enterobacteriaceae in Croatia, alongside class A and B carbapenemases. Polyclonal genetic background of K. pneumoniae isolates carrying ∼60 kb incL/M plasmid indicates that dissemination of the bla OXA48 gene is not driven exclusively by the spread of a single clone.