Genetic environment of the KPC gene in Acinetobacter baumannii ST2 clone from Puerto Rico and genomic insights into its drug resistance.

The objective of this study was to determine the whole genomic sequence of a KPC-producing A. baumannii in order to: (i) define its allelic diversity, (ii) identify the location and genetic environment of the blaKPC, and (iii) detect additional mechanisms of antimicrobial resistance. Next-generation sequencing, Southern blot, pulsed-field gel electrophoresis, multilocus sequence typing and bioinformatics analysis were performed. The organism was assigned to the international ST2 clone. The blaKPC-2 was identified on a novel truncated version of Tn4401e (tentatively named Tn4401h), located in the chromosome within an IncA/C plasmid fragment derived from an Enterobacteriaceae, probably due to insertion sequence, IS26. A chromosomally located truncated Tn1 transposon harboring a blaTEM-1 was found in a novel genetic environment within an antimicrobial resistance cluster. Additional resistance mechanisms included efflux pumps, non-ß-lactam antibiotic inactivating enzymes within and outside a resistance island, two class 1 integrons, In439 and the novel In1252, as well as mutations in the topoisomerase and DNA gyrase genes which confer resistance to quinolones. The presence of the blaKPC in an already globally disseminated A. baumannii ST2 presents a serious threat of further dissemination. PMID: 27259867 [PubMed - as supplied by publisher]
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research