First Occurrence of OXA-72-Producing Acinetobacter baumannii in Serbia

Abstract

ABSTRACTHere, we characterized the first OXA-72-producingAcinetobacter baumanniiisolate (designated MAL) recovered from a urine sample from a Serbian patient. Antimicrobial susceptibility testing, plasmid analysis, and whole-genome sequencing (WGS) were performed to fully characterize the resistome of theA. baumanniiMAL clinical isolate. The isolate was multidrug resistant and remained susceptible only to colistin and tigecycline. PCR analysis revealed the presence of the carbapenemase OXA-72, an OXA-40 variant. Extraction by the Kieser method revealed the presence of two plasmids, and one of these, a ca. 10-kb plasmid, harbored theblaOXA-72gene. WGS revealed 206 contigs corresponding to a genome of 3.9 Mbp in size with a G+C content of 38.8%. The isolate belonged to sequence type 492 and to worldwide clone II (WWCII). Naturally occurring β-lactamase-encoding genes (blaADC-25andblaOXA-66) were also identified. Aminoglycoside resistance genes encoding one aminoglycoside adenyltransferase (aadA2), three aminoglycoside phosphatases (strA,strB,aphA6), and one 16S RNA methylase (armA) conferring resistance to all aminoglycosides were identified. Resistance to fluoroquinolones was likely due to mutations ingyrA,parC, andparE. Of note, the resistome matched perfectly with the antibiotic susceptibility testing results.