Resistome and a Novel <i>bla</i> _NDM-1 -Harboring Plasmid of an <i>Acinetobacter haemolyticus</i> Strain from a Children's Hospital in Puebla, Mexico

Abstract

<i>Acinetobacter calcoaceticus-baumannii</i> complex isolates have been frequently associated with hospital and community infections, with <i>A. baumannii</i> being the most common. Other <i>Acinetobacter</i> spp. not belonging to this complex also cause infections in hospital settings, and the incidence has increased over the past few years. Some species of the <i>Acinetobacter</i> genus possess a great diversity of antibiotic resistance mechanisms, such as efflux pumps, porins, and resistance genes that can be acquired and disseminated by mobilizable genetic elements. By means of whole-genome sequencing, we describe in the clinical <i>Acinetobacter haemolyticus</i> strain AN54 different mechanisms of resistance that involve <i>bla</i>_OXA-265, <i>bla</i>_NDM-1, <i>aphA6</i>, <i>aac(6')-Ig</i>, and a resistance-nodulation-cell division-type efflux pump. This strain carries six plasmids, of which the plasmid pAhaeAN54e contains <i>bla</i>_NDM-1 in a Tn125-like transposon that is truncated at the 3' end. This strain also has an insertion sequence IS<i>91</i> and seven genes encoding hypothetical proteins. The pAhaeAN54e plasmid is nontypable and different from other plasmids carrying <i>bla</i>_NDM-1 that have been reported in Mexico and other countries. The presence of these kinds of plasmids in an opportunistic pathogen such as <i>A. haemolyticus</i> highlights the role that these plasmids play in the dissemination of antibiotic resistance genes, especially against carbapenems, in Mexican hospitals.