Genomic Analysis of the Multidrug-Resistant Acinetobacter baumannii Strain MDR-ZJ06 Widely Spread in China

ABSTRACT We previously reported that the multidrug-resistant (MDR) Acinetobacter baumannii strain MDR-ZJ06, belonging to European clone II, was widely spread in China. In this study, we report the whole-genome sequence of this clinically important strain. A 38.6-kb AbaR-type genomic resistance island (AbaR22) was identified in MDR-ZJ06. AbaR22 has a structure similar to those of the resistance islands found in A. baumannii strains AYE and AB0057, but it contained only a few antibiotic resistance genes. The region of resistant gene accumulation as previously described was not found in AbaR22. In the chromosome of the strain MDR-ZJ06, we identified the gene bla oxa-23 in a composite transposon (Tn 2009 ). Tn 2009 shared the backbone with other A. baumannii transponsons that harbor bla oxa-23 , but it was bracketed by two IS Aba1 elements which were transcribed in the same orientation. MDR-ZJ06 also expressed the armA gene on its plasmid pZJ06, and this gene has the same genetic environment as the armA gene of the Enterobacteriaceae . These results suggest variability of resistance acquisition even in closely related A. baumannii strains.