Genomic analysis of the multi-drug resistant Acinetobacter

24 We previously reported that the multi-drug resistant (MDR) Acinetobacter baumannii 25 strain MDR-ZJ06 belonging to European Clone II was widely spread in China. In this 26 study, we report the whole genome sequence of this clinically important strain. A 38.6 27 kb AbaR-type genomic resistance island (AbaR11) was identified in MDR-ZJ06. 28 AbaR11 has a similar structure to the resistance islands found in A. baumannii strains 29 AYE and AB0057, but it only contained few antibiotic resistant genes. The region of 30 resistant genes accumulation as previously described was not found in AbaR11. In the 31 chromosome of the strain MDR-ZJ06, we identified the gene blaoxa-23 in a composite 32 transposon (Tn2009). Tn2009 shared the backbone with other A. baumannii 33 transponsons that harbor blaoxa-23, but it was bracketed by two ISAba1 elements which 34 were transcribed in the same orientation. MDR-ZJ06 also expressed the armA gene on 35 its plasmid pZJ06, and this gene has the same genetic environment as the armA gene 36 of Enterobacteriaceae. These results suggest the variability of resistance acquisition 37 even in closely related A. baumannii strains. 38