Summary of the distribution and genetic context of the OXA-type enzymes in Acinetobacter baumannii. Summary of the distribution and genetic context of the OXA-type enzymes in Acinetobacter baumannii. The arrows and corresponding percentages represent the degrees of amino acid homology between the enzyme clusters. The enzyme clusters within large circles signify the acquired enzyme types, in contrast to the naturally occurring OXA-51 cluster within the large square. Anton Y. Peleg et al. Clin. Microbiol. Rev. 2008; doi:10.1128/CMR.00058-07