Abstract:Oxacillinase (OXA) belongs to class D β-lactamase, named for its high hydrolytic activity on oxacillin. OXA-type β-lactamases locate on chromosomes or plasmids, and their horizontal transfer among strains is mediated by mobile elements such as plasmids and transposons. Over a thousand variants have been derived to date. In recent years, carbapenem-hydrolyzing OXA have emerged and spread among strains, posing a huge challenge to clinical anti-infection treatment. In 2001, OXA-48 was found in a strain of Klebsiella pneumoniae in Turkey, which was the firstly reported carbapenem-hydrolyzing OXA in Enterobacterales. Subsequently, various variants of OXA-48 enzyme were identified and nominated as OXA-48-like enzymes. These enzymes not only have strong hydrolytic activity against penicillin, but also hydrolyze carbapenems such as ertapenem and meropenem, mediating resistance to various β-lactam antimicrobial agents, including carbapenems. Shewanella spp. is considered to be the origin of the blaOXA-48-like gene, and 12 OXA-48-like genes derived from Shewanella spp. have been reported. In order to comprehensively understand the characteristics and distribution of carbapenem-hydrolyzing OXA enzymes, this article reviews the origin, distribution status, epidemiological characteristics, and development trends of carbapenem-hydrolyzing OXA.