The pollution level of the blaOXA-58 carbapenemase gene in coastal water and its host bacteria characteristics

This paper investigated 10 carbapenemase genes and selected the hosts of these genes in the estuary of Bohai Bay. The results showed that the OXA-58 producer accounted for a large percentage of carbapenem resistant bacteria in the sampling points, whereas the VIM, KPC, NDM, IMP, GES, OXA-23, OXA-24, OXA-48 and OXA-51 producers were not detected in the study. In addition, 9 bacterial genera with 100% identical bla(OXA-58) sequences, including Pseudomonas, Rheinheimera, Stenotrophomonas, Shewanella, Raoultella, Vibrio, Pseudoalteromonas, Algoriphagus, Bowmanella and Thalassospira, were isolated from seawater. It is suggested that the host of bla(OXA-58) gene were varied and many kinds of them could survive in the seawater. Moreover, we preformed the quantitative RT-PCR and the result shown the abundance of bla(OXA-58) fluctuated between 2.8 x 10(-6) copies/16S and 2.46 x 10(-4) copies/16S, which was of the same order of magnitude as some common antibiotic resistance genes in environment. Furthermore, the variation trend of bla(OXA-58) gene suggested that pollution discharge and horizontal gene transfer could contribute to the increase of the gene in coastal area. (C) 2018 Elsevier Ltd. All rights reserved.