Emergence of IncX3 Plasmid-Harboring in a Isolated from Outdoor Aerosol in Wastewater Treatment Plant.

A carbapenem-resistant strain AA2CS carrying was detected in outdoor aerosols of a wastewater treatment plant (WWTP) in China and the whole genome was sequenced subsequently. AA2CS was captured in an aerobic tank with aerosol particles of sizes ranging from 4.7 to 7.0 μm. Besides , AA2CS also harbored 21 other antibiotic resistance genes and displayed a high level of resistance to ampicillin, cefotaxime, ceftazidime, tetracycline, and meropenem. was located on the IncX3 plasmid (pCSNDM-5) with an IS-IS5-----IS structure. pCSNDM-5 was highly homologous to other -carrying IncX3 plasmids in China and can be transferred to the recipient J53. To our knowledge, this is the first report of carbapenem-resistant Enterobacteriaceae in outdoor aerosols in WWTPs.