Profile and actual transmissibility of Carbapenem resistance genes: Intracellular and extracellular DNA in hospital wastewater. (1st March 2023)

• Record Type: Journal Article
• Authors: Zhang, Shengcen; Xu, Binbin; Chen, Mo; Zhang, Qianwen; Huang, Jiangqing; Cao, Yingping; Li, Bin
• Is Part Of: Journal of environmental management. Volume 329(2023)
• Publication Date: 2023-03-01
• Subjects: Hospital wastewater -- Carbapenem resistance genes -- Metagenomics -- Extracellular DNA -- Plasmids; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.117085
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: The current worldwide spread of carbapenem resistance genes (CRGs) has posed a major public health threat, which continues to grow in severity. Hospital wastewaters (HWWs) are major reservoirs for antibiotic resistance genes, while resistomes in HWWs are still poorly characterized when it comes to CRGs. We comprehensively characterized the profile and actual transmissibility of extracellular CRGs (eCRGs) and intracellular CRGs (iCRGs) in HWWs for the first time. In this study, CRGs showed similar relative abundance in treated and untreated HWWs. Meanwhile, HWWs treatments led to the enrichment of bla IMP-8, probably attributed to the promotion of Novosphingobium and Prosthecobacter after treatment. To evaluate the transmission potential of CRGs, extracellular and intracellular carbapenem-resistant plasmids were captured from HWWs by transformation and conjugation, respectively. We found an interesting phenomenon regarding the transmission characteristics of CRGs: bla KPC -carrying plasmids could only be captured by transformation, while bla NDM -carrying plasmids were captured by conjugation. Further experiments showed that HWW treatments increased the conjugation ability of bla NDM . In conclusion, our study demonstrated that HWWs are significant reservoirs of CRGs and various CRGs exhibit different modes of transmission in HWWs. CRGs cannot be removed by membrane bioreactor and chlorine disinfection. An urgent need is to develop more efficient wastewater treatments to limit CRG dissemination. Graphical abstract: Image 1 Highlights: Extracellular CRGs from HWWs are characterized metagenomically for the first time. CRGs can not be removed by membrane bioreactor and chlorination. Bla KPC and bla NDM exhibit different modes of transmission in HWWs. HWWs treatments promote the spread of bla NDM mediated by plasmids. The transmission of CRGs in HWW was mainly mediated by plasmids.