Behavior of last resort antibiotic resistance genes (mcr-1 and blaNDM-1) in a drinking water supply system and their possible acquisition by the mouse gut flora. (April 2020)

• Record Type: Journal Article
• Authors: Khan, Hira; Miao, Xiaocao; Liu, Mingkun; Ahmad, Shakeel; Bai, Xiaohui
• Is Part Of: Environmental pollution. Volume 259(2020)
• Publication Date: 2020-04
• Subjects: mcr-1 -- blaNDM-1 -- Antibiotic resistance gene -- Drinking water -- Mouse gut -- Horizontal gene transfer; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.113818
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Mcr-1 and bla NDM-1 antibiotic resistance genes (ARGs) confer resistance to colistins and carbapenems, which are often antibiotics used as a last resort in tertiary care hospitals. Dissemination of these two ARGs in drinking water supply systems and their effect on healthy gut bacteria are poorly studied. In this study, the dissemination of mcr-1 and bla NDM-1 in a drinking water supply system, and their effect on the antibiotic resistance of mouse gut bacteria are explored. Metagenome analysis revealed that source water (Taipu river and Jinze reservoir) was polluted with ARGs. Mcr-1 and bla NDM-1 can be disseminated through the water distribution system. Even advanced water treatments (ozone and biological activated carbon (BAC)) could not effectively remove mcr-1 and bla NDM-1 . Low concentrations of chloramine disinfectants in the water distribution system were not effective at limiting ARG abundance. Mobile genetic elements were also found to play a major role in the dissemination of ARGs via horizontal gene transfer (HGT) throughout the water supply system. Statistical analysis revealed that there was no effect of temperature on the abundance of mcr-1 and bla NDM-1 throughout the water supply system. A last resort ARG, mcr-1 can disseminate from drinking water to the healthy mouse gut. The presence of mcr-1 in a strain belonging to Enterococcus hirae, which is different from the strain belonging to the Bacillus cereus group isolated from drinking water, strongly supports the phenomena of HGT inside the gut. This research provides novel insights into the role of drinking water in disseminating ARGs to the gut and strongly suggests that drinking water may also play a major role apart from other factors known to be involved in the prevalence of last resort ARGs in the gut. Graphical abstract: Image 1 Highlights: mcr-1 and bla NDM-1 were found to disseminate from source to tap in water supply system. Advanced water treatment process could not effectively remove mcr-1 and bla NDM-1 . Chloramine disinfection had no effect on elimination of mcr-1 and bla NDM-1 . Last resort ARG mcr-1 could disseminate from drinking water to the gut via HGT. Drinking water is one of the reasons of last resort ARGs transfer in a healthy gut. Abstract : mcr-1 and bla NDM-1 can disseminate through drinking water supply systems and mcr-1 was found to disseminate from drinking water to the mouse gut.