Association of the colistin resistance gene mcr‐1 with faecal pollution in water environments in Hanoi, Vietnam

• Published in: Letters in applied microbiology Vol. 72; no. 3; pp. 275 - 282
• Main Authors: Nguyen, N.T., Liu, M., Katayama, H., Takemura, T., Kasuga, I.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.03.2021
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotic resistance; Antibiotics; Antimicrobial resistance; Colistin; Colistin - pharmacology; colistin resistance; Domestic wastewater; Drug Resistance, Bacterial - genetics; Environmental health; Escherichia coli - drug effects; Escherichia coli - genetics; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; faecal pollution; Feces - microbiology; Groundwater; Hanoi; Humans; Integrase; Lakes; Lakes - microbiology; mcr‐1; Phages; Plasmids - genetics; Pollution; Rivers - microbiology; Urban areas; urban water environments; Vietnam; Waste Water - microbiology; Wastewater; Water pollution; Water sampling; Vietnam; colistin resistance; Vietnam; faecal pollution; Hanoi; mcr-1; urban water environments
• ISSN: 0266-8254; 1472-765X
• DOI: 10.1111/lam.13421

Colistin is one of the antibiotics of last resort for human health. However, the dissemination of the plasmid‐mediated colistin resistance gene mcr‐1 is of great concern globally. In the One Health framework, the environment is an important component for managing antimicrobial resistance. However, little information is available concerning the prevalence of mcr‐1 in water environments. We aimed to reveal the prevalence of mcr‐1 in different water environments in Hanoi, Vietnam. Quantitative PCR was applied to detect mcr‐1 in four urban drainages receiving untreated domestic wastewater, three rivers, five lakes and two groundwater samples. Urban drainages contained higher concentrations of mcr‐1, suggesting that urban residents carry the gene. The class 1 integron‐integrase gene was identified as a good surrogate of antibiotic resistance genes including mcr‐1. A significant correlation was found between the levels of mcr‐1 and the human‐specific cross‐assembly phage, which is an indicator of human faecal pollution. These results indicated that the primary source of mcr‐1 in urban water environments is human faeces, which is consistent with the fact that most domestic wastewater is untreated in Hanoi. The control of untreated wastewater is critical for alleviating the spread of mcr‐1 in water environments in Vietnam. Significance and Impact of the Study: Plasmid‐mediated colistin resistance is a critical concern for public health. In Vietnam, where colistin has been mainly used for animal husbandry, the occurrence of colistin resistance in water environments remains unknown. This is the first study to demonstrate the prevalence of mcr‐1, which encodes colistin resistance, in urban drainages, rivers, lakes, and groundwater sources in Hanoi, Vietnam. The high correlation between the levels of mcr‐1 and the human‐specific cross‐assembly phage, a human faecal indicator, indicated that the discharge of untreated wastewater contributes to the spread of mcr‐1 in water environments.