Effects of environmental disinfection on microbial population and resistance genes: A case study of the microecology within a panda enclosure

Min Yan; Chunzhong Xu; Caiwu Li; Yongqi Feng; Juntang Duan; Ke Zhao; Daifu Wu; Guo Li; Shengzhi Yang; Xinfeng Han; Yue Xie; Yan Huang; Xiumei Yu; Jiawei Wu; Likou Zou

doi:10.1016/j.envres.2023.116662

Effects of environmental disinfection on microbial population and resistance genes: A case study of the microecology within a panda enclosure

Environ Res. 2023 Oct 15:235:116662. doi: 10.1016/j.envres.2023.116662. Epub 2023 Jul 13.

Authors

Min Yan¹, Chunzhong Xu², Caiwu Li³, Yongqi Feng², Juntang Duan², Ke Zhao¹, Daifu Wu³, Guo Li³, Shengzhi Yang⁴, Xinfeng Han⁵, Yue Xie⁵, Yan Huang³, Xiumei Yu¹, Jiawei Wu¹, Likou Zou⁶

Affiliations

¹ College of Resources, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
² Shanghai Wild Animal Park, Shanghai, 201399, China.
³ Key Laboratory of State Forestry and Grassland Administration (SFGA) on Conservation Biology of Rare Animals in the Giant Panda National Park, The China Conservation and Research Center for the Giant Panda (CCRCGP), Dujiangyan, 611830, China.
⁴ College of Life Science, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China.
⁵ College of Veterinary Science, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
⁶ College of Resources, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. Electronic address: zoulikou@sicau.edu.cn.

PMID: 37453509
DOI: 10.1016/j.envres.2023.116662

Abstract

Widespread use of disinfectants raises concerns over their involvement in altering microbial communities and promoting antimicrobial resistance. This study explores the influence of disinfection protocols on microbial populations and resistance genes within an isolated enclosure environment and in the gut of giant pandas (GPs) held within. Samples of panda feces, air conditioning ducts, soil and bamboo were collected before and after disinfection. High-throughput sequencing characterized the microbial flora of GP gut and environmental microbes inside the artificial habitat. Microbial cultures showed that Escherichia coli (34.6%), Enterococcus (15.4%) and other pathogenic bacteria deposited in feces and the enclosure. Isolates exhibit a consistent resistance to disinfectant, with the greatest resistance shown to cyanuric acid, and the lowest to glutaraldehyde-dodecyl dimethyl ammonium bromide (GD-DDAB) and dodecyl dimethyl ammonium bromide (DDAB). The total number of the culturable bacteria in soil and bamboo were significantly diminished after disinfection but increased in the gut. After disinfection, the richness (Chao1 index) of environment samples increased significantly (P < 0.05), while the richness in gut decreased significantly (P < 0.05). Ten genera showed significant change in feces after disinfection. Metagenome sequencing showed that 126 types of virulence genes were present in feces before disinfection and 37 in soil. After disinfection, 110 virulence genes localized in feces and 53 in soil. Eleven virulence genes including ECP and T2SS increased in feces. A total of 182 antibiotic resistance genes (ARGs) subtypes, potentially conferring resistance to 20 classes of drugs, were detected in the soils and feces, with most belonging to efflux pump protein pathways. After disinfection, the number of resistance genes increased both in gut and soil, which suggests disinfection protocols increase the number of resistance pathways. Our study shows that the use of disinfectants helps to shape the microbial community of GPs and their habitat, and increases populations of resistant strain bacteria.

Keywords: ARGs; Disinfection; Environment; Giant panda; Gut microbiota.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents / pharmacology
Bacteria / genetics
Disinfectants* / pharmacology
Disinfection*
Escherichia coli
Soil

Substances

didodecyldimethylammonium
ammonium bromide
Anti-Bacterial Agents
Disinfectants
Soil