title: Impact of wastewater from different sources on the prevalence of antimicrobial-resistant Escherichia coli in sewage treatment plants in South India.
abstract: The sewage treatment plant (STP) is one of the most important interfaces between the human population and the aquatic environment, leading to contamination of the latter by antimicrobial-resistant bacteria. To identify factors affecting the prevalence of antimicrobial-resistant bacteria, water samples were collected from three different STPs in South India. STP1 exclusively treats sewage generated by a domestic population. STP2 predominantly treats sewage generated by a domestic population with a mix of hospital effluent. STP3 treats effluents generated exclusively by a hospital. The water samples were collected between three intermediate treatment steps including equalization, aeration, and clarification, in addition to the outlet to assess the removal rates of bacteria as the effluent passed through the treatment plant. The samples were collected in three different seasons to study the effect of seasonal variation. Escherichia coli isolated from the water samples were tested for susceptibility to 12 antimicrobials. The results of logistic regression analysis suggest that the hospital wastewater inflow significantly increased the prevalence of antimicrobial-resistant E. coli, whereas the treatment processes and sampling seasons did not affect the prevalence of these isolates. A bias in the genotype distribution of E. coli was observed among the isolates obtained from STP3. In conclusion, hospital wastewaters should be carefully treated to prevent the contamination of Indian environment with antimicrobial-resistant bacteria.
authors.affiliation: Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan; Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan. Electronic address: akiba@affrc.go.jp.
authors.forename: Masato
authors.initials: M
authors.lastname: Akiba
authors.affiliation: Animal Inspection Division, Quarantine Department, Animal Quarantine Service, Yokohama, Kanagawa, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Senba
authors.affiliation: Tobu Livestock Hygiene Service Center, Fuefuki, Yamanashi, Japan.
authors.forename: Haruna
authors.initials: H
authors.lastname: Otagiri
authors.affiliation: Department of Civil Engineering, Manipal Institute of Technology, Manipal University, Manipal, Karnataka, India.
authors.forename: Valipparambil P
authors.initials: VP
authors.lastname: Prabhasankar
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.
authors.forename: Sachi
authors.initials: S
authors.lastname: Taniyasu
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Yamashita
authors.affiliation: Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Lee
authors.affiliation: Viral Diseases and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Takehisa
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Viral Diseases and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tsutsui
authors.affiliation: Department of Civil Engineering, Manipal Institute of Technology, Manipal University, Manipal, Karnataka, India.
authors.forename: Derrick
authors.initials: D
authors.lastname: Ian Joshua
authors.affiliation: Department of Civil Engineering, Manipal Institute of Technology, Manipal University, Manipal, Karnataka, India.
authors.forename: Keshava
authors.initials: K
authors.lastname: Balakrishna
authors.affiliation: Department of Microbiology, Melaka Manipal Medical College, Manipal University, Manipal, Karnataka, India.
authors.forename: Indira
authors.initials: I
authors.lastname: Bairy
authors.affiliation: Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Taketoshi
authors.initials: T
authors.lastname: Iwata
authors.affiliation: Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kusumoto
authors.affiliation: Wadsworth Center, New York State Department of Health and Department of Environmental Health Sciences, State University of New York at Albany, Albany, NY, USA.
authors.forename: Kurunthachalam
authors.initials: K
authors.lastname: Kannan
authors.affiliation: Pathology and Pathophysiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan. Electronic address: guruge@affrc.go.jp.
authors.forename: Keerthi S
authors.initials: KS
authors.lastname: Guruge
mesh_terms: D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D005838:Genotype; D006761:Hospitals; D007194:India; D012621:Seasons; D012722:Sewage; D064091:Waste Disposal Facilities; D062065:Wastewater / Q000382:microbiology*
chemical_list: D012722:Sewage; D062065:Wastewater
keywords: Antimicrobial resistance; E coli; Environmental contamination; Hospital effluent; India; Sewage treatment plant