title: Antibiotic resistance pattern and gene expression of non-typhoid Salmonella in riversheds.
abstract: In this study, antibiotic resistance and major phenol and genotypes of non-typhoid Salmonella spp. from riversheds in Taiwan were examined. In 236 water samples tested, 54 (22.9%) contained Salmonella spp. Fifteen Salmonella serovars were identified from the Salmonella isolates, and some common serovars are associated with infections of human and livestock, including Albany (27.8%), Newport (14.8%), Bareilly (13.0%), Derby (11.1%), and Typhimurium (7.4%). Various environmental factors may also affect the presence and proportion of different serovars in the receiving waters. In contrast, serovars with narrower range of hosts, e.g., Dublin, were rarely detected. The Salmonella isolates were subjected to eight antibiotics for drug resistance, and 51.9% of the samples were resistant to at least one tested antibiotics. Tetracycline and sulfadiazine were the two most ineffective antibiotics against the Salmonella isolates, and the results were indicative of long-term antibiotics abuse as fodder supplements in animal husbandry. The more commonly detected serovars such as Albany, Derby, and Typhimurium were also more likely to be resistant to multiple antibiotics. Finally, a significant correlation was observed between resistance to chloramphenicol and the resistance gene cmlA, suggesting that the resistance genotypes could persist in the environment even long after prohibition of the drug use. The high prevalence of antibiotic-resistant Salmonella spp. infers elevated infection risks that must be further examined.
authors.affiliation: Division of Urology, Department of Surgery, Tungs' Taichung Metro Harbor Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Chao-Yu
authors.initials: CY
authors.lastname: Hsu
authors.forename: Bing-Mu
authors.initials: BM
authors.lastname: Hsu
authors.forename: Wen-Tsai
authors.initials: WT
authors.lastname: Ji
authors.forename: Jung-Sheng
authors.initials: JS
authors.lastname: Chen
authors.forename: Tsui-Kang
authors.initials: TK
authors.lastname: Hsu
authors.forename: Dar-Der
authors.initials: DD
authors.lastname: Ji
authors.forename: Shao-Feng
authors.initials: SF
authors.lastname: Tseng
authors.forename: Yi-Chou
authors.initials: YC
authors.lastname: Chiu
authors.forename: Po-Min
authors.initials: PM
authors.lastname: Kao
authors.forename: Yu-Li
authors.initials: YL
authors.lastname: Huang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D015964:Gene Expression Regulation, Bacterial; D012475:Salmonella / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D013624:Taiwan; D014871:Water Microbiology
chemical_list: D000900:Anti-Bacterial Agents