title: Emergence and Diversity of Salmonella enterica Serovar Indiana Isolates with Concurrent Resistance to Ciprofloxacin and Cefotaxime from Patients and Food-Producing Animals in China.
abstract: Salmonellosis is a major global foodborne infection, and strains that are resistant to a great variety of antibiotics have become a major public health concern. The aim of this study was to identify genes conferring resistance to fluoroquinolones and extended-spectrum β-lactams in nontyphoidal Salmonella (NTS) from patients and food-producing animals in China. In total, 133 and 21 NTS isolates from animals and humans, respectively, exhibiting concurrent resistance to ciprofloxacin and cefotaxime were cultured independently from 2009 to ∼2013. All of the isolates were identified, serotyped, and subjected to antimicrobial susceptibility testing. Importantly, the isolates with concurrent resistance to ciprofloxacin and cefotaxime all were confirmed as S. enterica serovar Indiana. The presence of fluoroquinolone resistance genes and extended-spectrum β-lactamases (ESBLs) was established by PCR and DNA sequencing. The occurrence and diversity of different genes conferring fluoroquinolone resistance [qepA, oqxAB, and aac(6')-Ib-cr] with mutations in topoisomerase-encoding genes (gyrA and parC) and several ESBLs (including CTX-M-65, CTX-M-27, CTX-M-15, CTX-M-14, and CTX-M-14/CTX-M-15) were noteworthy. Genes located on mobile genetic elements were identified by conjugation and transformation. Pulsed-field gel electrophoresis, used to determine the genetic relationships between these isolates, generated 91 pulsotypes from 133 chicken isolates and 17 pulsotypes from the 21 clinical isolates that showed considerable diversity. Analysis of the pulsotypes obtained with the isolates showed some clones appeared to have existed for several years and had been disseminating between humans and food-producing animals. This study highlights the emergence of ciprofloxacin- and cefotaxime-resistant S. enterica serovar Indiana, posing a threat to public health.
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk Assessment, Beijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Bai
authors.affiliation: Center for Disease Control and Prevention of Henan Province, Henan, China.
authors.forename: Jiayong
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk Assessment, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Gan
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Center for Disease Control and Prevention of Henan Province, Henan, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Food Science, National Institutes for Food and Drug Control, Beijing, China.
authors.forename: Shenghui
authors.initials: S
authors.lastname: Cui
authors.affiliation: Center for Disease Control and Prevention of Henan Province, Henan, China.
authors.forename: Shengli
authors.initials: S
authors.lastname: Xia
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk Assessment, Beijing, China.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk Assessment, Beijing, China.
authors.forename: Shaofei
authors.initials: S
authors.lastname: Yan
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk Assessment, Beijing, China.
authors.forename: Jiahui
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk Assessment, Beijing, China.
authors.forename: Fengqin
authors.initials: F
authors.lastname: Li
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk Assessment, Beijing, China UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, Belfield, Dublin, Ireland xujin@cfsa.net.cn sfanning@ucd.ie.
authors.forename: Séamus
authors.initials: S
authors.lastname: Fanning
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for Food Safety Risk Assessment, Beijing, China xujin@cfsa.net.cn sfanning@ucd.ie.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002439:Cefotaxime / Q000494:pharmacology*; D002681:China; D002939:Ciprofloxacin / Q000494:pharmacology*; D026942:DNA Topoisomerases / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005243:Feces / Q000382:microbiology; D024841:Fluoroquinolones / Q000494:pharmacology; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D012475:Salmonella / Q000187:drug effects / Q000235:genetics; D012481:Salmonella Infections, Animal / Q000382:microbiology; D019779:Salmonella enterica / Q000187:drug effects* / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D024841:Fluoroquinolones; D002939:Ciprofloxacin; D001618:beta-Lactamases; D026942:DNA Topoisomerases; D002439:Cefotaxime