title: [Epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana isolated from retail chicken carcasses in six provinces, China].
abstract: OBJECTIVE
  To elucidate the epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana (S. Indiana) isolated from retail chicken carcasses in six provinces of China.
  
  
  METHODS
  A total of 2 647 Salmonella strains isolated from retail chicken carcasses collected from six provinces of China were subjected to antimicrobial susceptibility testing. All Salmonella isolates co-resistant to ciprofloxacin and cefotaxime were further characterized by serotyping, extended-spectrum beta-lactamases (ESBLs) producing strains screening and pulsed field gel electrophoresis (PFGE) typing.
  
  
  RESULTS
  Among 2 629 Salmonella isolates tested, 227 (8.52%) isolates were co-resistant to ciprofloxacin and ceftazidime/cefotaxime (Beijing: 11.67% (99/874), Jilin: 8.20% (60/726), Guangdong: 1.39% (7/502), Jiangsu: 15.61% (42/260), Shaanxi: 8.56% (16/186), Inner Mongolia: 0 (0/81)), and 224 of them were identified as S. Indiana. 213 (95.10%) isolates of S. Indiana were ESBLs producing strains. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates developed a multi-drug resistant profile and 17.86% (40/224) of them were resistant to all antibiotics tested except carbapenems, and 50.89% (114/224) of them resistant to 9 antibiotics, additionally, 25.45% (57/224) of them showed multi-drug resistance to 8 antibiotics. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates were divided into 32 PFGE clusters and 150 PFGE patterns. Strains of S. Indiana from same or different sampling site and time seemed to either share the same PFGE patterns or be differential to each other in different regions.
  
  
  CONCLUSIONS
  The results indicated that chicken carcasses collected from parts of China were heavily contaminated by ciprofloxacin and cefotaxime co-resistant S. Indiana and could serve as an important reservoir of ciprofloxacin and cefotaxime co-resistant Salmonella. Molecular subtyping results indicated that cross contamination or common pollution source might be in these strains.
authors.affiliation: Key Laboratory of Food Safety Risk Assessment of Health, China National Center for Food Safety Risk Assessment, Beijing 100021, China.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Hu
authors.forename: Yingying
authors.initials: Y
authors.lastname: He
authors.forename: Yeru
authors.initials: Y
authors.lastname: Wang
authors.forename: Shenghui
authors.initials: S
authors.lastname: Cui
authors.forename: Qiuxia
authors.initials: Q
authors.lastname: Chen
authors.forename: Guihua
authors.initials: G
authors.lastname: Liu
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
authors.forename: Baowei
authors.initials: B
authors.lastname: Yang
authors.forename: Jinlin
authors.initials: J
authors.lastname: Huang
authors.forename: Hongxia
authors.initials: H
authors.lastname: Yu
authors.affiliation: Email: lifengqin@cfsa.net.cn.
authors.forename: Fengqin
authors.initials: F
authors.lastname: Li
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002439:Cefotaxime / Q000494:pharmacology; D002645:Chickens / Q000382:microbiology; D002681:China; D002939:Ciprofloxacin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005506:Food Contamination; D005516:Food Microbiology; D008460:Meat / Q000382:microbiology*; D012475:Salmonella / Q000145:classification* / Q000302:isolation & purification*; D012703:Serotyping; D001618:beta-Lactamases
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D001618:beta-Lactamases; D002439:Cefotaxime