title: Prevalence of Salmonella Isolates from Chicken and Pig Slaughterhouses and Emergence of Ciprofloxacin and Cefotaxime Co-Resistant S. enterica Serovar Indiana in Henan, China.
abstract: The prevalence of Salmonella from chicken and pig slaughterhouses in Henan, China and antimicrobial susceptibility of these isolates to antibiotics was determined. From 283 chicken samples and 240 pig samples collected, 128 and 70 Salmonella isolates were recovered with an isolation rate of 45.2 and 29.2% respectively. The predominant serovars in chicken samples were S. enterica serovar Enteritidis, S. enterica serovar Hadar and S. enterica serovar Indiana, while those in pig samples were S. enterica serovar Typhimurium, S. enterica serovar Derby and S. enterica serovar Enteritidis. Resistance to ciprofloxacin was 8.6 and 10.0% for isolates from chickens and pigs respectively, whereas resistance to cefotaxime was 5.5 and 8.6%, respectively. Multidrug resistance (resistance to three or more classes of antimicrobial agent) was markedly higher in pig isolates (57.1%) than in chicken isolates (39.8%). Of particular concern was the detection of ciprofloxacin and cefotaxime co-resistant S. enterica serovar Indiana isolates, which pose risk to public health. All 16 S. enterica serovar Indiana isolates detected were resistant to ciprofloxacin, among which 11 were co-resistant to cefotaxime. The S. enterica serovar Indiana isolates accumulated point mutations in quinolone resistance determination regions of gyrA (S83F/D87G or S83F/D87N) and parC (T57S/S80R). Two plasmid mediated quinolone resistant determinants were found with aac (6')-Ib-cr and oqxAB in 16 and 12 S. enterica serovar Indiana isolates respectively. Cefotaxime-resistance of S. enterica serovar Indiana was associated with the acquisition of a blaCTX-M-65 gene. The potential risk of ciprofloxacin and cefotaxime co-resistant S. enterica serovar Indiana infection is a significant concern due to limited alternative treatment options. Reduction of Salmonella in chicken and pig slaughterhouses, in particular, ciprofloxacin and cefotaxime co-resistant S. enterica serovar Indiana will be an important measure to reduce the public health burden of Salmonella infections.
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: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Ruiting
authors.initials: R
authors.lastname: Lan
authors.affiliation: Henan Center for Disease Control and Prevention, 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, People's Republic of China.
authors.forename: Shenghui
authors.initials: S
authors.lastname: Cui
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for food safety Risk Assessment, Beijing, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Food Safety Risk Assessment, Ministry of Health, China National Center for food safety Risk Assessment, Beijing, China.
authors.forename: Yunchang
authors.initials: Y
authors.lastname: Guo
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: Henan Center for Disease Control and Prevention, Henan, China.
authors.forename: Ding
authors.initials: D
authors.lastname: Zhang
mesh_terms: D000003:Abattoirs; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D002439:Cefotaxime / Q000494:pharmacology*; D002645:Chickens / Q000382:microbiology; D002681:China; D002939:Ciprofloxacin / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D009154:Mutation; D010957:Plasmids; D015995:Prevalence; D012475:Salmonella / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D065288:Serogroup; D013552:Swine / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D002439:Cefotaxime