Abstract:To quantitatively investigate the contamination and antimicrobial resistance of Salmonella in chicken carcasses in broiler slaughterhouse in Qingdao.Methods A total of 141 chilled chicken carcasses were collected from 2 slaughterhouses in Qingdao of Shandong Province once a month from October to December in 2014. All samples were enumerated for Salmonella. Presumptive isolates were serotyped according to Kauffmann-White scheme. The antimicrobial susceptibilities of 11 antimicrobial agents against Salmonella isolates were determined by broth microdilution method.Results Overall, 105 samples (74.5%, 105/141) were positive for Salmonella and the median load was 43 MPN/100 g with the minimum value of 3.6 MPN/100 g and the maximum value of >1 100 MPN/100 g. A total of 355 isolates were obtained. Salmonella enteritidis was the most common serovar detected (220 isolates), followed by S.indiana (88 isolates) and S.agona (19 isolates). 90.4% of the isolates were resistant to at least one antimicrobial, and 88.7% (315/355) of the isolates were resistant to nalidixic acid. Of all 220 S.enteritidis isolates, 219 isolates were resistant to at least one antimicrobial, and 2.7% (6/220) were multi-drug resistant. Of all 88 S.indiana isolates, 85 isolates were multi-drug resistant, and the predominant resistant profile was GEN-CHL-CIP-NAL-AMP-SAM-CAZ-CTX-SXT. Of all 19 S.agona isolates, 18 isolates were susceptible to all 11 antimicrobials, while one isolate resistant to NAL.Conclusion The contamination rate of Salmonella in broiler slaughterhouse in Qingdao is high. S.enteritidis, S.indiana and S.agonist were the main serotypes. The overall drug resistance rate of Salmonella was higher and showed multi-drug resistance.