Laboratory network based surveillance of drug resistance of Salmonella enteritidis in Shanghai, 2006-2012

Objective The establishment of a laboratory network surveillance system and analyze the antibiotic resistance characteristics of Salmonella enteritidis, and provide scientific evidence for the prevention and control measures development. Methods A total of 184 foodborne and environmental strains and 1146 diarrhea strains of Salmonella enteritidis were isolated in 8 public health laboratories and 24 clinical laboratories from 2006 to 2012, their drug resistance to 16 antibiotics were detected by using disk diffusion method (K-B method) and the drug resistance database was established with WHONET software. Results The detection rate of Salmonella enteritidis in poultry meat was highest (155/184). The laboratory confirmed cases were mainly distributed in people aged 18-59 years and 60 years increased gradually. The resistant rate of all Salmonella enteritidis strains to nalidixic acid was over 90%. The multidrug-resistant strains (to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline) were isolated from chicken meat samples and 1 foodborne sample (in 2009), while foodborne strains and diarrhea strains resistant to cefepime were detected in 2011 and 2008 respectively. The resistant rates of diarrhea strains resistant to ciprofloxacin and cefotaxime were higher than those of foodborne strains. The strains resistant to the third generation cephalosporins and ciprofloxacin in lower age group accounted for approximately 2/3 and 1/2 of the total. Conclusion Community acquired and foodborne infections of Salmonella enteritidis were detected in Changning district. The multidrug resistant strains detected in Changning were probably highly pathogenic. It is important to improve laboratory's routine detection capacity, reduce the elderly and children's unnecessary antibiotic exposure for the mitigation of disease burden caused by Salmonella enteritidis infection.