Salmonella infection and drug resistance in patients with foodborne disease in Gansu, 2019−2021

  Objective  To analyze the infection status and drug resistance of Salmonella in patients with foodborne disease in Gansu province and provide evidence for the prevention and control of foodborne disease and the rational use of antibiotics.

  Methods  Salmonella isolated from the samples of foodborne disease patients in 15 sentinel hospitals in Gansu were serotyped and tested for drug susceptibility according to the manual of foodborne disease surveillance, and χ² test was used to compare the rates.

  Results  A total of 13 482 samples of patients with foodborne disease were collected in Gansu from 2019 to 2021, and 189 strains of Salmonella were detected with a detection rate of 1.40%, and the male to female ratio of the positive cases was 1.55∶1. Salmonella was detected in all age groups, and the detection rates in age groups 0–5 years, 6–17 years, 18–60 years and >60 years were 1.45%, 1.61%, 1.43% and 1.04%, respectively. The detection rates in the first, second, third and fourth quarters were 0.67%, 1.54%, 1.76% and 1.20%, respectively. The 189 strains of Salmonella belonged to 34 serotypes and the serotypes with high proportions were S. Enteritidis (30.69%), S. Typhimurium (19.58%), S. Typhimurium monophasic variant (8.99%) and S. Stanley (6.88%). Grains and their products (32.28%) were the mainly suspected food causing Salmonella foodborne diseases and household was the main place where Salmonella foodborne diseases occurred. The multidrug resistance rate of the 189 Salmonella strains was 68.78% (130/189) and there were 70 kinds of multidrug resistance spectrums. The resistance rate of Salmonella was higher to ampicillin (83.60%) and tetracycline (62.96%) and lower to azithromycin (9.52%), cefoxitin (5.82%) and imipenem (1.59%). There were significant differences in the drug resistance to cefotaxime, tetracycline, chloramphenicol, trimethoprim/sulfamethoxazole, ciprofloxacin and azithromycin among S. Enteritidis, S. Typhimurium, S. Typhimurium monophasic variant, S. Stanley and other serotypes of Salmonella (P<0.05).

  Conclusion  Salmonella was detected in patients with foodborne disease in all age groups in Gansu and the multidrug resistance rate of the Salmonella strains was high, indicating a serious drug resistance situation. Therefore, active surveillance for foodborne diseases and Salmonella drug resistance should be strengthened. At the same time, it is necessary to improve the market supervision of grains and their products and the health education about food safety to prevent and control the incidence of foodborne diseases.