Drug resistance and typing characteristics of Salmonella isolated from foodborne diseases in the Guizhou Province in 2021

Abstract

ObjectiveThe aim of this study was to evaluate the serotype， drug resistance， and molecular typing characteristics of Salmonella isolated from patients with foodborne diseases in Guizhou Province in 2021.MethodsA total of 164 Salmonella strains were isolated from patients with diarrhea under the Guizhou Provincial Active Surveillance of Foodborne Diseases program in 2021. These strains were subjected to slide agglutination serotyping test， minimum inhibitory concentration tests with 14 antibiotics， and pulsed-field gel electrophoresis （PFGE） for molecular typing.ResultsThe 164 Salmonella strains were divided into 25 serotypes. The dominant serotypes were S. typhimurium （46.34%，76/164）， S. enteritidis （15.24%，25/164）， and S. javana （9.15%，15/164）. The drug resistance rate of the 164 Salmonella strains was 100% （164/164）. The multidrug resistance rate was 86.59% （142/164）. Out of the 15 antibiotics tested， resistance was most frequently observed against ampicillin （95.12%，156/164）， tetracycline （78.05%，128/164）， and nalidixic acid （63.41%，104/164）. Seventy-two S. typhimurium， 24 S. enteritidis， and 15 S. javana strains were divided into 58， 12， and 3 different PFGE clusters， respectively.ConclusionThere were many Salmonella serotypes detected in patients with diarrhea in the Guizhou Province， and multidrug resistance was common. PFGE fingerprints demonstrated genetic diversity of the isolated strains. Monitoring of drug resistance in Salmonella should be strengthened， especially for the clinical treatment of S. typhimurium.

Keywords

• salmonella
• serotype
• drug resistance
• pulse-field gel electrophoresis
• guizhou province