Analysis of molecular type and antimicrobial resistance of clinical strains of Salmonella in Shaoxing, 2017-2019

Abstract

ObjectiveTo understand the molecular epidemiology and antimicrobial resistance pattern of clinically isolated Salmonella in Shaoxing city from 2017 to 2019.MethodsThe 245 Salmonella strains that were isolated from foodborne disease and diarrhea cases in Shaoxing were collected and serotyped. Broth microdilution method was performed to carry out drug resistance testing. Pulsed field gel electrophoresis (PFGE) and BioNumerics V7.1 software were applied to clustering analysis.ResultsThe 245 isolates of Salmonella were composed of sixty serotypes. The predominant serovars were Salmonella typhimurium (32.24%), Salmonella enteritidis (10.20%) and Salmonella london (6.94%). The 225 strains were resistant to 25 antibiotics at different degrees. Among these isolates, higher rates of resistance to ampicillin (77.14%), tetracycline (73.88%) and streptomycin (66.53%) were found and the multiple drug resistance rate reached 76.33%. On the other hand, the predominant serovars were digested with Xba Ⅰ, which contained 48, 11 and 12 different PFGE fingerprints, respectively.ConclusionSalmonella serotypes and PFGE fingerprints were highly diverse. Antibiotic resistance was concentrated in AMP-TET-STR.

Keywords

• salmonella
• serotype
• antimicrobial resistance
• pulsed field gel electrophoresis