Salmonella contamination and molecular typing in Huzhou from 2015 to 2021

Abstract

ObjectiveTo understand the pollution status of foodborne pathogens in Huzhou， so as to provide basis for the prevention and control of foodborne diseases.MethodsAccording to GB 4789.4—2016， 1 463 samples in 5 food categories were collected from Huzhou City during 2015—2021 for Salmonella monitoring. Serotype， antibiotic sensitivity test and pulsed field gel electrophoresis （PFGE） were carried out to isolate Salmonella. The results were analyzed by Excel and SPSS 19.0 software.ResultsForty seven Salmonella strains were detected from 1 463 samples and the total detection rate was 3.21%. Among all kinds of food， the detection rate of Salmonella in livestock meat was the highest （6.61%，23/348）. A total of 19 serotypes of Salmonella were detected， of which the dominant serotype was Salmonella Typhimurium. Salmonella serotypes detected in various kinds foods were different. Twenty strains of Salmonella isolated from 2019 to 2021 were tested for drug sensitivity and PFGE. The results showed that the isolates had strong resistance to AMP and TET， with resistance rates of 70% （14/20） and 60% （12/20） respectively. Molecular typing showed that after Xba I enzyme digestion， 19 strains of Salmonella produced 11 PFGE bands with high polymorphism.ConclusionFrom 2015 to 2021， Salmonella was detected in five types of food sold in Huzhou City， including two types of ready to eat food （Chinese cold dishes and bulk cooked meat products）. The dominant serotype was Salmonella Typhimurium. The positive detection was mainly from farm market， which had potential risk of foodborne diseases. The corresponding monitoring and supervision should be paid attention to.

Keywords

• salmonella
• molecular typing
• food
• contamination