1.Molecular typing and drug resistance of Salmonella in market-sold raw livestock meats in Shaoxing City
HE Qinfen ; JIANG Zhuojing ; TANG Shijie ; ZHOU Liangkang ; ZHANG Qinchao
Journal of Preventive Medicine 2024;36(10):915-920
Objective:
To investigate the molecular typing and drug resistance of Salmonella in market-sold raw livestock meats in Shaoxing City, Zhejiang Province, so as to provide the basis for the prevention and control of drug-resistant Salmonella.
Methods:
Salmonella isolates were detected and serotyped from raw livestock meat samples collected from supermarkets, agricultural markets and restaurants in Shaoxing City between March and November 2023. Molecular typing was performed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Antibiotic resistance phenotypes and resistance gene analyses were conducted using broth microdilution method and whole genome sequencing.
Results:
A total of 34 Salmonella isolates were detected from 329 samples and the positive rate was 10.33%. There were 14 serotypes, with S. Rissen (9 isolates, 26.47%) and S. London (8 isolates, 23.53%) being dominant. PFGE typing revealed 31 band patterns and 23 banding pattern clusters of Salmonella, and the similarity ranged from 30.80% to 100.00%, without dominant band patterns. MLST identified 15 sequence typing (ST) types, and S. Rissen were all ST469 and S. London were all ST155. Salmonella strains exhibited high levels of resistance to tetracycline (44.12%) and ampicillin (35.29%). Thirteen resistance patterns were identified, with 8 multidrug resistant patterns (29.41%). There were 8 classes of 14 resistance genes, with aminoglycoside resistance gene aac(6' )-Iaa found in 100.00% of the strains. The highest concordance rate between the resistance phenotype and gene was observed for phenicol antibiotics (97.06%), while there was no concordance between the quinolone resistance phenotype and genes.
Conclusions
S. Rissen and S. London are the predominant serotypes in market-sold raw livestock meats in Shaoxing City. The PFGE band types of the Salmonella isolates show polymorphism distribution, and MLST are mainly ST469 and ST155. The isolates have high levels of resistance to tetracycline and ampicillin, manifesting multidrug resistance.
2.Epidemiological characteristics of foodborne disease outbreaks in Shaoxing City from 2012 to 2022
XING Chao ; WANG Qimei ; REN Jianglei ; CHEN Jiming ; HE Qinfen ; JIANG Zhuojing
Journal of Preventive Medicine 2023;35(6):506-508,513
Objective:
To investigate the epidemiological characteristics of foodborne disease outbreaks in Shaoxing City, Zhejiang Province, from 2012 to 2022, so as to provide the evidence for improving the foodborne disease control strategy.
Methods:
Foodborne disease outbreaks in Shaoxing City from 2012 to 2022 were collected from National Foodborne Disease Outbreak Monitoring System in China, including populations, places of outbreak, pathogenic factors and suspected foods. The temporal distribution, regional distribution, distribution of outbreak places and pathogenic factors of foodborne disease outbreaks were descriptively analyzed.
Results:
A total of 89 foodborne disease outbreaks were reported in Shaoxing City from 2012 to 2022, covering totally 699 patients, with an average annual attack rate of 6.35%. The outbreak peaked during the period between June and October (73 outbreaks, 82.02%), and family was the predominant place of outbreak (41 outbreaks, 46.07%). There were 83 outbreaks with known pathogenic factors, including 51 outbreaks caused by microbial factors, with Vibrio parahaemolyticus, Salmonella and norovirus as predominant pathogens, and 29 outbreaks caused by fungi and their toxins, which were all poisonous mushrooms poisoning, resulting in 2 deaths. In addition, there were 3 outbreaks caused by chemical factors.
Conclusions
The outbreak of foodborne diseases predominantly occurred in summer and autumn in Shaoxing City from 2012 to 2022. Family was the predominant place of outbreak, and toxic mushroom poisoning was the most lethal pathogenic factor.