ABSTRACT
Salmonella is one of the major causes of foodborne disease outbreaks globally. Specifically, Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) is one of the major causes of zoonotic Salmonella infection in humans worldwide. In this study, we present data on antimicrobial resistance (AMR) and plasmid profiles of S. Enteritidis strains isolated from patients, food, and the environment in Siberia and the Far East of Russia obtained during Salmonella monitoring between 1990 and 2017. A total of 345 S. Enteritidis isolates were tested by the disk diffusion method with a set of 15 antibiotics using EUCAST breakpoints v. 10 and by plasmid profile analysis using the alkaline lysis method. The results have shown a substantial decrease in susceptibility to aminoglycosides and quinolones during the study period. No significant differences were found in the susceptibility of strains between regions as well as in the its correlation with different plasmid types of the pathogen. Several S. Enteritidis strains were found to be resistant to ampicillin, kanamycin, tetracycline, chloramphenicol, and cephalosporins. All tested S. Enteritidis strains were susceptible only to imipenem. In this study, we observed a relatively low level of AMR in S. Enteritidis strains isolated in Siberia and the Far East of Russia. Nevertheless, it is important to continue the molecular genetic monitoring and AMR surveillance of S. Enteritidis to track further increases in AMR using conventional phenotypic susceptibility testing and by introducing whole-genome sequencing to identify AMR mechanisms.
ABSTRACT
For the first time, in the literature review we presents the molecular genetic structure of Salmonella Enteritidis populations in Russia, and particularly, in Siberia and the Far East of the country. Pathogen population in Russia has been compared with Salmonella populations circulating in different countries of the world. It has been shown that the microbial population is heterogeneous, but it is possible to identify the dominant and main genotypes, which determine up to 90% of the total population morbidity. The data were obtained as a result of a 30-year monitoring (1988 to 2018) by studying the microbial plasmid profiles. It was shown that the same S. Enteritidis clones circulate throughout Russia, however, their significance in the population morbidity may vary depending on geographic and temporal characteristics. Population is characterized by heterogeneity and relative stability of the plasmid types' structure. At the same time, the population is also specified by variability, reflected as a simple change of the annual number of constantly detected plasmid types, and the appearance of new ones that can play a significant role in the etiology of Salmonella infection.
