Comparative Genome Analysis of Hungarian and Global Strains of Salmonella Infantis

Abstract

Introduction: The emergence and spread of new strains of zoonotic bacteria, such as multidrug resistant (MDR) Salmonella Infantis, represent a growing health risk for humans in and outside Europe due to foodborne infections of poultry meat origin. Objectives: In order to understand genome relations of S. Infantis strains from Hungary and from different geographic regions, we performed a comprehensive genome analysis of nine Hungarian and 67 globally selected strains of S. Infantis and 26 Salmonella strains representing 13 non-Infantis serovars. Results: Analyses of whole-, and accessory genomes, showed that almost all S. Infantis strains were separated from the non-Infantis serovars. S. Infantis strains from Hungary formed subclusters based on their time of isolation. In whole genome sequence analysis, the Swiss strains of S. Infantis were closely related to each other and clustered together with subclusters of strains from Hungary, Japan, Italy, United States, and Israel. The accessory genome analysis revealed that the Swiss strains were distinct from most of the strains investigated, including the Hungarian ones. Analysis of the cloud genes offered the most detailed insight into the genetic distance and relationship of S. Infantis strains confirming that the Swiss and Hungarian strains belonged to different lineages. As expected, core genome analysis provided the least discriminatory power for analysis of S. Infantis. Genomic sequences of nine strains from Brazil, Israel, Mexico, Nigeria, and Senegal (deposited as S. Infantis) proved to be outliers from the S. Infantis clade. They were predicted to be Salmonella Rissen, Salmonella Ouakarm, Salmonella Kentucky, Salmonella Thompson, and Salmonella enterica subsp. diarizonae. Conclusion: Accessory genome of S. Infantis showed the highest diversity suggesting a faster evolution than that of the whole genomes contributing to the emergence of multiple genetic variants of S. Infantis worldwide. Accordingly, in spite of the comprehensive analysis of several genomic characteristics, no epidemiologic links between these S. Infantis strains from different countries could be established. It is also concluded that several strains originally designated as S. Infantis need in databanks reclassification.

Comparative Genomics of Emerging Lineages and Mobile Resistomes of Contemporary Broiler Strains of Salmonella Infantis and E. coli

“…By using the high discriminatory cgMLST genotyping tool, we revealed for the first time the internal genomic structure of the epidemic PFGE clone B2, showing two main clusters each with a high genomic plasticity and potential for clonal diversification. This finding is in line with other reports, stating that the S. Infantis population is heterogeneous at the genomic level, with a more homogeneous repertoire of MDR plasmids, and with a potential to reflect geographical differences (Gymoese et al, 2019;Alba et al, 2020;Nagy et al, 2020).…”

Prevalence, Antibiotic Susceptibility Profile, and Associated Risk Factors of Salmonella Isolate among Diarrheal Patients Visiting Dessie Referral Hospital, Northeast Ethiopia

“…Those patients who consumed raw egg were likely contracting salmonellosis than those who did not consume such products. Moreover, according to [ 35 ], human and poultry isolates bore more antimicrobial resistance and virulence genes, and the meat pathway may be an important source of human infection by some clades of Salmonella enteritidis ST11 in East Africa, and according to [ 36 ], the emergence and spread of new strains of zoonotic bacteria, such as multidrug resistant (MDR) Salmonella infantis , represent a growing health risk for humans in and outside Europe due to foodborne infections of poultry meat origin.…”

Emergence of Multidrug-Resistant Salmonella enterica Subspecies enterica Serovar Infantis of Multilocus Sequence Type 2283 in German Broiler Farms

“…Enteritidis in poultry farms ( Szmolka et al, 2018 ). It is also suggested that the EU trade of broiler chicken and the pyramidal structure of the poultry industry may be factors of the rapid spread of emergent clones of S. Infantis carrying the pESI-like plasmid beyond national borders ( Alba et al, 2020 ; Nagy et al, 2020 ). The long term use of special groups of antimicrobial substances might have resulted in selection pressure and increased emergence of particular bacterial organisms ( Nógrády et al, 2007 , 2012 ).…”