Population structure of Salmonella enterica serotype Mbandaka reveals similar virulence potential irrespective of source and phylogenomic stratification

F1000Res. 2020 Sep 16:9:1142. doi: 10.12688/f1000research.25540.1. eCollection 2020.

Abstract

Background: Salmonella enterica serotype Mbandaka ( Salmonella ser. Mbandaka) is a multi-host adapted Non-typhoidal Salmonella (NTS) that can cause foodborne illnesses in human. Outbreaks of Salmonella ser. Mbandaka contributed to the economic stress caused by NTS due to hospitalizations. Whole genome sequencing (WGS)-based phylogenomic analysis facilitates better understanding of the genomic features that may expedite the foodborne spread of Salmonella ser. Mbandaka. Methods: In the present study, we define the population structure, antimicrobial resistance (AMR), and virulence profile of Salmonella ser. Mbandaka using WGS data of more than 400 isolates collected from different parts of the world. We validated the genotypic prediction of AMR and virulence phenotypically using an available set of representative isolates. Results: Phylogenetic analysis of Salmonella ser. Mbandaka using Bayesian approaches revealed clustering of the population into two major groups; however, clustering of these groups and their subgroups showed no pattern based on the host or geographical origin. Instead, we found a uniform virulence gene repertoire in all isolates. Phenotypic analysis on a representative set of isolates showed a similar trend in cell invasion behavior and adaptation to a low pH environment. Both genotypic and phenotypic analysis revealed the carriage of multidrug resistance (MDR) genes in Salmonella ser. Mbandaka. Conclusions: Overall, our results show that the presence of multidrug resistance along with adaptation to broad range of hosts and uniformity in the virulence potential, isolates of Salmonella ser. Mbandaka from any source could have the potential to cause foodborne outbreaks as well as AMR dissemination.

Keywords: Mbandaka; Salmonella; foodborne pathogen; pathogenesis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Anti-Bacterial Agents
  • Bayes Theorem
  • Humans
  • Phylogeny
  • Salmonella / genetics
  • Salmonella enterica* / genetics
  • Serogroup
  • Virulence / genetics

Substances

  • Anti-Bacterial Agents

Grants and funding

This work was supported in part by grants from the South Dakota Governor’s Office of Economic Development (SD-GOED) and the by the USDA National Institute of Food and Agriculture projects SD00H702-20 and SD00R646-18 awarded to JS, SD00H547-15 and SD00H701‐20 awarded to RK.