New strains, new threats: the rise of atypical non-typhoidal Salmonella serovars and what it means for global health

Salmonella is one of the most common causes of foodborne illness worldwide. These infections, in turn, exert an impact on both industry and healthcare settings. Salmonella is the agent that causes salmonellosis, a gastroenteric infection. Outbreaks of salmonellosis commonly arise from the consumption of contaminated foods of animal origin, and on occasion, from exotic and companion animals. The genus consists of more than 2,600 serovars, with Salmonella Typhimurium and Salmonella Enteritidis being the most commonly isolated serovars which cause non-typhoidal infection in susceptible humans. Moreover, factors such as global trade, government policy and globalization have led to an increased emergence of atypical salmonellae. Current limited literature suggests that these emerging atypical Salmonella serovars pose a unique threat to human health due to their novel host adaptations, antimicrobial resistance profiles, epidemiology and infection sources. Thus, this paper aims to provide a short overview of the current knowledge of the taxonomy of selected atypical serovars as well as their epidemiology, virulence factors and the impact they pose on the One Health paradigm. The aim of this being to highlight the ever-increasing importance of focusing research upon these variant serovars due to their changing incidence and diverse attributes.