Animal salmonelloses: a brief review of “host adaptation and host specificity” of Salmonella spp.

Grammato Evangelopoulou,Angeliki R Burriel,Spyridon Kritas,Alexander Govaris

doi:10.14202/vetworld.2013.703-708

Abstract

Salmonella enterica, the most pathogenic species of the genus Salmonella, includes more than 2,500 serovars, many of which are of great veterinary and medical significance. The emergence of food-borne pathogens, such as Salmonella spp., has increased knowledge about the mechanisms helping microorganisms to persist and spread within new host populations. It has also increased information about the properties they acquire for adapting in the biological environment of a new host. The differences observed between serovars in their host preference and clinical manifestations are referred to as “serovar-host specificity” or “serovar-host adaptation”. The genus Salmonella, highly adaptive to vertebrate hosts, has many pathogenic serovars showing host specificity. Serovar Salmonella Typhi, causing disease to man and higher primates, is a good example of host specificity. Thus, understanding the mechanisms that Salmonella serovars use to overcome animal species' barriers or adapt to new hosts is also important for understanding the origins of any other infectious diseases or the emergence of new pathogens. In addition, molecular methods used to study the virulence determinants of Salmonella serovars, could also be used to model ways of studying the virulence determinants used by bacteria in general, when causing disease to a specific animal species.

Highlights

Salmonella spp., belonging to the family of Enterobacteriaceae, are Gram negative, facultative anaerobic, straight rods, with peritrichous flagella
Despite the efforts of understanding the fundamental mechanisms of S. enterica's pathogenesis, the specific genes involved and the mechanisms needed for a serovar to express “host adaptation-host specificity” are yet to be defined
Research on the mechanisms involved when pathogens exert selective pressure on the host's immune system has led to the conclusion that “host adaptation” of a serovar helps it to competitively exclude other serovars in a given animal population

Summary

Introduction

Salmonella spp., belonging to the family of Enterobacteriaceae, are Gram negative, facultative anaerobic, straight rods, with peritrichous flagella. Such attempts of defining the pathogenicity determinants of Salmonella serovars causing infections in man and animals have resulted in grouping serovars in three major groups. One group includes serovars, such as Dublin and Choleraesuis, proven to cause systemic disease respectively in cattle and pigs only , while other animal species or man could be infected accidentally [12, 4].

Results

Conclusion