Genotypic diversity of Salmonella ser. Gallinarum strains isolated from 2012 to 2016 in Brazil

Abstract

Salmonella Gallinarum biovar Gallinarum (SG) is a host-specific avian pathogen causing fowl typhoid (FT), a notifiable disease that causes septicemia in poultry and significant economic losses. In the state of Santa Catarina, Brazil, several cases of FT were reported from 2012 to 2016. However, strains of these outbreaks have not yet been characterized, and the genotypic characterization of isolates is essential for epidemiological surveillance and outbreak investigations. The objective of this work was to study the genetic diversity of SG isolated from the FT outbreaks, aiming to identify similarity or dissimilarity among strains isolated from the reported foci. For this study, 56 SG strains were submitted to pulsed-field gel electrophoresis (PFGE). Through the PFGE analysis, a prevalent genotypic profile (57.1%) of SG was identified, suggesting the occurrence of an endemic clone, whose dissemination is possibly linked to the transport of infected birds across the regions. Fifteen other genotypic profiles were also obtained, evidencing the genetic variability of circulating strains and multiple contamination sources.