Molecular Detection of Some of the Salmonella Typhi Virulence Genes Isolated in the Province of Babylon/Iraq

Abstract

Typhoid fever remains a most important global health problem in low- and middle-income countries.The severity the pathogenesis depends on Salmonella’s possession of several virulence factors, encoded on Salmonella pathogenicity islands (SPIs). In current study 34 S. Typhi isolates were collected from patients suffering from typhoid fever who attended to Imam Al-Sadiq Teaching Hospital, and private medical clinics in Babylon province during the period from July to November 2020.Identification was done by cultural and biochemical tests, and finally identification by Vitek2 system. In current study, simple PCR assay was used to detect the existence of genes usually associated with virulence of Salmonella Typhi; five virulence-related genes detected in this study were; ctdB, tviA, sipA/sspA, spiC, and orfL, by using specific primers. Thirty-two isolates (94.1%) out of total 34 isolates showed positive results for tviA (typhi Vi) gene, while other virulence genes were detected in all (100%) isolated strain.This gene could be effective in the invasiveness of theS. Typhistrain. The results obtained from this study will help to understand the spread of S. Typhi virulence genotypes in Iraq.