Detection of some virulence factors of Salmonella typhi isolated from patients' blood by PCR and phylogenetic tree

Abstract

Typhoid fever is brought about by Salmonella enterice serovar typhi, which is a significant general medical issue in many developing nations. The severity the pathogenesis depends on Salmonella's possession of cytolethal distending toxin (CDT) and virulence factors such as fimbriae adhesions, which are important in the adherence, invasion and the development of typhoid fever, was as diagnosed serologically as well as diagnosis of Salmonella typhi causing these fever based on phenotypic and cultural characteristics. Therefore, the coding genes of CdtB protein and fimbriae were detected in molecular methods by PCR technique using special primers. while, the fim gene was 84.21% and CdtB gene was 100%. DNA sequencing was performed and this confirms the isolation obtained in our study. In addition, the phylogenetic tree was analyzed and registered at the gene bank site, where the sequence identity rate fim gene 99.26%, while sequence identity rate for CdtB gene was 99.31%.