From Eberthella typhi to Salmonella Typhi: The Fascinating Journey of the Virulence and Pathogenicity of Salmonella Typhi

Salmonella Typhi (S. Typhi),the invasive typhoidal serovar of Salmonella enterica that causes typhoid fever in humans, is a severe threat to globalhealth. It is one of the major causes of high morbidity and mortalityin developing countries. According to recent WHO estimates, approximately11-21 million typhoid fever illnesses occur annually worldwide,accounting for 0.12-0.16 million deaths. Salmonella infection can spread to healthy individuals by the consumption ofcontaminated food and water. Typhoid fever in humans sometimes isaccompanied by several other critical extraintestinal complicationsrelated to the central nervous system, cardiovascular system, pulmonarysystem, and hepatobiliary system. Salmonella PathogenicityIsland-1 and Salmonella Pathogenicity Island-2 arethe two genomic segments containing genes encoding virulent factorsthat regulate its invasion and systemic pathogenesis. This Reviewaims to shed light on a comparative analysis of the virulence andpathogenesis of the typhoidal and nontyphoidal serovars of S. enterica.