Molecular diagnosis of Salmonella typhi and its virulence in suspected typhoid blood samples through nested multiplex PCR

Publication date: Available online 23 May 2017 Source:Journal of Microbiological Methods Author(s): Solai Ramatchandirane Prabagaran, Vellingiri Kalaiselvi, Naganathan Chandramouleeswaran, Krishnan Nair Geetha Deepthi, Kootallur Narayanan Brahmadathan, Mariappa Mani A nested multiplex polymerase chain reaction (PCR) based diagnosis was developed for the detection of virulent Salmonella typhi in the blood specimens from patients suspected for typhoid fever. After the Widal test, two pairs of primers were used for the detection of flagellin gene (fliC) of S. typhi. Among them, those positive for fliC alone were subjected to identification of genes in Via B operon of Salmonella Pathogenesity Island (SPI-7) where four primer pairs were used to detect tviA and tviB genes. Among 250 blood samples tested, 115 were positive by fliC PCR; 22 of these were negative for tviA and tviB. Hence, the method described here can be used to diagnose the incidence of Vi-negative serovar typhi especially in endemic regions where the Vi vaccine is administered.

Source: Journal of Microbiological Methods - May 23, 2017 Category: Microbiology Source Type: research