Phenotypically and genotypically estimation of virulence factors in Salmonella serovar typhi isolated from patients with enteric fever in Al- Najaf, Iraq

Abstract. Zghair LS, Motaweq ZY, Lafta HC. 2022. Phenotypically and genotypically estimation of virulence factors in Salmonella serovar typhi isolated from patients with enteric fever in Al-Najaf, Iraq. Nusantara Bioscience 14: 128-133. Salmonella serovar Typhi, often known as enteric fever, causes typhoid fever and has been a major human infectious disease for centuries, surviving in poor sanitation and overcrowding. Only 64 (58.1%) Gram-negative bacteria were found from the 110 total specimens, with 46 (41.8%) Gram-positive bacteria. The 64 samples were divided into 42 (65.6%) males and 22 (34.4%) females. This work presents the isolation and identification of 64 Salmonella typhi isolates obtained from specimens. In addition, the flagellin gene was found in 64 isolated probable typhoid fever patients (fliC-d). In this study, phenotypic techniques were used to detect several virulence factors. The results showed that small colonies of L-form bacteria grow on the edges of a petri dish when one of the ?-lactam antibiotics (a class of antibiotics that includes penicillin) is given to wild-type bacteria, showing 52 (81.3%) of isolates could produce L-form and observed in 44 (68.75%). The ability to generate CFA/I and CFA/II were found in 68.7% of isolates. The large percentage of CFA produced showed CFA/III production, 64 (100%).