Fatemeh Fallah - Department of Clinical Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
Hossein Godarzi - Department of Clinical Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
Fariba Lahoorpour - Department of Pathology and Medical Laboratory Sciences, Faculty of Para Medicine, Kurdistan University of Medical Sciences, Sanandaj, IR Iran
Mojgan Bandehpour - Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran

Background: Salmonella enterica serovar typhi (S. typhi) the cause of the acute febrile disease typhoid fever is the major public health problem in developing countries. Asymptomatic carriers are the main sources of typhoid. The aim of this study was to investigate methods for isolation and identification of S. typhi in asymptomatic carriers. Materials and Methods: Two hundred stool samples were collected from foodstuff workers and distributors. Then culture characterization,biochemical tests, and nested-PCR were done. Results: One hundred and seventy-one (85%) of the total cases were male and the mean age of cases was 35 years. Stool culture yielded bacterial colonies consistent with fecal flora but did not yield S. typhi. In nested PCR technique just one of the 200 samples (0.5%) was positive for the S. typhi capsular gene (vi gene). Conclusion: Due to the improvement in the health status of the country and the low typhoid carriers, it is recommended that efforts be focused on other hygienic issues

Salmonella typhi, Carrier state, vi gene