الفهرس 
3. Types of Salmonella enterica and their strainsOnly 14 pages are availabe for public view
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Abstract
SUMMARY
Typhoid fever caused by Salmonella enterica serovar Typhi is endemic in
developing countries. Its detection by culturing on specific media or
serological methods like Widal test is a time consuming and/or less
sensitive than PCR technique. Here we apply a multiplex PCR dependent
detection for S. Typhi using two specific primers for invA and fliC genes.
76 patients with clinical suspicion of typhoid fever were examined. Two
sets of primers derived from invA and fliC genes specific for Salmonella
spp. and S. Typhi were used as multiplex PCR in order to detect the
pathogen in their blood samples. This was compared with traditional
culturing methods on two different chromogenic media [Melibiose,
mannitol and sorbitol (MMS) agar media specific for S. Typhi and
Salmonella-Shigella (SS) agar media]. Also the suspected typhoid samples
were tested by Widal O antigen.
The primer set 1 of fliC gene sensitivity was able to amplify 495 bp up
to10
-4
dilution which is corresponding to 8 cfu. The invA primer set 2
amplified 248 bp with sensitivity reached 5 cfu at 10
-5
of bacterial dilution.
The sensitivity of culture, Widal test and the multiplex PCR were 61.36%,
88.64% and 100%, respectively, while their specificity were 100%, 62.50%
and 86.49%, respectively. The multiplex PCR showed higher efficiency reached 93.42% than culturing and Widal test which was 77.63%.
The high sensitivity, specificity and efficiency of the studied multiplex
PCR encourage us to recommend it as a useful tool for S. Typhi detection
not only in clinically suspected negative culture individuals, but also for
the false positive Widal test cases of typhoid fever in