Identification of Salmonella typhi contamination by amplification fliC gene in grass-jelly from traditional markets and minimarket in Semarang city

Abstract

Grass-jelly is one of the most popular plants consumed by people in various forms. Contamination can cause various diseases, one of those is typhoid fever by Salmonella typhi. The purpose of this study was to detect S. typhi in grass-jelly based on molecular detection by amplification of the fliC gene using PCR. Validation was done by culture methods on SSA media and biochemical testing. The fliC gene amplification results in grass-jelly samples (A1, A2, B1, B2, C1, and C3) showed the DNA fragments size of about 1500 bp. Colony and biochemical characters isolate Peterongan were lead to S. typhi, whereas another isolate was another Salmonella spp. Grass-jelly samples from the Peterongan market in Semarang were positively contaminated by S. typhi and isolate from Pedurungan and the minimarket was another Salmonella spp. Molecular-based food testing is fast enough and accurate for detecting types of bacterial contaminants but the amplification of only the fliC gene cannot specific for S. typhi.