Serotype and genotyping of Salmonella sp. isolated from street foods in N’Djaména, Chad

Abstract

Group foodborne illness infections with Salmonella are often caused by the simultaneous consumption by several people of heavily contaminated food. The objective of this work was to determine the phylogenetic relationships between dietary strains of Salmonella sp. isolated from our samples and confirmed clinical strains. A total of 447 samples were collected and analyzed using standard food microbiology methods. Enterobacterial Repetitive Intergenic Consensus-Polymerase chain Reaction (ERIC-PCR) technique allowed confirmation that all our strains belong to the genus Salmonella. From ten (10) strains characterized, eight (8) different genotype profiles were identified. The different DNA fragments of the isolates were generated by ERIC-PCR and then revealed on the agarose gel and had bands ranging from 2 to 6 bands with sizes between 150 and 1500 bp. The two food strains of S. Mbadaka (1 and 2) presented identical profiles. However, it is noted that two (2) strains of S. Anatum had different ERIC-PCR profiles. There is also a very high resemblance between the strain of S. Anatum (strain 5) and the confirmed clinical strains (H5: Salmonella Typhi). The presence of risky germs in the food analyzed poses a public health problem and should call on the competent authorities and prompt the taking of corrective measures.