Occurrence and molecular characterization of Salmonella Typhimurium and Salmonella Enteritidis isolates from contaminated food samples from Palestine
Publication Type
Original research
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ABSTRACT: Salmonella is one of the most frequently isolated foodborne pathogens. It is of major public health
concern worldwide. Poultry meat and eggs represent important sources of Salmonellae organisms with an impact on
consumers’ health. This study aims to evaluate the occurrence of Salmonella Typhimurium and Salmonella Enteritidis
using multiplex PCR (mPCR) among isolates collected from samples of the local food market and to assess genetic
relationships between isolates of S. Typhimurium, which was the only serotype isolated from the tested food samples.
This was achieved using virulence factors profiling and fingerprint profiling, which were assessed by random amplified
polymorphic DNA (RAPD-PCR) and repetitive sequence PCR (REP-PCR). Both enterobacterial repetitive intergenic
consensus (ERIC-PCR) and interspersed repetitive DNA sequence BOXAIR-PCR were used for this purpose.
The overall occurrence percentage of S. Typhimurium and S. Enteritidis out of 51 isolates was 54.9% and 0.0%, respectively.
Only 13 out of 17 virulence genes were detected in these isolates. The occurrence of the detected virulence genes
among these isolates was 100%, 50.0%,46.4%, 39.3%, 35.7%, 35.7%, 32.1%, 25.0%, 25.0%, 17.6%, 14.3%, 14.3%,
3.6% for invA, sopB, prgH, sitC, pefA, tolC, cdtB, msgA, sifA, iroN, spiA, ipfC and pagC, respectively. The remaining
virulence genes were absent in all of the isolates. Based on the combination of the presence and absence of virulence
genes, eight profiles were detected among these isolates, the most common genetic profile was V5 (each 32.1%). Based
on this genetic profile at cut-off point 96.0%, both ERIC and BOX primers allowed for discrimination into 4 and 6 clusters
or clones of 16 S. Typhimurium isolates, respectively. Results of PCR typing methods showed that, three strains
clustered together using both ERIC-PCR and BOX-PCR typing methods and they had the same virulotype (V1), while
other four strains also clustered together by both typing methods and had the same virulotype (V4).
Contamination of food with Salmonellae, especially with S. Typhimurium, was high and affected the microbiological
quality of food. This emphasizes the need for rigorous public health

Journal
Title
Journal of the Hellenic Veterinary Medical Society
Publisher
Hellenic Veterinary Medical Society
Publisher Country
Greece
Indexing
Scopus
Impact Factor
0.5
Publication Type
Both (Printed and Online)
Volume
74
Year
23
Pages
12