Molecular Identification of Serotype O157 and Virulence Genes hly and eae A in Escherichia coli Isolated from Dried Vegetables Using Multiplex Polymerase Chain Reaction Method

Enterohaemorrhagic Escherchia coli strains can infect human beings through consuming animal and plant foods and cause foodborne infections along with diarrhea, hemorrhagic colitis, haemolytic-uraemic syndrome, thrombocytopenic purpura and even death. The present study aims to isolate and identify the pathogenic genes of Escherchia coli O157 strains from dried vegetables samples. This cross-sectional random study was carried out on 112 different dried vegetables samples collected from the herbal stores in Saveh. Biochemical tests and differential culture mediums were used for 112 samples to detect the presence of Escherchia coli. To detect serotype O157, the special antiserum O157 was used and the presence of the pathogenic genes hly and eae A was investigated using multiple polymerase chain reaction method. E. coli was found in 63 samples of 112 investigated samples and 20 samples contained serotype O157. Finally, gene eae A was detected in 2 samples and gene hly was detected in 1 sample. Since enterohaemorrhagic Escherchia coli O157: H7 is regarded as one of the main concerns of food health, it should be considered permanently. More extensive studies are needed on the sources, prevalence, fate and transmission of Escherchia coli O157: H7 near the environments supplying vegetables in order to determine the mechanisms of contamination before and also after harvesting, drying and packaging, and the ability to transfer contamination and pathogens to human.