Abstract
This study aimed to investigate the incidence and phenotypic and genotypic resistance of Escherichia coli isolates recovered from fast food in Sharkia Governorate, Egypt, as well as to evaluate the cinnamon and oregano essential oils treatments for inoculated minced meat with E. coli serotype O157:H7. The highest incidence of E. coli was found to be 44% in smoked herring, followed by kofta (40%), shawarma (36%), sausage (32%) and fried shrimp (24%). E. coli isolates were serotyped into O157:H7 (12.5%) and O128:H2 (12.5%) from kofta samples, O125:H21(25%) from both of sausage and fried shrimp, O119:H6 (12.5%) and O86a:H3 (12.5%) from shawarma; and O158:H7 (25%) from smoked herring. Six isolates belonging to E. coli serotypes O157, O158, O119, O128, O125 and O86a showed maximum resistance (100%) to erythromycin, gentamicin, cefepime, streptomycin, ampicillin, chloramphenicol and tetracycline. Moreover, 4 E. coli strains belonging to O157, O128, O125 and O86a serotypes showed moderate resistance (66.7%) to ciprofloxacin, sulfamethoxazole trimethoprim. The resistance genes including blaTEM, aadA1 and mphA were detected with a percentage of 100% in the six investigated isolates phenotypically resistant to ampicillin, gentamicin and erythromycin, respectively. The average count of E. coli serotype O157:H7 after 0.5-hour of dipping in essential oils (EOs) from oregano 2% (3.52 +/- 0.16) showed a significant decrease in comparison with that of the control. The average counts of E. coli serotype O157:H7 and reduction percentages after one hour of dipping in EOs from oregano 2% (3.41 +/- 0.99, 48.4%); and in EOs from cinnamon 2% (3.74 +/- 0.13, 43.4%) showed a significant decrease when compared with that of the control. Our study clarified that the average counts of E. coli O157:H7 after one hour of dipping in EOs from oregano 2% and cinnamon 2% were significantly reduced when compared with those counts after dipping in EOs from oregano 1% and cinnamon 1%, respectively. The present study confirmed that cinnamon 2% and oregano 2% had powerful antibacterial activities against E. coli O175: H7 recovered from ready-to-eat (RTE) meat products and prevent food poisoning.