Vegetables and Restaurant Salads as a Reservoir for Shiga Toxigenic Escherichia coli: Distribution of Virulence Factors, O-Serogroups, and Antibiotic Resistance Properties
Autor: | Ebrahim Rahimi, Pardis Emad, Amir Shakerian |
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Rok vydání: | 2016 |
Předmět: |
0301 basic medicine
Restaurants Virulence Factors 030106 microbiology Virulence Biology medicine.disease_cause Serogroup Microbiology 03 medical and health sciences Feces Antibiotic resistance Vegetables medicine Escherichia coli Animals Food science Close contact Escherichia coli Infections Shiga-Toxigenic Escherichia coli Escherichia coli Proteins Significant difference technology industry and agriculture Drug Resistance Microbial Manure 030104 developmental biology Food Science |
Zdroj: | Journal of food protection. 79(7) |
ISSN: | 1944-9097 |
Popis: | Close contact of vegetables with soil, polluted water, and animal manure and unsanitary conditions during processing of restaurant salads led us to study the distribution of virulence factors, O-serogroups, and antibiotic resistance properties in Shiga toxigenic Escherichia coli (STEC) isolated from vegetables and salads. Samples of vegetables and salad (n = 420) were collected and evaluated for the presence of E. coli using culture and a PCR assay. Total prevalence of E. coli in studied samples was 49.5%. E. coli was found in 49.6% of vegetable samples and 49% of salad samples. Leek and traditional salad had the highest incidence of E. coli. Significant differences in the incidence of E. coli were found between the hot and cold seasons. Of the 149 E. coli isolates from vegetable samples, 130 (87%) were STEC, and of the 59 E. coli isolates from salad samples, 50 (84%) were STEC. The most commonly detected virulence factors were stx1 and eaeA. A significant difference was found between the frequency of the attaching and effacing and the enterohemorrhagic E. coli subtypes. Serogroups O26 (46% of isolates), O157 (14%), O121 (10%), and O128 (9%) were the most commonly detected serogroups among the STEC strains. The tetA, sul1, aac(3)-IV, dfrA1, blaSHV, and CITM antibiotic resistance genes were found in 96, 47.7, 90, 51, 27, and 93% of isolates, respectively. The highest levels of resistance were found against ampicillin (96.6% of isolates), tetracycline (87%), and gentamicin (90%). This study shows the importance of vegetables and salads as potential sources of E. coli infection. |
Databáze: | OpenAIRE |
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