ABSTRACT
Introduction@#Foodborne diseases are a major public health concern worldwide. The report, which estimates the burden of foodborne diseases – states that each year as many as 600 million, or almost 1 in 10 people in the world, fall ill after consuming contaminated food. Of these, 420 000 people die, including 125 000 children under the age of 5 years. The 20.3% of diarrhea and 27.5% of die caused by contaminated foods are diarrheagenic Escherichia coli (DEC).@*Aim@#To identify of DEC and determine their antibiotic resistance from ready-to-eat salads@*Material and Methods@#A total of 40 bagged salad mix samples were collected from food markets in Ulaanbaatar, Mongolia. Escherichia coli (E.coli) strains were determined on the basis of MNS 6308:2012 standard and confirmed by polymerase chain reaction (PCR) in samples. DEC was identified using multiplex PCR. Bacterial susceptibility to antimicrobial agents determined by the Kirby Bauer disk diffusion method.@*Results@#Our results showed the presence of E. coli in 19 samples (47.5%). DEC isolates identified by multiplex PCR were defined as follows: the presence of eae and bfp for EPEC, the presence of lt for ETEC, the presence of ipaH for EIEC, the presence of stx1 and stx2 for EHEC, the presence of aap and aggR for EAEC, and the presence of daaE for DAEC. The multiplex PCR assays detected EHEC 6 (31.6%), EPEC 5 (26.3%), EIEC 1 (5.3%). EAEC and ETEC were not detected in samples. The E.coli isolates were 73.7% resistant to chloramphenicol as the first choice of treatment of diarrhea and high resistance (68.4-94.7%) to the cephalosporins. In our country, cephalosporins are widely used in medical practice for the treatment of infectious diseases.@*Conclusion@#In this study, about half of ready-to-eat salads are contaminated with E. coli. The three types (EHEC, EPEC, EIEC) of DEC pathotypes were identified in the ready-to-eat salads and high prevalent of antimicrobial resistance. Future research is required to track the contamination sources and develop appropriate steps that should be taken by industry and retailers to reduce microbial contamination in ready-to-eat salads.
ABSTRACT
In the last decade, ready-to-eat (RTE) salad vegetables are gaining increasing importance in human diet. However, since they are consumed fresh, inadequate washing during processing can bring on some foodborne illnesses, like salmonellosis, since these food items have natural contamination from soil and water. During 2009-2010, a total of 81 samples were purchased arbitrarily from local markets in Ankara, and were examined for Salmonella contamination. Salmonella screening was performed by using anti-Salmonella magnetic beads system and polymerase chain reaction (PCR) identification of the suspected colonies. Then, the antibiotic resistance profiles of four Salmonella strains identified (strains RTE-1, RTE-2, RTE-3, and RTE-4) were also investigated, since the mechanism by which Salmonella spp. have accumulated antibiotic resistance genes is of interest. All strains showed resistance against sulfonamides (MIC > 128 mg/L). Further results suggested that associated sulfonamide resistance genes were encoded by the 55.0 kb plasmid of strain RTE-1 that involves no integrons. As a result of using two primers (P1254 and P1283) in randomly amplified polymorphic DNA-PCR (RAPD-PCR) analysis, two common amplicons (364 bp and 1065 bp) were determined. The findings of this study provide support to the adoption of guidelines for the prudent use of antibiotics in order to reduce the number of pathogens present on vegetable and fruit farms. Besides, since it is shown that these bacteria started to gain resistance to antibiotics, it is necessary to further investigate the prevalence of them in foods.