INCIDENCE OF E.COLI O157:H7 IN SOME DAIRY PRODUCTS

Asmaa M. Elbastawesy, Azza M.M. Deeb, Nehad I. El-desoky
2016 Kafrelsheikh Veterinary Medical Journal  
A total of 104 dairy product samples (33 kareish cheese, 38 yoghurt and 33 sour cream) were randomly purchased from different shops, markets and street vendors in Kafer El-Sheikh city for isolation and serological identification of E.coli serotype O157: H7. 24.2%, 21% and 42.2% of kariesh cheese, yoghurt and sour cream respectively, contained E.coli. All the suspected strains were serologically identified for E.coli O157:H7, using E.coli O157:H7 kits. The organism could be detected in 3% of
more » ... tected in 3% of examined kareish cheese while could not be detected in yoghurt and sour cream examined samples. E.coli serotypes of .5% , 25% and 20%) and (12.5%,0 and 6.7%) of the isolates of each examined kareish cheese, yoghurt and sour cream samples respectively. Based on the obtained results in the current study, the fermented dairy products were a possible source of food poisoning caused by E.coliO157:H7.So, application of strict hygienic measures during processing of some dairy products and restriction of selling the dairy products to healthy authorized shops with high quality measures being very important. Incidence Of E.Coli O157:H7 In Some Dairy Products. Asmaa M. Elbastawesy et., al. A total of 104 dairy product samples (33 kareish cheese, 38 yoghurt and 33 sour cream) were randomly purchased from different shop, markets and street vendors in Kafer El-Sheikh City. The collected samples were transferred in ice box and examined immediately after arrival to the laboratory (Animal Health Research Institute, Kafer El-Sheikh branch). Isolation of E.coli O157:H7 according toFDA, (1995): Twenty five grams of prepared samples were added to 225ml of Enteroheamoragic E. Coli enrichment broth (EEB), homogenized then incubated at 37°C for 24 hours.Aloopful from the incubated broth was streaked onto Cefixime Tellurite Sorbitol Mac Conkey agar (CT-SMAC) plates and all plates were incubated at 37°C for 24 hours. Transparent, colorless with a weak pale brownish appearance (sorbitol negative) colonies were picked up on nutrient agar slopes as presumptive E.coli O157:H7. The purified colonies were subjected for further identification. Biochemical identification of bacterial isolates:- The isolated organisms were identified biochemically according to Macfaddin, (2000). Serological Identification of E.coli isolates: According to Kok et al., (1996) the isolates were serologically identified by using rapid diagnostic E.coli antisera sets DENKA SEIKEN Co., Japanfor diagnosis of E.coli. Incidence Of E.Coli O157:H7 In Some Dairy Products. Asmaa M. Elbastawesy et., al. : Laboratory practices for the identification of Shiga toxin-producing Escherichia coli in the United States, FoodNet Sites, 2007. Foodborne pathogens and disease,8, 555-560. -Holko, I., Bisova, T., Holkova, Z. and Kmet, V. (2006):Virulence markers of E.coli strains isolated from traditional cheeses made from unpasteurised sheep milk in Slovakia:, Food Control,17(5): 393-396. -Ibrahim, E. M. A. and Sobeih, M. A.(2006): Diarrhoegenic E. coli in Kareish cheese manufactured by different methods with special reference to E. coli O157:H7. . Minufiya Veterinary Medicine Journal, 4, 169-178. -Ibrahim, G. A., Sharaf, O. M. and El-Khalek, A. B. A.(2015): Microbiological Quality of Commercial Raw Milk, Domiati Cheese and Kareish Cheese. Sciences,5, 171-176. -Jordan, K. N., Oxford, L. and O'Byrne, C. P.(1999): Survival of low-pH stress by Escherichia coli O157: H7: correlation between alterations in the cell envelope and increased acid tolerance. Applied and Environmental Microbiology,65, 3048-3055.
doi:10.21608/kvmj.2016.108871 fatcat:asonxrxehbaqhhnaih75fnyd6m