Evaluation of the prevalence of enterotoxigenic and enteropathogenic Escherichia coli in raw milk and dairy products by Duplex-PCR

Subject Areas : Journal of Comparative Pathobiology

Abri, R., Razavilar, V., Javadi, A., Ahangarzadeh Rezaee, M., Zahraei Salehi, T. . ¹ ( . )

Received: 2017-02-12 Accepted : 2017-02-12 Published : 2017-06-22

Keywords: scherichia coli, Enterotoxigenic, Enteropathogenic, Raw milk products, Duplex-PCR,

Abstract :

Enterotoxigenic Escherichia coli is very important and usual, particularly in the developing countries and it is the main reason of diarrhea in travelers to developing countries. Enteropathogenic Escherichia coli strains are defined as intimin-containing diarrheagenic E. coli but do not produce Shiga toxin, which can cause diarrhea in humans and different animal species. Pathogenic Escherichia coli strains are commonly transmitted through contaminated food and water. The aim of this study was to identify Escherichia coli pathotypes in raw milk and dairy product samples using Duplex PCR. A total of 102 raw milk and dairy products samples were randomly collected from different localities in Western Azerbaijan and transferred in sterile conditions to department of food and drug microbiology lab, affiliated to Tabriz University of medical sciences. 46 E. coli were identified based on culture and a number of biochemical tests. Duplex PCR assay were developed for detection of enterotoxigenic and enteropathogenic Escherichia coli. The target genes selected for each category were the lt and st for ETEC, eae and bfp for EPEC isolates. According to the results, the rate of E. coli in samples was 45%. No ETEC strains were isolated from any of the samples examined and only 2 (4.34%) EPEC strains were identified. Previous studies and our results showed the high percentage of E. coli and EPEC in raw milk products.  It was concluded that using raw milk without pasteurization, and using traditional dairy products produced in unsanitary conditions and are the main resources for growth of E. coli pathotypes.

References:

 

1-      پورعلی بهزاد٬ م.٬ میرزایی٬ ح. (1390): مطالعه میزان آلودگی پنیر های سنتی عرضه شده در بازار تبریز به کلی فرم ها و اشریشیا کولای بیماریزا. مجله بهداشت مواد غذایی٬ 3: 71-80.

2-      وزیری٬ س.٬ نوروزی٬ م. (1390): بررسی میزان آلودگی پنیرهای محلی لیقوان تبریز به کلیفرم ها و اشرشیا کلی در شهر مراغه. مجله میکروب شناسی پزشکی ایران٬ :7 23-28.

 

3-      Abbar, F., Kaddar, H.K. (1991): Bacteriological studies on Iraqi milk products. J. appl. bacteriol.71: 497-500.

4- Altalhi, A.D., Hassan, S.A. (2009): Bacterial quality of raw milk investigated by Escherichia coli and isolates analysis for specific virulence-gene markers. Food control. 20: 913-917.

5- Araujo, V., Pagliares, V., Queiroz, M., Freitas‐Almeida, A. (2002). Occurrence of Staphylococcus and enteropathogens in soft cheese commercialized in the city of Rio de Janeiro, Brazil. J. Appl. Microbiol. 92: 1172-1177.

6- Aslani, M., Alikhani, M. (2009): Serotypes of enteropathogenic Escherichia coli isolated from children under 5 years of age. Iranian J. Publ. Health. 38: 70-77.

7- Bueris, V., Sicili, M. P., Taddei, C. R., Santos, M. F. D., Franzolin, M. R., Martinez, M. B., Ferrer, S. R., Barretto, M. L., Trabulsi, L. R. (2007): Detection of diarrheagenic Escherichia coli from children with and without diarrhea in Salvador, Bahia, Brazil. Memó. I. Oswaldo Cruz. 102: 839-844.

8- Canizalez-Roman, A., Gonzalez-Nunez, E., Vidal, J. E., Flores-VillasenorI, H., LEÓN-Sicairos, N. (2013): Prevalence and antibiotic resistance profiles of diarrheagenic Escherichia coli strains isolated from food items in northwestern Mexico. Int. J. Food Microbiol. 164: 36-45.

9- Estrada-Garcia, T., Lopez-Saucedo, C., Thompson-Bonilla, R., Abonce, M., Lopez-Hernandez, D., Santos, J. I., Rosado, J. L., Dupont, H. L., Long, K. Z. (2009):Association of diarrheagenic Escherichia coli pathotypes with infection and diarrhea among Mexican children and association of atypical enteropathogenic E. coli with acute diarrhea. J. clin. Microbiol. 47: 93-98.

10- Fadaei, A., Jamshidi, E., Kheiri, S. (2008): Comparison of bacterial contamination of raw and pasteurized milk used in Shahrekord in 2006. J. Shahrekord Univ. Med. Sci. 10:37-44.

11- Faramarzi, T., Jonidi Jafari, A., Dehghani, S., Mirzabeigi, M., Naseh, M., Rahbar Artesh, H. (2012): A survey on Bacterial Contamination of Food Supply in the West of Tehran. J. Fasa Univ. Med. Sci. 2: 11-18.

12- Hayes, M., Ralyea, R., Murphy, S., Carey, N., Scarllet, J., Boor, K. (2001): Identification and characterization of elevated microbial counts in bulk tank raw milk. Journal of dairy science: 84, 292-298.

13- Hiett, K. L., Seal, B. S. (2009): Use of repetitive element palindromic PCR (rep-PCR) for the epidemiologic discrimination of foodborne pathogens. Molecular Epidemiology of Microorganisms. Springer.

14- Holko, I., Bisova, T., Holkova, Z., Kmet, V. (2006): Virulence markers of Escherichia coli strains isolated from traditional cheeses made from unpasteurised sheep milk in Slovakia. Food Control. 17:393-396.

15- Ishii, S., Meyer, K. P., Sadowsky, M. J. (2007): Relationship between phylogenetic groups, genotypic clusters, and virulence gene profiles of Escherichia coli strains from diverse human and animal sources. Appl. Environ. Microb. 73:5703-5710.

16- Kuhnert, P., Boerlin, P., Frey, J. (2000): Target genes for virulence assessment of Escherichia coli isolates from water, food and the environment. FEMS Microbiol Rev. 24: 107-117.

17- Mohammadi, P., Abri, R. (2013): Isolation of Enteropathogenic Escherichia coli (EPEC) from raw milk in Kermanshah by polymerase chain reaction (PCR). Jundishapur. J. Microb. 6.

18- Najand, L. M., Ghanbarpour, R. (2007): A study on enteropathogenic Escherichia coli isolated from domestic Iranian soft cheese. Vet. Arh. 76:531.

19- Soomro, A., Arain, M., Khaskheli, M., Bhutto, B. (2002): Isolation of Escherichia coli from raw milk and milk products in relation to public health sold under market conditions at Tandojam. Pak. J. Nutr. 1: 151-152.

20- Tobias, J., Svennerholm, A.-M. (2012): Strategies to overexpress enterotoxigenic Escherichia coli (ETEC) colonization factors for the construction of oral whole-cell inactivated ETEC vaccine candidates. Appl. Microbiol. Biotechnol. 93: 2291-2300.

21- Vidal, M., Kruger, E., Duran, C., Lagos, R., Levine, M., Prado, V., Toro, C. & Vidal, R. (2005): Single multiplex PCR assay to identify simultaneously the six categories of diarrheagenic Escherichia coli associated with enteric infections. J. Clin. Microbiol. 43: 5362-5365.

22- Vilchez, S., Reyes, D., Paniagua, M., Bucardo, F., Molby, R., Weintraub, A. (2009). Prevalence of diarrhoeagenic Escherichia coli in children from Leon, Nicaragua. J. Med. Microbiol. 58: 630-637.