Document Type: Original Article

Authors

Department of Microbiology, College of Microbiology, Kerman Science and Research Branch, Islamic Azad University, Kerman, Iran

Abstract

Diarrhea is an important hygienic problem in under development countries. Among pathogenic agents Escherichia coli is the most etiologic agent of diarrhea in children below five years old. Some E. coli strains produce cytotoxins that have cytopathic effect on vero cell and identified as verotoxin. This study performs for resolve frequency of Vero Toxigenic Escherichia coli (VTEC) in Kerman city. Samples include 375 raw milk sample that obtained from city and 122 raw milk samples that collected from cattle farms. VTEC strains were serotype by Entro Pathogenic Esherchia coli (EPEC) antiserum. Verotoxin were measured by using vero cell. The results of this research show that from 375 raw milk samples (75.45 %) that prepared from Kerman city 7 samples (1.85 %) were contaminated and from 122 samples (24.55 %) that prepared from cow growth two samples have contamination with VTEC. Neutralization experiment show that from 9 VTEC strains that isolated from raw milk, 5 strain (55.5%) produce VT1 and 3 strains produce VT2 (33.3 %). Also one strain (11.11 %) produces VT1 and VT2. Degree of contamination within milks that sold in city than milk that prepare from cow growth have not any significant difference (P= 0.613). This study show VTEC have very important in Kerman city but O157:H7 serotype in the Kerman city have low frequency.

Keywords

Beutin, L., Borczyk, A., Wray, C. (1999). Bovine reservoir for Verotoxin producing Escherichia coli O157: H7 E. coli O157 in farm animals. CAB int, 53: 121-130.

Blanco, JE., Blanco, M., Mora, A. (1996). Methods used for the detection of verotoxigenic Escherichia coli in foods. Food Microb J, 34: 99-108.

Bouzari, S., Vatsala, BR., Varghese, A. (1994). Characterization of verotoxin-producing strains of enteropathogenic Escherichia coli (EPEC) from children with Diarrhea: effects of the toxin on rabbit intestine. Med J, 1: 47-51.

Conedera, G., Dalvit, P. (2004). Verotoxin producing E. coli O157 in minced beef and dairy products in Italy. Int J Food Microbiol, 96(1): 67-73.

Gillespie, IA., Obrien, SJ. (2005). Food borne general outbreaks of shigatoxin-producing E.coli O157 in England and Wales. Epidemiol Infect, 133(5): 803-808.

Honish, L., Predy, G., Hislop, N., Grochowska, K., Trottier, L., Kreplin, C. (2005). An outbreak of Escherichia coli O157:H7 hemorrhagic colitis associated with unpasteurized gouda cheese. Can J Public Health, 96: 182-184.

Jayarao, B., Donaldson, S. C., Straley, BA, Sawant, A.A., Hegde, NV., Brown, JL. A   2006. survey of foodborn pathogens in bulk tank milk and raw milk consumption among farm families in Pennsylvania. J Dairy Scien, 89: 2451-2458.

Katouli, M., Pachenary, A., Ketabi, GR. (1989). Vero cytotoxin production and Hela cell adherence of enteropathogenic Escherichia coli of infantile diarrhea in Iran. FEMS Microbiol Lett, 59: 177-180.

Konowalchuqk, J., Speris, J., Stavric, S. (1977). Vero response to a cytotoxin of Escheichia coli. Infec Immun, 18: 775-779.

Liptakova, A., Siegfried, L. (2004). A family outbreak of hemolytic uremic syndrom and haemorrhagic colitis caused by verotoxigenic Escherichia coli O157 from un pasteurized cows’ milk in Slovakia. Clinic Microbial Infect, 10(1): 576-578.

Mc Kee, R., Madden, RH., Gil Mou, A. (2003). Occurrence of verocytotoxin-producing Escherichia coli in dairy and meat processing environment. J Food Microbiol, 66: 1576-80.

Ralphexeal, A.  (1999). Enterohemorrhagic Escherichia coli and important food-born pathogen. Rev Path Digest, 22: 56-67.

Rey, J., Sanchez, S., Blanco, JE., Hermoso, J. (2006). Prevalence, serotypes and virulence genes of shiga toxin-producing E. coli isolated from ovine and caprine milk and other dairy products in Spain. Int J Food Microbio, 107: 207-12.

Trung, VN., Phung, V., Chinh Huy, Le., Andrej, W. (2005). Antibiotic resistance in diarrheagenic Escherichia coli and Shigella strains isolated from children in Hanoi, Vietnam. Antimicrob Agents Chemother, 49: 816-819.

Vanduynhoven, YT., Dejager, CM. (2002). Enhaced laboratory-based surveillance of shiga toxin producing Escherichia coli O157 in the Netherlands. Eur J Clinic Microbiol Infec Disease. 21: 513-22.

Walker, RI., Steele, D., Aguado, T. (2007). Analysis of strategies to successfully vaccinate infants in developing countries against enterotoxigenic Escherichia coli disease. Vaccine, 25: 2545-2566.

Wood, P L G., Clark, G. (2002). VTEC: a major public health threat in Denmark. Microbiol Res, 13 (5): 321-330.

Zhang, D., Liao, X. (2003). Pollution of EHEC O157:H7 six types of food in Hehan province. Weisheng Ganjiu, 32(5): 471-72.