Prevalence and distribution of the stx1, stx2 genes in Shiga toxin producing E. coli (STEC) isolates from cattle
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Abstract
Background and Objectives: Shiga toxin-producing Escherichia coli (STEC) strains are human pathogens linked to hemorrhagic colitis and hemolytic uremic syndrome. Shiga toxins (Stx1 and Stx2) are the major virulence factors of these strains. The aim of this work was to study the prevalence and distribution of stx1 and stx2 gene in E. coli O157:H7 and non-O157:H7 strains isolated from cattle in Shiraz, Iran.
Materials and Methods: Four hundred and twenty samples consisted of recto-anal mucosal swabs were collected from cattle. They were checked for the presence of the stx1 and stx2 gene using multiplex-PCR every 1 week over a 1-year period (2007-2008).
Results: A total of 146 strains carrying the stx1 and stx2 gene were isolated from 51 (12.14%) cattle. Overall, 15 (3.57%) were identified as O157:H7 and 131 (31.19%) revealed to be non-O157:H7. Both stx2 and stx1 genes were detected in 51 (34.93%) STEC isolates. Genotypes stx1 and stx2 were detected in 15 (10.27%) and 78 (53.42%) respectively. Seasonal distribution of stx genes revealed high percentage of positive animals in warm seasons. The gene sequence similarity ranged from 94 to 100%.
Conclusion: Frequency of stx1 and stx2 in animals and its relation to human disease is not well understood in Iran. The high prevalence of STEC in cattle seems to parallel that which is usually observed in warm seasons and it also parallels occurrence of human STEC. The higher prevalence of the stx2 gene than stx1 in strain populations isolated from cattle indicates a risk alert of E. coli O157:H7 being shed by cattle in these populations. Appropriate measures are now needed to prevent the spread of this life-threatening foodborne disease in our country.
Louie M, Azavedo J, Handelsman M, Clark C, Ally B, Dytoc M. Expression and characterization of the eaeA gene product of Escherichia coli serotype O157:H7. Infect Immun 1993; 61: 4085–4092.
Terrance MA, Genevieve ABG, Mildred RB, Koohm- araie M. Prevalence and Characterization of Non-O157 Shiga Toxin-Producing Escherichia coli on Carcasses in Commercial Beef Cattle Processing Plants. App En-viron Microbiol 2002; 68: 4847–4852.
Hussein SH, Brandolyn HT, Hudson AG. Verotoxin- producing Escherichia coli in sheep grazing an irrigat- ed pasture or arid rangeland forages. VTEC in Sheep 2003; 4: 358-364.
Riley LW, Remis RS, Helgerson SD, McGee HB, Wells JG, Davis BR, et al. Hemorrhagic colitis associ- ated with a rare Escherichia coli serotype. New Eng JMed 1983; 308: 681–685.
Bonardi S, Maggi E, Bottarelli A, et al. Isolation of verocytotoxin-producing Escherichia coli O157:H7 from cattle at slaughter in Italy. Vet Microbiol 1999;67: 203-211.
Molina PM, Parma AE, Sanz M. Survival in acidic and alcoholic medium of shiga toxin-producing Escheri- chia coli O157:H7 and non-O157:H7 isolates in Ar- gentina. BMC Microbiol 2003; 13: 3-17.
McDonough PL, Rossiter CA, Rebhun RB, Stehman SM, Lein DH, Shin SJ. Prevalence of Escherichia coli O157:H7 from cull dairy cows in New York state and comparison of culture methods used during preharvest food safety investigations. J Clin Microbiol 2000; 38:318-322.
Jamshidi A, Bassami MR, Rasooli M. Isolation of Escherichia coli O157:H7 from ground beef samples collected from beef markets, using conventional culture and polymerase chain reaction in Mashhad, northeastern Iran. Iran J Vet Res, Shiraz Univers 2008; 9: 72-76.
Paton JC, Paton AW. Pathogenesis and diagnosis of Shiga toxin-producing Escherichia coli infections. Clin Microbiol Rev 1998; 11: 450-479.
Acheson DW. How does Escherichia coli O157:H7 testing in meat compare with what we are seeing clini- cally? J Food Protect 2000; 63: 819-821.
Schmidt H, Scheeff J, Huppertz HI, Frosch M, Karch H. scherichia E.coli O157:H7 and O157:H2 strains that do not produce Shiga toxin: phenotypic and genetic characterization of isolates associated with diarrhea and hemolytic-uremic syndrome. J Clin Microbiol 1999; 37: 3491-3496.
Obrig TG. Interaction of Shiga toxins with endothelial cells: Washington, D.C., 1998.
Lindgren SW, Samuel JE, Schmitt CK, O’Brien AD.The specific activities of Shiga-like toxin type II (SLT- II) and SLT-II-related toxins of enterohemorrhagic Escherichia coli differ when measured by Vero cell cytotoxicity but not by mouse lethality. Infect Immun 1994; 62: 623-631.
Schmidt H, Scheef J, Morabito S, Caprioli A, Wieler LH, Karch H. A new Shiga toxin 2 variant (Stx2f) from Escherichia coli isolated from pigeons. Appl Environ Microbiol 2000; 66: 1205-1208.
Weinstein DL, Jackson MP, Samuel JE, Holmes RK, D. OBA. Cloning and sequencing of a Shiga-like toxin type II variant from an Escherichia coli strain respon- sible for edema disease of swine. J Bacteriol 1988;170: 4223-4230.
Ludwig K, Karmali MA, Sarkim V, Bobrowski C,Petric M, Karch H, et al. Antibody response to Shiga toxins Stx2 and Stx1 in children with enteropathic hemolytic-uremic syndrome. J Clin Microbiol 2001;39: 2272–2279.
Nataro JP, Kaper JB. Diarrheagenic Escherichia coli.Clin Microbiol Rev 1998; 11: 142-201.
Aslani MM and Bouzari S. An epidemiological study on Verotoxin-producing Escherichia coli (VTEC) infec- tion among population of northern region of Iran Ma- zandaran and Golestan provinces. Europ J Epidemiol 2003; 18 : 345-349.
Jomezadeh N, Farajzadeh Sheikh A, Khosravi AD, Amin M. Detection of Shiga Toxin Producing E. coli Strains Isolated from Stool Samples of Patients with Di- arrhea in Abadan Hospitals. Iran J Biolog Sci 2009; 9:820-824.
Salmanzadeh-Ahrabi S, Habibi E, Jaafari F, Zali MR.Molecular epidemiology of Escherichia coli diarrhoea in children in Tehran. Ann Trop Paediat 2005; 25 : 35-39.
Zahraei Salehi T, Mahzounieh M, Asadian F, Khosravi M. Virulence genes in Escherichia coli isolates from calves in shahrekord area, Iran. 16th European Congress of Clinical Microbiology and Infectious Disease, Nice, France 2006.
Shekarforoosh S, Tahamtan Y, Pourbakhsh A. Detec- tion and frequency of stx2 gene in E.coli O157 and O157 strains isolated from sheep carcasses in Shreaz- Iran. Pakistan J Biomed Sci 2008; 11 (8): 1085-1092.
Sepehriseresht S, Zahraei Salehi T, Sattari M, Tad- jbakhsh H, Aslani MM. Detection of shigatoxigenic Escherichia coli from fecal samples of calves and cattle by molecular and serological methods. Comparat Clin Pathol 2008; 3: 12-17.
Askari Badouei M, Zahraei Salehi T, Rabbani Khoras-gani M, Tadjbakhsh H, Nikbakht Brujeni G. Occurrence coli belonging to seropathotypes A and C. Microbiol 2008;154: 176–186.
Karmali MA, Mascarenhas M, Shen S, Ziebell K, John- son S, Reid-Smith R, et al. Association of genomic O island 122 of Escherichia coli EDL 933 with verocy- totoxin-producing Escherichia coli seropathotypes that are linked to epidemic and/or serious disease. J Clin Mi- crobiol 2003; 41: 4930-4940.
Keen EJ, Elder RO. Isolation of Shiga-toxigenic Escher- ichia coli O157 from hide surface and the oral cavity of finished beef feedlot cattle. JAMA 2002; 220: 756- 763.
Aljaro CG, Muniesa M, Jofre J, Blanch AR. Prevalence of the stx2 gene in coliform populations from Aquat- ic Environments. Appl Environ Microbiol 2004; 70 :3535–3540.
Bonardi S, Maggi E, Pizzin G, Morabito S, Caprioli A.Faecal carriage of Verocytotoxin-producing Escheri- chia coli O157 and carcass contamination in cattle at slaughter in northern Italy. Int J Food Microbiol 2001;66: 47-53.
Hancock DD, Besser TE, Kinsel ML, Tarr PI, Rice DH, Paros MG. The prevalence of Escherichia coli O157:H7 in dairy and beef cattle in Washington State. Epidemiol Infect 1994; 113: 199–207.
Ellingsona JLE, Koziczkowskia JJ, Andersona JL, Carl- sonb SA, Sharmab VK. Rapid PCR detection of entero- hemorrhagic Escherichia coli (EHEC) in bovine food products and feces. Mol Cell Probes 2005; 19: 213-217.
Ludwig K, Sarkim V, Bitzan M, Karmali MA, Bo- browski C, Ruder H, et al.Shiga Toxin-Producing Es- cherichia coli infection and antibodies against Stx2 and Stx1 in household contacts of children with enteropathic hemolytic-uremic syndrome. J Clin Microbiol 2002; 40:12-17.
Tesh VL, Burris JA, Owens JW, Gordon VM,coli isolates from diarrhoeic calves. Comparat Clin Pathol 2009; 9: 201-205.
Rahimi E, Momtaz H, Hemmatzadeh F. The prevalence of Escherichia coli O157:H7, Listeria monocytogenes and Campylobacter spp. on bovine carcasses in Isfahan, Iran. Iran J Vet Res 2008; 9: 365-370.
de Sablet T, Bertin Y, Vareille M, Girardeau JP, Gar- rivier A, Gobert AP, et al. Differential expression of stx2 variants in Shiga toxin-producing Escherichia Wadolkowski EA, O’Brien AD, et al. Comparison f the relative toxicities of Shiga-like toxins type I and type II for mice. Infect Immun 1993; 61 3392-3402.
Fagen PK, Hornitzky MA, Bettelheim KA, Djordjevic SP. Detection of Shiga-Like Toxin (stx1 and stx2), In- timin (eaeA), and Enterohemorrhagic Escherichia coli (EHEC) Hemolysin (EHEC hlyA) Genes in Animal Fe- ces by Multiplex PCR. Appl Environ Microbiol 1999;65 : 868-872.
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| Issue | Vol 2 No 1 (2010) | |
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