Document Type : Short Communication


1 Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

2 Department of Microbiology, Faculty of Veterinary Medicine, Branch of Karaj, Islamic Azad University, Karaj, Iran

3 Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran


Enterotoxigenic Escherichia coli (ETEC) produces different virulence factors allowing the bacterium to colonize and develop watery diarrhea. Proteomics studies have also introduced new protein belonging to the secretion pathways, antigen 43 (Ag43), which plays important role in E. coli pathogenesis. The objective of this study was to investigate O-types and virulence factors of E. coli isolates from neonatal calves diarrhea. Total of 120 isolates from diarrheic calves were genotyped for their O groups and the presence of virulence genes K99, F41 and STa as well as Ag43. The predominant O-type was O101 (51.00%) and the prevalence of K99, F41 and STa was 7 (5.80%). The Ag43 was detected in all samples with three different allelic patterns. Our results indicated that K99 positive isolates certainly have one of each 2200 bp or 1800 bp or both copies of Ag43 passenger domain, while negative K99 isolates lack the Ag43. The results reported here provide informative data regarding the prevalence of E. coli O-types and their virulence factors in enteric colibacillosis. The Ag43 that was more found in K99 positive isolates might be associated with diarrhea-causing E. coli strains in neonatal calves.


Main Subjects


    1. Constable PD. Antimicrobial use in the treatment of calf diarrhea. J Vet Int Med 2004; 18 (1), 8-17.
    2. Lorenz I, Fagan J, More SJ. Calf health from birth to weaning. II. Management of diarrhea in pre-weaned calves. Irish Vet J 2011; 64 (1): 9.
    3. Cho YI, Yoon J. An overview of calf diarrhea - infectious etiology, diagnosis, and intervention. J Vet Sci 2014; 15(1): 1-17.
    4. Franck SM, Bosworth BT, Moon HW. Multiplex PCR for enterotoxigenic, attaching and effacing, and Shiga toxin-producing Escherichia coli strains from calves. J Clin Mic 1998; 36 (6): 1795-1797.
    5. Foster D, Smith GW. Pathophysiology of diarrhea in calves. Vet Clin North Am Food Anim Pract 2009; 25 (1): 13-36.
    6. Nagy B, Fekete, PZ. Enterotoxigenic Escherichia coli in veterinary medicine. Int J Med Microbiol 2005; 295 (6-7): 443-454.
    7. Shams Z, Tahamtan Y, Pourbakhsh A, et al. Detection of enterotoxigenic K99 (F5) and F41 from fecal sample of calves by molecular and serological methods. Comp Clin Path 2012; 21(4): 475-478.
    8. Younis EE, Ahmed AM, El-Khodery SA, et al. Molecular screening and risk factors of enterotoxigenic Escherichia coli and Salmonella spp. in diarrheic neonatal calves in Egypt. Res Vet Sci 2009; 87 (3): 373-379.
    9. Nagy B, Fekete, PZ. Enterotoxigenic Escherichia coli (ETEC) in farm animals. Vet Res 1999; 30 (2-3): 259-284.
    10. Gyles CL, Fairbrother JM. Escherichia coli. In: Gyles CL, Prescott JF, Songer JG, et al (Eds). Pathogenesis of bacterial infections in animals. Ames, USA: Blackwell 2004; 193-223.
    11. Blanco J, Blanco M, Garabal JL, et al. Enterotoxins, colonization factors and serotypes of enterotoxigenic Escherichia coli humans and animals. Microbiologia 1991; 7(2):57-73.
    12. Güler L, Gündüz K, Ok Ü. Virulence factors and antimicrobial susceptibility of Escherichia coli isolated from calves in Turkey. Zoonoses Public Health 2008; 55 (5): 249-257.
    13. Harris JA, Roy K, Woo-Rasberry V, et al. Directed evaluation of enterotoxigenic Escherichia coli auto-transporter proteins as putative vaccine candidates. PLoS Negl Trop Dis 2011; 5(12): e1428. doi: 10.1371/journal.pntd.0001428.
    14. Luo Q, Qadri F, Kansal R, et al. Conservation and immunogenicity of novel antigens in diverse isolates of enterotoxigenic Escherichia coli. PLoS Negl Trop Dis 2015; 9 (1): e0003446. doi: 10.1371/journal.pntd. 0003446.
    15. Van Bloois E, Winter RT, Kolmar H, et al. Decorating microbes: Surface display of proteins on Escherichia coli. Trends Biotechnol 2011; 29 (2): 79-86.
    16. Leo JC, Grin I, Linke D. Type V secretion: Mechanism(s) of autotransport through the bacterial outer membrane. Philos Trans R Soc B Biol Sci 2012; 367 (1592): 1088-1101.
    17. Ramesh B, Sendra VG, Cirino PC, et al. Single-cell characterization of autotransporter-mediated Escherichia coli surface display of disulfide bond-containing proteins. J Bio Chem 2012; 287 (46): 38580-38589.
    18. Restieri C, Garriss G, Locas MC, et al. Autotransporter-encoding sequences are phylogenetically distributed among Escherichia coli clinical isolates and reference strains. Appl Environ Microbiol 2007; 73 (5): 1553-1562.
    19. Roche AJ, McFadden JP, Owen P. Antigen 43, the major phase-variable protein of the Escherichia coli outer membrane, can exist as a family of proteins encoded by multiple alleles. Microbiology 2001; 147 (Pt 1): 161-169.
    20. Sahl JW, Steinsland H, Redman JC, et al. A comparative genomic analysis of diverse clonal types of enterotoxigenic Escherichia coli reveals pathovar-specific conservation. Infect Immun 2011; 79 (2): 950-960.
    21. Caffrey P, Owen P. Purification and N-terminal sequence of the alpha subunit of antigen 43, a unique protein complex associated with the outer membrane of Escherichia coli. J Bacteriol 1989; 171(7): 3634-3640.
    22. Heras B, Totsika M, Peters KM, et al. The antigen 43 structure reveals a molecular Velcro-like mechanism of autotransporter-mediated bacterial clumping. Proc Nat Acad Sci USA 2014; 111 (1): 457-462.
    23. Wallecha A, Oreh H, Marjan W, et al. Control of gene expression at a bacterial leader RNA, the agn43 gene encoding outer membrane protein Ag43 of Escherichia coli. J Bacteriol 2014; 196 (15): 2728-2735.
    24. Murray C. Salmonella and Escherichia coli from veterinary and human sources in Australia during 1985 and 1986. Aust Vet J 1987; 64 (8): 256-257.
    25. Ojeniyi B, Ahrens P, Meyling A. Detection of fimbrial and toxin genes in Escherichia coli and their prevalence in piglets with diarrhea. The application of colony hybridization assay, polymerase chain reaction and phenotypic assays. Zentralbl Veterinarmed B 1994; 41 (1): 49-59.
    26. Wray C, McLaren I, Carroll P. Escherichia coli isolated from farm animals in England and Wales between 1986 and 1991. Vet Rec 1993; 133 (18): 439-442.
    27. Mainil J. Escherichia coli virulence factors. Vet Immunol Immunopathol 2013; 152 (1): 2-12.
    28. Picco NY, Alustiza FE, Bellingeri RV, et al. Molecular screening of pathogenic Escherichia coli strains isolated from dairy neonatal calves in Cordoba province, Argentina. Rev Argent Microbiol 2015; 47(2): 95-102.
    29. Pourtaghi H, Dahpahlavan V, Momtaz H. Virulence genes in Escherichia coli isolated from calves with diarrhea in Iran. Comp Clin Patho 2013; (22): 513-515.
    30. Acha S, Kühn I, Jonsson, P, et al. Studies on calf diarrhea in Mozambique: Prevalence of bacterial pathogens. Acta Vet Scand 2004; 45 (1-2): 27-36.
    31. Sherwood D, Snodgrass D, Lawson G. Prevalence of enterotoxigenic Escherichia coli in calves in Scotland and northern England. Vet Rec 1983; 113 (10): 208-212.
    32. Quinn PJ, Carter ME, Markey B, Carter GR. Clinical veterinary microbiology. Madrid, Spain: Wolfe Publishing 1994; 209-236.
    33. Shahrani M, Dehkordi FS, Momtaz H. Characterization of Escherichia coli virulence genes, pathotypes and antibiotic resistance properties in diarrheic calves in Iran. Biol Res 2014; 47 (1): 28.
    34. Tzipori S. The relative importance of enteric pathogens affecting neonates of domestic animals. Adv Vet Sci Comp Med 1985; 29: 103-206.
    35. Thorns C, Sojka M, Roeder P. Detection of fimbrial adhesins of ETEC using monoclonal antibody-based latex reagents. Vet Rec 1989; 125 (4): 91-92.
    36. Zhang W, Zhao M, Ruesch L, et al. Prevalence of virulence genes in Escherichia coli strains recently isolated from young pigs with diarrhea in the US. Vet Microbiol 2007; 123 (1-3): 145-152.
    37. Kauffmann F. The serology of the coli group. J Immunol 1947; 57 (1): 71-100.
    38. Dezfulian H, Batisson I, Fairbrother JM, et al. Presence and characterization of extraintestinal pathogenic Escherichia coli virulence genes in F165-positive E. coli strains isolated from diseased calves and pigs. J Clin Microbiol 2003; 41 (4): 1375-1385.
    39. Wells TJ, Totsika M, Schembri MA. Autotransporters of Escherichia coli: A sequence-based characterization. Microiology 2010; 156 (Pt 8): 2459-2469.
    40. Van der Woude MW, Henderson IR. Regulation and function of Ag43 (flu). Annu Rev Microbiol 2008; (62): 153-169.