Biology Reference
In-Depth Information
visible fecal contamination, especially in lambs that may have soft stools and
sometimes diarrhea. Moreover, a lack of GHP application at slaughterhouses can
occur during intensive production. The nondetection of VTEC in feces is likely due
to limited sensitivity of the method, considering the presence of a polymicrobial
flora and other PCR-inhibiting factors, such as bile salts.
The molecular method used here was useful as a rapid screening test for direct
detection of VTEC in food matrices. This method showed a greater sensitivity than
culture-based methods, but the latter are essential for confirming the presence of the
pathogen and for defining their pathogenic profiles. Furthermore, the application of
multiplex PCR allowed for the detection of different pathotypes of considerable
public health interest. These results, although preliminary, confirm the complexity
of ovine E. coli pathogenic profiles. Further molecular investigations will be
performed to both determine serotypes and detect other pathogenic factors (Paton
et al. 2004 ).
Acknowledgments This work has been supported by the Italian Ministry of University and
Scientific Research (PRIN 2007).
References
Blanco JE, Blanco M, Blanco J, Mora A, Balaguer L, Mourin M, Juarez A, Jansen WH (1996)
O Serogroups, Biotypes, and eae Genes in Escherichia coli Strains Isolated from Diarrheic and
Healthy Rabbits. J Clin Microbiol 34:3101-3107
Bonardi S, Leccese C (2006) Il ruolo della specie bovina e di altri ruminanti nell'epidemiologia
delle infezioni da Escherichia coli vero citotossici. Annali della Facolt` di Medicina
Veterinaria di Parma 26:205-218
Djordjevic SP, Ramachandran V, Bettelheim KA, Vanselow BA, Holst P, Bailey G, Hornitzky
MA (2004) Serotypes and Virulence Gene Profiles of Shiga Toxin-Producing Escherichia coli
Strains Isolated from Feces of Pasture-Fed and Lot-Fed Sheep. Appl Environ Microbiol
70:3910-3917
Karmali MA, Gannon V, Sargeantb JM (2010) Verocytotoxin-producing Escherichia coli
(VTEC). Vet Microbiol 140:360-370
Ogden ID, MacRae M, Strachan NJ (2005) Concentration and prevalence of Escherichia coli
O157 in sheep faeces at pasture in Scotland. J Appl Microbiol 98:646-651
Paton JC, Paton AW (1998) Pathogenesis and diagnosis of Shiga toxin-producing Escherichia coli
infections. Clin Microbiol Rev 11:450-479
Paton AW, Srimanote P, Talbot UM, Wang H, Paton JC (2004) A new family of potent AB(5)
cytotoxins produced by Shiga toxigenic Escherichia coli . J Exp Med 200:35-46
Pierard D, Muyldermans G, Moriau L, Stevens D, Lauwers S (1998) Identification of new
verocytotoxin type 2 variant b-subunit genes in human and animal Escherichia coli isolates.
J Clin Microbiol 36:3317-3322
Report EFSA (2010) Trends and Sources of Zoonoses and Zoonotic Agents and Food-borne
Outbreaks in the European Union in 2008. EFSA J 8:1496
Urdahl AM, Alvseike O, Skjerve E, Wasteson Y (2001) Shiga toxin genes ( stx ) in Norwegian
sheep herds. Epidemiol Infect 127:129-134
Zweifel C, Zychowska MA, Stephan R (2004) Prevalence and characteristics of Shiga toxin-
producing Escherichia coli, Salmonella spp. and Campylobacter spp. isolated from slaughtered
sheep in Switzerland. Int J Food Microbiol 92:45-53
Search WWH ::




Custom Search