Evaluation of Escherichia coli STb toxin in an in vitro organ culture model (IVOC) / Avaliação de toxina STb de Escherichia coli em modelo de cultura de órgãos in vitro (IVOC)

Cristina Paiva de Sousa, J. Daniel Dubreuil

Resumo


ETEC pathogenesis comprises adhesion to the small intestine, colonization and enterotoxin production. STb is one of the heat-stable toxins produced by ETEC. Previous reports, using culture supernatants of STb-positive ETEC strains, indicated loss of villous absorptive cells causing mild atrophy and microscopic alterations in jejunum mucosa. These culture supernatants contained many other compounds beside STb toxin and in addition the quantity of toxin in these supernatants was not determined. Thus, this study was undertaken to evaluate the effect of pure STb toxin on piglet jejunum explants in an in vitro organ culture (IVOC) model. Tissues of piglets of 11 weeks were used and put into culture. Morphometric analysis of tissues revealed that villous epithelial area was reduced in tissues treated with pure STb after 3, 4 and 5 hours (p < 0.0001) compared to untreated tissues. STb-treated tissues presented atrophic villi due to loss of villi tip. Our data shows that, in piglet jejunum explants, pure STb toxin can lead to cell modification and consequently to destruction, seen as villi atrophy. These changes result in a reduced absorptive area and could be partly responsible for the diarrhea observed in the animal following STb intoxication.


Palavras-chave


Escherichia coli, ETEC, STb enterotoxin, IVOC model, piglet jejunum

Texto completo:

PDF

Referências


Burgess, M.N., Bywater, R.J., Cowley, C.M., Mullan, N.A., Newsome, P.M., 1978. Biological evaluation of a methanol-soluble, heat-stable Escherichia coli enterotoxin in infant mice, pigs, rabbits, and calves. Infect. Immun., 21:526-531.

Dubreuil, J.D., 2008. Escherichia coli STb toxin and colibacillosis: knowing is half the battle. FEMS Microbiol. Lett., 278(2):137-145.

Erume, J., Berberov, E.M., Kachman, S.D., Scott, M.A., Zhou, Y., Francis, D.H., Moxley, R.A., 2008 Comparison of the contributions of heat-labile enterotoxin and heat-stable enterotoxin b to the virulence of enterotoxigenic Escherichia coli in F4ac receptor-positive young pigs. Infect. Immun., 76:3141-3149.

Girard, F., Batisson, I., Frankel, G.M., Harel, J., Fairbrother, J.M., 2005. Interaction of enteropathogenic and Shiga toxin-producing Escherichia coli and porcine intestinal mucosa: role of intimin and Tir in adherence. Infect. Immun., 73:6005-6016.

Gonçalves, C., Vachon, V., Schwartz, J.L., Dubreuil, J.D., 2007. The Escherichia coli enterotoxin STb permeabilizes piglet jejunal brush border membrane vesicles. Infect. Immun., 75:2208-2213.

Hitotsubashi, S., Fujii, Y., Yamanaka, H., Okamoto, K., 1992. Some properties of purified Escherichia coli heat-stable enterotoxin II. Infect. Immun., 60:4468-4474.

Kennedy, D.J., Greenbert, R.N., Dunn, J.A., Abernathy, R., Ryerse, J.S., Guerrant, R.L., 1984. Effects of Escherichia coli heat-stable enterotoxin STb on intestines of mice, rats, rabbits and piglets. Infect. Immun., 46:639-643.

Kosek, M., Bern, C., Guerrant, R.L., 2003. The global burden of diarrhoeal disease, as estimated from studies published between 1992 and 2000. Bull World Health Organ., 81(3):197-204.

Nagy, B., Fekete, P.Z., 2005. Enterotoxigenic Escherichia coli in veterinary medicine. Int. J. Med. Microbiol., 295:443–454.

Rose, R., Whipp, S.C., Moon, H.W., 1987. Effects of Escherichia coli heat-stable enterotoxin b on small intestinal villi in pigs, rabbits and lambs. Vet. Pathol., 24:71-79.

Whipp, S.C., 1990. Assay for enterotoxigenic Escherichia coli heat-stable toxin b in rats and mice. Infect. Immun., 58:930-934.

Whipp, S.C., 1987. Protease degradation of Escherichia coli heat-stable, mouse negative, pig-positive enterotoxin. Infect. Immun., 55:2057-2060.

Whipp, S.C., Moseley, S.L., Moon, H.W., 1986. Alterations in jejunal epithelium of three-week-old pigs induced by pig-specific, mouse-negative, heat-stable Escherichia coli enterotoxin. Am. J. Vet. Res., 47:615-618.

Zhang, W., Zhao, M., Ruesch, L., Omot, A., Francis, D., 2007. Prevalence of virulence genes in Escherichia coli strains recently isolated from young pigs with diarrhea in the US. Vet. Microbiol., 123:145–152.

Zhang, W., Berberov, E.M., Freeling, J., He, D., Moxley, R.A., Francis, D.H., 2006. Significance of heat-stable and heat-labile enterotoxins in porcine colibacillosis in an additive model for pathogenicity studies. Infect. Immun., 74:3107–3114.




DOI: https://doi.org/10.34188/bjaerv4n3-043

Apontamentos

  • Não há apontamentos.