[afro-nets] Open Learning Web site on Enteric pathogens (3)

["Salvatore Rubino" <rubino@uniss.it>]

Open Learning Web site on Enteric pathogens (3)
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Dear Friends of the Open Learning Web site on Enteric pathogens

A new lecture is available at:
http://www.aclisassari.com/acli-openlearning

Lucchesi P.M.A., Kruger A. (Argentina)
Lab.Inmunoquímica y Biotecnología. Fac. Cs. Veterinarias ? UNCPBA 
Tandil

Saa (STEC autoagglutinating adhesin) gene variants in verocytotoxigenic 
Escherichia coli

Verocytotoxigenic Escherichia coli (VTEC), also called shiga toxin-
producing E. coli (STEC), can cause diarrhea, hemorrhagic colitis and 
hemolytic-uremic syndrome (HUS) in humans. The pathogenesis of VTEC 
infection in humans is multifactorial and not fully understood, being 
the verocytotoxins the principal virulence factor. Most strains causing 
serious diseases also possess the eae gene that encodes the adhesin 
intimin, but its presence is not essential for virulence as there are 
some cases caused by eae-negative strains. Saa gene, described from an 
eae-negative VTEC strain responsible for an outbreak of HUS, encodes an 
outer membrane protein which appears to function as an 
autoagglutinating adhesin. Saa proteins from diverse VTEC strains show 
marked variation in size, due largely to differences in the number of 
copies of a 37-aa repeat unit in the C-terminal region. Based on these 
findings, we designed PCR primers to amplify the region coding for 
these differences and then investigated the distribution of saa gene 
variants in a collection of VTEC strains isolated from cattle and meat 
in Argentina. Gene saa was detected in 36 (31.6%) eae-negative strains 
and 5 variants were found. Two of them, those with a higher number of 
repeats, correspond to novel saa variants

Ciao Salvatore Rubino

--
Prof. Salvatore Rubino
Dip. di Scienze Biomediche
V.le San Pietro 43/b
07100 Sassari (Italy)
Tel:+39-79-228302
Fax: +39-79-212345
Cell: +39-3383865292
mailto:rubino@uniss.it