Relative cytotoxicity of Escherichia coli O157:H7 isolates from beef cattle and humans.
Foodborne Pathog Dis
; 6(3): 357-64, 2009 Apr.
Article
en En
| MEDLINE
| ID: mdl-19278343
ABSTRACT
Differences and similarities between Escherichia coli O157H7 isolates from beef cattle and those from sporadic human outbreaks are not fully elucidated. Here, we compared 44 O157H7 isolates of bovine and human origins (22 isolates of each) to better understand their cytotoxic potential. The Shiga toxin genes stx1, stx2, or both were detected in the 44 isolates, and all elicited Vero cell cytotoxicity. The greatest cytotoxicity was caused by bovine isolates having only stx2 and which represented the majority of such isolates (81.8%). However, no correlation was found between the level of stx gene transcription and cytotoxicity. All human and bovine isolates possessed variant type stx2 and stx2c, respectively, as determined by PCR-restriction fragment length polymorphism. Isolates harboring both stx1 and stx2 genes were much more frequent in human isolates (86.4%). The combination stx1-stx2c found in only four bovine isolates was less cytotoxic. It is clear that cytotoxicity alone cannot account for the apparent inability of O157H7 bovine isolates to cause diseases in humans. We have found that stx1-stx2-containing or stx1-stx2c-containing isolates were less cytotoxic than several bovine isolates having only stx2c, suggesting that the stx gene combination or other virulence genes in specific genetic lineages may affect the disease outcome.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
3_ND
Problema de salud:
3_neglected_diseases
/
3_zoonosis
Asunto principal:
Bovinos
/
Muerte Celular
/
Escherichia coli O157
/
Toxina Shiga I
/
Toxina Shiga II
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Foodborne Pathog Dis
Asunto de la revista:
CIENCIAS DA NUTRICAO
/
MICROBIOLOGIA
/
PARASITOLOGIA
Año:
2009
Tipo del documento:
Article
País de afiliación:
Canadá