Expression of Cholera Toxin under Non-AKI Conditions in Vibrio cholerae El Tor Induced by Increasing the Exposed Surface of Cultures
Por:
Sánchez J., Medina G., Buhse T., Holmgren J., Soberón-Chavez G.
Publicada:
1 ene 2004
Resumen:
The regulatory systems controlling expression of the ctxAB genes encoding cholera toxin (CT) in the classical and El Tor biotypes of pathogenic Vibrio cholerae have been characterized and found to be almost identical. Notwithstanding this, special in vitro conditions, called AKI conditions, are required for El Tor bacteria to produce CT. The AKI conditions involve biphasic cultures. In phase 1 the organism is grown in a still tube for 4 h. In phase 2 the medium is poured into a flask to continue growth with shaking. Virtually no expression of CT occurs if this protocol is not followed. Here we demonstrated that CT expression takes place in single-phase still cultures if the volume-to-surface-area ratio is decreased, both under air and under an inert atmosphere. The expression of key genes involved in the regulation of CT production was analyzed, and we found that the expression pattern closely resembles the in vivo expression pattern.
Filiaciones:
Facultad de Medicina, UAEM, Cuernavaca, Mexico
Facultad de Medicina, Av. Universidad 1001, Cuernavaca, Morelos, CP 62210, Mexico
Depto. de Microbiologia Molecular, Instituto de Biotecnologia, Univ. Nacional Autonoma de Mexico, Cuernavaca, Mexico
Univ. Autonoma de Baja California, Mexicali, Mexico
Centro de Investigaciones Quimicas, UAEM, Cuernavaca, Mexico
Dept. of Med. Microbiol./Immunol., Göteborg University, Göteborg, Sweden
Inst. de Investigaciones Biomedicas, UNAM, Circuito Escolar, México D. F., Mexico
All Open Access, Bronze
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