The presence of Vibrio cholerae 01 (Pacini, 1854) in its culturable and nonculturable stages was studied in water, sediment, plankton and mussel samples, from January to August 1995 in Todos Santos Bay, BC, Mexico. Fifty-two samples were analyzed without finding V. cholerae 01; however, non-01 V. cholerae was present in 28.8% of the samples. Forty-three strains of non-01 V. cholerae were isolated, 44% from plankton, 37% from water and 19% from sediment. Non-O 1 V. cholerae was not detected in mussel samples. The highest bacterial concentrations of coliforms, heterotrophic bacteria, Vibrio-like bacteria and the highest number of non-01 V. cholerae were found in the northern part of the bay. The lowest incidence of non-01 V. cholerae, as well as the lowest concentrations of the other bacterial groups were found in the southern part of the bay, where mussels are commercially cultured.

Recibido en agosto de 1999; aceptado en febrero de 2000 RESUMENSe evaluaron los porcentajes de eclosión de quistes de cuatro poblaciones de Artemia franciscana autóctona de México y en los nauplios obtenidos se cuantificaron los niveles de bacterias heterótrofas viables (VHB) y de bacterias con capacidad de crecer en el medio de agar tiosulfato-citrato-sales biliaressacarosa (TCBSB). La mayor eficiencia de eclosión (71.8%) se dio en los quistes de Texcoco y fue nula en los quistes de Yavaros. Las VHB presentaron niveles de abundancia semejantes en todas las muestras,