Microcrustaceos y Vibrio cholerae O1 viable no cultivable (VNC): resultados en la Cuenca del Rio Sali, Tucuman, Argentina

Vibrio cholerae habitually lives in marine and continental waters. According to "favourable" or "unfavourable" resources and environmental conditions, viable (VC) or viable non-culturable (VNC) states will be generated, surviving only the latter form. To address the problem of cholera in the Sal River Basin (Tucuman Argentina), samples were taken during the years 2003 to 2005, taking into consideration physic chemical, biological and sanitary aspects. To infer about the probable reservoirs of the pathogen, we examined the zooplankton of the Sal River ("Canal Norte" and "Banda Rio Sali") and Lules River. The highest taxonomic representation was recorded for copepods, especially Eucyclops neumani (Pesta, 1927), along with Acanthocyclops robustus (Sars, 1863), Metacyclops sp., Paracyclops chiltoni and Notodiaptomus incompositus (Brian, 1925), plus some rotifers and cladocerans such as Lecane sp. and Brachionus sp., Moina sp. and Leydigia sp. The occurrence frequency was low, not exceeding 25%. Canal Norte stood out as the best environment for the species richness, abundance and constancy of the community. The physicochemical variables associated with the zooplankton would coincide with the values that, for our records and previous reports, are known for the development of the pathogen. In summer periods there was coincidence between the presence of the VNC form of V. cholerae O1 (immunofluorescence with antibodies anti O1) and the development of zooplankton. VNC forms on ciclopoid copepods and chidorids cladocerans appendages or structures were observed, probably showing an affinity with chitin substrates.