Bacterias coliformes totales, feclaes y patógenas en el sistema lagunae Chantuto-Panzacola, Chiapas, México

Abstract

The objectives of this study were to document the spatial and temporal distribution of total and faecal coliforms as well as the pathogenic bacteria in water, sediments and organisms in the Chantuto-Panzacola lagoon system, Chiapas, México (1992-1993). The presence of coliform bacteria was determined by the MPN technique (Most Probable Number) as indicated in APHA (1970 and 1980). Pathogenic bacteria were characterized by their colonial morphology in selective culture media as recommended by the Bioxon manual (1993) and Mc Faddin (1984). The results showed total coliform levels in water and sediments wich ranged from not detectable to 24x10 cells/100ml, with similar results for faecal coliforms. In June and November 1992, the concentration was higher. The pathogenic bacteria were identified as Shigella sp., Salmonella thyphi, Escherichia coli, Klebsiella sp. and Enterobacter aerogenes. The results indicate that strong seasonal variation leads to natural self-purification in this lagoon system.