Equivalência de resposta entre a técnica de fermentação em tubos múltiplos e o sistema cromogênico colilert® na identificação de coliformes totais e termotolerantes

Abstract

The water is associated with major public health risks since it may be an important vehicle for infectious diseases transmission and, therefore, the assessment of its microbiological quality through the biological indicators of contamination such as the coliform represents the possibility of reducing the number of disease outbreaks. There are several methods such as the Multiple Tubes Fermentation technique (conventional method) and the Colilert® Chromogenic Enzyme System (quick method) which can be used for this purpose, thus being able to determine both total and thermotolerant coliforms like the Escherichia coli. In order to verify the equivalence between them, water samples from the Porangabuçu Lagoon were analyzed by successive dilutions, showing that both methodologies were able to detect total and thermotolerant coliforms equivalently. This, however, was not observed on the quantification, since the quick method showed higher counts and indicated a greater capacity of coliforms enumeration when applied the successive dilutions methodology.