Originals

DETECTION OF PROTOZOA AND COLIFORMS IN WATER FROM ALTERNATIVE SOURCES IN PETRÓPOLIS, RIO DE JANEIRO, BRAZIL
Vivian de S. Vaillant1; Beatriz C. Nunes2; Alynne da S. Barbosa2; Aloysio de M. F. Cerqueira3; Márcia S. Pinheiro3; Valmir Laurentino-Silva4, Otilio M. P. Bastos1; Adauto J.G de Araujo5; Claudia Maria Antunes Uchôa

The aim of this study was to evaluate the contamination by total coliforms, fecal coliforms, Escherichia coli, and the protozoans Giardia sp. and Cryptosporidium sp. in fresh water of alternative sources of surface catchment of Petrópolis, Rio de Janeiro. Eighty-eight samples were collected for the parasitological survey and 44 for the microbiological one from 22 sources in the dry as well as in the rainy seasons. To the parasitological analysis, sedimentation and fltation techniques were used before the microscopic examination and Enzyme-Linked Immunosorbent Assay (ELISA) was performed in 88 samples. Direct Immunoflorescence Assay (DFA) was performed in 67 randomly selected samples due to the kit availability. For the microbiological analysis, in turn, the multiple-tube technique was used, being E. coli confimed by Enterokit B®. Out of the samples, 11/88 (12.5%) presented positivity by microscopic examination, while 13/88 (14.8%) presented positivity for Giardia sp. antigens by ELISA and 2/67 (2.3%) by DFA. Microbiological analysis showed that 22/44 (50%) of the samples were contaminated by total coliforms, 9/44 (20.5%) by fecal coliforms and 8/44 (18.2%) by E. coli. There was detection of E. coli and/or Giardia sp. in 59% of the sources, which reveals the need for continuous monitoring, aiming to mitigate the risk of waterborne transmission of enteropathogens. ELISA seemed to be a useful technique for the evaluation of water contamination by Giardia sp., contributing to enhance the information about diagnosis in environmental samples.

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