Epidemiologia descritiva de Salmonella em ecossistemas aquáticos de diferentes áreas do Estado do Pará

Abstract

Surveillance of Salmonella serotypes in aquatic environments is an important procedure for the monitoring of human and animal infections. The analysis of 694 samples of water collected from river, creek, bay, beaches, lake, well, nascent, provisioning water, stream, drainage and sewage distributed along 11 districts in the State of Pará, Brazil, yielded 212 (30,5%) contaminated samples with 91 serotypes and 2,115 strains of Salmonella. In Belém, 77 sorotypes were identified out of 1,300 isolates from freshwater and sewage; S. Saintpaul, S. Panama, S. Muenster, S. Hadar and S. Agona were the most frequent serotypes. In the National Forest of Caxiuanã, 69,4% of water samples were positive for Salmonella and 17 serotypes were identified, being S. Panama, S. Miami and S. Gaminara the most frequent ones. Antibiotic resistance was described in 64.8% of the Salmonella isolates from aquatic environments, with a special importance to streptomycin (97,1%) and tetracycline (10,8%). The presence of Salmonella and thermo-tolerant coliforms in superficial and underground water was frequently associated, but E.coli was not isolated in ten occasions. Rappaport-Vassiliadis enrichment broth was more efficient than Selenite Cystine for the isolation of Salmonella when kept at 42,5ºC. The serotypes isolated from sewage closely resembled the isolates originated from human fecal cultures during the same period. The results show the dissemination of Salmonella in aquatic environments in the State of Pará and the risk to the health of the human population.