Isolation of Vibrio cholerae O1 from aquatic environments and foods in Pernambuco State, Brazil

No período de 1992 a 1994, foram analisadas 2.585 amostras de águas de diferentes ecossistemas, acrescidas de 91 espécimens de alimentos visando ao monitoramento de Vibrio cholerae O1 no Estado de Pernambuco. Nas 2.676 amostras foram detectadas 193 cepas de Vibrio cholerae O1 (7,21%) com predominância do sorovar Inaba (183-94,8%) sobre Ogawa (10-5,1%), todas classificadas no biotipo El Tor e sensíveis à tetraciclina. Numa parcela de setenta amostras selecionadas ao acaso, mas incluindo todas do sorovar Ogawa, foi evidenciada a produção de toxina colérica. A maior incidência do vibrião colérico em águas de rios, canais e de esgoto, representando 86% dos isolados, indicou a contaminação fecal por excretores como a causa preponderante na disseminação da bactéria nos sistemas aquáticos. Assinala-se a discreta ocorrrência de V. cholerae O1 nos alimentos processados (2,1%).Incidence of Vibrio cholerae O1 was studied in 2,585 samples from different aquatic environments and 91 from foods in Pernambuco State, northeastern Brazil, from 1992 to 1994. A total of 193 (7.21%) samples of V. cholerae were isolated with a higher prevalence of the Inaba serovar (183-94.8%) than the Ogawa serotype (10-5.1%). All isolates were classified as biotype El Tor, and resistance patterns to antibiotics showed that all strains were susceptible tetracycline. Some 70 random samples of Vibrio cholerae proved toxigenic, including all the Ogawa serovars. Incidence of V. cholerae O1 in river water and sewage (86.0%) pointed to fecal contamination as the most common source and vehicle for rapid spread of the microorganism in the aquatic environment. The vibrio was isolated in 2.1% of all food examined, which was less than expected