Vibrio parahaemolyticus isolados de ostras (Crassostrea rhizophorae) comercializadas em Fortaleza-CE, Brasil

Abstract

Vibrio bacteria are associated with epidemiological outbreaks due to consumption of raw oysters. This study aimed to quantify total, sucrose positive and negative Vibrio, isolate and identify V parahaemolyticus in fresh and frozen oysters, marketed in Praia do Futuroin Fortaleza, and to determine the virulence profile of these strains using Kanagawa and urease tests. It was analyzed 300 oysters: 150 marketed fresh and 150 frozen. Quantification was done by Standard Plates Counts and the strains were biochemically identified. In Kanagawa test was used Wagatsuma Agar and detection of urease was perfoimed in urea broth containing 1% of NaCl. Vibrio counts for fresh oysters varied from 475 est to 36,000 CFU (Colonies Forming Units) g-1-and for frozen oysters varied from 400 est to 26,250 CFU g-1. It was isolated 39 strains (48.8%) of V. parahaemolyticus of fresh oysters samples, and 10.2% were Kanagawa positive and a sample (2.6%) was positive, concomitantly, to the two tests. For frozen oysters it was isolated 49 strains (69%) of V parahaemolyticus, 16.3% were positive for Kanagawa test and only one (2%) was positive for urease test. We conclude that fresh oysters had a Vibrio microbiota higher than the frozen, but frozen had the further isolation of V parahaemolyticus. Both strains of these bacteria were urease and Kanagawa positive. So, mollusks can be a risk of illness if consumed without prior cooking.