Vibrio cholerae non-O1 in bivalve mollusks harvesting area in Bahia, Brazil

Abstract

The aim of this study was to characterize the antimicrobial resistance and pathogenicity potential of Vibrio cholerae isolates originated from water samples and bivalve mollusks. The strains were subjected to phenotypic identification and molecular confirmation using the species-specific initiator (OmpW); minimum inhibitory concentration (MIC) was determined; and the production of metallo-βlactamases (MβLs) and virulence potential of the strains by using the initiator ctxAB (cholera toxin), tcp (toxin co-regulator pilus), rfbO1 (serogroup O1) and zot (zonula occludens toxin) were investigated. Six isolates of the bacterium (three from water and three from bivalve mollusks) were confirmed through the biochemical and specific gene detection tests. The isolates presented a high susceptibility toward the tested antimicrobials (91%) (10/11). One of the strains from water showing resistance to imipenem (MIC 20 µg), and producing MβLs did not show any involvement of plasmids. The genes related to the virulence were not detected; and all of the V. cholerae isolates belonged to the non-O1 serotype. However, the presence of an imipenem-resistant and MβLs-producing V. cholerae in a river mouth aquatic environment, which is a natural aviary of bivalve mollusks, represents a risk to the health of the population and alarms the public health agencies.