Bactérias do gênero “Aeromonas” em ostras (Crassotrea rhizophorea) e água de cultivo: Caracterização bioquímica e molecular

Abstract

The Aeromonas bacteria are emerging pathogens that can be isolated from various aquatic environments and can be found in seawater, river water, fresh water, groundwater and various products of animal origin. In order to identify Aeromonas bacteria were analyzed 60 samples of oysters and 20 water samples obtained from the local farming and fishing for oysters in the city of Raposa and Humberto de Campos, MA. For isolation of Aeromonas used the conventional method, second (SAAD et al. 1995; MAJEED et al. 1990; VONK & Havelaar, 1988), and the characterization of the species was performed using the identification key Aerokey II (Carnahan et al., 1991). After the biochemical characterization, the Aeromonas isolates were subjected to molecular analysis by PCR and RFLP-PCR of 16S rRNA (Borrell et al., 1997). We identified 58 (96.67%) samples of oysters and 14 (70%) samples of water contaminated with Aeromonas. Of the 74 isolates of Aeromonas spp. obtained in biochemical analysis, 53 (71.62%) confirmed the characterization of the genus by molecular analysis. The identification of species 59.3% and 40.6% of isolates of Aeromonas spp. obtained from oyster samples were classified as A. hydrophila and A. caviae, respectively, and for isolates obtained from water samples, 60% were classified as A. hydrophila and 40% as A. caviae. The classification by RFLP-PCR 16S rRNA showed different band patterns of the proposed by Borrell et al. (1997), a result that may be related to high genetic heterogeneity of Aeromonas bacteria, primarily evidenced in isolates from environmental samples. Was observed in this study a large number of samples of oysters contaminated with Aeromonas spp., which may offer a health risk for consumers, since they are consumed fresh and that the species identified in this research are already recognized as potentially pathogenic for humans.