ABSTRACT
The present study evaluated the microbiological water quality and tissue lesions in gills from Nile tilapia (Oreochromis niloticus) and hybrid tambacu (Colossoma macropomum female x Piaractus mesopotamicus male). For this, water and gills were collected from fish farming at six locations in Itapecuru-Mirim County, Maranhão State. Microbiological water analyses revealed contamination by total coliforms, Escherichia coli and heterotrophic bacteria. In the gills, we observed a diversity of Gram-positive and Gram-negative bacteria. The tissue lesions were: lamellar fusion, interlamellar hyperplasia, sub-epithelial edema and telangiectasia. Inflammatory lesions were not observed. Significant statistical difference (p > 0.05) was not detected when comparing different gills lesions during rainy and dry season. The correlation between lesion and pond type was statistically different (p 0.05) for lamellar fusion and interlamellar hyperplasia which occurred more frequently at ground ponds. Regarding the frequency of lesions in the different fish species, there was statistical difference (p 0.05), and the tambacu was more sensitive to lamellar fusion while tilapia was more sensitive for the other lesions. In relation to the sampling stations, there was statistical difference for all the gill lesions. In conclusion, tissue lesions are nonspecific and function as a defense mech
ABSTRACT
Study of physical and chemical parameters and isolation of Vibrio parahaemolyticus in some water samples from Anil river estuary (São Luis, state of Maranhão, Brazil) at natural banks of mollusks. The technique of the most probable number (MPN) with enrichment and a subsequent isolation was used in Thiosulphate citrate bile salt agar (TCBS). In addition, some physical and chemical parameters were monitored in situ. The determinations for pH varied (7.25 to 7.90), O2 (0.20 to 1.2mg/L), TC (29 to 32C), S, (5 to 28.0 UPS), NH4+ (0.04 to 3.41mg/L), NO2- (0.10 to 1.91mg/L), PO43- (0.03 to 4.88mg/L). The presence of V. parahaemolyticus was detected in 56.1% of station I and 55.4% of station II with levels from 1.1x10 to 1.1x105MPN/mL). The results require some special attention from the environmental control and Public Health organizations as soon as possible because the riverain communities are exploring the alive resources from that ecosystem as their own feeding and commerce
Avaliação dos parâmetros físico-químicos e isolamento de Vibrio parahaemolyticus em águas do estuário do rio Anil (São Luís-MA, Brasil), em bancos naturais de moluscos. Foi utilizada a técnica do Número Mais Provável (NMP) com enriquecimento e subseqüente isolamento em agar tiossulfato-citrato-sacarose-sais-biliares (TCBS). Adicionalmente, foram monitorados in situ alguns parâmetros físico-químicos. As determinações para o pH variaram (7,25 a 7,90), O2 (0,20 a 1,2mg/L), TC (29 a 32C), S (5 a 28,0 UPS), NH4+ (0,04 a 3,41mg/L), NO2- (0,10 a 1,91mg/L), PO43- (0,03 a 4,88mg/L). Em 56,1% na estação I e 55,4% na estação II, apresentaram positividade, para V. parahaemolyticus, com níveis entre 1,1x10 e > 1,1x105NMP/mL. Os resultados exigem uma atenção especial por parte dos órgãos de Controle Ambiental e de Saúde Pública locais, uma vez que os recursos vivos deste ecossistema são sistematicamente explorados pelas comunidades ribeirinhas para fins de consumo e comercialização