Ecotoxicidade e eficácia de sanitizante na redução de Aeromonas hydrophila na água de cultivo e pele de Oreochromus niloticus
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Data
2011-12-19
Autores
Basile, Daniela Rodrigues Silva [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo do estudo foi determinar a toxicidade aguda do sanitizante (composto por glutaraldeído e cloreto de dimetil cocobenzil amônio) para tilápias (Oreochromis niloticus) e verificar a eficácia do produto utilizado na redução da população de bactérias do gênero Aeromonas presentes na pele dos peixes e na água de criação por contaminação experimental. Para os testes de toxicidade aguda, os animais foram expostos a 0,01, 0,02, 0,03 e 0,04 mL.L-1 e um grupo controle. O produto foi classificado pela toxicidade aguda e pelo risco ambiental de acordo com as classes de valores da CL50;48 horas. Foram realizados testes de ajuste de dose do produto e determinação do limite de tempo de exposição em condições de campo. Para o teste de eficácia os peixes foram expostos a três concentrações do produto (0,01; 0,02 e 0,03 mL.L-1 ) e um grupo testemunha nos seguintes tempos de exposição: zero, 20, 40 e 60 minutos. Amostras de água e pele dos animais foram coletadas ao final de cada tempo de exposição e submetidas às analises microbiológicas. A CL50;48h do produto foi de 0,02 mL.L-1 e esta dose apresenta baixo risco de intoxicação ambiental para a tilápia (O.niloticus). A utilização do produto como sanitizante de peixes foi mais eficaz na redução da população de A. hydrophila da pele do peixe do que na água de criação e quando utilizado na concentração 0,03 mL.L-1 ou 0,02 mL.L-1 por 60 minutos de exposição reduziu quase 1,5 log UFC.mL-1 na pele dos peixes
The aim of this study was determined to assess the acute toxicity of a sanitizer based on glutaraldehyde and cocobenzil dimethyl ammonium chloride compounds for tilapia (Oreochromis niloticus) and verify the effectiveness of the product used in the fish farm water on the reduction of the bacteria population of Aeromonas hydrophila presents on the skin of fish by experimental contamination. For acute toxicity tests, the animals were exposed to 0.01, 0.02, 0.03 and 0.04 mL.L-1 of the tested product and a control group. The product was classified according the acute toxicity and the assessment risk classes. Tests were performed for dose adjustment of the product and determining the limit of exposure time under field conditions for fish weighing between 25 and 60 g and 150 and 200 g. This dose adjustment was based on checking the signs of intoxication of the animals during the exposure time to the product. To the effectiveness test, fish were exposed to three concentrations of the product (0.01, 0.02 and 0.03 mL.L-1) and a control group (without administration of the product) in the following exposure times: zero, 20, 40 and 60 minutes. Water and skin samples were collected at the end of each exposure time and subjected to microbiological analysis. The LC50;48h estimated of the product was 0.02 mL.L-1 and it has been classified as extremely toxic and has a low risk of environmental poisoning tilapia (O.niloticus) when its concentrations is used. The use of concentrations 0.01, 0.02 and 0.03 mL.L-1 for 60 minutes of exposure is considered safe for tilapia, regardless of the fish size. The use of this product as a fish sanitizer was more effective in reducing the population of A. hydrophila on the skin of the fish than in water when used in the water. The concentration 0.03 mL.L-1 or 0.02 mL.L-1 for 60 minutes of exposure reduced by almost 1.5 log UFC.mL-1 in skin of fish
The aim of this study was determined to assess the acute toxicity of a sanitizer based on glutaraldehyde and cocobenzil dimethyl ammonium chloride compounds for tilapia (Oreochromis niloticus) and verify the effectiveness of the product used in the fish farm water on the reduction of the bacteria population of Aeromonas hydrophila presents on the skin of fish by experimental contamination. For acute toxicity tests, the animals were exposed to 0.01, 0.02, 0.03 and 0.04 mL.L-1 of the tested product and a control group. The product was classified according the acute toxicity and the assessment risk classes. Tests were performed for dose adjustment of the product and determining the limit of exposure time under field conditions for fish weighing between 25 and 60 g and 150 and 200 g. This dose adjustment was based on checking the signs of intoxication of the animals during the exposure time to the product. To the effectiveness test, fish were exposed to three concentrations of the product (0.01, 0.02 and 0.03 mL.L-1) and a control group (without administration of the product) in the following exposure times: zero, 20, 40 and 60 minutes. Water and skin samples were collected at the end of each exposure time and subjected to microbiological analysis. The LC50;48h estimated of the product was 0.02 mL.L-1 and it has been classified as extremely toxic and has a low risk of environmental poisoning tilapia (O.niloticus) when its concentrations is used. The use of concentrations 0.01, 0.02 and 0.03 mL.L-1 for 60 minutes of exposure is considered safe for tilapia, regardless of the fish size. The use of this product as a fish sanitizer was more effective in reducing the population of A. hydrophila on the skin of the fish than in water when used in the water. The concentration 0.03 mL.L-1 or 0.02 mL.L-1 for 60 minutes of exposure reduced by almost 1.5 log UFC.mL-1 in skin of fish
Descrição
Palavras-chave
Peixe - Criação, Tilapia (Peixe), Microbiologia aquatica, Bactérias, Aeromonas, Fishes
Como citar
BASILE, Daniela Rodrigues Silva. Ecotoxicidade e eficácia de sanitizante na redução de Aeromonas hydrophila na água de cultivo e pele de Oreochromus niloticus. 2011. x, 44 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2011.