RESUMO
The immunostimulatory effect of phospholipopeptide biosurfactant from Staphylococcus hominis (GenBank Accession No: KJ564272) was assessed with Oreochromis mossambicus. The non-specific (serum lysozyme activity, serum antiprotease activity, serum peroxidase activity and serum bactericidal activity), specific (bacterial agglutination assay) immune responses and disease resistance activity against Aeromonas hydrophila were examined. Fish were intraperitonially injected with water soluble secondary metabolite (biosurfactant) of S. hominis at a dose of 2 mg, 20 mg and 200 mg kg(-1) body weight. Commercial surfactant surfactin (sigma) at 20 mg kg(-1) was used as standard and saline as negative control. All the doses of water soluble biosurfactant tested, significantly enhanced the specific, nonspecific immunity and disease resistance from the day of post administration of phospholipopeptide biosurfactant till the tail of the experimental period. These results clearly indicated that the secondary metabolite isolated from S. hominis stimulates the immunity of finfish thereby could enhance aquaculture production.
Assuntos
Lipoproteínas/imunologia , Peptídeos/imunologia , Staphylococcus hominis/metabolismo , Tensoativos , Tilápia/imunologia , Aeromonas hydrophila/fisiologia , Testes de Aglutinação , Animais , Aquicultura , Resistência à Doença , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Imunização , Lipoproteínas/biossíntese , Muramidase/sangue , Peptídeos/metabolismo , Peroxidase/sangue , Inibidores de Proteases/sangue , Tensoativos/metabolismo , Tilápia/sangueRESUMO
The present study was designed to test the immunostimulatory efficacy of poly-ß hydroxybutyrate-hydroxyvalerate (PHB-HV) extracted from Bacillus thuringiensis B.t.A102 on the immune system of Oreochromis mossambicus. Fish were fed with 0%, 1%, 3% or 5% PHB-HV supplemented feed and were bled at regular intervals of 5 days. The specific immune response was measured in terms of antibody response to sheep red blood cells, the nonspecific immune mechanisms were analysed in terms of serum lysozyme activity, total peroxidases activity and antiprotease activity. The overall functional immunity was tested by experimental challenge with live virulent Aeromonas hydrophila. The results revealed that all the doses of PHB-HV supplementation in feed were effective in stimulating both specific and nonspecific immune mechanisms. The bacterial challenge experiment showed that highest dose of 5% PHB-HV supplementation was more effective than 1% and 3% doses. The study concludes that PHB-HV can be used as a potential immunostimulant in finfish aquaculture.