This study evaluated efficacy of maternal and larval immunisation against Lactococcus garviae infection and on the lysozyme and immunoglobulin (IgM) levels in rainbow trout Oncorhynchus mykiss (Walaum). Forty-eight-da...This study evaluated efficacy of maternal and larval immunisation against Lactococcus garviae infection and on the lysozyme and immunoglobulin (IgM) levels in rainbow trout Oncorhynchus mykiss (Walaum). Forty-eight-day-old larvae (mean weight 96 mg) originating from injected weekly with letrozole and immunised, only immunised and non-immunised parents were experimentally infected with the L. garvieae, and the mortality rate was recorded daily. Larvae were vaccinated by immersion at 58 days post hatch with live L. garvieae (109 cells/mL) for 15 min. Every third day post larvae vaccination, two larvae from each group were collected for analysis lysozyme (by a method based on the ability of lysozyme to lyse the bacterium Micrococcus lysodeikticus) and IgM (by enzyme-linked immunosorbent assay (ELISA)) parameters. Vaccinated and control larvae were tested for protection against L. garvieae 30 days post larvae immunization when the larvae were 88 days old. Larvae were challenged by bath exposure with live L. garvieae (109 cells/mL) for 2 min and monitored for mortality for at least 10 days following challenge. The challenge experiment with L. garvieae showed a significant reduction in larvae from immunised (54.44% ± 0.64%) and injected weekly with letrozole and immunised fish (52.96% ± 0.97%) compared to larvae from control fish (62.96% ± 2.22%). Vaccinated larvae originated from injected weekly with letrozole and immunised parents showed significantly higher lysozyme activity compared to other fish groups. Vaccinated larvae showed significantly less mortality compared to controls. The relative percent survival (RPS) values of larvae from only immunised, injected weekly with letrozole and immunised and non-immunised parents vaccinated with L. garvieae were 67.36% ± 0.9%, 68.05% ± 0.66% and 48.27% ± 2.79% respectively. The results indicate that the effect of maternal immunization rainbow trout against L. garvieae infection by eliciting the immune responses as indicated by an increase in the IgM level and lysozyme activity.展开更多
This study was carried out to investigate the effect of different concentrations of garlic (Allium sativum L.) extract in fish diet on survival rate, digestive enzymes and some biochemical parameters of Mugil cephalus...This study was carried out to investigate the effect of different concentrations of garlic (Allium sativum L.) extract in fish diet on survival rate, digestive enzymes and some biochemical parameters of Mugil cephalus larvae. Three hundred and sixty fish with mean weight 0.45 g were randomly divided into equal four groups;each one contained 3 replicates. Fish was fed with diets containing 0% (control), 0.5%, 1% and 3% concentrations of garlic extract (GE) in diet. 30 days after feeding, survival rate, different biochemical (larvae extract total protein, albumin, globulin, glucose, cholesterol and triglyceride) parameters and digestive enzyme activity (lipase, protease and amylase) were evaluated. There was a significant increase in survival rate of all groups fed with GE as compared to the control diet (P < 0.05). The administration of A. sativum in all levels significantly decreased (P < 0.05) the content of cholesterol, triglyceride and glucose in larvae extract. Also total protein, albumin and globulin levels had significantly increased in all groups fed GE (P < 0.05). The highest total protein (2.13 ± 0.12 g/dL), albumin (0.37 ± 0 g/dL), globulin (1.76 ± 0.12 g/dL), amylase (9.25 ± 0.14 U/mg protein), protease (4.20 ± 0.08 U/mg protein) and lipase (2.62 ± 0.14 U/mg protein) and the lowest serum triglyceride (22.78 ± 0.20 mg/dL), glucose (8.76 ± 0.09 mg/dL), cholesterol (3.69 ± 0.07 mg/dL) levels were observed in fish fed 3% GE in diet. Garlic inclusion in fish diet at 3% concentration is therefore beneficial for use in aquaculture to improve the general health and digestive enzyme activity of M. cephalus larvae.展开更多
This study evaluated transfer of maternal lysozyme and immunoglobulin (IgM) against Lactococcus garviea, the causative agent of lactococcosis to eggs and larvae in rainbow trout. Changes in circulating lysozyme and Ig...This study evaluated transfer of maternal lysozyme and immunoglobulin (IgM) against Lactococcus garviea, the causative agent of lactococcosis to eggs and larvae in rainbow trout. Changes in circulating lysozyme and IgM during development of eggs and larvae were measured by a method based on the ability of lysozyme to lyse the bacterium Micrococcus lysodeikticus and enzyme-linked immunosorbent assay (ELISA) respectively. For doing this, twelve broodstocks were injected weekly with 2.5 mg·kg-1 letrozole (an endocrine disrupter component) two months before spawning season and vaccinated intraperitoneally (i.p) with a bacterin (inactivated L. garviae) one month before spawning. Twelve broodstocks for vaccination and twelve female rainbow trouts as control group were also immiunised (i.p) with the bacterin and injected (i.p) with PBS respectively. Results showed that at day 8 after hatching, lysozyme and IgM levels during pre-larval stages decreased gradually, as yolks were absorbed. Lysozyme and IgM levels were significantly higher in the letrozole injected immiunised parents 30 days after immunisation as well as their larvae compared to the control group (p L. garviae) (one month before spawning) in maternal transfer of lysozyme and IgM levels to eggs and larvae.展开更多
文摘This study evaluated efficacy of maternal and larval immunisation against Lactococcus garviae infection and on the lysozyme and immunoglobulin (IgM) levels in rainbow trout Oncorhynchus mykiss (Walaum). Forty-eight-day-old larvae (mean weight 96 mg) originating from injected weekly with letrozole and immunised, only immunised and non-immunised parents were experimentally infected with the L. garvieae, and the mortality rate was recorded daily. Larvae were vaccinated by immersion at 58 days post hatch with live L. garvieae (109 cells/mL) for 15 min. Every third day post larvae vaccination, two larvae from each group were collected for analysis lysozyme (by a method based on the ability of lysozyme to lyse the bacterium Micrococcus lysodeikticus) and IgM (by enzyme-linked immunosorbent assay (ELISA)) parameters. Vaccinated and control larvae were tested for protection against L. garvieae 30 days post larvae immunization when the larvae were 88 days old. Larvae were challenged by bath exposure with live L. garvieae (109 cells/mL) for 2 min and monitored for mortality for at least 10 days following challenge. The challenge experiment with L. garvieae showed a significant reduction in larvae from immunised (54.44% ± 0.64%) and injected weekly with letrozole and immunised fish (52.96% ± 0.97%) compared to larvae from control fish (62.96% ± 2.22%). Vaccinated larvae originated from injected weekly with letrozole and immunised parents showed significantly higher lysozyme activity compared to other fish groups. Vaccinated larvae showed significantly less mortality compared to controls. The relative percent survival (RPS) values of larvae from only immunised, injected weekly with letrozole and immunised and non-immunised parents vaccinated with L. garvieae were 67.36% ± 0.9%, 68.05% ± 0.66% and 48.27% ± 2.79% respectively. The results indicate that the effect of maternal immunization rainbow trout against L. garvieae infection by eliciting the immune responses as indicated by an increase in the IgM level and lysozyme activity.
文摘This study was carried out to investigate the effect of different concentrations of garlic (Allium sativum L.) extract in fish diet on survival rate, digestive enzymes and some biochemical parameters of Mugil cephalus larvae. Three hundred and sixty fish with mean weight 0.45 g were randomly divided into equal four groups;each one contained 3 replicates. Fish was fed with diets containing 0% (control), 0.5%, 1% and 3% concentrations of garlic extract (GE) in diet. 30 days after feeding, survival rate, different biochemical (larvae extract total protein, albumin, globulin, glucose, cholesterol and triglyceride) parameters and digestive enzyme activity (lipase, protease and amylase) were evaluated. There was a significant increase in survival rate of all groups fed with GE as compared to the control diet (P < 0.05). The administration of A. sativum in all levels significantly decreased (P < 0.05) the content of cholesterol, triglyceride and glucose in larvae extract. Also total protein, albumin and globulin levels had significantly increased in all groups fed GE (P < 0.05). The highest total protein (2.13 ± 0.12 g/dL), albumin (0.37 ± 0 g/dL), globulin (1.76 ± 0.12 g/dL), amylase (9.25 ± 0.14 U/mg protein), protease (4.20 ± 0.08 U/mg protein) and lipase (2.62 ± 0.14 U/mg protein) and the lowest serum triglyceride (22.78 ± 0.20 mg/dL), glucose (8.76 ± 0.09 mg/dL), cholesterol (3.69 ± 0.07 mg/dL) levels were observed in fish fed 3% GE in diet. Garlic inclusion in fish diet at 3% concentration is therefore beneficial for use in aquaculture to improve the general health and digestive enzyme activity of M. cephalus larvae.
文摘This study evaluated transfer of maternal lysozyme and immunoglobulin (IgM) against Lactococcus garviea, the causative agent of lactococcosis to eggs and larvae in rainbow trout. Changes in circulating lysozyme and IgM during development of eggs and larvae were measured by a method based on the ability of lysozyme to lyse the bacterium Micrococcus lysodeikticus and enzyme-linked immunosorbent assay (ELISA) respectively. For doing this, twelve broodstocks were injected weekly with 2.5 mg·kg-1 letrozole (an endocrine disrupter component) two months before spawning season and vaccinated intraperitoneally (i.p) with a bacterin (inactivated L. garviae) one month before spawning. Twelve broodstocks for vaccination and twelve female rainbow trouts as control group were also immiunised (i.p) with the bacterin and injected (i.p) with PBS respectively. Results showed that at day 8 after hatching, lysozyme and IgM levels during pre-larval stages decreased gradually, as yolks were absorbed. Lysozyme and IgM levels were significantly higher in the letrozole injected immiunised parents 30 days after immunisation as well as their larvae compared to the control group (p L. garviae) (one month before spawning) in maternal transfer of lysozyme and IgM levels to eggs and larvae.
