جستجوی مقالات مرتبط با کلیدواژه « immunity » در نشریات گروه « علوم پایه »

Recombinant probiotics are increasingly acting as carriers for the expression and targeted delivery of recombinant or natural molecules to mucosal surfaces in nutrition and health. Probiotics-mediated delivery systems eliminate the need to purify molecules to a large extent and make it possible to deliver molecules to the mucosa. The concept of biological medicine is the oral administration of living recombinant microorganisms for the prevention or treatment of various diseases. Lactococcus lactis is a gram-positive bacterium from the group of lactic acid bacteria. Lactococcus lactis has been used for centuries in food fermentation, especially cheese, yogurt, sauerkraut and the like. Therefore, it is generally recognized as a safe situation by the Food and Drug Organization. In this review article, review articles related to lactococcus and its wide application in oral vaccine production from 1998 to 2020 were collected. Accordingly, the following databases were searched. Scopus, PubMed and Google Scholar databases. The keywords used in this study included "immunity, Lactococcus lactis and vaccine". Lactococcus lactis is generally recognized as safe and can be widely used in the food industry. Live recombinant Lactococcus lactis, as a biological drug, is administered orally as a live vaccine that expresses viral and bacterial antigens.

Over the last few decades, the aquaculture industry has grown and developed as one of the major food production industries. Increased stocking density and cultivated area are two ways to increase aquaculture production. Stocking density increases result in a decrease in water quality and the spread of pathogens. As a chemical substance, antibiotics are not widely accepted by consumers as a means of reducing pathogenic agents in aquaculture. Nowadays, probiotics are crucial to maintaining the health of farmed aquatic animals and increasing production performance without negatively affecting consumers. Probiotics are being used in more studies to achieve environmentally friendly sustainable aquaculture goals. Probiotics have been shown to improve water quality, feed efficiency, growth performance, digestive enzyme activity, immunity, and resistance to pathogens in shrimp aquaculture. The presence of probiotics helps shrimp under stressful conditions, such as handling, grading, transportation, vaccination, and disease treatment. In the aquaculture industry, probiotics are mostly Bacillus, Lactobacillus, Micrococcus, Enterococcus, Lactococcus, Streptococcus, and Carnobacterium species. This study examines the use and importance of probiotics in shrimp aquaculture, as well as their effects on water quality, growth performance, and immunity.

Streptococciosis is one of the most common bacterial diseases in cold water fish farms in Iran that causes a lot of losses to these farms every year and vaccination can be very effective in controlling this disease. In this study, the effectiveness of streptococcus/lactococcus vaccine was evaluated in both injection and bath methods in rainbow trout (Oncorhynchus mykiss) fingerling. For this purpose, four treatment groups include one-step vaccinated using the bath method group, two-step vaccinated using the bath method group, hyperosmotic fish group+two-step vaccine using the bath method, the group of fish vaccinated with the injection method, and a control group considered. In this regard, 350 fish with a weight of 4.2±0.36 were divided into 10 tanks (two replicates for each group). The fish were reared and tested for two months. In this study, 5 experimental groups including the control group, the group of one-stage bath vaccination fish, the two-step bath vaccination group, the group of fishes vaccinated with hyperosmotic environment+two-step bath vaccination, and the group of vaccination via injection method. Based on the results, total serum protein levels in all vaccinated fish were higher than those in the control group, and based on statistical analysis, the highest level was recorded in the fish vaccinated by injection and the two-stage hyperosmotic+vaccine bath method. Glucose values were also measured in both groups of two-step vaccinated fish and the injection method was higher than in other fish. The ALP, ALT, and AST levels in the injected fish group were higher than those of the other groups. Finally, the serum antibody levels for both Streptococcus iniae and Lactococcus garvieae bacteria was higher for the fish in the injection group and the two two-stage bath groups than the one-stage vaccinated fish. At the same time, no antibody was observed in the control group. Based on the results, the two bath steps vaccination more and less produces the same levels of serum antibody titer as the injection method in fish, at the same time, the bath method caused less injuries compared to the injection method in fish. So in situations where fish are under stress, bath vaccination with reminder doses can be critical and more effective.

The aim of this study was to evaluate the effect of substituting the dietary fish meal with blood powder on some blood immune factors of Nile tilapia. 150 speciemns of tilapia (30 ± 0.5 g) were fed diets containing 0 (control group), 25, 50, 75, and 100 % of blood powder, each in three replicates for 8 weeks. After this period, fish were anesthetized and the blood samples were taken from the caudal peduncle of fish with a heparinized syringe for evaluating the blood immune indicators. No significant differences were observed in ACH50, glucose, and triglyceride among the blood powder-fed fish and the control group (P>0.05). The highest reported value of ACH50 (148.36±23.13), was observed in 75% treatment and the highest values of glucose (145.72±21.44) and triglyceride (451.68±49.61) were observed in 100% blood powder fed treatment. However, there were significant differences in the activity of lysozyme, immunoglobulin, total protein, and cholesterol in the groups receiving blood powder with different percentages compared to the control group (P<0.05).  The results of this research showed that it is possible to replace fish meal with blood powder in the diet of Nile tilapia due to its strengthening effect on immune system.

The aim of this study was to evaluate the effect of short-term feeding of turmeric (Curcuma langa) and black pepper (Piper nigrum) on blood and immune parameters and liver enzymes of rainbow trout (Oncorhynchus mykiss) during 30 days. A total of 450 fish with an average weight of 24.95±0.70g were selected and in ten experimental groups, fed with diet containing turmeric (C) and black pepper (P) in a combined ratio (R) of 30, 50 and 70% at levels (L) of 0 (control), 0.25, 0.5 and 1%. Parameters with independent effect including AST at the level of 0.25%, lysozyme and complement at the level of 0.5% and RBC and hematocrit at the level of 1% had the highest levels. The highest amount of hemoglobin, total protein and the lowest amount of triglyceride and cholesterol were reported in the higher ratio of black pepper to turmeric (30%C + 70%P) at the level of 1% of plant supplement. The highest amount of globulin and total immunoglobulin was observed at the level of 0.25% of the diet and the combined ratio of 70%C + 30%P. Improvement of these parameters can be due to the positive effect of turmeric and black pepper combination on the immunity of rainbow trout. Therefore, it can be suggested that the 1% herbal supplements be used in the diet of rainbow trout.

The aim of this study was to compare the effects of dietary supplementation of vitamin C and formic acid on performance, carcass traits, immune organs, blood hematological and biological parameters of broiler chickens during heat stress. The experiment was conducted using a total of 120 day-old broiler chicks (Ross 308) by employing a completely randomized design with 3 treatments, 4 replicates and 10 birds in each replicate. Heat stress performed by setting room temperature on 34 ˚C for 8 hours per day from 29 to 42 days of age. The experimental treatments included: 1- basal diet (control), 2- basal diet + vitamin C (240 mg per kg of diet) and 3- basal diet + formic acid (0.5% of diet) in finisher diet. At the end of the trial, two birds from each replicate were slaughtered to measure the carcass traits. Blood samples were also taken from the wing vein of the chickens on day 42 to measure the biological and hematological parameters. Dietary supplementation of vitamin C and formic acid significantly improved daily body weight gain, daily feed intake and feed conversion ratio of the chickens (P<0.05). The supplemental vitamin C resulted in lower abdominal fat (P<0.05). Relative weights of spleen and bursa of Fabricius were significantly increased by dietary vitamin C (P<0.05). Dietary treatments increased total protein and declined total cholesterol and LDL-C levels, and vitamin C decreased glucose and increased HDL-C, T3 and T4 concentration of the blood (P<0.05). Vitamin C and formic acid significantly increased red blood cells (RBCs) and mean corpuscular haemoglobin concentration (MCHC) and decreased mean corpuscular volume (MCV) and heterophil to lymphocyte ratio (P<0.05). Dietary vitamin C and, to some extent, formic acid could eliminate the adverse effects of heat stress on broilers by having a positive effect on blood parameters and subsequently improved growth performance.

 

Although medicinal plants have been used in different ways in feeding poultry, including broiler chickens, the simultaneous use of essential oils and enzymes, especially microbial phytase enzyme, has been used less. Thyme and Mentha are plants that affect the immune system. The positive effects of phytase have been documented in poultry. The purpose of this research is to investigate the mutual effects of essential oils and phytase enzyme on intestinal microflora and immunity level of broiler chickens.

This experiment examines intestinal microflora and immune level (humoral immunity (HI test) and blood cells) using three levels of thyme essential oil, Mentha essential oil and microbial phytase with 8 treatments and 4 repetitions and a total of 32 test units for 42 days. It was done on broilers. Culture methods (MRS-Agar and EMB) and ELISA method and commercial biochemistry kits were used to check intestinal microflora and immune level, respectively.

Examining the main effects showed that the treatments that consumed thyme essential oil had lower coliform population and total aerobic bacteria (TAB) compared to other treatments (p<0.05). The level of humoral immunity showed a significant difference among different experimental groups (p<0.05). The treatments that did not receive essential oils of thyme and Mentha had the lowest ratio of heterophils to lymphocytes (p<0.05).

The results showed that the use of microbial phytase enzyme and thyme essential oil reduces the population of intestinal coliform bacteria and the use of thyme essential oil improves humoral immunity.

In the present experiment, the effects of normal and encapsulated thyme essential oil along with saturated and unsaturated fats on blood parameters and safety of broilers with normal and low protein diets were evaluated.

In this study, 384 Ross 308 broilers in a 2 × 2 × 2 factorial engagements with 8 treatments including (zero and normal and encapsulated thyme essential oil), (beef tallow and rapeseed oil) and common crude protein and 5% less than the recommended strain in 4 replications and 12 chicks per replication in 42 days and in the three experimental periods included starter (1 to 10 days), growing (11 to 24 days) and finisher (25 to 42 days) for investigation. Blood parameters and immunity of broiler chickens were tested by ELISA method and by spectrophotometer and using commercial biochemistry kits, in a completely randomized design.

In relation to the effects of experimental treatments on the biochemical parameters of the blood of chickens, the use of cow tallow, normal thyme essential oil and normal protein level, and rapeseed oil along with thyme essential oil and low protein diets, reduced the LDL level of chickens (P<0.05). The use of encapsulated essential oil of thyme and tallow increased the percentage of blood lymphocytes (P<0.05).

The results of this research show that in Ras 308 broiler chickens, the use of unsaturated fat, along with encapsulated thyme essential oil and the level of crude protein recommended for the strain, improves blood parameters in blood LDL level and the immunity of chickens on the percentage of lymphocytes. It seems that the combination of these substances has synergistic effects and can strengthen each other's biological effects.

Medicinal plant essential oil has antimicrobial and antioxidant properties and improve small intestine microbial population and feed digestibility and for this purpose its inclusion to broiler chickens’ diet as antibiotic replacement. Present study was conducted in order to compare the effect of different levels of Tanacetum balsamita hydroalcoholic essential oil with vitamin E and C on Ross-308 broiler chickens’ performance and immunity. Three hundred broiler chickens (equal number of male and female) were used in a completely randomized design in 6 treatments and 5 replicates with 10 birds in each. The dietary treatment consisted of: 1) basal diet as control group, 2 and 3) basal diet supplemented with 200 and 400 mg/kg Tanacetum balsamita hydroalcoholic essential oil, respectively, 4) basal diet supplemented with 200 mg/kg Vitamin E, 5) basal diet supplemented with 200 mg/kg vitamin C and 6) basal diet supplemented with 200 mg/kg virginiamycin antibiotic. The results showed that the amount of feed intake, body weight gain, feed conversion ratio and European production efficiency factor, IgG, IgM and total antibody titter against SRBC, New-castle disease and avian influenza virus’s antibody titer were not affected by dietary treatments (P>0.05). Treatments had no effect on toe web swelling index after 4 and 24h post injection period but broiler chickens fed diets containing 200 and 400 mg/kg Tanacetum balsamita essential oil had higher swelling index at 48h after injection whereas there were no significant differences between vitamin E and antibiotic groups (P<0.05) and chickens fed diets supplemented with 200 mg/kg essential oil and vitamin E and C had higher lymphocyte percentage and lower heterophil percentage and heterophil to lymphocyte ratio compared to control group (P<0.05). In conclusion, although Tanacetum balsamita essential oil improved cell mediated immunity of broiler chickens but the results revealed that due to its non-significant effect on broiler chicken’s performance and immunity, its addition to broiler chickens’ diet is not economically advisable.

The aim of this study was to evaluate the biochemical factors of blood and tissue damage of gills and liver of rainbow trout in 14-day exposure to acetaminophen. For this purpose, 300 pieces of rainbow trout juveniles with an average weight (12.52±2.5) were prepared and experimental treatments including 5 treatments and 3 replications were designed. Based on the obtained results, a significant increase in serum lysozyme and complement (ACH50) enzyme activity was observed in juvenile fish during exposure to acetaminophen. The amount of cortisol and glucose also showed a significant decrease in the amount of these indicators so that the highest amount of cortisol and glucose measured in the control group and the lowest amount was observed and recorded in treatment 5. The results of the study of tissue damage showed that in gill tissue, curvature and club formation of the tip of the secondary gill blade were due to the effects of low concentration (0.01 mg / l) of acetaminophen. At moderate concentrations (0.1 and 1) mg / l, hyperplasia, hypertrophy, clubbing of the tip of the secondary gill blade and welding of the secondary blade were observed. Liver tissue examination showed the most severe liver tissue lesions in fish exposed to 10 mg / l acetaminophen. The presence of acetaminophen caused damage to gill tissue and liver in rainbow trout juveniles. However, it increased blood safety markers such as lysozyme and complement and also significantly reduced cortisol. Which showed a decrease in stress levels in fish exposed to different levels of acetaminophen.

The objective of this study was to examine the influenceof quinoa seed-based diets in combination with phytase and protease enzymes on the serum biochemical parameters, nutrient digestibility, intestinal variables, tibia characteristics and immunity of broiler chickens. A total of 250 one-day-old broiler chicks (ROSS 308) were randomly allocated into 5 treatments with 5 replicate pens per treatment and 10 birds each. The experimental treatments were a corn-soybean meal diet as control group or control diet supplemented with 150 g/kg of quinoa seed alone olone or supplemented with protease, phytase and combination of protease and phytase. The results indicated a significant decrease in serum concentration of cholesterol, triglycerides and AST activity of broilers fed quinoa seed supplemented with protease and phytase than the control group (P<0.05).Jejunum and ileum length enhanced in broiler chickens which received all experimental diets compared with control (P<0.05).Nutrient digestibility coefficients of crude protein calcium and phosphorous were significantly greater in broilers fed on diets supplemented with phytase or phytase +protease (P<0.05).In tibia variables, the highest concentration of calcium and phosphorous was observed in phytase or phytase+protease supplemented diets (P<0.05).the relative weight of bursa and spleen as immunity organs was increased in broilers fed protease or phytase supplemented diets (P<0.05). In conclusion, the addition of phytase or protease enzymes to quinoa seed-based diet may be a suitable scenario to improve nutrient digestibility, immunity or some tibia characteristics in broiler chickens.

In the present study, the effects of startup and addition of ammonium chloride (NH4Cl) and sodium nitrite (NaNO2) salts for 4 weeks before fish stocking on efficiency of biofilter for removal of total ammonia nitrogen (TAN) from water, survival rate, growth performance, ammonia metabolizing and urea cycle enzymes activities as well as mucosal immunity of African cichlid (Labidochromis lividus) fingerling. The experimental unit was a recirculating aquaculture system (RAS) with water holding capacity of 200 L in which 20 fingerling fish with average weight of 3.06±0.07 g were stocked and cultured for 30 days. The experimental groups included the RAS without startup and adding salts (control, group 1), startup of RAS before fish stocking (group 2) and startup RAS with adding salts (group 3). Water from each experimental unit was sampled after 0, 10, 20 and 30 days of fish stocking. The results showed that the TAN concentration in the groups 2 and 3 was significantly lower than the control group (P<0.05). Nitrate concentration in the groups 2 and 3 was higher than the control group (P<0.05). The highest nitrate concentration was observed in the group 3 (P<0.05). Growth performance including final weight, weight gain, specific growth rate (SGR%), daily growth index (DGI) and body weight increase (BWI%) were higher in the groups 3, 2 and control, respectively (P<0.05). The food conversion ratio (FCR) in the groups 2 and 3 was lower than the control (P<0.05). The activities of glutamate dehydrogenase, glutamine synthetase and ornithine carbamyl transferase enzymes in liver and muscle tissues increased in the control and group 2 compared to the group 3 (P<0.05). The total immunoglobulin, lysozyme and alternative complement pathway activity (ACH50) of skin mucus increased in the groups 2 and 3 compared to the control; the highest levels were observed in the group 3 (P<0.05). The findings indicate that the startup of RAS with the addition of salts before fish stocking can be an effective way to improve the efficiency of biofilter in converting water ammonia to nitrate, survival rate, growth performance and health of the fish.

Many vaccines, including killed (inactivated) vaccines and new generation vaccines (recombinant and gene vaccine) due to the low immunogenic effects of the desired antigens, require compounds called adjuvants to increase antibodies, vaccine antigenicity, stabilization of its effectiveness, and appropriate stimulation of the immune system to lead to immune responses. Many compounds have been used for this purpose in vaccines for many years, the oldest of which is alum salts, which are used in many vaccines. However, the side effects of many of the synthetic compounds used as adjuvants have led new studies to design and introduce compounds that lack these side effects and can increase the induction of immune responses. These compounds are called biological adjuvants (bio adjuvants) which, because they are host peptides, have no side effects and have good results. In this article, while reviewing adjuvants, their mechanism of action, as well as the types of adjuvants in the world vaccine industry, the types of bio adjuvants, their structure, and effects are discussed.

The aim of this study was to evaluate the effect of feeding frequency and salinity on blood factors, immunity and stress indices of farmed stellate sturgeon (Acipenser stellatus) in 1399. For this purpose, 810 juvenile stellate sturgeon (average weight 12.24 g) in 9 treatments and each with three replications with three salinity levels and three feeding frequency levels were considered. Treatments included: Treatment 1: Twice daily feeding and zero salinity, Treatment 2: Four times daily feeding and zero salinity, Treatment 3: 6 times daily feeding and zero salinity, Treatment 4: Twice daily feeding and 6 g salinity Per thousand, treatment 5: four times a day feeding and salinity 6 grams per thousand, treatment 6: six times a day feeding and salinity 6 grams per thousand, treatment 7: twice daily feeding and salinity 12 grams per thousand, treatment 8: Four times feeding load 12 grams per day and salinity per thousand and treatment 9: 6 times per day and salinity 12 grams per thousand. The fish were reared for eight weeks. Blood samples were then taken from the fish. The results showed that in most cases, the number of white blood cells, red blood cells, blood indices in treatments 4 and 6 were higher than other treatments (P<0.05). Also, the amount of IgM, lysozyme and total immunoglobulin in treatments 3 and 4 were higher than other treatments (P<0.05). The results of stress indicators showed that the serum glucose and cortisol levels of fish had a statistically significant difference (P<0.05). According to the results, it can be said that it is possible to breed stellate sturgeon in different salinities and increasing the number of feedings helps this fish to withstand different environmental conditions. However, due to economic issues and labor costs, it is recommended to feed the fish 4 times a day.

The aim of this study was to investigate the antimicrobial effects of kefir as a dietary supplement on the growth and infection caused by Aeromonas hydrophila in Cyprinus carpio. Totally, 72 juvenile carp weighing approximately 10-15 g were used. The fish were divided into 4 groups fed with 3, 5 and 10% kefir and the control group (without adding kefir) with three replications (six fish per replication) and were fed 3% of their body weight daily. The antimicrobial effect of kefir against A. hydrophila was investigated as well. After two weeks, the levels of IgM, ALT, AST, ALP and total protein in fish serum were evaluated. The liver, kidney and spleen tissues of fish were examined for histological study. The results showed that the 48-h kefir product had the highest antimicrobial effect against A. hydrophila. Feeding the fish with 3% kefir caused significant increases in length and weight of the fish. The statistical analyses revealed that the levels of IgM, AST, ALP and the serum total protein were not significantly different between the four groups, while the average amount of ALT in treatment 3% exhibited significant difference, which was less than the other two groups, while was not significantly different from the control. All experimental groups exposed to A. hydrophila revealed tissue damage in liver, kidney and spleen. However, tissue damage was less in treatment 3%.

Effects of the microencapsulated Lactobacillus rhamnosus JCM 1136 on the blood parameters and body composition of rainbow trout (Oncorhynchus mykiss). In this study, first the probiotic bacteria L. rhamnosus JCM1136 were microencapsulated with coatings of sodium alginate and chitosan. Then, they were added to the food pellets and given to the fingerlings. For this purpose, 225 rainbow trout fingerlings (6.23 ± 0.17 g) in 5 treatments and each treatment with 3 replications were placed in California trays (220 × 30 × 15 cm). Treatment 1 (T1): Fish fed with 108 CFU/g microencapsulated probiotics with sodium alginate, treatment 2 (T2): fish fed with 108 CFU/g microencapsulated probiotics with sodium alginate and chitosan, treatment 3 (T3): fish fed with 108 CFU/g capsule-free probiotics, treatment 4 (T4): fish fed with probiotic-free sodium alginate-chitosan capsules and control treatment 5 (T5): fish fed with commercial free-probiotic and capsules pellets. At the end of the course, results indicated that the fishes fed with diet containing sodium alginate-chitosan microencapsulated probiotics in terms of blood parameters such as red blood cells, white blood cells, hemoglobin and hematocrit as well as the amount of carcass protein compared to control and other treatments were in better condition, which These differences were significant with control treatments fishes (p < 0.05).