BACKGROUND:  Among infectious diseases, Newcastle disease, due to being highly contagious and its rapid spread among poultry and other bird species, is a deadly viral disease and is considered a global threat to the poultry industry. Objectives: To determine the occurrence of Newcastle disease in poultry broiler farms reported to the Iranian veterinary organization during the study period. Methods: This is a cross-sectional study from September 2013 to March 2015. During this study, from 185 farms and a total of 3700 bird sera, cloacal and tracheal swabs were sampled and tested using a haemagglutination inhibition test and reverse transcriptase polymerase chain reaction respectively. Results: In this study, of a total of 185 farms reported to the Iranian Veterinary Organization, 115 farms (62.16%, 95%CI: 55.17-69.14) were positive for Newcastle disease viruses and then using specific primers, 69 farms (37.3%, 95%CI: 30.33-44.26) had vaccinal pathotype (non-acute) and 46 farms (25%, 95%CI: 18.76-31.23) had acute pathotype (field virus). The mean±SD age of infected poultry was 24.63±5.38 days and antibodies titer against Newcastle disease virus was 5.97±1.21. The highest mortality rates were observed in the spring (32.34%) and winter (26.9%), respectively. Mazandaran (37%) and Isfahan (22%) province had the highest percentage of farms with Newcastle disease. Conclusions: The findings of this study suggested virulent Newcastle virus strains are circulating in the Iranian commercial broiler farms in the mentioned time and with high occurrence. Therefore, the relevant authorities need to make correct decisions to reduce the risk of Newcastle disease in the Iranian poultry industry and its control.

BACKGROUND: Toxoplasma gondii is an obligate intracellular protozoon with worldwide distribution that infects human and a wide spectrum of warm- blooded animals. OBJECTIVES: The aim of the study is to survey the prevalence of T.gondii antibody in slaughtered livestock in slaughterhouse with modified agglutination test in Sanandaj in 2015. Methods: Totally 343 serum samples were collected from 130 cows, 111 sheep and 102 goats from May to July 2015 in Sanandaj slaughterhouse. Sera were examined with modified agglutination test (MAT) for T.gondii antibody and 1.40 titer antibody and above was considered as positive. Results: Antibodies of T.gondii were found in sera of 51 out of 343 (15.45%) samples. From 51 seropositive sera, 13 cows (23.84), 13 goats (12.74%) and 9 sheep (8.1%) were infected. The differences among species were statistically significant (P≥.002). Conclusions: Results indicate that T. gondii in sheep, goats and especially cows is prevalent, so consumption of undercooked meats should be avoided, also the prevention methods of infection should be taught to the people and due to the possibility of limitations in the results of serological tests, repetition of the study using molecular techniques is recommended

BACKGROUND: Probiotics have more functional effects on shrimp immunological                         parameters but there is less information on comparative effects of Commercial and Indigenous probiotics on post-larvae and larval stage of shrimp life. OBJECTIVES: This 60 day study was conducted to determine the effect of probiotic bacterium commercial and allochthonous (Bacillus subtilis and Bacillus licheniformis) on some of immune parameters and serum enzymes in the whiteleg shrimp (Litopenaeus vannamei). METHODS: Three experimental diets were supplemented with similar concentration of 1.5×106 Cfu/g by bacteria, commercial and allochthonous supplementation. Control  (without probiotic supplementation), D1 (commercial probiotic), D2 (commercial+allochthonous probiotic) and D3 (allochthonous probiotic) were used for the experiment. At the end of trial, to evaluate immune parameters, Shrimp hemolymph was collected by syringe into the ventral sinus of L. vannamei, transferred to a tube and allowed to anticoagulant. To investigate serum enzymes level, body shrimp were homogenized and extracts were analyzed biochemically. RESULTS: Total haemocyte count (THC), large granular cells (LGC), semi granular cells (SGC) and hyaline cells (HC) treated with commercial probiotics increased in comparison with control and significant difference was observed (P<0.05). Enzyme alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly decreased in the experimental groups compared with control (P<0.05). However, post-larvae enzyme alkaline phosphatase was not found to be significantly affected by probiotic supplementation (P>0.05). CONCLUSIONS: The probiotic Bacillus influenced the increase of the immune parameters haemolyph and decreased serum enzymes level and it is appropriate for supplementation in the diet of whiteleg shrimp post-larvae.

BACKGROUND: The mechanism of pathogenesis and the role of virulence factors of avian pathogenic E. coli is still ill-defined. The ostrich industry is expanding, resulting in the interaction between poultry and ostrich. It is reported that the investigation of iss and bor virulence genes together, due to their structural and functional similarities, is valuable. Objectives: The investigation and comparison of presence of two genes involved in serum resistance, iss and bor, in E. coli isolated from apparently healthy ostriches and poultry with colibacillosis. Methods: As a cross-sectional study, E. coli was recovered from fecal samples of apparently healthy ostriches and poultry with colibacillosis, and iss and bor genes were screened and compared via PCR in E. coli isolates. Results: iss frequencies, with no statistical difference, were 50% and 64.4% in E. coli isolated from apparently healthy ostriches and poultry with colibacillosis, respectively (P>0.05). 31.8% and 15.6% of E. coli isolated from apparently healthy ostriches and poultry with colibacillosis were positive for bor, respectively, with no statistical difference (P>0.05). 11.1% of isolates from colibacillosis and 18.2% of isolates from apparently healthy ostriches feces, with no statistical difference, were positive for both genes (P>0.05). Conclusions: Equal statistical distribution of both genes, bor and iss, between apparently healthy ostriches and poultry with colibacillosis and the health level of studied ostriches indicated that E. coli isolated from ostrich, probably employs other virulence factors instead of bor and iss to establish a disease. This hypothesis needs to examine more virulence genes in ostrich-origin E. coli. In addition, the ostrich feces could be introduced as a source of iss and bor genes.

BACKGROUND: Antioxidant compounds and unsaturated fatty acids play an important role in improving the immune response and intestinal microflora in broiler chickens. Objectives: The aim of this study was to investigate the effects of different sources of antioxidant and soybean and rapeseed oils on humoral immune responses, intestinal microflora and some of the blood parameters of broiler chicken. Methods: A total of 480 male broiler chicks (Ross 308) were randomly allocated in a factorial arrangement (2×5) based on a completely randomized design with 10 treatments and 4 replicates during 42 days of age. Experimental factors consisted of different sources of antioxidant (rosemary, thymus and satureja essential oils at level of 300 ppm and vitamin E at concentration 200 mg/kg and without antioxidant) and vegetable oils (soybean and rapeseed oils at concentration of 4 percent of diet). Immune characteristics and intestinal microflora population were evaluated. Results: The use of different soybean and rapeseed oils had no significant effect on antibody titer (P>0.05) but the use of antioxidants improved immune responses against Newcastle disease (P<0.01). Also, the use of rosemary, thymus and satureja essential oils increased serum level of blood high density lipoprotein and reduced blood low density lipoprotein (P<0.001).  Furthermore, the concentrations of cholesterol and triglyceride increased in without  antioxidant treatment (P<0.001).Also, use of antioxidant treatments caused significant decrease of heterophil to lymphocyte ratio (P<0.05), then these result are consistent with the immune response against Newcastle disease. Furthermore, escherichia coli to lactic acid bacteria ratio increased in rosemary and thymus essential oils treatments compared with without antioxidant treatment (P<0.05). Conclusions:The use of dietary soybean and rapeseed oils did not have a significant effect on different traits of broiler chicken, but adding dietary antioxidants improved immune responses and intestinal microflora and in between different antioxidants, the use of essential oils compared with vitamin E  induced significant improvement of traits.

BACKGROUND: Increasing population and food provision is one of the most important problems in the world, thus aquaculture plays an important role in the production of food and human needs. OBJECTIVES: This study was to investigate the effect of Celmanax prebiotic on growth performance, hematological and biochemical factors of juvenile Oncorhynchus mykiss. METHODS: For this study, 780 juvenile rainbow trout with an average weight of 18 ± 2 g were randomly divided into four groups with three replications. 0, 2, 4 and 6 percent of Celmanax were added into diets and the fishes were fed with 5% of body weight for 8 weeks 3 times. At the end of experiment, investigation of the growth indices, blood sampling and serum preparation for hematological and biochemical tests were performed. RESULTS: The results showed that fishes fed with diets containing 4% Celmanax prebiotic had better growth indices (final length, final weight, weight gain, percentage of weight gain and specific growth rate) compared to control (P≤0.05). Comparison between experimental treatments demonstrated that immune indices significantly increased with increase of prebiotic levels in the diet (P≤0.05). So that, the highest level of hemoglobin, red blood cell, white blood cell and neutrophil were related to fishes fed with 6% of Celmanax prebiotic diet. Also, the highest levels of immunoglobulin, albumin, glucose and lsozyme and the lowest levels of cholesterol and triglyceride and cholesterol were observed in fishes fed with 6% of Celmanax prebiotic diet, which showed a significant difference with control (P≤0.05). CONCLUSIONS: Increasing levels of Celmanax prebiotic in the diet caused an improvement in the growth and immunity system of rainbow trout.

BACKGROUND: Ichthyophthiriasis induced by a freshwater teleost pathogen “Ichthyophthirius multifiliis” is one of the most important parasitic diseases with substantial economic losses to the aquaculture industry. Although malachite green, copper sulphate, formalin, and chloramine-T have been used to treat ichthyophthiriasis, there are  no chemicals that can be used safely and effectively to control this parasitic disease. As a result, application of natural, safe and strong components to prevent ichthyophthiriasis is of great importance. Objective: The aim of the present research is to determine the short-term effectiveness of tannic acid (TA) on the parasite theronts of I. multifiliis. Methods: In this study, TA as a main phenolic acid at different concentrations (0.0-7.0 mg/L) was applied to determine its acute toxicity against I. multifiliis theronts in various exposure times (1-3 h). The results were also statistically compared to the findings obtained from the control treatment and the positive control sample (15mg/L  formalin). Results: There was a significant and direct correlation between TA concentration and exposure time in order to enhance the mortality rate of I. multifiliis theronts. An increase in levels of TA and exposure time in the studied ranges can significantly intensify the mortality number (P<0.05). The used natural phenolic constituent similar to 15 mg/L formalin led to a significant reduction in number of these theronts (> 80%) at 60 min. Conclusions: Use of a standard phenolic agent such as TA at higher concentration and longer exposure time can potentially decrease the number of I. multifiliis theronts and control ichthyophthiriasis.

BACKGROUND: Free cyanide is a potent toxic agent in the aquatic environment.  Freshwater fish are the most cyanide-sensitive group with high mortality at free cyanide concentrations above 20 μg/L. Exposure to cyanide ions can cause stress, increased mortality and place an appreciable metabolic load on fishes. Rhodanese is a ubiquitous mitochondrial enzyme in both prokaryotes and eukaryotes that detoxifies cyanide (CN-) by converting it to thiocyanate (SCN). OBJECTIVES: The purpose of this investigation was to determine and compare the pattern of tissue distribution of Rhodanese in different tissues of four native Barbus fish including Mesopotamichthys sharpey, Tor grypus, Luciobarbus xanthopterus and Luciobarbus barbulus. METHODS: Fishes (10 from each species) with length of 32.5 ± 6.5 and weight of 440 ± 110   were collected from five major fishing reservoirs of Karoun River including Gotvand, Shushtar, Molasani, Darkhoine and Ahvaz. Rhodanese activity was assayed by the method of Sorbo in the liver, kidney, gill and intestine. The unit of enzyme activity was defined as micromoles thiocyanate formed per minute at 37 °C and pH 9.2 and enzyme activity was expressed as U/mg protein. RESULTS: Rhodanese activity was detected in all tissues studied, albeit in different amounts. Specific activities of Rhodanese (U/mg protein) in different tissues ranged from 0.135 to 0.337 in the liver, 0.113 to 0.262 in the kidney, 0.121 to 0.157 in the gill, and 0.094 to 0.162 in the intestine, respectively. CONCLUSIONS: The highest activity of Rhodanese in all four species was observed in the liver and kidney, followed by the gill and intestine. Our results suggest that Rhodanese may be functional in many physiological activities in these species which needs to be clarified in detailed.

BACKGROUND: Hydatid cyst is an infection with global distribution that is caused by the larval stage of the tapeworm of Echinococcus. The long-term survival of the hydatid in the host shows the parasite has advanced highly effective strategies for escaping the host defense. Deaths are caused by parasitic infections which are often due to tissue damages that result in host cell death, this is known as apoptosis. So it is important to know the process and the role of apoptosis that is created or controlled by a parasite. OBJECTIVES: Investigation of cytotoxicity effect, induction of apoptosis and mechanism of induction of apoptosis of cattle hydatid fluid on bovine lymphocyte cells as efficient cells of immunity were studied. METHODS: In this study, the cytotoxicity effect of bovine hydatid fluid (HF) on lymphocyte cells was investigated as effective immune cells against Echinococcus granulosus by MTS method. Then the mean of the expression of caspase-3, Bax and Bcl-2 genes in bovine lymphocytes treated/untreated was determined with fertile and infertile hydatid cyst fluid using Real Time PCR method. RESULTS: The viability mean of lymphocytes was significantly lower in the fertile HF treated lymphocytes compared to both infertile HF-treated lymphocytes and cell control. Bax gene expression was significantly (P=0.046) higher in the fertile HF-treated lymphocytes compared to both infertile HF-treated lymphocytes and cell control. Although Caspase 3 was higher in this group, the difference was not significant. Also, expression of Bcl-2 gene in fertile fluid treated lymphocytes was found to be lower than that of infertile and control. CONCLUSIONS: Present study indicates that hydatid cyst fluid molecules can probably induce apoptosis in immune cells in vitro and the parasite’s ability to stay alive for a long time in the host by controlling the host immune response from the apoptosis pathway.

BACKGROUND: Although numerous reports support the beneficial effects of supplementing chromium (Cr) on broiler performance under normal and stress conditions, the optimal level has not been determined yet. OBJECTIVES: This study was conducted to investigate the effects of different levels of supplemental Cr on performance, cortisol, and thyroid hormones of broiler under normal and stress conditions. METHODS: A total of four hundred forty-eight broilers were used. Broilers allocated into 2×4 factorial experiment included: stress (normal and stress) and 4 levels of supplemental chromium (0, 1000, 2000, 3000 ppb) since day 18. A completely randomized design with 8 treatments and 4 replicates (14 birds per replicate) was used. Dexamethasone used as a stressor for one week (stress period, STP) then experiment continued to day 46 (recovery period, RCP). RESULTS: Feeding 1000 and 2000 ppb Cr improved feed conversion ratio (FCR) and increased T4 compared to 0 and 3000 ppb Cr in stressed broilers in STP (P<0.05). Feed intake (FI), body weight (BW) and T3 concentration were higher in broilers fed with 1000 ppb Cr in the diet and reared without stress in STP (P< 0.05). Despite the negative effect of stress on performance in RCP, dexamethasone-stressed broilers had better FCR. Feeding stressed birds with 1000 ppb Cr increased blood cortisol whereas it reduced cortisol in the normal-reared birds. CONCLUSIONS: The Dietary supplementation of 1000 and 2000 ppb Cr reduced deleterious effects of physiological stress. Moreover, 1000 ppb Cr improved FI and BW of broilers under normal condition at first week. Feeding high level of chromium under normal and stress conditions did not improve the performance.