نشریه تحقیقات دامپزشکی و فرآورده های بیولوژیک
سال سی و پنجم شماره 2 (پیاپی 135، تابستان 1401)

Phage display technology is a powerful and progressing technique with a wide range of applications that, has proven its effectiveness in many of biological fields, including, production of anti-toxin antibodies, drug discovery, production of monoclonal antibodies, molecular imaging, gene therapy, vaccine development, isolation of specific binding peptides for venom components, studies of immunogenicity, development of new vaccines, and nanotechnology. One of the important areas of this technology is the production of anti-toxin antibodies against venom of poisonous animals, especially snakes. With the advances that this technology has made in the production of anti-toxin antibodies, it seems that in the not too far future, this technology can be used to produce new generation of antivenoms and solving of the existing antivenom problems. Despite of the many applications of the phage display technology, however, like other techniques, it has some problems such as need to high skill, losing the desired clones or no pairing of light and heavy corresponding chains same as the original antibody-producing cells, which may be seen when using the phage display technology. In this review article, an attempt has been made to examine phage display technology, its applications and limitations.

Newcastle disease (ND), avian influenza (AI) and infectious bursal disease (IBD) cause severe damage to the poultry industry. Vaccination is often used to prevention or control the spread of poultry diseases. Inactivated vaccines are used to produce the uniform antibody titer, the increase antibody levels and its shelf life. In this study, the ND, AI and IBD triple inactivated vaccine was designed and prepared in laboratory scale. Then its immunization potential was evaluated in SPF chickens. To produce the triple vaccine, the ND V4, avian AI H9N2 and IBD 07IR standard strains were separately propagated in embryonated eggs. The viral suspensions were inactivated after virus titration. Different amounts of each virus were considered as a dose and introduced as a vaccine after standard control tests. The prepared vaccine was injected along with an imported vaccine to different groups of SPF chickens and HI, VN and ELISA tests were performed on serum samples. The HI titer was 7.6 for ND and 6.7 for AI. In the VN test, the neutralization index for IBD was 3.5. In the ELISA test, the antibody titer against ND was 8481, for AI 7569 and for IBD 3108. These data did not differ significantly from the results of the imported vaccine. The results showed that the developed triple inactivated vaccine provided good immunity and also had no side effects for SPF chickens.

In this study, an indirect ELISA test was developed for the determination of the level of antibodies against Cobra venom in equine sera after each injection step. Toxic fractions of Naja naja oxiana snake venom was used as antigen. The test allowed to reveal an increase of antibodies in response to the venom injection and it can be applied to the evaluation of the efficacy of immunization. To the development of the indirect ELISA, dilutions of 1/50, 1/500, and 1/1000 of positive and negative control sera against concentrations of 0.5, 1, and 2 µg/well of the venom were used. From this 2 µg/well of venom and 1:1000 serum dilution was found to be sufficient enough for the estimate of antisnake antibodies. After ELISA development, serums obtained from blood samples of horses immunized with venom were tested to evaluate the trend of increase in antivenom titer at each stage of venom injection. The average optical density of samples after the third injection was 1.213; this is 5.8 times that of the horse samples behind the first step of immunization. All horses had an adequate antivenom titer after the fifth injection. The results suggest that ELISA can be used to determination of antivenom titer in horse sera especially during the initial stages of immunization.

Urinalysis provides the valuable information about physiological and pathological conditions of the patients. The aim of this study was to determine accuracy of human urinary dipsticks for assessment of different biochemical parameters such as pH, specific gravity, protein, glucose, bilirubin and leukocyte in canine urine samples. For this purpose, urine samples of 60 dogs were collected and paired measurements of the urinary parameters with both different commercial dipsticks (Kimia and MN) and standard tests were analyzed. The correlation coefficient was fair between the assayed urine protein with two urine strips and standard method (r=0.68). For glucose, correlation coefficient was good between reference method and the urine strips (r=0.78). In the case of protein and glucose, both strips showed excellent sensitivity and negative predictive value (NPV). Correlation coefficient was good between reference method and the urine strips (r=0.91). Although correlation was significant between urine specific gravity assayed using refractometer and strips (r=0.38), correlation coefficient was poor. It seemed that employing human urine strips was not suitable method for evaluating specific gravity and refractometer was preferred. In conclusion, it is suggested that human urine strips can be used to determine protein, glucose and pH in urine of dog.

The aim of this study was to investigate the effect of lyophilization on which strain in comparison with acute strain in the development of immune response in BALB/c mice. To this end, 40 BALB/c mice were divided into 5 groups each of 8 heads. The first group: NC1 (acute strain), the second group: lyophilized NC1 (acute strain), the third group: NCR (attenuated strain), the fourth group: lyophilized NCR (attenuated strain), and the fifth group: control. Three weeks after induction of vaccines, blood sampling was performed for ELISA and interferon-gamma tests. The results showed that the hemorrhagic immune system performed well (P <0.05, OR (CI95%)), and all four immunosuppressed groups had a significant difference in humoral immune response compared to the control group. An important result was the interferon test, which revealed that the lyophilized form in the acute strain had no significant difference in the level of interferon gamma compared to the control group, while lyophilized attenuated strain also had a significant difference between the levels of IFN-γ compared to the control (P <0.05, OR (CI95%)). This study showed that the lyophilized attenuated strain N.caninum is also able to produce a humoral and cell mediated immune and can be considered as an appropriate candidate for further studies on vaccine production.

This study was performed to determine the prevalence of Linguatula serrata in sheep and goats by observing the parasite in the mesenteric lymph nodes and measuring the antibody titer by indirect haemagglutination test and also evaluating the activity of serum complement activity by classical method and lysozyme. 791 samples of blood and mesenteric lymph nodes from sheep (456) and goats (335) were collected in the slaughterhouse of Ahvaz (Khuzestan province). The results showed that 7.8% of all ruminants in the present study were infected with L. serrata. There was no significant difference in the level of complement activity by classical method and lysozyme activity between infected and non-infected animals. Also, using an indirect haemagglutination test, in addition to accurately identifying infected samples from non-infected animals, the levels of IgG and IgM antibodies against L. serrata were estimated. IgG levels in infected samples were higher than IgM levels and the levels of these antibodies were significantly lower in non-infected samples. Overall, the present study suggests that this parasite in the intermediate host may escape from some important components of the innate immune system (such as the complement and lysozyme). Although the results of the present study showed that infection with the parasite increased the level of some antibodies, but these changes do not seem to provide the conditions for the eradication of the parasite.

Babesiosis is a tick-borne disease caused by protozoa of the genus Babesia. This study aimed to determine the B. bigemina and B. bovis among cattle of Lorestan Province. A total of 258 blood samples were collected via the jugular vein from healthy cattle, randomly. The extracted DNA from blood cells was amplified by Babesia-all primers, which amplify an approximately 400bp DNA fragment from the region of the 18S rRNA gene from various members of the genus Babesia. All cattle positive samples were further analysed for the presence of B. bigemina and B. bovis by specific semi-nested PCR. B. bigemina and B. bovis were identified by specific semi-nested PCR in 17.8% and 19.4% of cattle blood samples, respectively. Chi-square tests were used to compare molecular prevalence values relative to climate, altitude, longitude, latitude,  farm type, hygiene, vectors, use of acaricide, distance from other farms, contact with wild ruminants, farm density, race, age, and sex were recorded for each animal. Among these factors, a significant association was only found between the prev-alence of B. bigemina infection and farm density (P< 0.05). Multivariable logistic regression analysis revealed that farm type and farm density were significant risk factors for B. bovis infection in cattle of Lorestan province (P< 0.01). The results of this study can be used in strategic planning for the prevention and control of bovine babesiosis in dairy cattle in the west of Iran.

Phenolic compounds are known as the most important substance with antimicrobial properties and also as active components of essential oils such as thyme and savory. The aim of this study was to evaluate the effect of thymol on the growth and expression of nor1 gene in Aspergillus flavus isolates.

In this study, the antifungal effect of thymol on Aspergillus flavus was evaluated. Also, evaluation of nor1 gene expression of samples treated with thymol after culture in YES specific medium was determined by Real Time-PCR.

The minimum inhibitory  concentration (MIC) of thymol on Aspergillus flavus isolates ranged from 400 to 200 g / ml. Analysis of gene expression by Real Time-PCR method showed that thymol reduced the expression of nor1 gene in Aspergillus flavus isolates.  The expression of nor1 gene in each of the sensitive and resistant isolates was calculated to be 0.06% and 1.69%, respectively.

Due to the fact that the first step in the production of this toxin is the expression of a reductase enzyme of the nor1 gene to convert NOR1 (norsuluronic acid) to aflatoxin. Therefore, the lack of expression of this gene  inhibit the production of toxins. In this study, it was shown that thymol can have inhibitory effects on the growth and expression of nor1 gene  Because food contamination with aflatoxins is a threat to public health, the use of natural compounds and products is essential to reduce food contamination.

Gastric ulcers are created by various reasons. Faster healing of wounds is more challenging to researchers. The aim of this study was to histopathgological evaluation of the effect of phenytoin and theranekron-impregnated polyglactin 910 yarns on healing process of gastric surgical wound in the rabbits. Twenty-one male white Newzland rabbits were divided into three groups of control, phenytoin and theranekron. A gastrotomy incision with one cm in length was made in the greater curvature of the gastric wall, and then was sutured in Cushing pattern with phenytoin and theranekron-impregnated Vicryl yarn. For histopathological evaluation at days 3, 7 and 21 after surgery tissue samples were taken and stained with hematoxylin eosin and Masson-Trichrome. Histopathological changes were analyzed by using the Kruskal-Wallis test. The results of the histopathological studies showed that in the phenytoin and theranekron groups the rate of inflammatory cells, fibroblasts and vascularization were significantly (P<0.05) lower than  the control group and rate of epithelial cell formation was significantly higher than  the control group but between phenytoin and theranekron groups were not significantly difference.

The most basic application of protein hydrolysis is nitrogen supply for bacterial culture media. Considering that about 200 million doses of Clostridium bacteria are used annually in our country and to produce this vaccine dose, 16 tons of hydrolyzed protein (peptone) is needed. Currently, this need is supplied through imports. Therefore, achieving the technical knowledge of peptone production from various inexpensive sources in the country is essential. Therefore, due to the development of vermicompost worm farms, inexpensiveness, availability, high protein in the body, hydrolysis protein of this animal was performed. Due to the development of vermicompost worm farms, inexpensiveness, availability, high protein in the body, protein hydrolysis of this animal was performed. Samples of worms were purchased from farms around Mashhad. For disposal of digestive system materials, worms were placed in a clean water and sand container for 24 hours. Then, by homogenizing them in water for 30 minutes, homogeneous suspension and uniformity of them were provided. Subsequently, chloroform was performed in two 30-minute times at 25c and 60c temperature, remove fat from protein tissue. Using six-normal hydrolytic hydrochloric acid vapor phase at 110c for 10 hours, protein hydrolysis was performed. Complete drying of the sample was completed in 3 hours under vacuum conditions with one bar pressure and 70°C. In this study, from the initial value of 10 gr of vermicomposting worms, three gr of hydrolyzed proteins were produced This amount of hydrolysis protein produced was 30% of the initial weight of worms.

The aim of this study was to determine the most effective ratio of forage to concentrate on feed intake, body weight, feed conversion ratio, and quality and quantity of carcasses of male Zel fattening lambs. The present study was performed using 20 male Zel lambs aged 16 weeks with an average weight of 27.8 kg for 90 days in a completely randomized design with four treatments and five repeats. Experimental treatments included different ratios of forage to concentrate at 20:80, 30:70, 40:60, and 50:50. The research data were analyzed by LSmeans procedure and regression in SAS software. Effect of different ratios of forage to concentrate on all yield traits (P <0.01), slaughter weight (P <0.05), weight gain during feeding period (P <0.05), daily weight gain (P <0.05), feed intake (P <0.01), feed conversion ratio (P <0.01), the weight of gastrointestinal contents (P <0.05), hot and cold carcass weight (P <0.05), carcass percentage (P <0.05) and thickness Backfat was significant (P <0.05). The change in the mentioned traits was observed linearly, increasing the concentration ratio to forage (P <0.01). As the percentage of concentrate in the feed increases feed intake increases. Due to the higher energy and nutrient content of concentrate than forage, lambs that consumed more concentrate had higher body weight and slaughter weight. Based on the results for optimal performance in fattening lambs, a ration with a ratio of forage to concentrate equal to (50:50) is recommended.

Toxoplasma gondii is one of important intracellular parasites which is prevalent in human and animals worldwide and almost one third of humans in overall they are compromised by infection with this parasite. Since toxoplasmosis can cause serious complications in humans, especially in the congenital form and in immunocompromised individuals, the identification of infectious sources will play an important role in the prevention and control of this infection. The present study was carried out in different in Kermanshah City, Iran. The aim of this study was to evaluate the seroprevalence of Toxoplasma gondii in in free-ranging chickens. One hundred and twenty serum samples from free-ranging chickens (Gallus domesticus) were tested for anti-Toxoplasma antibodies using ELIZA test with using from fully-automated LIAISON system. Three ml of venous blood was taken from the brachial vein. The blood samples were left to clot then centrifuged at 3000 rpm for 5 minutes. Serum samples stored at 4 ºC for 24 hours, then kept in -20 ºC until the time of testing. After fluidization of sera in the environment, 1 ml from any of samples transferred to 2 ml tubes and put in the analyzer. Twenty seven out of 120 sera (22.5%) were positive for the presence of anti-Toxoplasma gondii antibodies in serum. The results indicated broiler chickens may have a potential risk of infection with Toxoplasma gondii and have the ability to transmit the infection to humans.

The effect of replacement brown macroalgae (Sargassum ilicifolium) with fishmeal, intestinal tissue structure of Asian Lates calcarfer, with an initial weight of 29±1 g, in a completely randomized design with 4 treatments and three triplicates for 6 weeks was done. The experimental diets were prepared using a control diet and three diets including brown macroalgae with replacement at level 3, 6 and 9%. The obtained results indicated that there was no significant difference between enterocyte length, villi width and muscle thickness in intestinal tissue between different treatments and the control group (P>0.05). However, replacement of sargassum algae at the level of 6% on the villi length and villi uptake level of intestinal tissue showed a significant difference (P<0.05). According to the results, the use of sargassum macroalgae at the level of 6%, in the diet of Asian seabass, had a positive effect on studied parameters of intestinal tissue.

Enriching the fatty acid composition of poultry meat is an important issue. This study was conducted to investigate the effect of Algasan pigment on the fatty acids profile of Japanese quail meat with four treatments, three replicates, and 17 chickens per replicate in a completely randomized design. Experimental diets include: 1- Basic diet (control), 2- Basic diet + 0.1% Algasan (A1), 3- Basic diet + 0.2% Algasan (A2), 4- Basic diet + 0.3 % Algasan (A3). At 38 days of age, two male quails were randomly selected from each replicate to determine the fatty acid profiles of the meat. The data were analyzed by SAS software and the mean squares of the parameters were compared by Tukey test. The results showed that the control treatment had the highest percentage of myristoleic acid (0.245), oleic acid (0.260), and trans linoleic acid (0.150), A1 treatment had the highest percentage of heptadecanoic acid (0.160), oleic acid (35.350) and total fatty acids with an unsaturated bond (43.035) and the lowest percentage of omega-6 fatty acids (30.060), A2 treatment had the highest echosamenoic acid (0.185), cis linoleic acid (30.185), omega-6 fatty acids (32.485) and total polyunsaturated fatty acids (33.100) and A3 treatment had the most trans linolenic acid (0.200) (P≤0.05). In general, the results of the present study show that Algasan pigment at the level of 0.1% of the diet can be effective in improving the fatty acids profile of quail meat.