BACKGROUND: Today, the fight against the bacteria causing foodborne diseases is of particular importance in the packaging of seafood. It is therefore vital to find new compounds with antibacterial properties.OBJECTIVES: In the present study, antibacterial properties of synthetic nanocomposite zinc chromite-zinc aluminate (ZnCr2O4-ZnAl2O4) on E. coli and Pseudomonas aeruginosa were studied.METHODS: After synthesis of nanocomposite, antibacterial activity of nanocomposite zinc chromite-zinc aluminate was evaluated via disk diffusion method, Minimum Inhibition Concentration (MIC), and Minimum Bactericidal Concentration (MBC) using the microdilution method.RESULTS: The results of this study revealed a higher sensitivity reaction of Pseudomonas aeruginosa (18.6±1.2 mm) compared to E. coli (12.7 ± 1.4 mm). No significant differences were observed between Gentamicin antibiotic and synthetic nanocomposite against Pseudomonas aeruginosa (P<0.05). The minimum MIC and MBC concentrations were seen in Pseudomonas aeruginosa (1.66 mg/ml) and the maximum concentration of MIC belonged to E. coli (5 mg/ml).CONCLUSIONS: In this study, the effects of nanoparticles on these gram-negative bacteria could be attributed to the small diameter of the ions, and hence the greater penetrability of these nanoparticles despite the wall's resistance. Based on the results, zinc chromite-zinc aluminate nanocomposite showed a better performance compared with gram-negative bacteria, specifically Pseudomonas aeruginosa resistant bacteria, and could be used for further studies in fisheries product packaging.

BACKGROUND: Fresh sausages are classified as one of the most perishable meat products due to the lack of using chemical preservatives.OBJECTIVES: The present study aimed to increase the refrigeration time of fresh sausages using Zataria multiflora Boiss. essential oil.METHODS: In this study, samples of fresh sausages, containing different concentrations of Zataria multiflora Boiss. essential oil (0, 0.05, 0.1, and 0.2 %), were prepared and stored under the refrigerated condition for 17 days. Subsequently, they were evaluated for microbial, chemical, and sensory properties at six time intervals (days 0, 2, 4, 6, 10, and 17).RESULTS: Based on the results of the study, by adding Zataria multiflora Boiss. essential oil to fresh sausages, the microbial count in the treatments containing high concentrations of essential oil (0.1 and 0.2 %) was significantly different from that in the control group (P<0.05). The amount of volatile nitrogen bases at the beginning of the study was 14 mg/ 100 g and after six days, in the control group, it reached 32.1 mg/ 100 g. Meanwhile, in the treated samples, it was less than 25 mg/ 100 g up to day 10. Moreover, at the end of the study, the level of TBARS in the control group reached 1.48 mg malondialdehyde /kg while this level was less than 0.78 mg malondialdehyde / kg for the groups treated with Zataria multiflora Boiss. essential oil. The results of this study also showed that the addition of essential oil has a non-significant effect (P>0.05) on sensory properties.CONCLUSIONS: Zataria multiflora Boiss. essential oil was found to have the potential to increase the shelf life of fresh sausages without adverse sensory effects.

BACKGROUND: Sex determination is an essential issue in certain fish species, like sturgeons. During the rearing management, distinguishing between male and female fish is an important process for producing meat or caviar.OBJECTIVES: The current study aimed to find the feasibility of electric organ discharge (EOD) frequency ‎generating to introduce a novel method of sex determination in three freshwater species, namely the ‎black ghost knife fish (Aptronotus albifrons), goldfish (Carassius auratus), and the Sterlet ‎sturgeon (Acipenser ruthenus), as non-electric fishes.METHODS: In this regard, following sex detection, EOD frequency ‎of fishes were recorded via an oscilloscope. In addition, knife fish was used as a reference sample on which a lot of work has been done to evaluate the accuracy of the method and the use of the oscilloscope. Furthermore, the EOD frequency of male and female ‎Sterlet sturgeons was recorded and reported for the first time in this study.RESULTS: The frequency ‎magnitude was significantly different in genders of Sterlet (P<0.05) with higher EOD frequency in males ‎than in females. There was no recorded frequency in goldfish ‎male and female. EOD frequencies, which were recorded in male and female of black ghost fish, ‎represented significant differences compared with the other studies (P<0.05).CONCLUSIONS: The results achieved ‎in this study revealed that sex differences are one of the effective parameters in terms of EOD ‎frequency inequality; this non-invasive method can be utilized for sex identification of valuable ‎species, like sturgeon. However, it is required to gather advanced equipment and conduct further ‎research in physiology and biology of reproduction for accurate recording of electrical frequencies ‎and detection of their origins.

BACKGROUND: Neosporosis is a disease caused by the protozoan Neospora caninum, which is characterized by abortion in cattle and neuromuscular paralysis of various organs, particularly the hind limbs of dogs. The diagnosis of neosporosis is often made by serological molecular tests.OBJECTIVES: This study was conducted to investigate the presence of N. caninum oocysts in the feces of dogs. METHODS: A total of 100 fecal samples were collected from indoor and outdoor dogs during 2018-2019 around Tabriz. Information about age, location, and history of antiparasitic treatment of the dogs were recorded in a questionnaire. Primarily, fecal samples were examined microscopically for Neospora ocysts. After breaking the collected oocysts through freeze-thaw and sonication, DNA contents of the oocysts were extracted and analyzed via PCR.RESULTS: In a light microscopic study, oocysts were observed in 45 (45 %) of the fecal samples. In the PCR study, 21 of the 45 cases tested positive for Neospora infection (21 %). All the positive cases of infection were observed in molecular examination in dogs older than one year. The positive cases were observed in 2 % of the domestic dogs, 8 % of the stray dogs, 6 % of the kennel dogs, and 5 % of the rural dogs. Furthermore, 19 % of the infected dogs had no history of antiparasitic treatment; only 2% had a history of antiparasitic treatment. The results of statistical analysis showed that the rate of infection in dogs around Tabriz with Neospora caninum was significantly (P<0.05) related to the animal's living environment and history of antiparasitic treatment. However, this rate was found to have no significant relationships with the age of the animals.CONCLUSIONS: Due to the high rate of infection with Neospora caninum in dogs in Tabriz, it is necessary to apply preventive methods in traditional and industrial farms around this city and use rapid diagnosis methods in them.

BACKGROUND: Omega-3 fatty acids can be conducive toreducing the harmful effects of physiological stress through reducing the stimulatory activity of glutamatergic neurons.OBJECTIVES: The aim of this study was to investigate the effects of omega-3 fatty acids on performance, blood parameters, and the profile of fatty acids in the egg yolks of laying hen under stress.METHODS: This study was performed using 96 LSL-Lite laying hens in a 2 × 3 factorial experiment with 2 factors, namely stress (no dexamethasone and 1.5 mg/kg of diet dexamethasone) and omega-3 fatty acids (the levels of 0, 0.24 and 0.48 % of diet), in a completely randomized design for 70 days from 35 to 44 weeks of age.RESULTS: Physiological stress reduced the feed intake, the percentage of egg production, and egg mass in laying hens (P<0.05). Omega-3 fatty acid supplements had no effects on these traits. The groups receiving 0.48 % of omega-3 fatty acids had the lowest heterophil:lymphocytes (P<0.05), and there was no difference between stressed and non-stressed groups. The ratio of omega-6 to omega-3 fatty acids was higher in birds previously affected by stress (P<0.05). Feeding with omega-3 fatty acids in birds increased omega-3 fatty acids in egg yolk and reduced the ratio of omega-6 fatty acids to omega-3 in laying hens (P<0.05).CONCLUSIONS: Based on the results of this experiment, physiological stress had a negative effect on performance traits, and the use of omega-3 fatty acids in laying hens under stress had no effect on performance traits. Physiological stress altered the profile of fatty acids and increased the proportion of omega-6 to omega-3 fatty acids in egg yolk. The use of omega-3 fatty acids reduced the negative effects of stress and improved the profile of fatty acids in egg yolk.

BACKGROUND: Over the recent years, Neospora caninum has been one of the most important causes of abortion in dairy cattle. OBJECTIVES: We conducted the present study in order to investigate the seroprevalence of N. caninum in dairy cattle in Semnan province and its effect on abortion. METHODS: 237 blood samples were obtained from various Semnan dairy farms and 104 bulk dairy samples from four milk collection centers in Semnan, Garmsar, Damghan, and Shahrood were tested for sera and milk utilizing ELISA (Svanova Biotech AB) test kits. RESULTS: The results revealed that 87.27 % of bovine serum was positive. The percentage of opacity density (OD) of positive sample (PP) ranged from 72.17 to 137.3 (114.21±24.65). In addition, the average rate of milk seroprevalence to the parasite was 95.23 % in Semnan province. CONCLUSIONS: The frequency of Neospora caninum infection in blood and milk was high in Semnan, yet no significant relationships were observed with abortion (p < /em>>0.05).

BACKGROUND: The defects of the central nervous system caused by viruses are associated with tissue changes in certain areas of this system. OBJECTIVES: We conducted the current work to determine and categorize the pathologic pattern of central nervous system lesions in stillbirths and newborns small ruminants with neurological symptoms in Semnan province. METHODS: Primarily, we selected the affected animals and carried out systematic post mortem examination of lambs and kids. Subsequently, brain and spinal cords were completely removed. Processing, sectioning, and staining from different regions of the central nervous system was performed and 15 different regions of the brain and 10 different levels of the spinal cord were prepared. Subsequently, the histopathological study was performed and the observed lesions were arranged. RESULTS: This study was performed on 20 lambs and kids with nonsuppurative inflammatory lesions in the brain and spinal cord. In the gross examination of the brain and spinal cord, we observed 4 cases of arthrogryposis, 1 case of spinal cord hypoplasia, 2 cases of hydranencephaly, 2 cases of porencephaly, and 1 case of cerebellar hypoplasia. According to the presence of nonsuppurative inflammation in the brain and spinal cord, 20 positive cases were categorized into 4 groups. In the first 3 groups, the main lesion was nonsuppurative encephalomyelitis and the main lesion of the fourth group was nonsuppurative encephalitis. Accordingly, 6 cases in the first group had extensive and inclusive nonsuppurative inflammation in over 75%  of the brain and spinal cord sections; in the second group, five cases had multiple scattered nonsuppurative inflammation in 50% - 75% of the brain and spinal cord sections; in the third group, five cases had non-inclusive and focal nonsuppurative inflammation in less than 50% of the brain and spinal cord sections, and in the fourth group, 4 cases had nonsuppurative inflammation in the brain without lesion in the spinal cord. CONCLUSIONS: It seemed as though in each of the four pathological patterns, certain viral agents were responsible for the pathological changes.

BACKGROUND: The use of additives, such as medicinal plants, may result in improved digestion and fermentation and consequently, animal production. OBJECTIVES: The present experiment was conducted to determine the most appropriate amount of Ziziphora cliniopodiodes plant to be utilized in lamb diet and its effect on digestibility, fermentation, growth performance, blood, and quality of carcass and meat. METHODS: Different amounts of Ziziphora cliniopodiodes (0, 0.2, 0.4, 0.6, 0.8, 1 %) were added to diet of lambs. The best diet was selected based on gas production method and fed to male lambs with an average weight of 41 ± 2 kg in a completely randomized design with three treatments and six replications. The selected diets for feeding lambs included: control diet (Ziziphora cliniopodiodes) and control diet supplemented with 0.2 or 0.4 % Ziziphora cliniopodiodes. Feed intake, digestibility of nutrients, fattening performance, blood and rumen fermentation parameters, protozoan population, and certain meat quality indexes were measured. At the end of the experiment, the carcass traits were studied. RESULTS: The obtained results herein revealed that the potential of gas production, partitioning factor, truly degradable organic matter, dry matter intake, apparent digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber, glucose, cholesterol, triglyceride, blood urea nitrogen, and protozoa population were not affected by the experimental diets. There was a significant difference among the experimental diets for daily weight gain, the total weight gain of lambs, and microbial biomass production. The highest records belonged to the diet containing 0.2 % Ziziphora cliniopodiodes. Antioxidant characteristics, colorimetric indices, and pH of meat were not affected by the applied treatments. CONCLUSIONS: In general, according to livestock experiments, the best amount of Ziziphora cliniopodiodes to be employed was 0.2 %, which improved certain fermentative and performance traits.

BACKGROUND: There have been many reports on spinal cord injuries in humans and animals, which is  a major medical and veterinary concern; therefore, the present research project was carried out to devise an appropriate treatment approach. OBJECTIVES: The purpose of the present study was to apply the modified Allen’s test and Royan Impactor Devicein order to 1) induce spinal cord injury on rhesus monkeys and 2) gain the ultimate confirmation by clinical examinations and MR imaging for application in human and veterinary medicine. METHODS: Royan Impactor Device  was used to induce spinal cord injury on rhesus monkeys. Five rhesus monkeys were anesthetized with ketamine, xylazine, and isoflurane. Laminectomy  was done at the level of T9-T10, and a 50 g weight was then dropped from a 12 cm height through a guide tube onto a 10 mm2 impact plate on the exposed spinal cord. RESULTS: The results of the present study showed signal changes with decreasing the trend in the T2W of spinal cord in sagittal and axial areas due to hematoma, inflammation, pressure on spinal cord, and tissue destruction after spinal cord injury. In the clinical examination of all samples, spinal cord shock symptoms, marked by bladder distention, disappeared 3-5 days post spinal cord injury. Not all measurable factors related to the severity of the injury  were restored to the normal condition until the end of the study although their severities were reduced to some extend. CONCLUSIONS: Modified Allen’s test and the instrument that we designed for this study were able to satisfy the needs of the researchers in treating the spinal cord injury.

BACKGROUND: Despite the availability of effective conjugate vaccines, Haemophilus influenza (HI) and Haemophilus somnus (HS) still result in enormous global morbidity in both human and cattle. Vaccines failure to protect against different strains can lead to the spread of Hemophilus infections. The absence of various epitopes from Haemophilus strains in existing vaccines is one of their weaknesses. Therefore, selection of a conserved and common set of proteins in the invasive strains of HI and HS is essential for predicting epitopes as potential vaccine candidate. OBJECTIVES: The aim of this study was to design an effective polyepitopic vaccine against invasive HI and HS strains using in silico approaches. METHODS: First, the protein sequences were retrieved from the databases and were aligned to determine the conserved areas with the Clustal omega software. Then, B and T cell epitopes identification was done for OapA, OMP6, PD, D15, IgA1 Protease and TbpA proteins using various immunoinformatic servers. The high ranked epitopes were selected from mentioned proteins. The selected epitopes were fused together by appropriate linkers. This designed construct was analyzed for physicochemical and structural characteristics using related servers. RESULTS: 6 TCD4+ and 3 B cell epitopes were selected to design the final construct from 6 common proteins. The immunoinformatics analysis revealed that the designed polyepitopic peptide is a safe, soluble, hydrophilic and thermostable antigen that could be a potential vaccine. CONCLUSIONS: The polyepitopic construct can be considered as a vaccine candidate against Haemophilus.