BACKGROUND: Toxoplasma gondii is a zoonotic obligate intracellular protozoan parasite that infects all warm-blooded animals as well as human worldwide. Human is infected with Toxoplasma parasites by eating half-cooked meat of livestock or oocyte. OBJECTIVES: The purpose of this study was to determine the presence of Toxoplasma in aborted fetuses of sheep using the serological method in North Khorasan province. METHODS: In this study, from 2015 to 2017, 133 samples of the thoracic fluid in aborted fetuses of sheep from different cities of North Khorasan Province were collected and sent to the central laboratory of Bojnourd. For each sample, a questionnaire was prepared for gathering information such as age and city, and then, the antibody level was determined in each sample by ELISA method. RESULTS: In this study, the age of 133 aborted fetuses of sheep was more than 120 days. Also, of the 133 aborted fetuses of sheep, 14 samples (10.53%) were infected with Toxoplasma parasites. The highest and lowest rate of Toxoplasma infection was observed in 2016 and 2017, respectively. Also, the most infection was found in Shirvan and Faroj cities. Results of chi-square test showed that there was a significant difference between year and abortion in sheep due to infection with Toxoplasma parasite (P<0.05). There was not significant difference between the frequency of this parasite infection and aborted fetuses in different areas (P> 0.05). CONCLUSIONS: The results of this study indicate that Toxoplasma gondii infection is one of the causes of abortion of sheep in North Khorasan province, and sheep is one of important sources of meat and dairy products in this area, Therefore, observance of public health tips and the complete cooking of meat and boiling milk is emphasized.

BACKGROUND: Parasitic helminthic diseases are one of the most common diseases of humans and animals that threaten the health of human societies. Nowadays, different methods are used for recovery of eggs parasites from soil samples. Therefore, in order to reduce the amount of mistakes caused by the artifacts (waste and disposable materials for diagnostic purposes), it is necessary to design and use a special device to collect more accurately the eggs of helminthic parasites. OBJECTIVES: The purpose of this study was to design and use a rapid method for collecting different Toxocara spp. eggs in order to determine the prevalence of soil contamination. METHODS: In this study, for recovery of Toxocara parasite eggs from collected soil samples, a sieve screen was used with plastic body (polyvinyl chloride compressed plastics) in a cylindrical shape with a mesh of 150 µm (can be changed), as well as the cap and holder,for the use of modified sucrose flotation method to isolate and identify Toxocara species eggs. RESULTS: In the current study, single cell, multicellular, and infective Toxocara eggs were recovered from collected soil samples. The results of prevalence of Toxocara eggs in collected soil specimens showed that 38.5% (CI: 95%, 32.03-45.40%) were recovered using vertical sieve screening and using the traditional technique and flotation method 21.5% (CI: 95%, 16.37-27.70%) were recovered, which showed a significant difference between the two groups (P˂0.05). CONCLUSIONS: Compared to the conventional and standard sucrose flotation method, using the sieve screen in addition to recovery of Toxocara parasite, it can be used in epidemiological studies to investigate the presence of eggs of nematode parasites such as Ascaris lumbricoides and Trichocephalus, as well as other eggs of zoonotic helminths in soil samples, and the percentage of true egg parasites in the soil samples in epidemiological studies.

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.

BACKGROUND: Cobalt is an essential nutrient for ruminants which is required for the synthesis of vitamin B12 by the ruminal microflora. Cobalt deficiency can lead to a deficiency of vitamin B12, which plays a major role in many metabolic reactions in the body. OBJECTIVES: This study was conducted to evaluate cobalt status in the serum and liver of cattle. METHODS: In different seasons, the blood serum and liver concentration of cobalt in slaughtered cattle in Urmia city were measured by atomic absorption in 151 and 196 cattle, respectively.   RESULTS: The results of cobalt measurement indicated that in 12.6% of serum and 21.4% of liver samples the concentration of cobalt was less than normal range with the Mean ± SD value of 0.64 ± 0.25 µg/dl and 0.15 ± 0.04 µg/gDM, respectively. The seasonal variations of cobalt values were assessed in serum and liver samples and following results were obtained: spring (2.18 ± 1.64 µg/dl, 0.23 ± 0.13 µg/gDM), summer (3.42 ± 1.04 µg/dl, 0.42 ± 0.27 µg/gDM), autumn (3.45 ± 0.37 µg/dl, 0.47 ± 0.38 µg/gDM) and winter (2.75 ± 0.59 µg/dl, 0.35 ± 0.09 µg/gDM). CONCLUSIONS: According to the results of this study, it seems that there is a subclinical deficiency of cobalt in cattle of this region and it is recommended that preventive measures be considered to prevent the complications and disorders caused by its clinical deficiency.

BACKGROUND: Staphylococcus aureus is one of the most important pathogenic microorganisms in meat products, especially those that are repeatedly handled by hand in the production process. Beta-lactam drugs, especially new generations of Cephalosporins, are used for treatment of most infections that are caused by Staphylococcus aureus. But the production of beta-lactamase enzyme by some strains has led to the failure for treating the infections that are associated with this organism. OBJECTIVES: The present study was conducted to evaluate the prevalence and comparison of the antimicrobial effect of methanolic extracts of red pepper and red onion on Staphylococcus aureus with beta-lactamase gene that was isolated from minced meat in Semnan city. METHODS: For this reason, sampling from 30 distribution and supply centers of packaged meat in Semnan city was performed in hygienic conditions and all of the samples were tested for presence of Staphylococcus aureus with beta-lactamase gene by biochemical methods and molecular confirmation by PCR assay. Also, the antibacterial effect of red pepper and red onion extracts on these isolates was evaluated by minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC), well distribution and bacterial growth curve tests. RESULTS: The results showed that 16.6 percent of samples were contaminated with Staphylococcus aureus with beta-lactamase gene. Red pepper and red onion extracts had good antibacterial effects on these isolates and in all the tests, the red pepper extract was more effective than the red onion extract. CONCLUSIONS: By proving stronger antimicrobial effect of red pepper, it is recommended to use pepper in sufficient amounts along with onion in foods that are made from minced meat like all kinds of Kebab.

BACKGROUND: The probiotic must survive in sufficient numbers after gastric and duodenal transit to be able to colonize the large intestine. The viability of a probiotic in the human upper GI tract is mainly influenced by low acidity of the stomach and bile salt in the small intestine. Currently, consumers are more interested in natural antibacterial compounds as food preservatives, like herbal essential oils and extracts. To provide a balance between sensory acceptability and antimicrobial efficacy, the use of sublethal concentrations of EOs in combination with other preservation methods has been proposed. However, it should be considered that bacterial cell exposure to sublethal stresses may result in decreased sensitivity to the same stress and even to other stresses. OBJECTIVES: The aim of this study was to evaluate the stress response of probiotic strain Lactobacillus rhamnosus GG, pre-exposed to sublethal level of Ziziphora clinopodioides EO. METHODS: The sublethal and lethal levels of Ziziphora clinopodioides EO, bile salt and pH stresses were determined for Lactobacillus rhamnosus GG. Then stress response of Lactobacillus rhamnosus GG pre-exposed to the sublethal level of Ziziphora clinopodioides EO were compared to cultures which were challenged directly with the lethal level of each stress (control). The growth of Lactobacillus rhamnosus GG was also assessed under bile salt and acid pH stress condition. RESULTS: The sublethal and lethal levels of Ziziphora clinopodioides EO and the lethal level for bile salt and pH were 1000 ppm, 1500 ppm, 0.2% and 2.5 respectively. In the test tubes, the number of cells that survived increased significantly and the growth curve of Lactobacillus rhamnosus GG has been affected in pre-exposed cultures. CONCLUSIONS: Exposure to sublethal concentration of Ziziphora clinopodioides EO can induce cross-protection against bile salt and pH stresses.

BACKGROUND: European chub (Squalius cephalus) is a member of Cyprinidae family and is classified as fresh water fishes which live in a group in roaring rivers. Siahrood runs from the south east to the Caspian Sea. OBJECTIVES: The main objective of this study was determination and identification of parasites of European chub in the Siahrood river. METHODS: In the current study, a total number of 96 fishes with average weight of 42 ± 3 gr and average length of 15 ± 1 cm were collected during winter, spring, summer and autumn 2015. The collected fishes were transported to parasitology lab with oxygenated plastic bags and were kept in aquarium till examination. Sample collection was conducted from skin, gills, fins and eyes and prepared wet mount was studied with optical microscope. Samples which are positive for presence of parasite were fixed and identified at the level of genus or species by biometric characterization and identification keys. RESULTS: In the present study, 6 species of endo parasites and ecto parasites were detected from different organs of Siahrood’s European chubs that included: 2 protozoan species from gills, Ichthyophthirius multifiliis with the highest positive samples in summer; Trichodina sp. with the highest positive samples in spring; 1 Myxozoa species from the intestine, Myxobolus  muelleri with the highest positive samples in winter; 3 Monogenea species, Dactylogyrus vistulae and Diplozoon paradoxum from the gills with highest positive samples at autumn and summer respectively; Gyrodactylus mutabilitas from the gills and the skin with the highest positive samples in summer. CONCLUSIONS: It seems the major factors affecting the variable presence of parasites in different seasons are ecological and environmental variation of the river in different seasons and the effects of these changes on fishes physiology and parasites life cycle.

BACKGROUND: One of the important parts of the cardiovascular system is the cardiac vessels. Ultrasonography which is the method of choice for evaluating the heart and vessels in all living animals can also be used in this fish. OBJECTIVES: This study was conducted to make a full understanding of the anatomic and echocardiographic characteristics of these vessels in beluga and suggest standard methods of ultrasonography for this species. METHODS: In this study, a total of 10 immature belugas were selected. The transducer was placed on the ventral surface of the body, between pectoral fins and transverse and sagittal images were obtained. By moving the anterior and posterior regions the vessels were investigated. After the ultrasound examination, anatomic studies were performed. Length and diameter of the vascular compartment were measured and analyzed by SPSS 16 software and Paired Sample T – method (P>0.05). RESULTS: In ultrasonography, blood flow was visible because of the movement of echoic particles. Two precardiac vessels joining between the liver lobes constituted and common vascular compartment before entering the sinus venosus. In the anatomical study, the ventral aorta was bifurcate near the gills. The right liver adjacent to the vessel was shorter and wider than the left one. Moreover, the common vascular compartment was shorter and wider than the liver adjacent to the vessels. The ventral aorta was longer and wider than the right precardiac vessel and common vascular compartment but was shorter than the left precardiac vessel (P>0.05). CONCLUSIONS: Due to lacing thorough anatomic and ultrasonographic studies concerning the cardiac vessels in this species, this study can be a cornerstone for further researches of this kind. In this study the long left precardiac vessel is named Common cardinal vein and wide right vessel is named Hepatic vein.

BACKGROUND: Antibacterial drug use in food producing animals, in addition to the very beneficial effects on the prevention, treatment, and control of infectious diseases, can lead to health risks including microbial resistance and drug residues. This survey was conducted due to the lack of information on the status of antibacterial drug use in dairy farms of Qom province. OBJECTIVES: To study the usage pattern of antibacterial drugs and compliance with public health- related measures in dairy cattle farms in Qom province. METHODS: In this study, 100 dairy herds were surveyed in three areas of Qom province including the southern part (Kahak), West (Jafar-abad and Khalajestan) and central part (Qom and the suburbs) using a questionnaire and direct interview. RESULTS: Injectable oxytetracycline, tylosin, penicillin + streptomycin were the most frequently used antibacterial products in dairy farms of Qom province (94%, 89% and 87%, respectively). A range of other antibacterial drugs showed high percentages of usage, as well. Among the 9 intramammary products, Tetranebalon®/Mastijet Forte® and Linconeocin MC® with 50% and 40% of frequency were the most commonly used products. Also, in a significant percentage of dairy farms, the milk collected from livestock treated with antibacterial drugs for mastitis (35%) or other illnesses (41%) was introduced into the milk reservoirs to be used in humans. CONCLUSIONS: In Qom province, there was an overuse of antibacterial drugs and high percentage of dairy farm units that did not follow the principles of rational drug therapy and the withdrawal times of milk and meat. This could be due to inadequate awareness of livestock workers regarding the public health implications of using these drugs and insufficient monitoring of veterinary authority in the province.

BACKGROUND: Chicken major histocompatibility complex region (MHC) is important in the productive traits, immune responses, resistance to infectious diseases and phylogenetic relationships. OBJECTIVES: This study was investigated for single nucleotide polymorphisms of MHC region related to the immune system in commercial broiler and layer chickens. METHODS: One hundred blood samples were taken from commercial broiler and layer chickens and genomic DNA was extracted by salting out method. The allelic polymorphisms were investigated in B-L, B-F and B-G loci using PCR-RFLP and MspI enzyme. RESULTS: For two commercial broiler and laying populations, in the 374 bp locus of B-L, only BB genotype was detected but in the 1048 bp locus of B-F, two genotypes of CG and GG were identified in broiler chickens. The C allele contained four bands of 515, 410, 75 and 47 bp, and the G allele with five bands of 410, 302, 213, 75 and 47 bp. In B-G (401 bp) locus, three genotypes of MM, MN and NN and two alleles of M with one band (401 bp) and N with two bands (350 and 51 bp) were identified. In total populations, the Shannon information index was calculated to be 0.45 and 0.73 in markers loci of B-F and B-G, and the fixation index values were -0.20 and 0.34, respectively. The highest observed heterozygosity index for B-F and B-G loci was 0.34 and 0.23, respectively. CONCLUSIONS: Considering the confirmation of the presence of polymorphism in two loci of the B-F (in commercial broiler population) and B-G (in commercial broiler and layer populations), these sites can be used as genetic marker in breeding programs to increase resistance to diseases.