BACKGROUND: Many toxic elements enter human food in different ways by various industries which can put people's lives in danger. Heavy metals can be rarely removed from the body after absorption and deposition in tissues, which can lead to diseases and complications in the body. Mercury is one of the heavy metals that can posion people after consumption of contaminated seafood. The measurement of pollutants such as mercury that present in aquatic animals and environment is one of challenges for humans.OBJECTIVES: This study aims to measure the amount of mercury accumulation in the edible tissue of whiteleg shrimp (Litopenaeus vannamei) found in farms of Bushehr Province in Iran.METHODS: In this research, 70 whiteleg shrimps were collected during four sampling stages in July, August, September and October for two consecutive years. Total mercury level was measured by the cold vapor method.RESULTS: The level of mercury was 0-0.009 mg/kg of body weight, while the recommended limit for mercury is 0.1 mg/kg according to the WHO. The microscopic study on tissue sections did not show any histopathological changes.CONCLUSIONS: The mercury level in the edible tissue of whiteleg shrimps in Bushehr province is much lower than the recommded level and does not pose any danger to residents and consumers.

BACKGROUND: The effect of nanoherbal substances in the treatment of infectious diseases before mating or during pregnancy must be evaluated. Saponin has adverse effects on a pregnant mother and her fetal through complex mechanisms.OBJECTIVES: This study aims to investigate the toxic effects of saponin encapsulated by ferritin nanoparticles (Nanosaponin) on fetal lung development in female mice with Streptococcus pneumonia.METHODS: Extraction of crude saponin from licorice roots was done by the powder heating and using 20 % ethanol and diethyl ether. Then, n-butanol and 5 % sodium chloride solution were added to the aqueous layer. The mice were divided into five groups of 10 including control, pneumonia, pneumonia treated with ferritin, pneumonia treated with saponin, and pneumonia treated with nanosaponin. Then, two groups of untreated pregnant pneumonia and pregnant pneumonia treated with nanosaponin were separated. In this study, tumor necrosis factor alpha (IFN-γ), heparin-binding epidermal growth factor-like growth factor (HB-EGF), Methyl-CpG binding domain 2 (MBD-2), and kruppel like factor 2 (KLF-2) genes were evaluated in the maternal lungs, and TNF-α level was evaluated using ELISA method in the fetal lungs. Maternal tissue, uterus tissue, and fetal lung were examined by hematoxylin and eosin staining, and maternal body tissue was examined by trichromason staining and Oxidative stress parameters were investigated.RESULTS: Nano saponin decreased the expression of IFN-γ (P<0.05) (P<0.01), MBD-2 (P<0.05) and HB-EGF  genes, KLF-2 protein level and TNF-α levels in fetal lung.The thickness of uterine myometrium and blood flow of endometrium increased the number of live embryos and the rate of successful pregnancy. In addition, Nano saponin effectively improved the oxidative stress response in the fetus without any harmful effect on the mother's liver tissue.CONCLUSIONS: The nanosaponin has no toxic effects on the sudy organs of the mother and fetus. It has therapeutic effects on the fetal lung development process after the infection of mother with Streptococcus pneumonia.

BACKGROUND: Salmonellosis is a dangerous disease that can threaten the health of humans and animals. This disease can lead to economic losses annually; therefore, many studies have been conducted to prevent this disease.OBJECTIVES: The current study aims to design a recombinant chimera protein HBHA-Omp28 as a vaccine against Salmonella typhimurium.METHODS: The nucleotide and amino acid sequences of Omp28 and HBHA proteins were first extracted from the NCBI database. Then, the recombinant chimera of HBHA-Omp28 was bioinformatically assembled using a rigid linker. Epitope prediction of T and B cells, antigenicity, allergenicity, and physicochemical features assessments of HBHA-Omp28 were done using Immune Epitope Database (IEDB), ABCpred, VaxiJen, AllerTOP and ProtParam online servers, respectively. To assess the secondary and tertiary structures, the Self-Optimized Prediction Method with Alignment (SOPMA) and the Iterative Threading ASSEmbly Refinement (I-TASSER) server were used, respectively. Molecular docking between recombinant chimera and TLR4/MD2 receptor was assessed by ClusPro server. Finally, after codon optimization of nucleotide sequence of recombinant chimera to express in Escherichia Coli k-12 strain, the cloning of recombinant chimera in pET21-a (+) vector was examined.RESULTS: The designed recombinant chimera was classified as an antigenic and non-allergenic protein with molecular weight of 34.19 kDa. According to the results of molecular docking study, the HBHA-Omp28 protein was able to bind to TLR4/MD2 receptor using 9 hydrogen bonds. The results of cloning study demonstrated that HBHA-Omp28 successfully cloned into pET21-a (+).CONCLUSIONS: The designed recombinant chimera can be an appropriate vaccine against salmonella bacteria.

BACKGROUND: Body condition and its relationship with inflammatory indicators in the transition period of ewes can be used as a key to prevent the occurrence of metabolic complications in this period.OBJECTIVES: This study aims to determine the levels of inflammatory markers and their relationship with body condition and energy status in the transitional period in Makuei ewes.METHODS: This study was performed on 45 female peri-parturient Makuie ewes aged 3-5 years with 2-4 breeding lambs. Blood samples from the jugular vein were prepared in three periods, 21 days before delivery, baseline (time zero), and 21 days after delivery.RESULTS: The mean glucose and cholesterol concentrations were not significantly different between the groups with low, moderate, and high body conditions. Non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) concentrations were significantly higher in groups with lower and higher body condition scores (BCS) than in the normal group. There was a significant positive correlation between energy-related indices (NEFA, BHB) and the BCS of the pregnant and lactating ewes. The concentration of fibrinogen, sialic acid, and blood ceruloplasmin increased in the first three weeks and decreased after delivery. These indices significantly increased in relatively obese and lean groups than in the normal group during the study. The correlation of BHB and NEFA with sialic acid, ceruloplasmin, and fibrinogen was also reported in the study groups in the pre- and post-partum periods.CONCLUSIONS: Ewes with normal BCS (2.75-3.25) have a good energy status. Low levels of NEFA in ewes indicate that the mobility of fats is low, and the inflammation process is lower in the transition period of these animals. Furthermore, low BCS can be a predisposing factor for inflammation in ewes during the pre-partum period. This effect may be due to the increased metabolic requirements and compromised immune function associated with negative energy balance in the transition period of ewes.

BACKGROUND: Gallibacterium anatis is a recently defined genus, which is a member of the Pasteurellaceae family. This advantageous pathogen is frequently found as part of the normal microflora of the upper respiratory tract and lower genital tract of the healthy poultry. Provided with appropriate conditions, it leads to various diseases, such as salpingitis, peritonitis, and loss of egg production with mortality in layer flocks. According to previous studies, multiple antibiotic resistance has been observed among G. anatis isolates, which can impose high costs on layer flocks. Due to the lack of the pathognomonic symptoms in the conflicts caused by this bacterium,  not enough comprehensive research has been conducted to date on the condition of this disease in Iran.OBJECTIVES: This study aimed to investigate the infection rates of this bacterium via PCR.METHODS: 295 tracheal swabs were collected from 10-layer flocks. Subsequently, the suspected colonies were isolated and identified with morphological features, differential cultivation, and PCR.RESULTS: 43.72 % of the samples were positive.CONCLUSIONS: The results of this study indicated that laying farms in Iran were infected with Gallibacterium anatis; thus, certain measures should be taken to control the factors reducing the production of layer flocks.

BACKGROUND: Corynebacterium pseudotuberculosis and Trueperella pyogenes are two important pyogenic bacteria that cause many annual economic losses worldwide. Currently, antibiotic resistance of these bacteria is on the rise. Early detection of infection with these bacteria is important for controlling the infections caused by these two bacteria.OBJECTIVES: This study aimed to investigate the contamination of cattle cutaneous abscesses with  Corynebacterium pseudotuberculosis and Trueperella pyogenes in five large cattle farms around Tehran and propose an accurate method for a rapid detection of these two bacteria.METHODS: Out of 60 cows involved in cutaneous abscesses in the summer of 2018, sterile sampling was performed to diagnose the bacterial agent that caused the abscess. Bacteriological examination of the samples was performed using standard biochemical reactions and polymerase chain reaction using specific primers.RESULTS: Of the 60 samples studied, 25 % (15.60) were isolated as Corynebacterium pseudotuberculosis and 20 % (12.60) as Trueperella pyogenes. In 55 % of the samples (33.60), both bacteria were present simultaneously. All the samples detected using biochemical reactions were confirmed by the polymerase chain reaction.CONCLUSIONS: Corynebacterium pseudotuberculosis and Trueperella pyogenes are the main causes of cutaneous abscess in cattle farms around Tehran. Because the accurate diagnosis of the cause of abscesses is very important for effective treatment, polymerase chain reaction, based on 16S-23S rDNA and 16S rRNA, can be used to rapidly and accurately detect these bacteria in the early stages of the infection.

BACKGROUND: Reducing the protein and amino acid content of diet or altering the dietary electrolyte balance were suggested as the effective strategies to prevent the harmful effects of the heat stress in poultry.OBJECTIVES: This study surveyed the effects of various levels of threonine and dietary cation-anion balance on the broiler chickens under the heat stress conditions.METHODS: 700 one-day-old male broilers (Ross 308) were used for 6 weeks under high- temperature conditions. This experiment was conducted using a 2 × 3 + 1 factorial experiment based on a completely randomized design, with 7 treatments (5 replicates per treatment and 20 birds per replicate). Experimental factors included two threonine concentrations (recommended level and 10 % above recommended level) and three dietary electrolyte balances (175, 250, and 325 mEq/kg). The control group considered the treatment with a normal threonine concentration (recommended level) and a dietary electrolyte balance of 250 mEq/kg under optimal temperature conditions.RESULTS: Although there was no interaction between threonine level and electrolyte balance, the electrolyte balance of 175 meq/kg increased the performance index compared to the electrolyte balance of 250 or 325 mEq/kg (P<0.05). The villus height to crypt depth ratio and villus surface area in the jejunum improved with an electrolyte balance of 175 or 250 mEq/kg (P<0.05). A decrease in the dietary electrolyte balance increased in the nitrogen-corrected apparent metabolizable energy (P<0.05). Besides, an increase in the population of lactobacilli and bifidobacteria in the cecum, as well as an increase in protein digestibility, were observed by increasing levels of threonine in the diet (P<0.05).CONCLUSIONS: Based on these results, a high level of threonine or a low electrolyte balance in diet (175 mEq/kg) may improve the performance, metabolizable energy, and intestinal microbial flora of broilers reared under heat stress.

BACKGROUND: Stocking density is one of the most important problems in the poultry industry, which impair their production and welfare.OBJECTIVES: This experiment was done to evaluate the effect of organic selenium supplementation on the growth performance, blood metabolites, and the meat quality of broiler chickens in different stocking densities.METHODS: 216 one-day-old male broiler chickens (Ross 308) were used in 2×2 factorial arrangements by 2 stocking densities (7 and 15 birds/m2) and 2 levels of selenomethionine (0 and 0.4 mg/kg) in a completely randomized design with 4 treatments and 4 replicates.RESULTS: The feed intake (FI), and body weight gain (BWG) were significantly affected by the stocking density and selenomethionine (SE-MET) supplementation in the overall experiment (P<0.05). FI and BWG decreased and feed conversion ratio decreased in 15 bird’s density, while SE-MET inclusion improved these traits (P<0.05). Increasing stocking density increased the plasma glucose (P<0.05). Blood glutathione peroxidase and lymphocyte levels reduced at 15 bird’s density, while increased by 0.4 mg SE-MET supplementation (P<0.05). Increasing stocking density increased blood heterophil, while SE-MET inclusion decreased it (P<0.05). Meat pH and cooking loss were not affected by stocking density. Dripping loss (DL) increased, and water holding capacity (WHC) decreased at 15 bird’s density, but 0.4 mg SE-MET decreased DL and significantly increased WHC (P<0.05).CONCLUSIONS: It was concluded that increasing stocking density had the negative effects on the growth performance and meat quality of broiler chickens; however, the supplementation of 0.4 mg of SE-MET to diet can improve the growth performance, blood metabolites and meat quality of broiler chickens.

BACKGROUND: Blowfly (Lucilia sericata; Diptera: Calliphoridae) is an external parasites of domestic animals and the causative agent of myiasis, which is involved in the transmission of a  number of bacterial pathogens. Application of chemical insecticides is one of the most common methods for controlling this pest, which have recently been reported resistant populations of L. sericata to some insecticides. Therefore, identifying and recommending new and low-risk insecticides for humans and environment is of prime importance.OBJECTIVES: This research aimed to investigate the toxicity of insecticides deltamethrin, spinosad, pyridalyl, and pirimiphos-methyl on the third instar larvae of L. sericata.METHODS: In the present study, the bioassay tests were performed by immersion of larvae in concentrations of insecticides that caused 10 to 90% mortality of larvae, as a factorial experiment in a randomized complete block design. Additionally, the median lethal concentration (LC50)  was determined from the probit analysis of bioassay data for the studied insecticides.RESULTS: The results of analysis of variance and the comparison of the mean mortality (%) of third instar larvae were significant at the level of 1% probability. According to bioassay tests, the estimated LC50 values for deltamethrin, spinosad, pyridalyl, and pirimiphos-methyl were 186.49, 26.88, 85.08, and 134.97 mg L-1, respectively. Overall, the results revealed that spinosad and pyridalyl had the highest lethal effect on blowfly larvae while deltamethrin had less advers effects on this pest.CONCLUSIONS: Spinosad, as a relatively new insecticide, with very low toxicity towards mammals and other non-target organisms, showed the highest lethal effect on blowfly larvae and can be an appropriate alternative to older insecticides in controlling this pest.

BACKGROUND: Homocysteine (Hcy) is a sulfur-containing amino acid derived from methionine. Several studies have suggested that plasma Hcy may be a useful biomarker of cardiovascular disease in human. There is limited information about serum homocysteine in heart diseases of dogs.OBJECTIVES: The present study aimed to assess the concentration of serum total Hcy and evaluate the relationship between its concentrations and serum levels of cholesterol, triglycerides, and activities of creatine phosphokinase and aspartate aminotransferase in small breed of dogs with endocardiosis.METHODS: For this purpose, a total of 15 dogs (seven males and eight females) with acquired endocardiosis were confirmed by clinical examination, auscultation, thoracic radiography, and echocardiography. In addition, 15 normal dogs of the similar age, breed, and weight were selected as the controls. All the examinations performed on the patients were carried out on the healthy dogs. Homocysteine was measured via an enzymatic method. Additionally, the activities of CPK and AST and the levels of cholesterol and triglycerides were assessed utiling commercial kits. Subsequently, the data were analyzed with t- student test and one- way ANOVA and Pearson’s linear correlation test was used to determine the relationship between serum homocysteine levels with triglycerides, cholesterol, CPK, and AST.RESULTS: The results revealed no significant differences concerning serum homocysteine level and AST activity between the two groups; meanwhile, the increase in serum triglycerides and CPK activities in dogs with heart disease was statistically significant compared to that in the control group. However, there was no significant correlation between homocysteine and the other measured parameters.CONCLUSIONS: The present study indicated that the role of homocysteine as a new risk factor associated with dog endocardiosis is questionable and it seems as if in human studies related to homocysteine and heart disease, the selection of dog as animal model requires further investigation.