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.

BACKGROUND: Yersiniosis or enteric redmouth disease (ERM), caused by Yersinia ruckeri, is a serious bacterial disease in the farmed salmonids that causes economic problems in this industry. OBJECTIVES: This study was aimed to assess the experimental pathogenicity of Yersinia ruckeri in Rainbow trout (Oncorhynchus mykiss). METHODS: Two hundred Rainbow trout weighting 100-120 g, challenged with different strain of Yersinia ruckeri were obtained from affected trout farms using intra peritoneal injection route at a concentration of 108 cells/ml (0.1 mL per fish) to evaluate the virulence of these isolates. Each treatment group included 10 fish in two replicates and control fish received 0.1 mL sterile normal saline (0.9% NaCl). Following the intra peritoneal challenge, macroscopic and microscopic findings were determined. The most virulent strain was then used to determine the lethal concentration (LD50) using both intra peritoneal and bath method at dilutions of 103-1010 cells/mL. RESULTS: Macroscopically, anorexia, lethargy, circular swimming near the surface, blackening of skin, exophthalmia, hyperemia and hemorrhage in different parts of body, anal prolapse, enlarged liver and spleen were observed. Microscopically, hyperemia of hepatic sinusoids and vessels, necrosis and vacuolization of hepatocytes, increase in the abundance of macrophage centers in kidney, dilatation of Bowman’s space, degeneration and necrosis of kidney tubules, severe necrosis and detachment of intestinal villi, hyperplasia and clubbing of epithelial cells of secondary lamellae, spleen cell necrosis, goblet cell hyperplasia and thickening of epidermis layer in the tongue mucosa were observed.  The LD50 of intra peritoneal injection was calculated 1.2×106cells per fish 48 h post challenge. In bath route, LD50 was obtained 5×108 Cells/ml after 96 h. CONCLUSIONS: The results obtained from this study show virulence diversity of native strains.

Backgrounds: In endurance riding, the exercitation ability of horses during long periods and distances wre evaluated. Objectives: investigating the causes of elimination among participated horses in the 2013-2014 national endurance rides. Methods: by being present at four competition courses. Results: out of 176 horses, 74 (%42) were eliminated and the data of 23 horses (%13) as a control group was collected. Lameness was the highest cause of elimination, with 29 (%39.2) horses. High heart rate was in the second stage, by assigning 13 (%17.55) horses. Elimination because of illegal cases had been the next major reason, which allocated up to 12 horses (%16.2). Metabolic disorders, flutter, excessive exhaustion and dehydration, had 7(%9.5), 10(%13.5), 1(%1.35) and 2(%2.7) cases respectively. Significant correlation was found between the gender and the occurrence of flutter, so that 8 of 10 cases (%80) of the flutter cases were among males. As the distance was rising, the number of elimination because of metabolic disorders had increased too, that means there was significant relationship between these recent parameters. There were significant correlations between preservation method and metabolic disorders and dehydration. As the league progressed, the number of total elimination was enhancing too, but the difference between elimination because of illegal reasons and flutter was noticeable; each of them had opposite process. Significantly, both serum calcium concentration (mg/dl) means of all eliminated blood samples (10.10±0.37) and the control group (11.19±0.17) have been higher than serum calcium concentration of the group eliminated due to flutter (9.41±0.34) (P<0.05). Significantly, the mean of serum total protein concentration (g/dl) of the group which was eliminated because of the flutter incidence (7.87±0.11) has been higher than all eliminated samples (7.75±0.11) and the control group (6.61±0.16). Conclusions: The results of the indurance competition in this research in our country are alike with international data in other countries.

BACKGROUND: Recently chitosan nanoparticles have been applied as an immunostimulant and adjuvant in biomedical fields. OBJECTIVES: In this study the adjuvant effects of nanochitosan, derived from shrimp shell's chithin, on immunogenicity of Aeromonas hydrophila vaccine in common carp were evaluated. METHODS: Totally 300 juvenile common carp (51±5.6 g, Mean ±SD) were randomly divided into four groups each contained three subgroups with 25 fishes. Groups 1, 2 and 3 were immunized intraperitoneally with A. hydrophila vaccine. No adjuvant used in group 1, but nanochitosan and freund adjuvant were used with vaccine in groups 2 and 3 respectively. Group 4 (Control) injected with normal saline instead of vaccine. Fish were immunised at days zero and 14 and fishes were reared in the same situation for 6 weeks. Serum samples were taken every other weeks and immunological parameters including WBC, serum lysozyme and bactericidal activity, serum complement activity, NBT reduction activity, total protein and globulin levels and anti A.hydrophila antibody titer were compared among the groups. At the end of experiment all groups were challenged with LD50 concentration of A. hydrophila and mortality recorded for ten days. RESULTS: WBC, serum lysozyme and complement activity, NBT activity, globulin level and anti A.hydrophila antibody titer were increased in nanochitosan and freund groups compare to control group (P<0.05). Serum bactericidal activity and serum albumin level showed no significant change among the groups (P>0.05). Challenge mortality decreased in immunised groups compare to control. CONCLUSIONS: Nonochitosan posses proper adjuvant effects which is comparable with freund adjuvant and can be a good candidate as an alternative to current adjuvant in fish vaccines.

BACKGROUNDS: Toxoplasma gondii is an intracellular parasite, which is widely prevalent in sheep throughout the world. Parasite infection can occur pre- or post-natally. Congenital ovine toxoplasmosis occurs following a primary infection in a pregnant ewe and leads to abortion and stillbirth of the fetus causing important economical losses to sheep industry. OBJECTIVES: The present study was conducted to evaluate the presence of T. gondii DNA in brain samples from fetuses of slaughtered ewes in Khorramabad, west of Iran. METHODS: In total, 60 brain samples of ovine fetuses were collected. Examined fetuses were categorized in three age groups (4 months). Fifty grams of each sample was homogenized by mortar and pestle. DNA extraction was performed using a DNA isolation kit (MBST, Iran). A polymerase chain reaction (PCR) which targets the repeated element (RE) of the organism was used for tissue samples. Brain samples were considered T. gondii-positive if the expected band size (529 bp) appeared. RESULTS: T. gondii was detected in 4 out of 60 (6·7%) examined fetuses. No case was recorded in the age group