SCIENTIFIC-RESEARCH IRANIAN VETERINARY JOURNAL
Year:2015 | Volume:11 | Issue:3|Papers Count:17

Aeromonas hydrophilais a ubiquitous and opportunistic aquatic microorganism, that conflicting views have been expressed concerning whether Aeromonas hydrophila is a primary pathogen of freshwater fish or a secondary opportunistic pathogen. Under stress condition, such as temperature changes, handling or poor water quality, this bacterium becomes a pathogen. Aeromonas hydrophila has been associated to the dominant infectious agent of hemorrhagic septicemia in freshwater cultured fishes. In this study, a total of 200 pieces of patient cultured carp (126 common carp, 39 silver carp and 35 grass carp) were taken from Khuzestan province farms. A total of 125 and 31 isolates were identified as Aeromonassp. and Aeromonas hydrophila respectively by biochemical methods and PCR analysis by specific primers such as 16srRNA for aeromonas sp., and 16srRNA and lipase for detection of Aeromonas hydrophila. The results showed that Aeromonas sp. and Aeromonas hydrophilaare responsible for 62.5% and 15.5% of carp septicemia respectively and prophylactic measures should be considered. It also concluded that PCR assay provides a highly sensitive and specific tool for the detection of Aeromonas hydrophila compared with biochemical methods.

Hepatic ischemia-reperfusion (IR) injury may affect different biological and functional roles of the liver. Liver accounts as an important organ for metabolizing different compounds and drugs in which cytochrome P450s (CYPs), play an important role. This study aimed to investigate the effects of IR injury on the gene expression of the major CYPs isoforms in the rat liver. Four groups (n=5) of male Sprague-Dawley rats underwent 60 min lobar hepatic ischemia followed by 1, 6, 12 or 24h reperfusion, and a sham-operated group was selected as control. At the end of each reperfusion period, blood samples were taken to evaluate enzyme alterations induced by IR and then animals were euthanatized and tissue samples were taken to study IR-induced changes in gene expression of some CYPs isoforms. Total RNA was isolated from the rat liver tissue and then cDNA was synthesized from an mRNA template. The level of mRNA expression in the liver was analyzed by real-time PCR using specific primers for CYP450 isoforms. The levels of ALT, AST and ALP in the groups subjected to IR was significantly (P<0.05) increased during different times of reperfusion and reached to the peak 6h after the reperfusion. However, the level of CYP1A1, CYP3A1 and CYP2E1 mRNA was significantly (P<0.05) decreased during 6, 12 and 24h of reperfusion. These results showed that IR injury may induce down regulation of the individual CYP450 isoforms and these changes may affect CYP-mediated drug metabolizing activities by the liver.

Bovine viral diarrhea is one of the most important diseases of cattle caused by a pestivirus (BVDV) within the family Falviviridae. BVDV also affects reproduction system and results in a great loss. E2 protein is the most important structural protein of the virus for induction of protective immunity. The purpose of this study was to clone and express the E2 protein gene in E.coli. The gene was amplified by RT-PCR and cloned into pMAL-c2x plasmid. The identity of the cloned gene and the accuracy of cloning were confirmed by sequencing and the protein expression in E.coli was assessed by SDS-PAGE. Antigenic nature of the recombinant E2 was determined by immunoblotting and the protein was shown to be soluble, after sonication of bacterial cells. Results indicate that the aforementioned recombinant plasmid expresses the E2 protein, efficiently.

In this study the effects of feeding Trachyspermum copticum seed and vitamin E on egg quality, hen performance and blood antioxidant status were investigated. A total number of 216 Hy-Line W-36 laying hens at 70-week of age were randomly allocated to 6 treatments with 3 replicates in a complete randomized design. Laying hens were fed on the experimental diets, using four levels (0, 1, 2 and 3%) from Trachyspermum copticum powder as natural antioxidant, in comparison to two levels of vitamin E (100 and 200 mg/kg diet) for 10 weeks. Results showed that increasing Trachyspermum copticum powder level from 0 to 30 g/kg of diet increased plasma antioxidant capacity (P<0.05) but reduced malondialdehyde (MDA) content of serum (P>0.05). Results that Vitamin E supplementation had no significant effect on the MDA levels of serum but reduced their MDA levels, moreover significantly increased plasma antioxidant capacity, in comparison to the control group (P<0.05). All laying hens had similar laying rate, average egg weight, egg mass and feed conversion. Feed consumption of hens fed diets containing 1%Trachyspermum copticum powder were significantly lower than the other group. Experimental diet increased the yolk color in comparison to the control group (P<0.05). It would be concluded from this study that Trachyspermum copticum could be used as natural antioxidant during laying period.

Scorpionism is a common problem that occurs in tropical and subtropical countries. Hemiscorpius lepturusis one of the most dangerous scorpion species, endemic in Khuzestan. The aim of the current study was to clarify the possible histopathological implications due to injection of H. lepturus scorpion venom in sheep. The study performed on 12 native male sheep in which the age and weight average were about 6 months and 20.72±1.61 Kg respectively. Four groups (3 rams in each group) were chosen randomly (1 group as control and the other 3, as experimental groups). Three doses of H. lepturus venom included: 0.01, 0.05 and 0.1 mg/kg BW were injected subcutaneously into the three experimental groups and just 1 mL of distilled water were injected to control group as the same way. After death or after 72 hours, the animals were subjected to necropsy. In most animals, histopathological evidence of lesions, were confined in the liver and skeletal muscles (injection site), whereas the other injuries such as in brain and urinary bladder lesions were at minimum. Lesions such as petechiae (at necropsy), hemorrhage and congestion (in histopathology), which may due to vascular injuries were seen in various organs (such as liver, kidney, lung, bowel and heart). These findings may be due to vascular injuries. Vascular injuries were also the reason of edema in many organs. The results showed that the pathological lesions were existed at least in two parts of the studied organs in the sheep receiving venom. Existence of the leisons imply that the venom of H. lepturus scorpion is dangerous in sheep and serious complications such as death will take place.

Chitosan, a natural nontoxic biopolymer is derived by deacetylation of chitin, has received considerable attention for its commercial applications in the food industry. In the present study, the ability of chitosan and chitosan nanoparticles to sensitize Listeria monocytogenes to low pH was assessed. To achieve this purpose, cells of L. monocytogenes were exposed to pH 4 and 5 adjusted by adding hydrochloric and acetic, acids into TSB, in the presence of 0.0, 0.05, 0.1 and 0.2 % chitosan, for one hour. Chitosan did not show antibacterial activity at pH 5, while 0.2 % nanochitosan madeL. monocytogenes cells more sensitive to this pH. However, antibacterial activity of both chitosan and nanochitosan were higher at pH 4, where 0.2 % chitosan and 0.1 and 0.2 % nanochitosan made significant reductions in viable population of this bacterium in comparison with the control and the lower concentrations (p<0.05). Furthermore, results showed that, in the presence of both the acids, the effect of nanochitosan on reduction of the acid tolerance of the bacterium was significantly more than chitosan (p<0.05). Results of the fluorescent staining demonstrated that chitosan and nanochitosan exerted their effect by disrupting the cellular membrane of the cells and in the same concentrations, nanochitosan had higher effect than chitosan (p<0.05).

This study was carried out to evaluate the effects of dietary α-tocopherol (α-Toc), pomegranate peel extract (PPE) and pomegranate peel (PP) on humoral and cellular immune response, antioxidant enzymes and hematological in broiler chickens. Three hundred and eighty four 1-d-old male broiler chickens (Ross 308) were randomly allocated to 8 groups (4 replicate pens of 12 birds per each), and fed for 42 days. Eight dietary treatments were including; control diet without supplement, control diet mixed with 200 mg/kg α-Toc, and 100, 200 and 300 mg/kg PPE, and 1, 2 and 3 g/kg PP. For evaluation of changes in the immune system, variations of antibody titer by injection of sheep red blood cells were measured at 26 and 32 days ages. At of 28 days of ages, two birds per each experimental group were challenged by phytohemagglutinin and the response was determined to evaluate the cellular immune system. At 41 days of ages, 2 birds per each replicate were bled for assessing cholesterol, triglycerides, LDL blood serum and liver enzymes AST. The oxidation was evaluated by measuring of malondialdehyde MDA and antioxidant enzymes. The results showed that the humoral immune response in chickens fed diets containing α-tocopherol acetate and pomegranate extract peel was improved (p<0.05). However, cellular immune response did not effect by phytohemagglutinin challenge (p>0.05). Antioxidant enzymes Activity, triglycerides, and MDA were influenced by supplementation of diets with α- tocopherol acetate and extract pomegranate peel (p>0.05). Whereas, other hematologic parameters and liver enzymes were not affected. In conclusion, dietary supplementation with 200 and 300 mg/kg pomegranate peel extract PPE may improve immune system response, reducing oxidation and triglyceride levels of broiler chickens.

Changes in kidneys, prostate gland and testes dimensions are evaluated by ultrasonography which may be greater or smaller than their normal values in some diseases. The aim of this study was evaluation of correlation between renal, prostatic gland and testicular dimensions in native healthy dogs by ultrasonography. The study was conducted on 30 native, adult healthy dogs. Ultrasonography was performed based on standard method and length, width and height of kidneys, prostate gland, testes and aortic diameter were measured carefully. Pearson correlation coefficient was used for correlation between measurements. There was a direct significant correlation between length, width and height of kidneys, prostate glands, testes with each other and with aortic diameter (P<0.05). Ratio mean of kidneys length to length of prostate glands, testes and aortic diameter, were 2.6, 2.3 and 7.2, respectively. Ratio mean of kidneys width to width of prostate glands, testes and aortic diameter were 1.4, 1.9 and 4.0, respectively. Ratio mean of kidneys height to height of prostate glands, testes and aortic diameter, were 1.7, 2.3 and 4.4, respectively.

In this study, the presence of methicillin-resistant gene (mecA) and antibiotic resistance pattern were investigated in coagulase positive staphylococci (Staphylococcus aureus and Staphylococcus pseudintermedius) isolated from referred dogs to Veterinary Hospital of Ahvaz. Nasal swabs were collected from 143 dogs referred to Veterinary Hospital of Ahvaz and were cultured in mannitol salt agar (MSA) and blood agar. Coagulase-positive staphylococci were identified by routine identification methods. From 67 coagulase-positive staphylococci (13 isolates Staphylococcus aureus and 54 isolates Staphylococcus pseudintermedius) and by using specific primers for the methicillin-resistant gene (mecA), 28 (41.79%) isolates possessed themecA gene. The presence of this gene was showed in 7 Staphylococcus aureus(25%) and 21 Staphylococcus pseudintermedius (75%) isolates. Among isolates carrying methicillin resistance gene (mecA), maximum resistance was to ampicillin (92.85%) and then to penicillin (57.14%), cloxacillin (42.58%), oxacillin (35.71%), tetracycline (32.14%), ceftazidime (25%), erythromycin and azithromycin (21.42%), gentamicin and Ceftizoxime (14.28%), methicilline, norfloxacin, meropenem, and cotrimoxazole (10.71%). No resistance was observed to vancomycin, chloramphenicol, rifampin, and nitrofurantoin in these isolates. Among isolates without methicillin resistance gene (mecA), highest resistance was to ampicillin (84.61%) and then to penicillin (48.71%), tetracycline (23.07%), oxacillin (20.51%), gentamicin (7.69%), chloramphenicol, erythromycin, azithromycin, cotrimoxazole (5.12%) and ceftazidime (2.54%) respectively. No resistance was observed to oxacillin, meropenem, vancomycin, ceftizoxime, rifampin, methicilline and nitrofurantoin. Identification and monitoring of methicillin-resistant staphylococci and determination of their antibiotic susceptibility pattern are essential for successful treatment and preventing the spread of antibiotic-resistant strains. These studies have also led to awareness and promote effective practices to prevent the spread of resistant strains.

Theileriosis is caused by an intracellular protozoan parasite ofTheileria species, which is transmitted by Ixodidae ticks. Recognition of the vector ticks is essential in each area for establishing some integrated preventive measures against the disease. Therefore, 219 ticks were collected from the body surface of 150 sheep suffering from fever and anemia, in different parts of the province, during April - August 2012. Also, thin blood films were prepared from the peripheral blood of these animals. DNA of the tick salivary glands including 152Rhipicephalus sanguineus, 13 R. bursa and 54 Hyalomma anatolicum anatolicumwere extracted. Then PCR, using a pair of 520 bp specific primer of SSurRNA gene of Theileria ovis, as well as a pair of specific primer for amplification of 785bp of T. lestoquardimerozoite surface antigens, was performed. The PCR revealed that 37 out of 152 R. sanguineus(24.34%) were positive for Theileria ovis, whereas none of R. bursa ticks were positive. Also, 5 out of 54H. a anatolicum (9.25%) were positive for T. lestoquardi. The microscopic examinations of blood smears showed that 19 out of 150 blood smears (12.66%) contained the piroplasmic forms of Theileria species. Regarding the vast distribution of R. sanguineusin the area, it seems that this tick may be the main vector of Theileria ovis in Lorestan province, Iran.

This experiment was carried out to investigate the effects of physical form of feed (pellets and mash) and different levels of whey powder (0, 4 and 8%) on jejuna morphological changes. In this trial, 240 Ross 308 male broilers assigned at 6 treatments and 4 replications (10 chicks per replicate) in a completely randomized design with a 2 x 3 factorial method. Weight gains, feed intake and feed conversion ratio were measured at the end of each experimental period (10, 24, and 42 days of age). At the 25th and 42th days of experimental periods, 2 chicks near to mean of pen selected and samples of jejunum were collected from small intestine. Data were analyzed by GLM procedure of SAS 9.1 software and means were compared by Tukey at 5% significance. Results revealed that mash and whey diets significantly increased the width and length of villus on the 25th day, (P<0.05). Mash diets contained 4 and 8% whey powder increased villus width and height. Indeed, mash diet increased the depth of jejunum crypt at 42 days (P<0.05). With regard to results of this experiment, pellet diets improved the performance.

Anaphylactic shock in farm animals after use of some drugs and biologic reagents is usual. In September of 2013, Pasteurella vaccines were injected to in 1200 non-pregnant cows and calves that were older than 3 months. Thirty minutes to 12 hours after vaccination, confusion, collapse, hypoxia, hypotension, orbital edema, tachypenea, tachycardia and cyanotic mucous membranes were seen. Furthermore, in some cases, the sign of sweating, nausea, dyspnea and profuse sweating discharge of eye, mouth and nose were seen and 3 cows were died. Emphysema, edema and lung congestion were seen at necropsy. A significant increase in the number of RBC and neutropenia was observed. According to the history, clinical and laboratory findings and necropsy, anaphylactic shock caused by vaccine side was detected.