مجله تحقیقات دامپزشکی
سال شصت و هشتم شماره 2 (بهار 1392)

Infection with Ehrlichia canis، a gram negative obligatory intracellular bacterium، causes canine monocytic ehrlichiosis which is the worldwide disease in dogs. The objective of this study was to investigate the prevalence of E. canis in thrombocytopenic dogs using nested PCR and diagnostic role of thrombocytopenia in the infection. Blood samples collected from 40 dogs attended in Teaching small animal hospital of Tehran University were classified as group A (platelet counts below 101. 000/µL، thrombocytopenic، n=11)، B (101. 000-200. 000/µL، thrombocytopenic، n=15) and C (platelet counts more than 201. 000/µL، non-thrombocytopenic، n=14) according to their platelet counts. 16S rRNA was analyzed by nested PCR using specific primers. 16S rRNA gene fragment of E. canis were detected in five samples of group A (45. 5%)، three samples of group B (20%)، and one sample of group C (7. 1%). Prevalence rate of infection was statistically higher in group A than the other groups (p=0. 02). In total، approximately one third of thrombocytopenic dogs had demonstrable E. canis infection (30. 7%). while thrombocytopenia cannot be considered as specific marker for detection of E. canis infection، it can be used as a surveillance test prior to other diagnostic methods.

Using a rapid and cost benefote test for diagnosing of hydatidosis، a zoonotic، can be beneficial as a diagnostic.

The aim of the present study was to design and assess the performance of a dipstick method for diagnosting of cystic echinococcosis.

Hydatid cyst fluid antigens and homogenized antigens of protoscolex were prepared and its electrophoretic pattern was determined by SDS-PAGE. Afterthen، for providing the hyperimmune serum، rabbits were injected by hydatid cyst fluid and protoscolex antigens along with complete freund adjuant and then incomplete freund adjuant. The immune sera were evaluated by dot ELISA. Dipstick was prepared based on nitrocellulose paper as solid phase and coated with antigens which were dotted in the upper surface of the nitrocellulose strip. PBS was used as negative control and rabbit sera non-infected were used as positive control. As a negative control the lower part of the strip was coated by PBS. Each strip was floated in the serum (1:100 dilution) for 7min، washed for 7min and floated in the second antibody 7min. Afterthen، they were washed and incubated in chromogen/substrate diaminobenzidin for 2min to show the coloured band at the site of coated antigen.

Our findings revealed 15 protein fractions in fluid antigens and 9 protein band in protoscolex antigens at the range of 29-130 kDa and 25-90 kDa، respectively. Meanwhile، the protoscolex antigens at in 1:10 dilution and fluid antigens at in 1:20 dilution showed the best results to diagnose hyper immune serum of 1:10 dilution.

This rapid Dipstick assay test can be considered as a suitable immunodiagnostic test for hydatid cyst disease; however further investigations should be done to improve its specificity through preparing highly purified antigens.

Leptospirosis as a common zoonotic diseases has a worldwide distribution. To Investigate of seroprevalence leptospiral infection in slaughtered camels (Camelus dromedarius) province of Yazd، Iran. Blood samples were collected from 128 camels. Sera were initially screened at serum dilution of 1:100 against six live antigens of (Leptospira interrogans serovars pomona، canicola، hardjo، ballum، icterohaemorrhagiae، grippotyphosa) using microscopic agglutination test. The values ||“| 50% in a dilution l: 100 were considered as positive ones. Sera with positive values were titrated against reacting antigens in serial dilutions from l: 100 to 1:400. Antibodies against one or more serovars were shown in 30 (32. 4%) sera at dilution |“|1:100. Among the positive sera، pomona (57. 9%) canicola (23. 7%)، hardjo (10. 5%)، grippotyphosa (5. 3%) and icterohaemorrhagiae (2. 6%) were the most frequent serovars،respectively. Furthermore antibodies against more than one serovar were found in 8 (26. 6%) of positive sera. It seems that leptospiral with various serovars could be considered as a prevalent infection in camels of the central part of Iran.

Lactococcus garvieae is one of the main causative agents of Streptococ-cos is/Lactococcosis in farmed fish particularly in rainbow trout causing remarkable losses each year. To study the genetic diversity of Lactococcus garvieae strains recovered from the mortality of farmed rainbow trout in different provinces of Iran. METHODES: The Gram positive cocci were first obtained from the kidney tissues of diseased trout. The bacterial isolates were grown on blood agar and were then identified by PCR method. Their genetic diversities were then studied using RAPD. The recovered gram positive cocci strains were identified as L. garvieae producing a 1100bp in PCR procedure. In RAPD studies using 6 random primers (P1-P6)، only primer P4 was able to produce higher number of bands (five bands). Therefore، using this primer four profile patterns consisting of 560-1330 bp in 5 bands، 56–1260bp in 5 bands، 560-1260bp in 4 bands and 560-1200bp in 5 bands were obtained. The phylogenetic tree of the RAPD product using UPMGA software included these strains in three different clusters with four different genetic groups. The results of this study clearly show that L. garvieae strains from the diseased rainbow trout in the north part of Iran are geneticly different from those in the west country، although there is some genetic similarity between some strains of these two regions of country.

Infectious bronchitis is an acute، highly contagious، viral disease of poultry with worldwide distribution، and is continuously evolving through point mutation and recombination of their genome; subsequently the emergence of IBV variants complicates disease control. To investigate genetic characterization of new IBV variants isolated from commercial chicken flocks in Iran collected between 2009 and 2010. METHODES: The partial S1 gene of the spike protein، covering a hypervariable and constant regions، was amplified and sequenced using conventional RT-PCR. Phylogenetic analysis revealed four viruses designated as Razi-HKM891، Razi-HKM892، Razi-HKM893 and Razi-HKM894. Deduced amino acid sequence comparison with other IBV genotypes، published in the GenBank database، indicated that the isolates Razi-HKM891 and Razi-HKM894 were placed into the pathogenic 793/B serotype. However، the isolates Razi-HKM892 and Razi-HKM893 were different with previously described isolates in Iran. The Razi-HKM893 is closely related to recently published isolates from countries in Middle East and likely indigenous to Iran. These findings is essential for improving the disease control strategies and thus emphasize the importance of continuous surveillance of the disease and of sharing the information to the global scientific community، which would help to fill the epidemiological gaps in the regions and to validate the robustness of diagnostic screening.

Retained fetal membrane decreases reproductive performance of dairy cows. The objective of this study was to evaluate the effect of Presynch Ovsynch protocol on reproductive performance of retained fetal membrane cows in Iranian dairy farm. This experiment accomplished on 244 Holstein dairy cows of a commercial dairy herd in Tehran. At least 24 hour after calving، the cows with or without retained fetal membrane were allocated into Presynch-Ovsynch and control groups، randomly. Commencement of injection in Presynch-Ovsynch group was between 23 and 27 days post calving، and cows were inseminated at 60-61 days after calving. In control group، cows were inseminated based on observation of estrus after voluntary waiting period. Data were analyzed using ANOVA and Chi-square. Days of first service were lower in synchronized cows than the control ones (61. 5 vs. 105. 5; p<0. 05). Days open was lower in Presynch Ovsynch treated cows with history of retained fetal membrane than untreated cows with history of retained fetal membrane (124. 2 vs. 169; p=0. 007). Proportion of cows conceived by 200 days in milk was smaller in untreated cows with history of retained fetal membrane compared with cows in other groups (64% VS. 85. 3%; p=0. 007). In conclusion، using Presynch-Ovsynch protocol and timed insemination improve fertility and reproductive performance in retained fetal membrane cows through decreasing days open.

Negative energy balance (NEB) during first days of calving can cause metabolic and reproductive diseases in dairy cows. To evaluate the prevalence of hyperketonemis and its relationship with periparturient diseases in dairy cows of the Qom province، Iran. Two hundred and seven cows were being investigated over 2- 4 weeks after parturition in dairy farms of Qom. Serum levels of b-hydroxy butyric acid (BHBA) concentrations of blood were measured to evaluate subclinical ketosis. All cows were clinically examined and any diseases which have been occurred during early two months after birth values were analyzed using Chi- square and Mann- Whitney U tests to compare mean values of serum BHBA concentrations in different groups and Pearson test for finding any relationship between groups. Cows showed retained placenta (n= 20، 9. 56%)، metritis (n= 2، 0. 95%)، milk fever (n= 3، 1. 44%)، laminitis (n= 1، 0. 47%)، clinical ketosis (n= 2، 0. 95%)، mastitis (n= 3، 1. 44%)، hepatic lipidosis (n= 1، 0. 47%) and left displacement of abomasums (LDA) (n= 2، 0. 95%). Parturition number، live bodyweight of newborn calves and previous open days in cows with higher than 1 mmol/L BHBA concentrations، were significantly greater than those cows with BHBA concentration lower than 1 mmol/L (p<0. 05). While 55. 17% of the cows with higher than 1 mmol/L BHBA concentration showed different post parturition diseases، 6. 8% cows with lower than 1mmol/L BHBA concentr-ations have been involved with such diseases. In this respect، two groups showed significant difference (p<0. 05). Since periparturient diseases of dairy cows showes significant relationship with hyperketonemia، both condition should be cousidered in veterinary care.

Aspartame، as a synthetic sweetener، has been widely used in food products during the recent decades and renal excretion of aspartame lasts several days. The aim of the present study was to investigate the dose-dependent effects of aspartame on morphometrical and histometrical changes of the kidney in immature mice. 24 immature female Balb/C mice، were randomly categorized to three experi-mental and one control groups of 6 mice each. Experimental and control groups received aspartame100، 200 and 400 mg/kg/bw respectively and distilled water with the same method for 21 days. At the end of the experiment، the mice were weighed and anesthetized their right kidneys were stained with Hematoxylin and Eosin. body weight difference showed significant decrease in experimental groups of 100، 200، 400 mg/kg/bw (1. 43±0. 198، 1. 64± 0. 281، 2. 60±0. 388) respectively compare to the control groups (4. 65±0. 139)، length، width، diameter and weight of kidneys had significant decrease between experimental and control groups (p<0. 05). In the case of histometrical changes، the diameter of glomeruli، diameter of renal corpuscles and the height of epithelium of proximal and distal convoluted tubules showed significant decrease in experimental groups compared to control group (p<0. 05). The diameter of urinary space and lumen of proximal and distal convoluted tubules، experimental groups showed significant increase compared to control group (p<0. 05). This can be concluded that aspartame can induce morphometrical and histometrical changes in mice kidney.

Motilides mainly erythromycin have a great ability to increase abomasal emptying rate. The aim of this study was to evaluate the effect of erythromycin as a prokinetic agent on abomasal emptying rate and Immunoglobulin G absorption in neonatal calves. Twelve Holstein neonate calves were divided into two groups (treatment and control) of 6 Calves each. One hour after birth، treatment and control groups were injected by Erythromycine (8. 8 mg/kg; IM) and normal saline (IM). After 30 minutes، calves were fed by 3 liters of colostrum using esophageal tube. Venous blood samples for determination of plasma IgG were obtained at 1، 3، 6، 9، 12، 18، 24، 36، 48 hours and 5 and 7 days after birth. The results showed that administration of erythromycin caused a significant increase in the serum IgG level (20. 394 mg/mL)، compared to the control group (15. 021 mg/mL). This study revealed that erythromycin increases the serum IgG level probably through abomasal emptying acceleration.

Immunostimulants play an important role in strengthening the immune system of fishes and prevention of various diseases. This study was carried out to evaluate the effect of different levels of Immunoster (IS) and Immunowall (IW) immunostimulants on hematological، biochemical and immune indices in farmed juveniles great sturgeon (Huso huso) over 8 weeks. After one month acclimatization period to rearing conditions and basal diet، 450 farmed juveniles great sturgeon (95. 58 ± 9. 38 g) were categorized as a completely randomized designing into five treatments (Control، IS 1%، IW 1%، IS 3% and IW 3%) in three replicates groups and kept at a density of 30 fish per tank. At the end of 8th week، blood samples were randomly collected (9 fish per treatment). The values of hematocrit، hemoglobin، mean corpuscular hemoglobin (MCH)، mean corpuscular value (MCV)، mean corpuscular hemoglobin concentration (MCHC)، WBC، RBC، cell differentiation، total protein، albumin، IgM and lysozyme were determined. Hematocrit، hemoglobin (except IS 1%)، WBC (except IW 3%)، MCH، MCV (p<0. 05) and percent of neutrophil showed an increase in both immunostimulant treated groups compared the control one. Meanwhile the maximum lymphocyte count was seen in IW 3%. It was also observed an increase in total protein، albumin (except IS 3%) and lysozyme concentrations of the treated groups compared the control one. It can be concluded that Immunoster and Immunowall can improve hematological، biochemical and immune indices in juvenile farmed great sturgeons.

Reducing the detrimental effects of free radicals، in biological and food systems by antioxidants، is important، thus providing antioxidants is necessary issue in community health and food safety. The aim of the present study was to determine antioxidant properties of the essential oil and various extracts obtained from summer savory. Summer savory were extracted using different type solvents and chemical composition of hydro-distilled volatile oil from the aerial part of the plant and analyzed by GC/MS. the antioxidant activities were measured by 2، 2''- diphenyl-1-picrylhydrazyl (DPPH°) free radical scavenging and b-carotene-linoleic acid assays. 32 compounds، which representing 98/92% of the essential oil، were detected as major components: (thymol، carvacrol and terpinene، respectively). While IC50 for DPPH radical-scavenging activity were 38. 46± 0. 12، 37. 73 ±0. 17، 30. 76±0. 63 µg/mL for water، methanol، and ethanol extracts، respectively، it was 96. 15±0. 13 µg/ml for essential Oil. 80. 3، 76. 25، 74. 3 and، 52. 46 % inhibition were shown for water، ethanol، methanol extracts and essential oil in b-carotene/linoleic acid assay، respectively. These parameters for BHT were 4. 9±1. 9 µg/mL and 88. 88% for DPPH and b-carotene-linoleic acid tests، respectively. According to the results in this study، all treatments comparing with control، displayed strong antioxidant and radical_scavenging properties. The highest radical scavenging effect was observed in ethanol extract. The aqueous extract exhibited the greatest inhibition compared with others. Meanwhile، in both assays the extracts had more antioxidant activity than the essential oil (p<0. 05). It seems the extracts (aqueous and alcoholic) and essential oil، could be considered as a cheap، easily accessible and potential source of natural antioxidants for food and pharmaceutical purposes.

Nucleotides as low molecular weight intracellular compounds play key roles in diverse physiological and biochemical functions including encoding genetic in-formation and mediating energy metabolism. To determine effects of different levels of dietary nucleotides (NT) on fatty acid profile in rainbow trout. This experiment was carried out in 700 L circular tanks with 40 fish per tank. NT was added to the diet at a rate of 0. 0، 0. 05، 0. 1، 0. 15 and 0. 2 percent. Fish with average weight of 11. 35±0. 32 g were fed 5 times a day (3-5% of body weight) over 8 weeks. After 56 days of feeding، Eicosapentaenoic acid and Linolenic acid levels increased in fish fed on 0. 2% NT compared to the control group. No significant difference (p>0. 05) was in polyunsaturated fatty acids (PUFA)، n-3، n-6، n3/n6 and saturated fatty acids (SFA) among groups. It can be concluded that dietary nucleotides exerted positive effects on fatty acid composition in rainbow trout.

Bisphenol A (BPA)، an industrially chemical compound، is abundantly used as a primary raw material for production of polycarbonate plastics، epoxy resins and many industrial productions. To show the effect of BPA on plasma steroid hormone variations، male Yellowfin Seabream were subjected to this compound. Fish were intraperitonealy injected by dissolved BPA in coconut oil (10، 50، 100 and 150 µg/g-1 week-1) of over 2weeks. Plasma samples were collected on days 0، 7 and 14. Plasma levels of steroid hormones (testosterone and 17b-estradiol) were determined by radioimmunoassay. Plasma levels of 17b-estradiol hormone in BPA treated fish was significantly increased in a dose dependent manner، after 7 and 14 days of exposure (p<0. 05). Plasma levels of testosterone showed decrease in response to different concentrations of BPA. However this decrease in testosterone levels was significant only in response to 100 and 150 micrograms per gram of BPA. It can be concluded that short term exposure of Yellowfin Seabream (Acanthopagrus latus) to BPA can make destructive effects in reproductive system.