فهرست مطالب

Archives of Razi Institute
Volume:62 Issue: 1, Spring 2007

  • تاریخ انتشار: 1386/02/11
  • تعداد عناوین: 8
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  • M. Farhoodi, R. Toroghi, M.R. Bassami, M. Kianizadeh Pages 1-6
    Chicken infectious anaemia is a viral disease in young chickens which characterized by aplastic anaemia and immunosuppression. Between January 2004 and July 2005, an unusual hemorrhage in subcutaneous and intramuscular tissues of broiler chickens at slaughter houses of Mashhad, Isfahan and Tehran provinces were occurred. Postmortem examination revealed severe hemorrhages in the wings and muscles of the legs and atrophy of the thymus in all the affected chicks. Twenty two flocks, collected from slaughter houses of these provinces investigated in this study. PCR was carried out for detection of DNA virus in pooled liver and thymus suspensions and blood samples were collected for ELISA assay. All of the collected tissue samples from the affected flocks were found to be positive. Totally 440 serum samples collected from the affected flocks were tested in which 316 (71.8%) of the sera were seropositive with seroprevalence ranging from 25% to 100%. The number of PCR positive samples was significantly higher than seropositive samples measured by ELISA. In conclusion, it seems that CIAV has a widespread distribution among the Iranian broiler flocks and the virus plays a critical role in development of hemorrhage in broiler chickens at the slaughter houses.
  • M.J. Mehrabanpour, H. Dadras, S.A. Pourbakhsh, S.M.H. Hoseini, M. Motamedifar, A. Mohammadi Pages 7-13
    In order to adapt LaSota strain of Newcastle disease virus (NDV) on chick embryo fibroblast (CEF) cells, 0.1 ml from LaSota vaccine produced in Razi vaccine and serum research institute inoculated to the CEF cells and was passaged five times in the CEF grown in Eagle’s minimum essential medium (MEM). First to third passages were blind but in fourth passage cytopathic effect of virus was observed. Fifth passage viruses were propagated in SPF embryoneted eggs and then harvested allantoic fluids showed presence of NDV with the titer of 108 EID50/ml. Plaque assays performed on this harvest using two agar overlays; one supplemented with trypsin, DEAE dextran and magnesium sulfate, the second with neutral red along with the mentioned supplements, overlaid 72 hours after first one. Eight hours later, plaques of adapted virus appeared with various sizes ranging from 1 mm to 3 mm in the diameter. Discrete plaques were observed in the 10-6 dilution and the calculated titer of virus was 3×107 pfu/ml. Agar medium overlays without above mentioned supplements obtained no plaque at any dilutions.
  • S. Mahdavi, A. Tavasoly, S.A. Pourbakhsh, R. Momayez Pages 15-22
    The study was conducted to determine the type, frequency and severity of gross, histopathologic changes, effect of route of infection and also, tissue tropism of serotype 793/B (4/91) infectious bronchitis virus. 20 day-old specific pathogen free chicks were inoculated intra-tracheally and intra-orally with 793/B serotype and lesions studied histopathologically at interval up to 10 days post-inoculation (pi). The mortality was 7.5% in the IBV-inoculated groups but not in the controls one. Grossly, a small amount of clear mucus and slight congestion were present in the lumen of the trachea, also congestion observed in the lungs. Swollen and pale kidneys due to IBV infection were slightly severe. At the early stage of infection, the histopathological changes in the lungs, kidneys, intestines, were similar in both groups. So, the route of infection with IBV may affect the incidence of disease is not supported. At the late stage of infection, the changes of kidneys were more severe and characterized by nephritis with formation of lymphoplasmacytic nodules in kidneys and other feature of infection with this serotype on intestine was enteritis of both IBV-inoculated groups.
  • G. Moazeni Jula, A. Jabbari, F. Vahedi Darmian Pages 23-30
    To isolate and detect anthrax spores form soil in different regions of Iran in order to find the anthrax foci‚ a total of 668 environmental specimens were collected during 2003-2004. Bacterial endospores were extracted from soil specimens via flotation in distilled water, incubation at room temperature, filtration, heat shock and culture on blood agar and selective PLET media. Bacillus anthracis was identified using conventional bacteriological, biochemical and biological tests. Viable B. anthracis spores were isolated from 61 (9.1%) soil samples of the 668 collected specimens in which 21 (34.4%) isolates were encapsulated with different virulence from very high virulence to low virulence and the others (40 isolates) were unencapsulated. The isolated bacteria and their virulence were confirmed with Polymerase Chain Reaction (PCR) using B. anthracis‚ cap and pa specific primers. They also confirmed by inoculation into laboratory animals. Isolation of B. anthracis from soil in this study is reported for the first time in Iran. The encapsulated virulent bacteria were isolated from soil specimens of Isfahan, Khuzestan, West Azarbaijan, Khorasan, Charmohal Bakhtiari and Gazvin provinces. It is recommended that due to existence of highly virulent strains of B. anthracis in these regions, a review of implementation of control programs such as regular vaccination of all susceptible livestocks and surveillance of the disease in animals and human in such endemic areas is required.
  • R. Avizeh, M. Mohebali, M. Sheikholslami Pages 31-37
    Visceral leishmaniasis is a parasitic infectious disease from dogs and canids to human that is caused by protozoans of the genus Leishmania. Information on the prevalence of canine leishmaniasis is necessary to define control measures for zoonotic leishmaniasis. This seroepidemiological survey was performed in dogs from Ahvaz district using by DAT and ELISA. Blood was randomly collected in 38 pure or mixed breed dogs presented to veterinary hospital of Shahid Chamran university (urban dogs) and 172 mongrel dogs of 10 villages around Ahvaz city (rural dogs). A high level of concordance (98%) was found between the titers measured by DAT and ELISA then DAT selected as valid and simple test. The detected seroprevalences based on DAT were 2.6% and 16.3% in urban and rural dogs respectively. No statistically significant differences were observed between male and female seroprevalences in each groups and among various villages (P>0.05). Regarding age-groups of rural dogs, the lowest of seroprevalence (5.3%) was found in dogs younger than one year of age and the highest (33.3%) in dogs older than seven years. Only between of these two groups was statistically significant difference (P<0.05). This study revealed the importance of the dog as a reservoir for visceral leishmaniasis in Ahvaz district. It seems that seroprevalence of disease in rural dogs from Ahvaz district is similar to endemic area as of Mediterranean countries.
  • R. Momayez, P. Gharahkhani, S.A. Pourbakhsh, R. Toroghi, A.H. Shoushtari, M. Banani Pages 39-44
    Newcastle disease virus (NDV) was isolated and identified for the first time from a flock of Japanese quail suspected to ND in Iran. Birds of the flock aged variously, and some of them died from the disease. Loss of appetite, weakness and decrease in egg production, diarrhea and nervous symptoms were the main clinical signs in the birds. Hemorrhagic lesions of the intestinal tracts and proventriculus were found in gross pathology investigations. Samples were taken for bacteriology, parasitology and virology. The results of parasitology and bacteriology examinations were negative. The virus was isolated only from brain samples and was identified as Avian Paramyxovirus type 1 (APMV-1) by HI test using NDV-Specific antibody. The pathogenicity of the virus was identified by mean death time (MDT) in embryonated chicken eggs, intracerebral pathogenicity index (ICPI) and intravenous pathogenicity index (IVPI) in chickens. Values 40, 1.62 and 2.31 were obtained for MDT, ICPI and IVPI respectively. These results indicate that isolated APMV-1 belongs to NDV velogenic strains with severe pathogenicity. According to these findings vaccination against NDV in quail farms of Iran is highly recommended.
  • A. Sotoodehnia, A. Moazenijula, A. Naseri Rad, A. Jabbari Pages 45-48
    Mycoplasma agalactia was cultured in PPLO broth medium supplemented with sterilized normal horse serum in fermentor. Cultivation process continued at 37 ºC under aerobic conditions and growth was terminated after 26 hours cultured period with 2.2×109 Mycoplasma per ml. Samples were taken at different stages of growth. Culture was inactivated with 0.04 %v/v formaldehyde and the vaccine was adjuvanted with saponin with final concentration of 1/1000 w/v. Results indicated that the yield of Mycoplasma was higher than the vaccine produced in large flasks using the same culture media. The produced vaccine in the fermentor was safe in guinea pig, sheep and goat according to OIE instructions. Based on the present findings, Mycoplasma agalatia can easily grow in fermentor for the purpose of vaccine production instead of its conventional production in large flasks.
  • M.H. Hablolvarid, M.R. Gholami Pages 49-51
    Large creamy color livers of some chickens from a commercial broiler flock, reared in Tehran province, were noticed in a slaughter house. Myeloid leukosis (myelocytoma) characterized by presence of typical gross and microscopic lesions was diagnosed. Further studies for assessment of prevalence of this disease in broiler breeders and broilers flocks was suggested.