Archives of Razi Institute
Volume:53 Issue: 1, Winter 2001

Five infectious bronchitis viruses (lRV) were isolated from commercial chickens. One of them was isolated from a layer flock vaccinated with H 120 on day old and the others were originated from broiler flocks without receiving the vaccine. Ali the isolates caused embryo mortality and or dwarfing, stunting, curling. clubbing of the down and urate deposits in the.. kidney. In tracheal organ cultures (TOCs), the isolates caused typical ciliostasis. Electron microscopy confirmed ail the isolates have Coronavirus morphology. The isolates were also confirmed by dot-immunobinding assay using polyclonal antibody to IBV. In one-day-old specific pathogen free chicks, ail the isolates could induce typical respiratory di stress of lB at 36- 48h postinoculation by intraocular route. Virus-neutralization test showed that two isolates were recovered from broiler flocks did not neutralize by monospecific Massachusetts (Mass) antiserum. indicating the presence of other serotypes in commercial chicken flocks in Iran.

Avian inlluenza (AI) is a viral disease of poultry worldwide and earlier diagnosis of the disease is very imponant in control programs. Among immunohistochemical staining techniques, the poultry laboratory diagnosticians have used indirect immunoperoxidase (HP) assay for rapid diagnosis of avian viral diseases. In Ihis study the HP assay was optimized, then compared with the standard AI virus (AIV) isolation procedure on trachca. lung and kidney tissue samples. The samples were prepared from broiler chicken experimentally infected with the reference H9N2 subtype of AIV as weil as clinical specimens. For preparation of frozen tissue sections samples were embedded in OCT compound and put rapidly in liquid nitrogen and kept al -70°C. The tissue sections were fixed and subjected to llP assay by using a type A specific polyclonal and goat anti-chicken peroxidase conjugaled antibodies. The sensitivity, specificity, positive and negalive predicalion values llP assay were 78. 90, 80 and 88%, respectively.

An experimental avian inlluenza (AI) oil-emulsion vaccine was fonnulated with a ratio of 4 parts oil adjuvant ISA-70 and 1 part formai in inacti\ated NChickenllranlZMT -101 (101 )/98(H9N2) antigen. Thirty 2-week-old Aryan broilers and thirty 2·week-old white Hy-line pullets were vaccinated subcutaneously. The latter was delivered a booster 10 weeks after primary vaccination. Ali vaccinated and control birds were bled for hemagglutination-inhibition (HI) test at least one week intervals. Hall' of the birds were challenged via intranasal and intravenous routes with a H9N2 strain at 8 and 27 weeks of age in broiler and layer birds. respectively. A high HI titers were observed in both vaccinated and unvaccinated birds, when examined at 2 weeks postchallenge (PC). Viral isolation or shedding from tracheal and c10acal swaps of both vaccinated broiler and layer was decreased at 2 weeks PC, as compared with unvaccinated control birds. Ali control birds became morbid, and egg production decreased on day 3 Pc. The results suggested that the inactivated oil-emulsion H9N2 AI vaccine may be protects both chickens against viral shedding and egg drop in field conditions.

This experiment was conducted to determine the effects of feed restriction (FR) on performance and the immune system of Arian and Ross strains. Feed efficiency was significantly better for restricted birds. Body weight (BW) of the restricted chickens was significantly lower than those of the ad libitum group at day 42. Arian strain had lower BW at day 21 but higher BW at day 42 th an Ross strain. Birds in FR group showed a significant increase in percentage of CD4+ (helper T cell) and decreased CD8+ (cytotoxic T cell) at day 21 and 42. T cell subsets of Ross and Arian birds was not significantly different on day 21, but in day 42 the Arian chickens had higher CD4+ and lower CD8+ than those of Ross chickens. Antibody response to sheep red blood cells was significantly higher in the birds on the FR group at day 21. Antibody titer was not affected by strain at day 21 but Ross chickens had higher antibody liter than Arian chickens at day 42. The results indicate that the feed restriction may have sorne adavantages, mainly by increasing feed efficiency and immune system competence.

Forty-eight isolates of hydatid cyst collected from sheep and camels slaughtered in different areas of Iran were analyzed by polymerase chain reaction and restriction fragment length polymorphism techniques. The results indicated that the isolates could be categorized into two distinct and uniform genotype grouping, the camel/dog strain,group (Genotype 6) and cosmopolitan common sheep strain group (Genotype 1) of E.granulosus. These isolates can potentially act as a risk factor for human health in the country.

The illhihitory effects of aOatoxin BI (AFB 1) on hepatic DNA biosynthesis was compared in growing and day-old chickens. A single ip dose of AFB 1 (0,25.50.100 or 200llg/kg BW) was administered to groups of hen and dayold female Hybro-broiler chickens pre-treated with [)Hj-thymidine. Ali the chic kens were given laheled thymidine 22h prior to AFB 1 administration and sacrificed 2h after AFR 1 injection. Livers were removed and processed' for DNA isolation and estimation of thymidine incorporation into nuclear DNA. A differential inhibitory effect of AFBI on DNA biosynthesis in hen and chicks was noticed. The overall results showed that as compared to gro\\ ing chic kens. youngers are relatively more refractory to AFB I-induced inhibition in DNA biosynthesis. A single dose of AFBI (25.50. 100 or 200 Ilglkg BW) administered to day-old chickens caused on average 23-28% inhibition in DNA biosynthesis. Whereas under similar conditions of dose and treatments to the growing group, a greater (36-47%) but dose-dependent inhibition in hen's liver DNA is recorded.

The c1inical and laboratory findings associated with OJPtlJ.lporidil/m infection in four broiler flocks were rcported. The severity of C'I:ljJtlJ.l'Poridi/lm-indllced disease is greatly compounded by the pre~ence of nther pathogens .. Tracheal ~wab culture on blood agar re\'ealed a bacterillm. which id.:ntilicd as ()/'I1ithohllcteriwn rhinotmchellle by further biochemical and scrolngical characteristics. This isolatc was resistant to enrolloxacin and Ilumequine. and sensitive to ampicillin and tiamulin. Escherh'hio coli isolated from heart of the carcasses was resistant to ail conventional antibiotics. Eimeriu tendla was also detected in the ceca of sorne carcasses of this Ilock. Simultaneous isolation of Chuile)'i. C!ostriclil/m perfrinf{em type A. and E. coli serogroup 08 in a broi 1er Ilock affectec\ by gangrenous dermatitis and serious weight gain loss was also reported.

Fourteen isolates of infectious bronchitis virus (IBV) from Iran in 2001 were typed by a type-specific multiplex RT-PCR. The RT-PCR reaction has been designed to detect and differentiate strains of Massachusetts, D274 and 4/91 (793/B) types. Based on the DNA band produced in RT-PCR, twelve isolates were c1assilied in the type Massachusetts and two isolates (13/2001 and 14/2001) in the type 4/91. The identity of isolate 14/2001. as being from the type 4/91, was also confirmed by sequence analysis of its RT -PCR product. The result of this study shows the presence of at least two types of IBV in Iran.

Ten Hybridomas secreting monoclonal antibodies directed against the Fglycoprotein of MKI3 (Iranian isolate) strain of Newcastle disease virus (NOV) have isolated which 6 of them showed positive reaction in different tests. Ali of these antibodies are IgM c1ass with K .chain which showed sharp and single band on F-Protein (56000 Dalton) in western blot assay. Ali these antibodies reacted with same epitope on competitive ELISA. On cross reactivity analysis with different avian viruses ail were specifie to NOV only and did not show any reaction with other virus. The importance and application of these antibodies would be on specifie identification of NOV. highly purification of F-protein of NOV specially on preparation of recombinant F-protein on subunit vaccine, developing anti-idiotype vaccine and al50 blocking the c1eavage site of F-protein which resulting in decreasing pathogenicity of virus.

Ten Hybridomas secreting monoclonal antibodies directed against the Fglycoprotein of MKI3 (Iranian isolate) strain of Newcastle disease virus (NOV) have isolated which 6 of them showed positive reaction in different tests. Ali of these antibodies are IgM c1ass with K .chain which showed sharp and single band on F-Protein (56000 Dalton) in western blot assay. Ali these antibodies reacted with same epitope on competitive ELISA. On cross reactivity analysis with different avian viruses ail were specifie to NOV only and did not show any reaction with other virus. The importance and application of these antibodies would be on specifie identification of NOV. highly purification of F-protein of NOV specially on preparation of recombinant F-protein on subunit vaccine, developing anti-idiotype vaccine and al50 blocking the c1eavage site of F-protein which resulting in decreasing pathogenicity of virus.

During 1993 to 1999, 28 endometrial biopsies of infertile mares were examined. The tissue sampi es were fixed in 10% of buffered formai in. sectioned and stained with H&E method. The appropriate categorization based upon Kenney (1986) technique was used. Aiso in histopathological examination, there were acute and chronic endometritis, periglandular and interstitial fibrosis, hemorrhage, glandular atrophy, cystic glands, Iymphatic dilation, hypertrophy and hyperplasia of endometrial glands. In proportional frequency acute and chronic endometritis, were 21.4% and 10.7%, respectively. Other lesions such as endometrosis and normal endometrium were 25% and 42.9%. Edema, hemorrhage and fibrosis were the mosl frequent lesions. 14 cases (50%) were type 1, 9 cases (31.2%) were type liA. 5 cases (17.8%) were type liB and no case was in type III. It has been calculated that about 50% of infertile mares had a normal endometrium.