Archives of Razi Institute
Volume:54 Issue: 1, Winter 2002

The protein profiles of 25 avian Pasteurella multocida isolates were studied by discontinuous polyacrylamide gel electrophoresis. The Coomassie blue stained gel showed that each whole cell protein lysate of P mu/tocida contained over 30 protein bands ranging from 24 to 174 KDa. Majority of protein bands was located in the mid section of the gel between 30 and 97 KDa. Ali isolates were similar in the majority ofprotein bands. The major difference between protein patterns of isolates was revealed in the position of a major outer membrane prote in band (H Protein) presented in the 34-38 KDa regions. According to molecular mass, the isolates were c1assified in three protein profiles. Restriction enzyme analysis (REA) of chromosomal DNA by Hpall distinguished six groups, two ofwhich contained a single isolate. The Iranian vaccine strain (PMI030) and thirteen field isolates belonged to REA type 1. There was not any relationship between serotype, protein profile and REA pattern of the isolates.

The histopathologic effects of Iranian Newcastle disease viruses isolated From different outbreaks across the country wcre studied on difTerent organs of specifie pathogen free chickens. Clinically, time and sequence of the signs' occurrence were varied among the groups receiving different isolates. Depression was the first c1inical sign observed by 48h postinfection (PI) in ail groups except two groups, which showed depression by 97h PI. Grossly, among the three systems, gastro-intestinal, respiratory and central nervous system that were examined in infected groups, the latter two showed less remarked lesions. Macroscopically, From 72h PI toward the end of experiment the spleen showed atrophy in ail infected groups. At 96h PI and later on, the brain was slightly hyperaemic in limited infected groups. The early findings were observed in proventriculus, Iiver, small intestine and spleen. Generally ail nine Iranian Newcastle disease viruses can affect visceral organs [aster than other organs and could be placed in viscerotrop velogenic group.

The immunosuppression ofaflatoxinB. (AFB.) on humoral immune response to foot-and-mouth disease (FMD) vaccination was evaluated. fifty-two male guinea pigs were assigned to two treatment groups or20 (A, B) and three control groups of 4. Groups A and B were vaccinated with an inactivated FMD vaccine aftcr they were dosed 0.63mg of AFB /Kg once, and on days l, 3, 14 and 21 respectively. Booster doses were injected 28 days after primary vaccination. Antibody titers against FMD virus were higher in the vaccinated, non-aflatoxin exposed group than in those exposed to aflatoxin. Significantly difference (P<O.OS) was detected only in group B that was shown an average weight loss of 2Sg and persisted through second vaccination. The result indicates that aflatoxin can depress the humoral immune responses of guinea pigs to FMD vaccination and the immunotoxicity was round to be dose related.

A total of 209 milk samples were collected from the udder halves of 178 native dairy ewes at 2 weeks afier lambing until the 10th week postpartum. Those, which were c1assified by bacterial culture and California Mastitis Test (CMT) as positive. were deemed to have glands with subclinical mastitis (SCM). The periodic prevalence rate of SCM was 39%. The most common bacterial isolates from SCM cases were coagulase negative staphylococci (41 %), Bacil/us cereus (33%). StaphylococcliS aureus (22%) and Streptococcus spp. (4%). The mean activity of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were higher in milk from SCM udders than in milk from healthy udders (p<O.O 1). There were no significant differences in blood serum LDH, ALP and aspartate aminotransferase (AST) of healthy and subclinical mastitic ewes. The increment in LDH and ALP in milk of udders shows the presence of tissue damage provoked by SCM. Thus, these parameters might be suitable for use in the early diagnosis of subclinical mastitis in ewes.

Stress response indices including plasma cortisol. glucose, cholesterol, and total plasma proteins of red snapper (Lutjanus argentimaculatus) exposed to three different concentrations of water soluble fraction (WSF) of a crudc oil \Vere investigated. The experiment \Vas eonducted in a flow-through seawater system under tropical conditions and the concentrations of the toxicant \Vere assayed based on naphthalenes contents of WSF of crude oil as 0.107,0.052 and 0.028 ppm. Sublethal exposure to WSF of crude oil had a marked impact (P<0.05) on plasma cortisol, glucose, cholesterol and total plasma prote in. Dose-response relationships were obscrved in most of the affected parameters. The rcsults rcvcaled that, in the expcrimental tish both the primary and sccondary stress responses were activated following exposurc to diffcrcnt concentrations of the toxicant. The immunosuppressive effects of WSF of crude oil on tish following activation of stress rcsponscs arc discussed.

The effects of dietary vitamins C (VC), E (VE) and sunllower oil (SFO) on immune responses ofheat-stressed male broiler chickens were evaluated. Ali birds were kept under consistent temperatures from 10:00 to 20:00 and from 20:00 to 10:00 throughout the 1-49 day of age period. Antibodies to Newcastle disease virus (NDV) in serum on thelOth day ofpostimmunization at 18, 35 and 48d of age were determined. At 7wk, CD4/CD8 T lymphocyte ratios in peripheral blood were determined. VC, VE, SFO or their interaction had not signilicant effects on immune responses indices and total mortality. However. chicks fed the VE-supplcmentcd diet had a higher antibody titer against NDV at 18 and 48d of age and higher CD4/CD8 lymphocyte ratios. In addition. increasing SPO from 0 to 2.5%, enhanced anti-NDV levels at 18 and 35d of age and increased CD4/CD8 ratios at 49d of age. Moreover, total mortality was decreased with increaseing VC concentration from 0 to 255ppm, VE from 0 to 288ppm and SFO from 0 to 2.5 and 5%. These results suggest that immune responses and especially mortality in hcat-stressed broiler chickens be ameliorated by use of SFO accompanied by dietary VE or VC supplementation.

The immunogeneticity of monovalent mumps vaccine, in order to conferring long time immunity against the wild virus, prepared From RS-12 local strain was evaluated. The paired serum samples were collected from a total of 160 children before and after vaccination against mumps with the monovalent vaccine. From these children, 156 ones showed an increased anti hemmaglutinin antibody by HI test. The geometric mean titer (log2 ) was calculated 3.04 From 96 seronegative" cases, 95 of them were produced detectable antibodies. Seroconversion of RS-12 strain is estimated 99%. Booster effect of the vaccine is confirmed by 4-fold increasing in HI titer in 64 seropostitive cases. Increasing of immune case up to 140 (87%) is the other reason for effectiveness of the vaccine. Consequently RS-12 attenuated strain can be a suitable candidate for production of monovalent mumps and polyvalent vaccines, in combination with the other infectious agents, which set up on conventional vaccination program.

The anaphylactic reactions in caule and buffaloes following haemorrhagic septicaemia vaccination in different parts of Iran were reported. The free endotoxin as an allergic substance is a component of liquid phase of the vaccine. A dense culture of bovine Pasteurella multocida type 8:2 was prepared in tri ptose phosphate broth supplemented by yeast extract. The bacterial cells were separated by centrifugation and alum gel precipitation methods. The safety trials of the vaccines conducted in mice, rabbits, guinea pigs, callie and buftàlos. The shock reaction did not occur either in laboratory or farm animais, which were tested in both controlled and field conditions.

For detection of goat pox antibodies, a single radial haemolysis (SRH) technique using soluble antigens (SAgs) of the virus was developed. In comparison with CIE, ELISA and AGP as diagnostic tests, SRH is a rapid, simple, and reproducible, time efficient and inexpensive test. The plates oftest result could be kept for two months at 4°C. Results of SRH test showed only 20% difference with serum neutralization test, as the golden test.

The prevalence of cryptosporidial infection in human and horse has been determined in Mashhad. The cryptosporidium spp. oocysts from horse and human fecal samples were floated and concentrated by Sheather's sugar flotation technique and were stained by the modified Ziehl-Neelsen procedure. Out of 300 horse samples, 26.66% were infected. We cou Id not find any significant differences between the rates of equine cryptosporidiosis in co Id and warm seasons, and between different sexes. In human, cryptosporidial infection was diagnosed only in persons (3 out of a total of 120) who were in contact to animais. Our results also indicate that more likely infection wou Id primarily occur in animal, and human would be a secondary host for cryptosporidium.

14 (18.4%) of 76 Staphylococclls allrells strains were isolated from patients who referred to central pathobiology laboratory in Kashan found to be resistance to vancomycine. The resistance pattern was carried out using the agar screen plate according to NCCLS procedure. The resistance rates to other antibiotics were oxacillin 96.1 %, penicillin 92.1 %, c10xacillin 63.2%, cephalothin 23.7% and gentamicin 4.5%. The Sallrells strains isolated in our laboratory have been found to be multiple resistant. Since the resistance of Sallrells to vancomycin is emerging and increasing, which are particularly important in nosocomial infections, it is very important to carry out a drug susceptibility test before attempting to treat.