فهرست مطالب

Archives of Razi Institute
Volume:61 Issue: 1, Winter 2006

  • تاریخ انتشار: 1385/02/11
  • تعداد عناوین: 9
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  • Y.E. Tahamtan, S.A. Pourbakhsh, S.S. Shekarforoush Pages 1-6
    Escheric hia coli O157:H7 lives in the intestines of healthy cattle, and can contaminate meat during slaughtering pr actices. Detection of the low infectious dosage of bacterium requires a sensitive method. We developed polymerase chain reaction (PCR) assays to detect the gene Stx2 irrespective of the bacterial serotype. In this study, the detection limit of the PCR protocol in detecting Stx2 in E. coli O157:H7 without prior enrichment was 103 CFU/ml, and with 4 h prior enrichment in modified tryptic soy broth was 102 CFU/ml. During a period of 7 months (December 2004 to June 2005), 154 slaughtered cattle at Shiraz slaughterhouse, were randomly selected and examined for surface carriage of E. coli O157:H7 via detection the Stx2 gene of verotoxigenic E. coli by PCR technique. E. coli O157:H7 was found in 14 of 145 (9.65%) feedlot cattle and in 1 of 9 (11.1%) dairy cull cows. This is the first report of the presence of E. coli O157:H7 in cattle from Iran.
  • H. Bozorgmehrifard, Z. Rajabi, S.M. Peighambari Pages 7-11
    Avian Leukosis Virus Subgroup-J (ALV-J). Mycoplasma gallisepticum (MG) and MycopJasma synviae (MS) are important pathogens in chickens that cause severe economical losses in poultry industry throughout the world. Seven broiler grandparent flocks of Iran (six broiler strains) were sampled randomly at the ages of 8-63 wk (100 samples from each flock) for antibody detection to ALV-J, MG, and MS by ELISA. One sample C0.9%) of flock F was antibody positive to MG. About me MS. There were 2 (2.1%), 2 (2.1%), 2 (2.1%), 8 (8.7%), 4 (4.3%), 9 (9.8%) and 2 (2.1%) positive samples from those collected from flocks A. B. C D. E, F and G. respectively. However, in all flocks tested, the mean S/P ratio was < 0.5 and rlius all flocks as recommended by the manufacturer were antibody negative to MG and MS. All plasma samples collected from flocks A. B and D were negative for ALV-J antibody. However, there were 2 (2.9%). 39 (51%). 5 (6.6%) positive samples from those collected from flocks C, E, and F., respectively. Only me flock E was antibody positive to ALV-J (according To the manufacturers instructions), because in other flocks the mean S/P ratios were < 0.6. The findings of tills study showed that one of the broiler grandparent flocks in Iran exposed to the ALV-J virus.
  • M. Kafi, M.R. Mcgown, H. Bielefeldt, Ohmann Pages 11-19
    Twelve (Experiment I) and four (Experiment II) multiparous dairy cows seronegative to pestivirus were selected and randomly assigned to either a control group which did not become infected or a treatment group in which all cows became infected following intranasal inoculation 9 days before AI. The experimental induction of infection was carried out with 2 ml of non-cytopathic pestivirus (BVD virus) suspension containing 5 log10 TCID50/ml (Experiment I) and 4.5 log10 TCID50/ml (Experiment II). In both experiments, the cows were superovulated on day 10±2 of the cycle using the standard procedures. The cows in Experiment I were artificially inseminated at 12 and 24 h after the onset of estrus and a non-surgical ova/embryo collection was performed 7 days after AI. In Experiment II, the cows were slaughtered on day 8 after superovulation-induced estrus and the ovaries submitted for gross and histopahological examination including immunohistochemistry. Mean (±SE) number of ovulatory sized follicles on day of AI and corpora lutea palpated on day 7 after AI were significantly (p<0.05) higher in control un-infected cows compared to that of the pestivirus infected cows (17.1 ± 2.6 vs 9.2 ± 1.1 and 12.2 ± 2.7 vs 2.8 ± 0.9), respectively. On histopathological examinations, the mean (±SE) number of unovulated lutenised follicles (≥ 9mm in diameter) present on the ovaries of the control cows on day 8 after estrus was 6.8±4.9 compared to 12.5±5.4 for the infected cows. Further, many corpora lutea in the ovaries of infected cows had a hypoplastic or atrophic wall. In conclusion, the present study demonstrated that pestivirus infection during the period of final growth of preovulatory follicles results in a disturbance in ovulation and development of corpus luteum leading to a poor superovulatory response in multiparous dairy cows.
  • A. Rezaei Mokarram, M.J. Alonso Pages 13-25
    The aim of me present work was to investigate rhe potential utility of nanoparticles made of chitosan (CS) and also CS chemically modified with polyethylene glycol (CS-PEG) as new vehicles for improving na^al vaccine delivery. For mis purpose, diphtheria toxoid (DT) was chosen as a model antigen. DT was entrapped within nanoparticles made of CS of different molecular weight, and also made of CS-PEG, by an ionic cross linking technique. DT-loaded nanoparticles were characterized for their size, surface charge, loading efficiency and in vitro release of antigenically active Toxoid. The nanoparticles were then a dmini stored intranasally to conscious mice in order to study their feasibility as vaccine carriers. The resulting nanoparticles had a size. which varied depending on the formulation conditions and on the PEG derivatization. between 100 and 500 nm. They exhibited a positive electrical charge (approx. +40 mV) which was substantially reduced for the PEGgylated CS nanopal tides (approx. -10 mV) and showed and excellent DT loading capacity (loading efficiency between 50-100% depending on the formulation). Tlie results of the in viti''o release studies displayed a biphasic release of antigenically active toxoid. the intensity of the first phase being less pronounced for CS-PEG nanoparticles than for CS nanoparticles. Following intranasal administration, DT-loaded nanoparticles elicited an increasing and enhanced humoral immunogenic response (IgG liters), as compared to the fluid vaccine. Similarly, the mucosal response (IgA levels) achieved at 70 days post-administration was significantly higher for me DT-loaded CS nanoparticles than for the fluid vaccine. Interestingly, this response was not affected by The CS molecular weight but it was positively influenced by the PEGylation of CS. CS and CS-PEG nanoparticles are promising carriers for nasal immunization with DT.
  • E. Fallah, M. Farshchian, A. Mazlomi, J. Majidi, A. Kusha, A. Mardi, N. Mahdipoorzareh Pages 27-33
    To examine the seroprevalence of zoonotic visceral leishmaniasis (ZVL) among rodents in Azarshahr County, and to assess the possible association of infection among rodents in respect with transmission/prevalence of the disease among children, a survey was conducted during 2003-2004. Azarshahr County is an endemic region for leishmaniasis and this research is the first study in determining the host reservoirs in this county. In this survey, 265 rodents belonging to 7 genera/species were trapped alive. Anti-Leishmanial antibodies were detected through direct agglutination test (DAT), indirect fluorescent antibody tests (IFAT) and microscopic examination. Fourteen (5.3%) animals were shown to be seropositive, 27 (10.2%) provided relatively lower titers, and 224 (84.5%) turned out to be seronegative. Amastigotes of Leishmania were observed in 4 seropositive rodents including 1 Meriones persicus, 2 Cricetalus migratorius and 1 Mesocicetus auratus after dissection and parasitological examinations. Multiple analyses of PCR were used to reassure the identity of purified isolates and infected clinical samples. According to the results of this study, the isolates were identified as Leishmania infantum and those infected rodents are assumed to be potential host reserviors for visceral leishmaniasis in the region. This work is the first report of detecting L. infantum infection in Cricetalus migratorius, Meriones persicus and Mesocricetus auratus from Azarshahr of Iran.
  • B. Mosallanejad, A. Malmasi, M. Mohebali, M. Tabatabayi, A. Bahonar, F. Sasani Pages 35-41
    The efficacy of Clindamycin and Monensin were evaluated in the prevention of oocyst shedding of kittens with Toxoplasma gondii (Tehran strain). In this study, 28 healthy kittens aged 1.5 – 2 months old divided randomly into 4 groups of seven. In group 1, Kittens were fed with the infected brain tissues of mice, all of seven kittens (100 %), shed oocyst, nearly 1 week after infection, which lasted for 8 to 9 days. In group 2, kittens were fed with infected brain tissues of mice and Clindamycin at dose of 20 mg/kg from day -3 to + 21 after infections, none of seven kittens, shed any oocyst. In group 3, kittens were fed with Clindamycin at dose of 10 mg/kg, same as group 2, two of 7 kittens (28/6%), began to shed oocyst from day 11 to 18 after infection. Kittens of group 4 that were fed with Monensin at dose of 0.02 % incorporated in dry food did not shed any oocyst. Data analysis revealed that Clindamycin 20mg/kg and Monensin 0.02% had a 100% inhibitory effect against Toxoplasma gondii (Tehran strain). No adverse reactions were observed during the experimental period.
  • A.M. Bahrami, Doulet Khaliwand, A. Bahrami Pages 43-48
    Humoral immune response of vaccine-I (supermatent from sonicated sporulated oocyst), vaccine –II (sediment from sonicated sporulated oocyst) and vaccine –III (un-sonicated sporulated oocyst) against conccidiosis in chickens was determined by indirect haemagglutination (IHA) test. IHA antibody titre was significantly higher (p<0.05) in chicks vaccinated with vaccine-I as compare tp vaccine-II and vaccine-III. The IHA antibody titre of chicks vaccinated with vaccine-I ranged from 1:8 to 1:8192,1:16 1:512 for vaccine II and 1:2 to 1:64 for vaccine III. Vaccine I gave 100 per cent protection and oocysts appeared in the faeces (100-200 per gram) on day 10 post challenge which gradually increased (600-900 per gram) on day 16 and 200-400 on day 20 post challenge. Vaccine II gave 60 per cent protection and oocyst appeared in the faeces (3,50,000-4,50,000 per gram) on day 8 post challenge which gradually increased (700,000-900,000 per gram) on day 16 and 100,000 –200,000 on day 20 post challenge. Vaccine III gave 30 per cent protection and oocyst appeared in the faeces (8,50,000-9,00,000 per gram) on day 7 post challenge which gradually increased (11,400,000-12,00,000 per gram) on day 16 and 8,40,000-9,00,000 on day 20 post challenge. In control group, characteristic bloody diarrhoea was observed in all the chicks and oocysts appeared in the faeces (10,00,000-12,50,000 per gram) on day 5 post challenge of faeces which gradually increased (15,00,000-17,50,000 per gram) on day 16 post challenge. Results of the humoral and challenge response indicated that the Vaccine I indicated a stong protection as immune chicks contained high level of antibodies that resisted heavy dose of challenge and gave 100 per cent protection.
  • A. Farahnak, I. Mobedi, H. Ghobadi Pages 49-52
    Limited studies have been done on nematodes of Bellamya bengalensis (fresh water snails) in the world. Following, our clinical observations on eye disease in a fish ponds, which were contained Bellamaya bengallensis snails, present study was made to determine of nematodes fauna of Bellamya bengalensis and evaluation of their medical and veterinary importance in Khouzestan province. For this purpose, 1143 Bellamya snails were collected from Ahoudasht and Chogha Mish regions, including fish pond in the central areas of Khouzestan province during 2002-2003. Bellamya snails examined for nematodes with emerging or crushing methods and identified by systematic key references. In addition, to confirm of clinical observations in the field, an experimental infection protocol was designed in our laboratory. From the total of Bellamya snails which examined for nematodes, 27(2.36%) snails were found to be infected with Oionchus nematode parasite. In the experimental infection, cloudy appearance of cornea was observed. These results have been recorded for the first time and show the importance of Bellamaya snails in the region
  • M.R. Gholami, M.H. Hablolvarid, A. Ezzi Pages 53-55