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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Real-time RT-PCR,H5 outbreak,pigeon,Surveillance
- چکیده:
- چکیده انگلیسی: Avian influenza (AI) virus (H9N2 and H5 subtypes) infections in birds cause major concerns around the world. The majority of the avian species, such as domestic, pet, and wild birds, are natural and experimental hosts of avian influenza viruses. There are global concerns about members of the Columbidae family, namely pigeons or doves, for their role as the potential interspecies bridge in influenza A viruses ecology. The acquired scientific data in this regard is still not clear since there are doubts about whether or not they transmit viruses between susceptible populations, and spread viruses among farms during outbreaks. To monitor H5 and H9 influenza virus infection status in the rural, backyard, and domestic birds, an annual active surveillance program was performed from September to October 2016. In December 2016, an outbreak of highly pathogenic avian influenza (HPAI) virus subtype H5N8 was detected in a layer farm in Tehran province, Iran. The present research was conducted to study H9N2 or H5 infections in pigeons within HPAI H5N8 2016 outbreaks and annual national AI surveillance in Iran. For this purpose, cloacal swabs and tissue samples (trachea, lung, brain, liver, heart, pancreas, and cecal tonsil) were collected and examined by real-time reverse transcription-polymerase chain reaction (RT-PCR) method and virus isolation. Results of the tests performed on the swab and tissue samples were negative for H5 nor H9N2 viruses. The samples in real-time RT-PCR that after three passages still showed negative results in HA and molecular tests were considered negative. Moreover, the Newcastle disease virus was isolated in most of the samples taken from dead pigeons, after inoculation in embryonated chicken eggs.
- انتشار مقاله: 02-07-1397
- نویسندگان: N. Motamed,A. Shoushtari,M. H. Fallah Mehrabadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Newcastle disease,Backyard poultry,Effectiveness,Haemagglutination inhibition (HI),ND.TR.IR vaccine
- چکیده:
- چکیده انگلیسی: Newcastle disease causes many economic losses to the poultry industry in most countries. This disease is endemic in Iran. Backyard poultry is considered the reservoir of Newcastle virus; however, there is either no vaccination program against Newcastle, or it is performed in a restricted manner. Commercial live vaccines are inactive and sensitive to temperature; moreover, vaccine delivery to villages and remote areas requires special equipment and high cost to maintain the cold chain. This study evaluated the effectiveness of a thermostable Newcastle vaccine produced by the Razi Institute (ND.TR.IR) on the backyard poultry. In four provinces, at least 4 villages were selected as the treatment group, and the same number was selected as the control group. At least, 30 birds were sampled in each village. In each group, blood samples were collected before vaccination and 2 weeks later, and the serum titer of the samples was examined with the haemagglutination inhibition test. The arithmetic mean and standard deviation of the sample titers at the rural level were compared using paired t-test before and after vaccination in each group. Moreover, Repeated Measures ANOVA was utilized to compare the vaccinated and control groups in terms of the titer changes before and after vaccination. In this study, 584 and 389 samples were taken from the treatment (53 households in 20 villages) and control groups (33 households in 14 villages). The mean serum titer values of Newcastle were 4.51±3.03 and 6.64±2.48 in the treatment group before and after vaccination, respectively (P<0.001). The increase in mean titer of the treatment group (2.31 log) was statistically higher than that in the control group (0.66 log) (P<0.001). Out of 584 birds, 517 (88.5%) ones had titer above 3 in the second turn in the treatment group. The thermostable vaccine (ND.TR.IR) produced by the Razi institute is suitable for backyard poultry, which immunizes them against Newcastle disease. Appropriate vaccination programs for backyard poultry should be made; moreover, vaccination of backyard poultry can be effective in preventing the circulation of the field viruses.
- انتشار مقاله: 01-12-1396
- نویسندگان: M.H. Fallah Mehrabadi,S.A. Ghafouri,A. Shoushtari,F. Tehrani,S. Masoudi,M. Abdoshah,S. Amir Hajloo,M. Shabani
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Iran,Antibody titer,broiler farms,H9N2 avian influenza virus
- چکیده:
- چکیده انگلیسی: Avian influenza virus (AIV) H9N2 is endemic in Iran and its large-scale circulation in the poultry industry of the country is devastating. This virus was first reported in the industrial poultry populations of Iran in July 1998. Some of the published studies showed that inactivated avian influenza (AI) vaccines are capable of inducing an immune response and providing protection against morbidity and mortality in different countries (Vasfi et al., 2002; Tavakkoli et al., 2011). Low pathogenicity avian influenza subtype H9N2 virus has been reported to have a zoonotic potential and widespread distribution in Iran. Therefore, water-in-oil emulsion vaccines are employed to control the disease in chickens (Nili and Asasi, 2003). This cohort study was conducted during July 2016-November 2017 in broiler chicken farms of Qazvin province, Iran to investigate the serological change trends in broiler chickens in this region. Level of immunity against the H9N2 virus was evaluated by hemagglutination inhibition assay. Fifteen farms out of thirty enrolled units used AI H9N2 killed vaccines. The minimum of mean antibody titers (MATs) was 4.54-2.42 and the maximum of MATs was 4.54+2.42 on day 3. In addition, the minimum and maximum MATs on day 50 were 0.4-0.64 and 0.4+0.064, respectively. The transfer rate of H9N2 AIV antibodies from the serum of breeders to the serum of chickens was calculated as 60.35% in our study. A significant difference was revealed between the maternal mean antibody titers (MMATs) and the MATs on day 3 (P<0.001). In addition, the difference between the MATs on day 3 and the MATs on day 10 was found to be significant (P<0.01). Moreover, MATs were significantly different between the vaccinated and unvaccinated herds on day 40 (P<0.05), while no significant difference was observed on days 3, 10, 20, and 30 (P>0.05). According to the results of this study, antibody titers in the vaccinated farms did not reach the protective level until the end of the rearing period. Most of the unvaccinated herds experienced a spurt in antibody titers due to exposure to the virus. Consequently, biosecurity measures must be implemented more seriously and strictly in broiler farms.
- انتشار مقاله: 16-10-1396
- نویسندگان: K. Mirzaie,A. Shoushtari,S. Bokaie,M.H. Fallah Mehrabadi,S.M. Peighambari
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: H5,avian influenza virus,Real-time RT-PCR
- چکیده:
- چکیده انگلیسی: Avian influenza viruses (AIV) affect a wide range of birds and mammals, cause severe economic damage to the poultry industry, and pose a serious threat to humans. Highly pathogenic avian influenza viruses (HPAI) H5N1 were first identified in Southeast Asia in 1996 and spread to four continents over the following years. The viruses have caused high mortality in chickens and various bird species and deadly infections in humans. Multiple conventional methods have been so far introduced for the detection and identification of avian influenza viruses. Traditional virus isolation methods are gold standard protocol in AI detection; nonetheless, virus isolation in embryonating chicken eggs (ECE) is not a rapid method for the detection of influenza viruses since it is time-consuming and labor-intensive. Furthermore, the isolation of highly pathogenic viruses, such as H5, needs BSL3 laboratories. Real-Time Reverse Transcription-Polymerase Chain Reaction (RRT-PCR) is a sensitive and specific method for the detection of influenza viruses. The application of these nucleic acid-based techniques has increased our ability to identify and perform influenza virus care programs, especially in surveillance programs. The current study aimed to detect H5 subtype of avian influenza (AI) virus using fast, specific, and sensitive TaqMan RRT-PCR. Notably, single step RRT-PCR was used to prevent possible laboratory contamination. The specificity of this test was evaluated using nucleic acid extracted from several poultry pathogenic microorganisms and negative clinical specimens from AI-uninfected birds. The sensitivity analysis of the RRT-PCR assay was performed using in vitro-transcribed RNA copy and 10-fold serial dilution of standard AI virus with specific titer. The results indicated the high sensitivity of this method and the lowest detectable dilution of this method based on RNA copies and 1:10 serial dilutions of the standard virus was 10 1.9 EID50 /100.
- انتشار مقاله: 05-12-1396
- نویسندگان: S.G. Mirzaei,A. Shoushtari,A. Noori
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Avian Influenza,Culture,Real-Time RT- PCR,Comparison,H9N2
- چکیده:
- چکیده انگلیسی: Avian influenza H9N2 subtype viruses have had a great impact on Iranian industrial poultry production economy since introduction in the country. To approach Rapid and precise identification of this viruses as control measures in poultry industry, a real time probe base assay was developed to directly detect a specific influenza virus of H9N2 subtype -instead of general detection of Influenza A viruses- which has been endemic over two last decades in the country. An Iranian avian influenza virus strain of A/Iran/chicken/772/1998 H9N2 subtype were selected as reference strain for of primers and probe designing. The high agreement value of 99% indicated that the devolved real time assay for detection of H9 subtype viruses could easily replace the conventional method of virus isolation particularly in investigation of viruses like national surveillance plan. The limit of detection was almost one EID50 which was the least real infectious unit could be detected. So it can be said that this sensitive assay provided a powerful tool to not to miss any significant viral biological activity neither in the host body nor in the environment. A high level of correlation coefficient (R2 = 0.998) also indicated a good correlation between Ct values and viral concentrations. , it can be conclude that the real time RT-PCR could be easily replace virus isolation in detection of H9N2 influenza viruses especially in large monitoring program. The ability in quantifying of the virus concentration extends usage of test in more accurate studies.
- انتشار مقاله: 06-06-1395
- نویسندگان: S. G. Mirzaei,A. Shoushtari,A. Nouri
- مشاهده