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Resultados 31-40 de 44
Molecular analysis of the nucleocapsid gene and 3' untranslated region of two infectious Bronchitis Virus field isolates from Iranian poultry farms
2011
مردانی, کریم | Mardani, Karim | Morshedi, Ahmad | Vasfi marandi, Mehdi | Talebi, Alireza
Infectious bronchitis (IB) is an economically important disease of chickens. Due to the emergence of new variants of infectious bronchitis virus (IBV), the control of IB has become a serious problem for the poultry industry worldwide. In the present study, the nucleocapsid gene (N) and 3' untranslated region (UTR) of two IBVs isolated from Iranian poultry farms were sequenced and compared with other IBV strains. Based on nucleotide identity, the N gene and 3' UTR sequences of Iranian IBVs showed 90% similarity to the commonly used IBV vaccine strains, H52 and H120. However, based on phylogenetic analyses, Iranian IBVs were found to cluster separately from the IBV vaccine strains used in Iran as well as other IBVs isolated in China, Australia and the United States. It was concluded that IBVs circulating in Iran are genetically distinct from IBV vaccine strains that have been used in Iran for many years. Therefore, it is important to develop a new vaccine based on these newly identified strains for controlling IB in Iranian poultry farms.
Mostrar más [+] Menos [-]Exon 2 Ovar-DRB1 gene polymorphism in the Iranian Sangsari sheep
2011
نیکبخت بروجنی, غلامرضا | Nikbakht borojeni, Gholamreza | Derakhshandeh, Abdollah | Talebnia, Reza
The major histocompatibility complex (MHC) plays a central role in the control of disease resistance and immune response. Extensive genetic diversity in MHC genes provides a valuable source for genetic improvement, via selection, in many domestic animals. Exon 2 of the class II MHC, termed Ovar-DRB1 in domestic sheep (Ovis aries), has been suggested as important disease resistance and immune response gene. We characterized Ovar-DRB1 in DNA samples from 138 individuals of a population of the Iranian Sangsari sheep breed using PCR-RFLP. Eight DRB1 alleles were identified among Iranian Sangsari sheep, including one previously unrecognized allele. Eight homozygous genotypes were observed: a, b, c, d, f, g, h and N. Genotype bb was the most common pattern (46 of 138). Heterozygous genotypes (ag, cb, cd, bf, and bN) were also observed. The observed homozygosity and heterozygosity values were 0.6377 and 0.3623, respectively, vs expected values of 0.220 and 0.779. Iranian Sangsari population deviate significantly from the theoretical proportions (FIS = 0.5283; p = 0.0005). In conclusion, PCR-RFLP analysis allows rapid identification of Ovar-DRB1 types and discrimination of homozygous and heterozygous genotypes. This study indicates that the exon 2 region of the Ovar-DRB1 gene is highly polymorphic in the Iranian Sangsari sheep breed.
Mostrar más [+] Menos [-]Detection of single Dactylogyrus spp. in DNA extracted from infected gill tissue of fishes using Polymerase Chain Reaction
2011
ابراهیم زاده موسوی, حسینعلی | Mousavi, Ebrahimzadeh | Shayan, parviz | Soltani, Mehdi | Ebrahimzadeh, Elahe | Rostami, Mina
Dactylogyrus spp. are monogenean worms found mostly as ectoparasites on the gills of several fish species, including carp and goldfish. These parasites are commonly detected by microscopic analysis of the gill lamellae, but this is time-consuming and technically difficult. In contrast to this conventional method, molecular techniques provide specific, sensitive and safe detection of parasites. In the present study, polymerase chain reaction (PCR) and subsequent DNA sequencing were used to detect Dactylogyrus spp. Specific common primers were designed to amplify the ITS-1 region of the rRNA gene of Dactylogyrus spp. Dactylogyrus worms were collected from 100 goldfishes and identified using a dissection microscope. Then, single worms were used for DNA extraction. To evaluate the PCR, a single parasite was added to a parasite-free gill, which then had its DNA extracted. Subsequently, the PCR products were purified and sequenced. Comparison of the nucleotide sequences of the PCR products with GenBank sequences showed that there was 100% homology with sequences from two Dactylogyrus spp., namely Dactylogyrus vastator and Dactylogyrus dulkeiti (registered under accession numbers AJ 564159 and AJ 564126, respectively). The results obtained from sequence analyses were consistent with species identification by microscopy. Therefore, the results show that it is possible to develop a sensitive and precise PCR method for the detection of Dactylogyrus-infected fish using DNA extracted from the whole gill.
Mostrar más [+] Menos [-]Karyotype of NIH, C57BL/6 and Razi strains of laboratory mice (Mus musculus)
2011
توده دهقان, فاطمه | Motedayen, mohammad hasan | Teimorzadeh, shohreh | Shafaei, Kamalo din
The laboratory mouse is recognized as the pre-eminent model for genetic research. Awareness of chromosomal patterns of experimental animals increases their value for a variety of different fields of study. We aimed to study mitotic chromosome preparations from NIH, C57BL/6 and Razi strains of mice, which are outbred, inbred and partially inbred laboratory mice respectively. Bone marrow cells were prepared from 36 male and female mice, 12 from each strain, and stained by use of Giemsa staining and G-banding methods. Karyotyping of the samples showed that there was no difference in chromosomal numbers among the three mice strains, also the metaphase preparations of their diploid cells contained 40 chromosomes (2n = 40) and all chromosomes were telocentric. However, some differences in band tonality and the size of chromosomes were seen.
Mostrar más [+] Menos [-]Nucleotide sequence analysis of the Second Internal Transcribed Spacer (ITS2) in Hyalomma anatolicum anatolicum in Iran
2011
حدادزاده, حمیدرضا | Haddadzadeh, Hamidreza | Shayan, Parviz
Ticks are important acarina that infest animals. They are obligatory blood sucker arthropods which economically impact cattle industry by reducing weight gain and production. Moreover, they are important vectors of viral, bacterial, rickettsial and parasitic pathogens infecting humans and animals. In view of the importance of Hyalomma anatolicum anatolicum in pathogen transmission, including Theileria lestoquardi in Iran, the accurate identification of this tick is critical. Although many keys are available as aids, morphological identification of tick species such as Hyalomma anatolicum anatolicum (Koch, 1844; Hoogstral and Kaiser, 1959) is difficult and expert knowledge is required. False morphological identification at the level of species and subspecies is common, particularly for Hyalomma excavatum complex members which are prevalent in Iran. For example, the high similarity between Hyalomma anatolicum anatolicum and Hyalomma anatolicum excavatum is the cause of confusion in the identification of these species. In this study, polymerase chain reaction (PCR) techniques were used for identification of Hyalomma anatolicum anatolicum based on analysis of the gene sequence of the Second Internal Transcribed Spacer (ITS2) of this tick. The ITS2 nucleotide sequence of Hyalomma anatolicum anatolicum was 963 base pairs (bp) in length and exhibited 93% homology with other GenBank registered ITS2 sequences of this subspecies (accession no: FJ593700.1). The complete ITS2 region sequence was identified in this study and registered in GenBank under accession number HQ123320.
Mostrar más [+] Menos [-]Increasing of serum nitric oxide metabolites in chicken Eimeria infection
2011
Pirali Kheirabadi, khodadad | Hassanpour, Hossein | Nourani, Hossein | Farahmand, Elham | Cheraghchi Bashi, Mehdi
In order to determine the involvement of nitric oxide in the pathogenesis of coccidiosis induced by Eimeria, 30 chickens were challenged with mixed sporulated oocysts of four species of Eimeria (E. acervulina, E. maxima, E. necatrix, and E. tenella) at 26 days of age. There was an increasing of oocyst shedding in the infected birds at 6, 10 and 14 days post-infection. Histopathological examination revealed a loss of epithelial tissue, congestion of blood vessels, severe muscular edema and necrosis of submucosa. The sum total of nitrite and nitrate was increased in the serum at 6, 10 and 14 days post-infection progressively, but was only significant (P < 0.05) at 10 and 14 days post-infection compared to earlier days. The nitrate amounts were also significantly higher at days 10 and 14. It can be concluded that infection by four species of Eimeria stimulated NO production after infection. It is therefore possible that NO is involved in the pathogenesis of coccidiosis
Mostrar más [+] Menos [-]Prevalence, Molecular Characterization and Serology of Shiga toxin-Producing Escherichia coli Isolated from Buffaloes in West Azerbaijan, Iran
2011
yaaghoobzadeh, neda | Ownagh, Abdo Alkarim | Mardani, Karim | Khalili, Mohammad
This present study is the first to report the presence of Shiga toxin-producing Escherichia coli (STEC) in buffaloes in Iran. A total of 360 fecal samples were collected from buffaloes from different regions in the west Azerbaijan province of Iran and cultured for the isolation of E. coli using routine biochemical tests. From the fecal samples, 340 E. coli were isolated and, of these, 26 STEC isolates were identified. The STEC isolates were further analyzed for the presence of specific virulence genes. Among the STEC isolates, 11 (42.3%) isolates were positive for the stx1 gene, nine (34.6%) were positive for the stx2 gene and six (23%) were positive for both of these genes. Six (23%) STEC isolates harbored the hly gene and two (7.6%) isolates were positive for the eae gene. Based on serotyping, only one (3.8%) isolate was of the O157 serotype, while the other 25 (96.1%) belonged to non-O157 serotypes. The results of the present study provide the first evidence that buffaloes could be a reservoir for STEC in Iran, especially those belonging to non-0157 serotypes.
Mostrar más [+] Menos [-]Influence of Permethrin and Cypermethrin on Behavior in the Mouse
2011
کوهی, محمد کاظم | Koohi, mohammad kazem | Fallah, Fazel
Permethrin and Cypermethrin are synthetic pyrethroids, belonging to a group of insecticides with low mammalian toxicity and high insecticidal activity. The present study evaluated sub-acute toxicity of dermally administrated permethrin and cypermethrin in mice. Behavioral examination included assessments of lethality, weight gain, grooming, analgesymetry, anxiety, grasping, motor activity, and despair in response to inescapable swim stress. The study was conducted on 70 adult male mice, which were exposed dermally via the whole tail zone for 10 s once daily for 28 consecutive days at concentrations of 0%, 0.1%, 1% and 10% of each compound. No significant changes were observed in body weight gain, grooming behavior or pain sensation among the treated and control groups. However, the following effects were observed in the experimental groups: a tendency towards increased motor activity compared to controls (47% in P0.1% group, P = 0.025), a tendency to lose grasping faster than controls (48% and 40% decreased in P10% and C1% groups, respectively, (P < 0.05), shorter stay in the long arms and longer stay in the short arms on the elevated plus maze task compared to controls (up to 84% difference , P < 0.05), and failure in terms of floating on the inescapable swim stress task (500% and 900% increase in interruption times in the P10% and C10% groups, respectively, P < 0.05). In conclusion, upon long-term dermal exposure, synthetic pyrethroids may lead to increased motor activity, decreased grasping tendency and/or ability, increased apathy, and increased despair in the mouse animal model.
Mostrar más [+] Menos [-]Pathological and bacteriological study of lobe distribution of lesions in buffalo (Bubalus bubalis)
2011
سیاری, منصور | Sharma, Ravieendat
The correlation between the bacteriological agent of buffalo pneumonia and its pathologic characteristics were investigated. In the present study, 333 samples of buffalo lungs in Iran were studied for pneumonial lesions and evidence of bacterial and viral infection. The type of pneumonia was classified as interstitial, fibrinous or purulent bronchopneumonia and the anatomical location of lesions was also recorded. In 201 samples with interstitial pneumonia, the lungs were found to be noticeably elastic, edematous and pale. Microscopically, thickening of the alveoli walls, hyperplasia and increased numbers of monocytes was seen. Lesions were mostly found in the right and left diaphragmatic lobes. The 55 samples with fibrinous bronchopneumonia were macroscopically bright and marbled and firm in texture. Thickening of the alveoli walls and large numbers of neutrophils were evident at the microscopic level, and the majority of lesions were located in the diaphragmatic lobes. Microscopically, a large number of neutrophils but few macrophages were seen. Of the 24 samples with purulent bronchopneumonia, most lesions were found in the left diaphragmatic lobe. The main bacteria that were isolated were: Pasturella spp, Staphylococcus aureus, Pseudomonas cuosis, Acinetobacter spp, Arcanobacterium pyogenes, Escherichia coli and Proteus spp. Given the importance of buffalo in milk and meat production for Khuzestan province, this study could be considered as a basis for future attempts to reduce buffalo mortality due to respiratory diseases.
Mostrar más [+] Menos [-]Salmonella infection in birds kept in parks and pet shops in Tehran, Iran
2011
پیغمبری, سید مصطفی | Peighambari, Seyed Mostafa | Yazdani, Azam | Hojjati, Peyman
Salmonellosis is one of the most important zoonotic diseases worldwide. Salmonella infections in wild birds are reported frequently. The objectives of this study were to isolate Salmonella serovars from a large collection of samples obtained from pet birds in Tehran, Iran, and then to determine the serotypes and antimicrobial susceptibility profile of the isolates. Between October 2007 and August 2008, 668 samples from 24 different species were collected from birds kept in parks and pet shops of Tehran. Samples contained cloacal swabs from large birds, freshly-dropped feces from small birds and, infrequently, carcasses. Multiple samples from the same bird were pooled and considered as an individual sample. All samples were cultured for the isolation and identification of Salmonella serovars according to standard procedures. Serotyping was performed by slide agglutination test to determine the O and H antigens of the isolates. The antimicrobial susceptibility of the isolates was determined to a panel of 30 antimicrobial agents using the agar disc diffusion method. In total, 19 Salmonella isolates (2.8%) were identified. Samples that were positive for Salmonella originated from canaries (10 out of 62, 16.1%), pigeons (5 out of 139, 3.6%), psittacines (3 out of 130, 2.3%), and eagles (1 out of 2, 50%). All Salmonella isolates were susceptible to danofloxacin, norfloxacin, levofloxacin, amikacin, gentamicin, and tobramycin. Resistance to other antibacterial agents was variable and ranged from 0-57.9%. There were 17 resistance patterns among the isolates. Serotyping identified nine isolates (47.3%) as serogroup B, six isolates (31.5%) as serogroup C, and four isolates (21%) as serogroup D. The findings of this study showed the presence of Salmonella infection among captive birds. Due to the close contact between these type of birds and humans, these findings present an important risk for public health.
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