Iranian Journal of Veterinary Medicine
Year:2011 | Volume:5 | Issue:2|Papers Count:17

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.

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.

Twelve left camel forelimbs were collected, and ultrasonography was performed at five different levels around the metacarpal region. Limbs were then cut in the transverse plane at levels corresponding to the ultrasound images. Transverse and sagittal plane images were taken at each of the five levels, keeping all ultrasound imaging factors constant. Echogenicity, diameter, width and cross sectional area of the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT) and suspensory ligament (SL) were evaluated. Characteristics of echogenicity and different tendon and ligament sizes were measured and discussed.

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.

Avian chlamydiosis is one of the most important infectious diseases of birds. Despite the rapid growth of exotic bird populations in Iran, there is little or no information on the specific infections that these types of birds carry. In this study, conventional isolation methods were used in cell culture to study occurrence of infection in pet birds. Samples from the conjunctiva, choana, and cloaca and/or droppings were provided from 17 birds of different species. The samples were used to infect McCoy cell culture to isolate Chlamydophila psittaci. The inoculated cells were fixed, stained by Giemsa, mounted on slides using Entellan â and observed by light microscope for the presence of typical chlamydial inclusion bodies. Chlamydophila psittaci was isolated from four birds including a ring-necked parakeet (Psittacula krameri), an Alexandrine parakeet (Psittacula eupatria), an African grey parrot (Psittacus erithacus), and a Timneh grey parrot (Psittacus erithacus timneh). All negative cultures were passaged a further two times. To the best of our knowledge; the report represents the first isolation of chlamydia from birds in Iran.

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.

Pelecaniformes are large water birds feeding by hunting fish and living usually in the sea and in fresh water. Ectoparasitic lice of the genus Piagetiella are interesting from an ecological standpoint as they are found in the pouches of pelicans. Unlike chewing lice, which live on the body surface of the host, P. titan lives in the oral cavity of white pelicans (Pelecanus nocrotalus, L.). This study aimed to determine the infestation of white pelicans with P. titan in Urmia Lake, Northwest Iran, between June and August from 2004 to 2006. Sixty-two juvenile white pelicans at three different age groups of <1 (n= 8), 1-2 (n=23) and 3-7 (n=31) weeks were investigated and 59 birds were found infested with lice. A total of 1637 lice were collected from the oral cavity and body of the birds, with the number of lice ranging from one to 112 per bird. P. titan were identified according to the criteria described by Price (1970), including the number of setae in various parts of body, the structures of prosternal, mesosternal and metasternal plates, the structures of female and male genitalia, presence of two ventral stout subapical setae on tibia II-III and the number of the ctenidia on femur III. This report describes P. titan on pelicans for the first time from Iran.

Hair samples from 58 healthy camels were examined for the presence of saprophytic fungi. One -hundred and seventy-four samples were obtained from three different locations of dromedary camel's body. Several fungal specific media were used for isolating and identifying the saprophytes. Fungal isolates belonged to 15 genera. The most common in order of frequency were members of the genera Aspergillus (48% of the total examined camels), Penicillium (16.1%), Mucor (14.2%), Alternaria alternata (5.6%), Rhizopus (3.1%), Chrysosporium (2.7%), Acremonium (1.1%), Scoupolariopsis (1%), Cladosporium (0.8%), Fusarium, Psuedallescheria boydii and Stachybotrys atra (0.2%). The highest frequently yeasts isolated were related to Candida species (6%), followed by Geotrichum candidum (0.6%) and Malassezia species (0.2%). Skin infections caused by any of the contaminants were not encountered. The study demonstrates that Aspergillus, Penicillium and Mucor species were the common components of healthy camel skin mycoflora, and that camel hair analyzed in this study was free from true dermatophyte.

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.

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.

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.

As lactating cows in severe negative energy balance have poor reproductive performance, the effect of dietary fat supplementation (fish oil, soybean oil) on PGFM secretion, ovarian function and blood metabolites is investigated. In this experiment, the effects of dietary polyunsaturated fatty acids on plasma metabolites, ovarian function and prostaglandin secretion of 20 primiparous Holstein cows was studied. The cows were randomly allocated to one of four groups that were fed either: 1) a control diet, 2) a diet with 3% (Feed dry matter basis) fish oil, 3) a diet with 3% soybean oil, or 4) a diet with 1.5% fish oil and 1.5% soybean oil. Groups were synchronized using the heat-synch method and were fed their respective diets for 35 days, allowing 14 days for dietary adaptation and 21 days for data collection. Concentration of plasma glucose, triglycerides and low density lipoprotein (LDL) cholesterol were not affected by the treatments, but plasma total cholesterol and high density lipoprotein (HDL) cholesterol concentrations were significantly higher in cows that consumed the oil-containing diets (p<0.05).The number of follicles, corpus luteum size and plasma estradiol, progesterone and prostaglandin F2? metabolite (PGFM) concentrations were similar across all treatments. However, the size of the largest follicle was significantly greater in cows that consumed a diet containing fish oil or soybean oil (p < 0.05). These results suggest that polyunsaturated fatty acids can influence both ovarian and uterine function in cows, but further studies are required to test their effects on dairy cow reproduction.