IRANIAN JOURNAL OF VETERINARY RESEARCH (IJVR)
Year:2011 | Volume:12 | Issue:4 (37)|Papers Count:17

Avian pathogenic E. coli (APEC) is responsible for economic losses in all poultry farms. Certain virulence factors have been proposed as a means of controlling APEC infections, including some proteins to be used for vaccination. In the study we report here, one of the major virulence factors, the iss (increased serum survival) gene, from E. coli strain c1378, isolated from poultry colibacillosis in Iran, was cloned to construct a prokaryotic expression vector, in order to analyze the Iss protein. The iss gene was successfully cloned into the pGEX-3X vector. The construct was transformed into E. coli BL21 to express the Iss protein under induction. The Iss protein was expressed as a glutathione-S-transferase (GST) fusion protein. GST::Iss protein was sequenced by MS/MS MALDI-TOF techniques to confirm its amino acid sequence. BLAST analysis of the Iss protein showed high similarity with previously submitted sequences. Overall, it seems that the Iss protein from strain c1378 could be used as a good antigen to vaccinate against poultry colibacillosis. GST::Iss protein is currently being used as recombinant protein in SPF chicken models with the goal of evaluating the immune response for APEC control. In conclusion, we constructed a prokaryotic expression vector of the iss gene, and express and sequence the Iss protein from E. coli strain c1378 isolated from systemic colibacillosis.

Teucrium polium is used for treatment of visceral pain in Iranian folkloric medicine. In this study antinociceptive mechanisms of T. polium hydroethanolic extract were examined by acetic acid-induced writhing test as a model of visceral pain in male NMRI mice. To reveal the antinociceptive mechanisms of the extract, we examined the effects of opioidergic, serotonergic, adrenergic and histaminergic antagonists on extract-induced antinociception. The results of this study showed that pretreatment with naloxone, chlorpheniramine and cimetidine significantly attenuate the antinociceptive effect of the extract. However, cyproheptadine and phentolamine had no effect. Our results clearly show antinociceptive effects of T. polium may be mediated by opioidergic and histaminegic H1 and H2 receptors.

The aim of this study was to determine the combination effect of latanoprost and pilocarpine on the intraocular pressure and pupil size in normal rabbits. In this study, 18 rabbits were randomized to three groups of 6 animals each. The right eyes of rabbits in group 1 were treated topically with latanoprost, in group 2 with pilocarpine and in group 3 with latanoprost and pilocarpine. The left eyes received placebo. Drugs were instilled once a day at 8 am over 4 days. IOP and pupil diameter measurements were made at 8 am, 10 am, 12 noon, 2 pm and 4 pm during the 4 days of treatment, the 2 days that preceded treatment, and 3 days following treatment. The occurrence of blepharospasm and conjunctival hyperemia were also evaluated at the same times that the measurements were made. The mean IOPs were significantly lower than the contralateral eyes in 8 of the 20 time intervals (40%) in both latanoprost and pilocarpine-treated and in 18 of 20 time intervals (90%) in latanoprost plus pilocarpine-treated eyes in the treatment period. The mean daily hypotensive effects of latanoprost, pilocarpine and their combination were 4.5 (31%), 2 (14.4%) and 5 mmHg (34.7%), respectively. Although the mean IOPs in group 3 have decreased more than other groups, the differences between the three groups are not significant. Conjunctival hyperemia was observed in the treated eyes of the three groups. It is concluded that topical instillation of the combination of latanoprost and pilocarpine was not as effective in IOP reduction than by drugs alone and that hyperemia is the most frequent side effect observed during the treatment period.

Morphological and histochemical study of the abomasal epithelium in camel (Camelus dromedarius) was carried out by light and scanning electron microscopes. The lining of the abomasum was divided into four regions, i.e. cardiac, pseudocardiac, fundic and pyloric. Our investigation revealed that the cardiac and pseudocardiac regions occupy a wide part of the abomasum in camel and it reaches approximately the third-fourth of the abomasum. Our gross anatomical observation showed small diverticulae in the Fundic region, this part was covered with thick mucosal folds that have been separated by deep branching furrows. In the histological study we observed that, the mucosa has extensive gastric folds and small invaginations or gastric pits, which were in continuation with the gastric glands. The mucosal surface was covered with simple columnar epithelial. Our histochemical revealed that the surface epithelium in abomasum was negative to AB and positive to PAS staining, whereas in the gastric pit cells it was positive to AB and PAS staining, but gastric gland cells were negative to PAS and positive to AB staining. In the SEM study, after complete removal of mucin from the surface of the mucosa, simple columnar epithelial cells with a mean length of 20 mm were observed, and some epithelial cells have been arranged as flower body (FB). Also, we observed hexagonal structures on the surface of the abomasums that resembled honeycomb structure (HC). Mean diameter of these HC structures was 30-40 mm. For the first time our investigation revealed these FB and HC structures in the abomasal mucosa of camel.

Fusarium verticillioides (F. verticillioides) is not only a primary pathogen of maize, but also can cause disease in other crops such as sorghum. Pathogenicity is related to mycotoxin production such as fumonisin. In the present study, 24 isolates of F. verticillioides, which were previously identified by phenotype based methods, were re-identified using restriction fragment length polymorphism (RFLP) analysis. Digestion of the polymerase chain reaction (PCR) products with the restriction enzyme TasI allowed identifying four non-verticillioides strains that were discarded from our study. The genetic variations among the remaining 20 strains of F. verticillioides were analysed by random amplified polymorphic DNA (RAPD)-PCR method with 4 primers. Of the four primers tested, two primers produced polymorphic amplification patterns. Dendrogram for each primer indicated the distance of the strains to each other. Using primers of A, B, C and D, the isolates were divided to 8, 9, 7 and 7 groups, respectively. The results of this study indicated genetic relationship among DNA polymorphic patterns with geographic regions and the severity of fumonisin B1 (FB1) production. It seems that RAPD analysis is a suitable technique for strain typing of F. verticillioides.

This study investigated the concentration/time dependent effects of nanosilver colloid on the motion parameters of the ejaculated ram spermatozoa in vitro. After incubation of sperm samples for 30, 60, 120 and 180 min in the presence of nanosilver colloid (0, 0.001, 0.01, 0.1, 1 and 10 ppm), the motion parameters were evaluated by computer assisted sperm analysis. There was a significant (P<0.05) decrease in most motion of sperm parameters (the fast, slow and non-progressive motility, VCL, VSL, STR, MAD, ALH, WOB, VAP and LIN) in treated groups compared to their corresponding controls, especially after 120 min of incubation. On the other hand, there was a significant (P<0.05) increase in sperm immotility in comparison with the control group in all times at 1 ppm nanosilver colloid. At a concentration of 10 ppm, spermatozoa were completely inactivated. It is concluded that nanosilver colloid depresses sperm functions, especially motility parameters, which can be a causative agent for sperm infertility induced by nanosilver cytotoxicity.

The PB2 protein of influenza A viruses has been shown as host range determinant. In this study PB2 gene of five H9N2 isolates from Tehran province during the period of 1998-2001 were partially amplified and sequenced to do phylogenetic study. Iranian isolates could be classified in Eurasian lineage according to their PB2 gene sequences. The PB2 genes of these isolates are different from those of Middle-East countries such as the UAE, Pakistan and Saudi Arabia, as well as India, and it is probable that their ancestors have undergone reassortment with other subtypes. The Nucleotide sequences of their PB2 are highly similar to each other with 97.5-99.6% homology percentage showing the least mutations in their genes during the period of 1998 to 2001. The PB2 of the Iranian isolates contain Glutamic acid-(E) in position 627, Aspartic acid-(D) in 701 and Serine-(S) in 714 as other avian isolates.

Aflatoxins (AFs) are natural contaminants of feed and feedstuffs, thus the study of the noxious effects of these agents on the male reproductive system is of outstanding importance. Our aim for this study is the evaluation of the effects of oral administration of aflatoxin B1 on the reproductive hormonal changes in adult male rat. Twenty eight Wistar strain male rats were selected for this study. The rats were divided into 4 groups, viz, control (C), test groups (T1, T2, and T3). The toxin doses were prepared in sterile distilled water at 0.8 ppm, 1.6 ppm, 3.2 ppm, and administered through oral gavages, 1 ml/animal/day to groups T1, T2, and T3, respectively for 48 days and each animal of group C was gavaged with 1 ml/day sterile distilled water. The hormonal assays were carried out using ELISA biochemical kits for serum FSH, LH, prolactin testosterone and 17b-estradiol. Results showed that, the levels of serum LH and testosterone were lower (P<0.001), but conversely the levels of FSH and prolactin were higher (P<0.001) in the test groups. The level of 17b-estradiol was affected by significantly falling (P<0.01) only in group T3. We conclude that, the oral administration of the aflatoxin B1 strictly alters the concentrations of FSH, LH, prolactin, and testosterone in male Wistar rats.

Leptospirosis is a zoonosis of worldwide distribution, caused by Leptospira interrogans. It is a well-known cause of bovine reproductive losses such as abortion, infertility, stillbirth and birth of weak calves. In this research, the relationship between the seroprevalence rate of Leptospira spp. infection and abortion in industrial dairy farms of Hamedan province, Iran was studied. A total of 80 blood samples were taken from aborted cows in six dairy farms. Sera were tested for antibodies against 6 serovars of Leptospira interrogans (hardjo, pomona, canicola, grippotyphosa, icterohaemorrhagiae and ballum) using microscopic agglutination test (MAT). Antibodies were detected in 18 (22.5%) of the aborted cows, including 17 (21.25%) against L. canicola and 1 (1.25%) against L. pomona. It is concluded that dogs (shepherd and stray) and wild carnivores may have an important role to maintain and transmit the L. canicola infection to the cattle population in this region, therefore, vaccination of cattle and shepherd dogs should be applied.

Between July and August 2009, a total of two hundred crossbreed dogs in three contiguous littoral provinces of Guilan, Mazandaran and Golestan were sampled. Circulating antigens and/or microfilariae of Dirofilaria immitis were found in 25.5% of dogs in the whole studied area. The highest infection rate was found in Guilan (51.42%), followed by Golestan and Mazandaran provinces (15.38% and 7.69%, respectively). Prevalence values were not influenced by age and sex in the whole area; the values detected in low altitude regions were 4.6 times the values found in high altitude areas. This is the first detailed survey on canine dirofilariasis in these coastal provinces of Iran. Guilan province, with its certain hyper endemic counties, was shown to be the most endemic for canine heartworm infection in the country. Chemoprophylaxis should be considered for the dog population in these areas.

Ornithobacterium rhinotracheale (ORT), a species of bacteria, is known to be associated with respiratory disease, growth retardation, mortality and decreased egg production. The aim of the present study was to determine seroprevalence of the infection and to identify the microorganism by bacteriological and molecular methods. In this study, 460 serum samples and also 290 tracheal swabs were collected from 29 broiler chicken flocks in slaughter houses. Serological results showed that 24 out of 460 (5.12%) serum samples related to 5 flocks were positive for ORT by ELISA test. ORT was isolated from tracheal swabs of 3 flocks (1.03% out of 290 tracheal swabs) by culture and confirmed as ORT by specific primers in PCR method. Statistically, there was no significant difference between the rate of isolation and ORT serum titers (P>0.05). Antibiotic sensitivity test using standard disk diffusion technique was performed with 13 antibiotics. All the isolates were resistant (100%) to erythromycin, tetracycline, oxytetracyclin, enrofloxacin, ciprofloxacin, flumequin, lincospectin, furazolidon, and 100% of them were found to be susceptible to ceftriaxon and tiamulin, but 2 isolates (66.7%) were moderately sensitive to tylosin and amoxicillin and sensitive to florfenicol. This study is the first report of the prevalence of ORT, bacterial isolation and molecular method in broiler chickens after broiler breeder vaccination in Guilan province.

Subclinical mastitis is considered as one of the most prevalent diseases in dairy cows, causing drastic loss in the dairy industry. Oxidative stress, induced by reactive oxygen species (ROS), is believed to be a primary factor in various cattle diseases including mastitis, but there are few studies regarding the role of ROS in subclinical mastitis. This study was undertaken to i) study the changes in activities of erythrocyte glutathione peroxidase (e-GSH-Px) and its functional component, selenium (Se); ii) compare the activities of erythrocyte superoxide dismutase (e-SOD) and its functional components, Cu and Zn in cows with subclinical mastitis and normal cows. Milk and heparinized blood samples were collected from 45 normal cows and 45 cows with subclinical mastitis from dairy cows in Tehran province, Iran. Somatic cell counts (SCC), activities of GSH-Px and SOD and concentrations of Cu, Zn and Se were measured. No significant difference (P>0.05) was shown between GSH-Px and SOD activities and also between the concentrations of Cu and Zn in the studied groups. There was a marginal significant difference (P=0.05) between the Se concentrations in the normal cows and cows with subclinical mastitis. The correlation between SCC and SOD was positive and significant (P<0.05). It was concluded that optimum antioxidant intake in the feed may enhance the resistance against subclinical mastitis.

The aim of this study was to determine the seroprevalence of Toxoplasma gondii in mares and stallions in the province of Ankara. Sera from 168 clinically healthy horses were tested for the presence of Toxoplasma gondii antibodies using the Sabin Feldman dye test. Toxoplasma gondii infection was determined in 62 (36.9%) of 168 horses with the titers ranging from 1:16 to 1:256.

A 40-day-old male Holstein breed calf with a complaint of inability of moving the tongue in and out as well as difficulties with breastfeeding was referred to the veterinary clinic. A notch in the middle of the tongue tip was evident during oral examination. In addition, a thin tissue band between the ventral surface of the tongue and floor of the oral cavity was seen in the calf. A diagnosis of partial ventral ankyloglossia was made. Horizontal to vertical frenuloplasty was performed to correct the ankyloglossia. The day after the surgery, greater mobility of the tongue was evident. It was concluded that most of the clinical signs, including problems during eating and breastfeeding were due to limitation of tongue movements. Horizontal to vertical frenuloplasty may improve clinical full function of tongue movement.