مجله تحقیقات دامپزشکی
سال هفتاد و پنجم شماره 2 (تابستان 1399)

Toxoplasma gondii is an intracellular protozoan parasite that can infect most species of warm-blooded animals, including birds and humans. Because of feeding habits of domestic chickens, prevalence of Toxoplasma infection in free-range chickens is considered as a suitable indicator of environmental distribution of oocysts.

The present study was designed to investigate the seroprevalence of Toxoplasma infection in domestic chickens from Khorramabad and compare the results obtained from serological and molecular methods.

In total, 97 serum samples were randomly obtained from domestic chickens and examined for the presence of anti-Toxoplasmaantibodies using modified agglutination test (MAT). Fifty grams of muscles (mixture of breast and heart) and whole brain from seropositive chickens were separately homogenized and examined by PCR which targets the repeated element (RE) of the parasite.

Anti-Toxoplasma antibodies were observed in 21 of 97 (21.64%) sera. T. gondii DNA was detected in 10 out of 21 (47.61%) seropositive chickens (with titres of ≥1:20). The low agreement between serological and molecular results can be explained by several factors such as possibility of cross-reactions in MAT and/or limited sample size in PCR.

These results indicate that domestic chickens may have an important role as a source of infection for cats and individuals living in rural areas.

Ticks are one of the most important ectoparasites in animals that cause economic losses in livestock industry. So, removal or reduction of ticks on animals is necessary. Cysteine proteases are among the compounds that play an important role in the physiological action of ticks and are a good candidate for the anti-tick vaccine. Cathepsins is one of the most important cysteine proteases.

The aim of this study was cloning and expression of recombinant cathepsin L gene of Rhipicephalus annulatus in order to evaluate its immunogenicity.

After collection the ticks were cultivated. Then RNA was extracted from ticks, cDNA was synthesized by using specific primer of cathepsin and amplification by RT-PCR. The desired genes were cloned into expressional pQE30 plasmid. Further, a shorter sequence of the cathepsin gene (654 bp) was prepared as a synthetic plasmid. The expression of the protein produced by both recombinant plasmids in the E.coliBL21 prokaryotic expression system is carried out and the immunity of the recombinant proteins was evaluated by Dot Blot and Western Blot using serum of challenged rabbits with recombinant protein and calves infected with ticks were examined and compared.

The results of this study indicate that the protein derived from recombinant plasmid No. 2 had higher expression and purity due to its solubility. Also, the challenge of rabbit serum with these proteins was able to identify both recombinant proteins. But the serum of challenged calves with ticks did not show a satisfactory response with recombinant proteins.

Although the sera reaction of calves infested with ticks was lower than the challenged rabbits sera with cathepsin L, this result was expected, because L cathepsin protein is considered as a concealed antigen.  Overall, the recombinant cathepsin L could be an appropriate candidate for immunizing calves against Rhipicephalus annulatus, although it seems further investigations are necessary.

The protozoancryptosporidiumisan important intestinal parasitic infection in domestic ruminants that has the potential for transmission between humans and livestock throughout the world and Iran.

The present study was undertaken to determine cryptosporidiuminfection in different age groupsof cattle and water buffaloesin farms of Mahabad suburb, Iran.

For this purpose, a total number of 248 fresh fecal samples were randomly collected from rectum of cattle and water buffaloesin farms of 4 villages from May2016 to May 2017. The fecal samples were subjected to floatation technique andcryptosporidiumoocysts were collected using Sucrose Gradient and Percole flotation technique and stained with modified Ziehl-Neelsen technique.

Overall prevalence of cryptosporidiuminfection was 50% (124/248). The highest rate of infection was significant in female calves (30.65%) less than one year-old. The highest infection rate was significantly found in summer (20.16%). Cryptosporidium parvum and C. andersoni were identified in 40.32% (100/248) and 9.68% (24/248) of examined cattle, respectively. Mixed infection was 8.47%.

The results of this study indicated that C.parvum was prevalent in cattle of the region, therefore, further molecular studies are recommended to determine the genotypes of the parasiteas a potential zoonotic agent.

Heavy metals and metalloids are among the most stable and resistant to decomposition elements that, in the presence of high concentrations in aquatic tissues, threaten their own and human health.

The aim of this study was to determine the composition and order of the elements accumulation in the edible muscle tissue of pike from Siah Darvishan River as one of the most valuable and economical fish and also to evaluate its health for human nutrition.

In the present study, concentration of eleven elements (As, Fe, Hg, Zn, Pb, Se, Cd, Cr, Cu, Mn, Ni) in the muscle tissue of 25 pike (Esox lucius) collected with the Cast net in the summer of 2016 from Siah Darvishan River, Guilan province, Iran were surveyed by Varian Atomic absorption spectroscopy.

The lowest and highest mean accumulation of elements were obtained as follows: Zinc 25.89 - 28.80, Iron 21.85 - 24.26, Copper 6.78 - 8.15, Manganese 1.77 - 2.12, Lead 0.68 - 0.73, Selenium 0.59 - 0.62, Arsenic 0.53 - 0.62, Cadmium 0.38 - 0.41, Nickel 0.24 - 0.28, Chromium 0.17 - 0.19 and Mercury 0.087 - 0.098 microgram per gram dry weight, respectively.

According to the results of this study, mean concentrations of all elements in the muscle tissue of pike, except the four elements Manganese (1.956 ± 0.178), Lead (0.698 ± 0.028), Arsenic (0.572 ± 0.044) and Cadmium (0.393 ± 0.018) were observed to be lower than explained threshold limit value (TLV) of FAO/WHO international standard.

Nowadays due to the extensive use of antibiotics, antimicrobial resistance is recognized as a global concern for the health of animals and humans. The consequences of antimicrobial resistance are resistance of zoonotic pathogenic factors and reductions in the effectiveness of treatment for many diseases.

The aims of this study are the monitoring and prevalence of antimicrobial residues of the poultry carcasses in Kerman poultry abattoirs.

A cross sectional study was conducted from June 2015 to October 2016. A total of 474 samples were collected from Kerman province poultry abattoirs and tested with four plate test (FPT) method. Data were analyzed  using Descriptive statistics for qualitative data with 95 % confidence interval.

A total of 38 samples were positive (8/02 %), Antibiotics isolates included: Fluoroquinolone, Macrolide, Cephalosporin, β-lactam, Tetracycline, Sulfonamide and Amino glycoside. The highest rate of antibiotics isolated in positive samples was Fluoroquinolone (36/1 %) and the lowest rate was cephalosporin (4/1 %). Half of the samples were positive for one type of antibiotic (Fluoroquinolone), 28/9 % for two types of antibiotics, 13/1 % for three types of antibiotics, 5/2%  for five kinds of antibiotics and 2/6 % for six kinds of antibiotics.

The results of the study showed that about 10 percent of the meat consumed in this province has antimicrobial residues. Therefore, it can be suggested that proper management strategies for controlling the veterinary drug usage in poultry farms be implemented.

Many herbs such as fenugreek and orange have compounds with antioxidant properties, which can increase the shelf life of foods. Considering that fish are a popular food among consumers, they are susceptible to rapid corruption.

In this study, to improve rainbow trout (Oncorhynchus mykiss) fillet shelf life at refrigerated condition, orange juice concentrate and chitosan coating enriched with Fenugreek (Trigonella foenum-graecum) essential oil was used.

In the present study, 8 treatments were evaluated for 12 days at refrigerator temperature for Chemical indicators PH value, Total volatile nitrogen (TVN), Thiobarbituric Acid (TBA), Peroxide value (PV), Free Fatty Acid (FFA), and Sensory Properties.

According to statistical results, fish fillets coated with chitosan enriched with 2% fenugreek essential oil and immersed in orange juice concentrate were lower than other groups for all chemical indicators and had a significant difference with the control group (P<0.05). In the DPPH test, the most inhibitory effect after BHT (butylated hydroxy toluene) was orange juice with 1.39 brix and then black pepper 2%, respectively. In the RP test, the absorbance of the coated sample with chitosan containing fenugreek essential oil and orange juice concentrate with BHT did not show any significant difference (P>0.05). Sensory evaluation also showed that the chitosan-coated sample containing fenugreek essential oil and orange juice concentrate improved the sensory index during storage compared to other groups, especially the control group.

According to the results, it can be stated that the use of orange juice concentrate, chitosan coating and fenugreek essential oil have a significant effect on reducing the oxidation process of rainbow trout fillet at refrigerator temperature.

Abomasal hypomotility plays an important role in pathogenesis of some abomasal disorders such as abomasal bloat which has the same serious side effects associated with using synthetic drugs for its treatment, such as diarrhea and antibiotic resistance. To decreasing these side effects, administration of herbal medicine is a good way.

To determine the effect of oral administration of turmeric aqueous extract on rate of abomasal emptying rate in neonatal lambs.

This study was conducted on twelve five-day-old Sangsari-female-lambs (average weight 3 kg). All lambs received five oral treatments, including saline (30 ml), erythromycin (400 mg), turmeric 200 mg/kg, turmeric 250 mg/kg, and turmeric 300 mg/kg, respectively. At 0, 30, 60, 90, 120, 150, 180, and 240 minutes after each treatment, plasma samples of lambs were taken. The rate of abomasal emptying was determined with acetaminophen absorption test.

Treatment with erythromycin and three different doses of aqueous extract of turmeric (200, 250, 300 mg/kg) increased the rate of abomasal emptying in comparison to the negative control treatment, significantly (P<0.05). The stimulatory effect of erythromycin on abomasal emptying was higher than aquatic extract of turmeric, significantly (P<0.05). No clinical side effects were observed following the administration of erythromycin and turmeric in lambs.

This study showed that aqueous extract of turmeric has a stimulatory effect on lamb's abomasal emptying but more studies are needed on the effect of this plant’s components on abomasal emptying.

There is paucity of information about Anaplasma marginale (A. marginale) infection in water buffaloes and there have not been any reports of clinical anaplasmosis in the buffaloes in Iran.

Molecullar and hematologic survey on A. marginale infection in apparently healthy buffaloes referring to Ahvaz abattoir.

Samples of blood and spleen tissue were obtained from 103 healthy buffaloes referring to the slaughterhouse. Blood samples were subjected to microscopic examination and PCR assay while spleen specimens were only analyzed by PCR. In this study, a nested-PCR method was used to amplify a fragment of the groEL gene of the bacterium.

According to PCR, 31.1% and 1.9% of examined blood and spleen samples were found positive for A. marginale, respectively. The buffaloes which were positive in spleen tissue PCR test were positive in blood PCR, as well. Microscopically, Anaplasma-like organisms were found in 15.5% of stained blood smears. There was a slight Kappa agreement between stained blood smears and PCR. No significant difference was found in hematologic values between the infected and non-infected buffaloes based on PCR results.

Significant occurrence of infection with A. marginale in the studied buffaloes can indicate the probable role of buffalo as a reservoir of the disease agent and its transmission to the cattle.

Equine arteritis virus (EAV) causes respiratory disease, abortion and sometimes, neurological signs. Stallions which are permanently infected with the virus, are the constant carriers of the virus in their semen and transmit the virus to other horses through sexual contact.

The aim of this study was to evaluate EAV infection in horses in four provinces of Iran and its relationship with age, sex, and race.

Blood samples were taken from 149 horses with different sex, age and race with history or clinical signs associated with equine viral arteritis, including the manifestation of respiratory disease (fever, nasal secretion, coughing), nervous signs (ataxia, dysmetria, recumbency) and abortion. The commercial ELISA kit was used for viral antibody detection.

From 149 sampled horses, 11 cases (7.4%) were found to be positive for EAV. Seropositive cases were recorded in Tehran (2.7%), Golestan (4.3%), Khuzestan (6.7%) and West Azerbaijan (23.8%) provinces.

This survey confirmed the presence of EVAV in horses from four provinces of Iran with the sensitive (98.3%) and special (98.9%) test. Therefore, consideration should be given to the control and prevention programs for the spread of this virus.

Many of the negative effects of heavy metals can be reduced by diets containing anti-oxidant compounds such as vitamins and herbs.

The aim of this study is evaluation of the effect of Clove essential oil and Ascorbic acid on growth performance and intestinal villi morphology in Japanese quail following oral administration of Lead.

A total of 120 one-day old quails were divided into 4 groups with 30 quails in each group (3 replicates). The group 1 was fed with basal diet, the groups 2 and 3 were fed with basal diet + 150 and 450 mg/kg diet clove essential oil respectively, the group 4 was fed with basal diet + 500 ppm ascorbic acid (vitamin C) in diet. All groups received 100 ppm lead acetate in drinking water during the experimental period (7-35 days). At day 35, 3 segments of intestine (duodenum, jejunum and ileum) were isolated.

The group clove 450 ppm and ascorbic acid had significantly more body weight than control (P<0.05). Also, the group clove 150, 450 ppm and ascorbic acid had significantly less Feed Conversion Rate (FCR) than control (P<0.05). The group clove 450 ppm and ascorbic acid had significantly greater villi dimensions and absorptive surface in the different segments of the intestine in comparison to control (P<0.05).

The results showed that adding ascorbic acid and clove essential oil to Japanese quail diet, reduced the negative effects of lead on body weight, feed conversion ratio and intestinal villi absorptive surface.

This study was conducted to characterize two fowlpox viruses isolated in Iran and study their phylogenic relationship.

The aim of this study was to determine the identity of two pox viruses recovered from a tissue sample with typical lesions of fowl pox and red mites from a laying farm. Fowl pox in poultry industry causes significant economic losses associated with decreased egg production, reduced growth, blindness and increased mortality. The pox virus, by direct or indirect contact, may also be transmitted through vectors such as mites and fleas. Dermanyssus gallinae also known as the poultry red mite is the most important blood feeder ectoparasite affecting poultry, in particular, laying hens. In addition to its significant economic losses, it is considered as a potential vector for a number of important avian pathogens.

Both isolates were inoculated to chorioallantoic membrane (CAM) of embryonated chicken eggs, detected by specific PCR for pox virus 4b gene and characterized by sequencing and phylogentic analysis.

Both isolates developed pock lesions in CAM of embryonated eggs. A 578 bp fragment of the poxvirus 4b gene was amplified in both isolates by PCR. The sequence analyses revealed that the two isolates were 100% identical and placed in the same branch. The nucleotide sequence of these two isolates showed a similarity of 73 to 100% to the other selected avian pox sequences available in the GenBank.

These results confirmed that Dermanyssus gallinae are considered to be an important vector for the spread of fowl pox virus in the flocks. Therefore, controlling the red mites in poultry farms will not only inhibit problems such as blood feeding, decreased production and reduced growth rate, it can reduce the transmission of diseases and pathogenic agents in the farms.

Feline Odontoclastic Resorptive Lesion (FORL) is one of the most common diseases in oral cavity of adult domestic cats.

Evaluation of different types of FORL by radiography and computed tomography in order to accurately and early diagnose of disease.

In this retrospective study during 1 year, among 68 CT scans and 17 radiographs of the head of referral cats to veterinary hospital, University of Tehran, 18 cases of FORL (10 CT scans and 8 radiographs) having different degrees of teeth involvement in accordance with stages of FORL were described and diagnosed. For this purpose, radiographic images of teeth in lateral, oblique and dorsoventral views were prepared and also CT images of 2D in transverse, sagittal and dorsal views and 3D were constructed for evaluation of dental and bones reactions.

In radiography and computed tomography, FORLs lesions are classified into five stages. In Stage 1 there is mild cementum and enamel loss but this stage is usually not noted on dental radiographs but may be felt on clinical exploration. In Stage 2 there is moderate cementum and enamel loss with dentinal loss that does not involve the pulp. In Stage 3 there is severe loss involving the pulp cavity with remaining  tooth integrity. In Stage 4 there are extensive dental hard tissue losses and most of the tooth has lost its integrity. In Stage 5 there are remnants of dental hard tissues as irregular opacities. Furthermore, in this study it was proved that FORL occurs in male more than female cats and mandibular premolar teeth are the most affected ones.

Considering that FORL has different stages and consequently has different severity, accurate diagnosis of this disease by radiography and computed tomography can help prevent progression of disease and results in fast and successful treatment.

Nowadays, researchers are converted silver to nanometer dimensions and using nanotechnology to achieve suitable performance and preserve the poultry health and they are used silver nanoparticles are used for poultry nutrition as a nutritional supplement. On the other hand, at the molecular level no complete reports in poultry breeding have been provided.

This study was conducted to evaluate cytochrome P450 gene expression in broiler chickens fed with silver nanoparticles.

This experiment a completely randomized design with 450 single-day Cobb 500 broiler chicks was divided into five treatments and six replications (15 birds in each replicate). Chickens were fed with (1) control (basal diet), (2) basal diet containing 1% zeolite, (3) basal diet containing 1% of zeolite-coated with 0.5% silver nanoparticles, (4) Basal diet containing with 0.15% organic acids and (5) Basal diet containing 1% of zeolite-coated with 0.5% of silver nanoparticles and 0.15% organic acids in with or without heat stress condition.

Results demonstrated the level of expression of cytochrome P450 in broilers fed zeolite (Z) in the 21st day of experiment, silver nanoparticles coated with zeolite in combination with organic acid (NSOA) in 42nd day without heat stress condition and silver nanoparticles coated with zeolite (NS) in day 42 with heat stress condition in intestine and liver had significant increase in expression in comparison with control (C) treatment (P<0.05).

In conclusion, result showed that zeolite and silver nanoparticles were identified as inorganic, chemical and exogenous substances in liver and intestine and up-regulated expression of pollution biomarkers genes. Whereas this effect is not identified in organic acid.

The importance of digestive accessory glands and spleen in human, domestic animals and birds has been studied for many years.

The aim of this study was to investigate the structural features of these organs in see-see.

Regarding the present study, 14 male and female see-see were randomly selected, from which, tissue samples of three males and three females were obtained. After preparation in the usual way, the samples were stained using hematoxylin and eosin methods.

Liver involves two lobes, including right and left ones. Posterior border of the left lobe has a short cut which results in division of the left one into two sections. Gallbladder is extended in visceral level of the right lobe, from middle to posterior edge of it. Due to the lack of full penetration of capsule blades into the liver's parenchyma, lobulated tissues are unknown. Epithelium of the gallbladder is of simple cylindrical type; however, some areas there have very few goblet cells. See-see's spleen is red-brownish, pear-shaped, and is located in the posterior part of visceral level of the liver's left lobe. Spleen is embedded by muscle connective capsule. There are no splits of spleen capsule into parenchyma of the gland. Pancreas is an elongated organ in the situation between two arms of duodenum which is divided into three lobes including dorsal, ventral and splenic. Very delicate and short blades of the capsule are penetrated into the gland and it is divided to lobules. The endocrine part of pancreas consists of alpha and beta islets of Langerhans in large and small sizes.

The results show that the structure and tissues of the liver, spleen and pancreas, despite the slight differences in morphological aspects, are similar to other birds.

Opioids and nitric oxide (NO) are functionally linked in the regulation of intestinal motility.

To investigate the role of NO in the opium induced bowel dysfunction in mice.

Sixty-six male mice received incrementally doses of the following treatments in six groups for 5 consecutive days: 1) Opium (0.2, 0.3, 0.4, 0.5 and 0.6mg/30g/day), 2) N-nitro-L-arginine methyl ester (L-NAME, 5,7.5,10,15 and 20mg/kg/day), 3) L-arginine (5-20mg/kg/day), 4) Opium+L-NAME, 5) Opium+L-arginine and 6) distilled water. At the end of the treatment, the abdomen was opened; some pieces of duodenal and proximal colon were taken to determine NO synthase (NOS) expression and nitrite levels, and some isolated rings from those parts of small and large intestine were prepared and transferred to the organ bath system to study intestinal motility. RT-PCR was used to determine the NOS gene expression. To determine the small intestinal transit, 30 mice in six groups, were used for oral administration of charcoal+gum in vivo.

Opium decreased amplitude of the duodenum and ileum contractions, but increased frequency of duodenal and mid colon contractions (P<0.05). While the gene expression of inducible, neuronal and endothelial NOS was increased in colon (P<0.05), a reduced neuronal and endothelial NOS gene expression was shown in duodenum. The charcoal+gum transit was decreased in opium-treated animals compared to the control group (19.9%). However, L-arginine increased this transit while L-NAME decreased it.

Opium induced intestinal smooth muscle spasms, which result in the decreased intestinal movements. The alterations in NOS gene expression may be a compensation mechanism against opium-induced intestinal dysfunction.