مجله تحقیقات دامپزشکی
سال هفتاد و پنجم شماره 1 (بهار 1399)

During the last two decades, anthelmintic drugs have been increasingly applied against gastrointestinal parasites of sheep in Iran.

For this purpose, drug resistance to albendazole (Alb) and fenbendazole (Feb) in gastrointestinal nematodes in sheep of Saqez multiplicity was assessed.

In in-vivo experiment, a total number of 90 sheep in three groups (30 sheep/group) with EPG≤150 were examined for nematode resistance to Alb and Feb. They were treated with Alb and Feb or untreated (as a control group).

There was significant difference between Alb and Feb treated groups and control group. The EPG in Alb, Feb and control groups was 59.8±1.93, 18.8±1.258 and 204.07±4.81, respectively. There was drug resistance against Alb in compassion with control group (R=71%). There was suspicion drug resistance for Feb in comparison with control group (R=90.66%).

From the results of the present study, it was concluded that there was absolute and suspected drug resistance against Alb and Feb in sheep of Saqez municipality, Iran, respectively.

Ovine theileriosis is an important hemoprotozoal disease of sheep and goats in tropical and subtropical regions which causes high economic loss in the livestock industry.

The aim of this study was the differential detection of Theileria species in sheep using PCR method.

Two hundred blood samples of sheep were investigated in order to differentially diagnose Theileria species. DNA was extracted from blood samples and DNA samples were amplified using specific primers designed for 18S rRNA, TamS1 and TaSp genes.

In this study, from 200 examined samples, 42 samples (21%) were infected by Theileria spp. and none of them were infected by Babesia spp. Moreover, from these 42 positive samples, 24 samples (57.1%) were only infected by T. ovis. 12 samples (28.5%) were only infected by T. lestoquardi, 2 samples (4.7%) were only infected by T. annulata and 4 samples (9.5%) were simultaneously infected by T. lestoquardi and T. ovis. The results of nucleotide sequencing showed that PCR product of 18S rRNA from T. lestoquardi has 99 and 95% similarity with T. annulata and T. ovis respectively. T. lestoquardi and T. annulata showed 86% similarity. Also TaSp gene of T. ovis in comparison with T. annulata and T. lestoquardi showed 96 and 86% similarity, respectively.

In the present study could be shown that the two genes (TamS1 and TaSp) from examined three genes could be used for Theileria species specific diagnosis by PCR.

Application of different source of minerals and their effect on metabolic performance a current issue in animal science and research centers.

The objective of this study was synthesis of selenium nanoparticles and to investigate its effect compared with other selenium sources on the blood parameters associated with the liver functional index of Holstein dairy cow.

This study was conducted in two phases: laboratory and farm. Oxidation-reduction chemical reactions were used to synthesize selenium nanoparticles. The formation and non-change of Se nanoparticles size were confirmed by particle size analyzer. In order to perform farm experiment, 6 dairy cows were allocated into three treatments and 2 replicates in a 3×3 Latin square experiment with 28 days change over the period. The animals were distributed to three treatment groups. Treatments (diets) were 1) control (sodium selenite source), 2) colloid sodium selenite and 3) selenium nanoparticles. Blood parameters associated with the liver functional index, including albumin, bilirubin and total cholesterol were measured in the present experiment. Also, dry matter intake of cows was recorded.

The blood plasma cholesterol of cows fed the colloidal sodium selenite was higher than cows fed the selenium nanoparticles (P-Value =0.01). The blood serum albumin (P-Value =0.03) and bilirubin levels (P-Value =0.04) were lower in group 3 compared with group 1. Dry matter intake was not affected by treatments.

According to the results of this experiment it seems selenium nanoparticles supplementation   improves blood parameters associated with the liver functional index, which can better improve immune system of dairy cows than two other sources of selenium.

Thyme extract has the antimicrobial and antioxidant components that can be useful for the broilers under heat stress condition.

This experiment was conducted to investigate the effects of Thymus vulgaris extract in comparison with some common feed additives on performance, blood biochemical parameters and antibody response in broiler chickens under heat stress conditions.

This study was conducted using 192 one-day-old male broiler chicks (Ross 308) in a completely randomized design with 8 treatments in 4 replicates and 6 chicks per replicate. Treatments were as follows: 1) basal diet + standard temperature conditions (positive control); 2) basal diet + heat stress conditions (negative control); 3) negative control + 200 mg virginiamycin; 4) negative control + 150 mg Protoxin probiotic, 5) negative control + 250 mg vitamin C, 6) negative control + 250 mg vitamin E, 7) negative control + 250 mg thyme extract, and 8) negative control +500 mg thyme extract per kg diet.

Dietary thyme extract at the rate of 500 mg/kg as well as probiotic and vitamin E increased (P<0.05) body weight gain (2202, 2183 and 2199, respectively) and improved feed conversion (1.65, 1.74 and 1.66, respectively) compared with negative control group (body weight gain 1960 g and feed conversion ratio 1.96). Moreover, 500 mg/kg dietary thyme extract, probiotic and vitamin C reduced triglycerides, total cholesterol and low density lipoprotein during heat stress conditions (P<0.05). All dietary supplements groups significantly increased antibody titers against red blood cells as compared with negative control.

In general, the results of the present study suggest that thyme extract at the level of 500 mg/kg of diet can be recommended as an alternative to the common feed additives to improve growth performance and health benefits of the heat-stressed broilers.

Cheese is a dairy product that is popular in the world. Prebiotics and probiotics are increasingly being used to produce potentially symbiotic foods, particularly through dairy products as vehicle. It is well known that both ingredients may offer benefits to improve host health.

In this study prebiotic effect of Olive leaf extract or survival of Lactobacillus casei in UF cheese production during 10 weeks storage in cold condition was researched.

After provision of aqueous extract of olive leaf, probiotic bacteria and starter culture were prepared for inoculation. This extract was added to UF cheese in the presence of the bacteria then, counting of L.Casei on MRS-bile agar with pour plate was done during 10 weeks of storage and sensory evaluation was performed after 10 weeks of cheese storage at 4 °C.

The number of L. Casei was affected significantly by the addition of OLE (P<0.05). The bacterial growth had a significant relationship with the increase in OLE concentrations (P< 0.05). After 10 weeks, in all probiotic cheese, the concentration of L. Casei was at the level of 106 - 108 cfu/g. Also, sensory quality was positively affected by the presence of OLE in cheese samples. Cheese sample produced with the addition of 0.5% of OLE was the most desirable.

The number of Lactobacillus casei was significantly increased during the storage weeks due to the addition of different concentrations of olive leaf extract. The number of probiotic was increased with increasing concentrations of the extract (P<0.05). Also, positive effects on the sensory properties of cheese samples affected by olive leaf extract were observed and the most common cheese sample was 0.5% of this extract.

Basil (Ocimum basilicum L.) is widely used as a food flavoring. The essential oil of this plant has antimicrobial effects on some foodborne pathogens.

The purpose of this study was to evaluate the effect of different concentrations of basil essence on the microbial and sensory properties of traditional Iranian white cheese during the period.

Cheese samples were prepared from local producers with concentrations of 0, 150 and 250 ppm of basil essential oil. On day 0, 15, 30, 60 and 90, the cheese samples were tested for the number of aerobic mesophilic bacteria, coliforms, Staphylococcus aureus, and also on the 90th ripening day for the sensory characteristics.

The results of microbial assays showed that concentrations of 150 and 250 ppm of basil essential oil had a significant (P<0.05) inhibitory effect on aerobic mesophilic bacteria in the 60 and 90 days of ripening; meanwhile, the significant (P<0.05) inhibitory effect on the population of coliforms was observed on days 30, 60 and 90. Moreover, the concentration of 150 ppm of basil essential oil on day 90 and the concentration of 250 ppm on days 30, 60 and 90 demonstrated a significant (P<0.05) inhibitory effect on the population of Staphylococcus aureus. Sensory evaluation revealed that concentrations of the essential oil had no significant effect on the sensory properties of the samples.

It can be concluded that the above concentrations of basil essential oil can be used as a natural preservative in Iranian traditional White cheese.

Staphylococcus aureus is one of the most important human pathogens that cause infection and also food intoxication by secreting various enterotoxins. Conventional culturing methods to detect S. aureus have some limitations such as being time-consuming due to bacterial growth and low precision and sensitivity in detecting viable but non-cultivable cells.

The objective of this study was to detect and quantify enterotoxigenic (A-E) S. aureus in cream pastry products applying PCR coupling with propidium monoazide (PMA) to distinguish dead and live cells.

One hundred samples were randomly collected from pastry shops in Amol, in a period of 2 months. After preparing dilutions, bacterial pellets were separated and treated with PMA before DNA extraction. Real time PCR was conducted in order to quantify S.aureus cells and enterotoxigenic strains using specific primers.

Results of conventional method were close to PMA-qPCR data (P>0.05), but data from qPCR that includes live and dead cells shows more bacterial count than two other methods. Sensitivity of the method applied in the present study, detecting low number of S.aureus cells (less than 10/g) seems considerable.

Findings showed that applying PCR coupling with PMA results in more reliable data than conventional culturing method. Regarding this approach being time-effective, considerably sensitive and specific, it is expected that it be used in food quality control labs in monitoring systems in future.

Titanium dioxide nanoparticles (TiO2NPs) are used in many commercial products, including paints, sunscreens and edible products, and can be used directly and indirectly in aquaculture. Due to the widespread application of these nanoparticles, the investigation of their possible effects on aquatic organisms is necessary.

The purpose of this study was to investigate the histopathological effects of waterborne TiO2NPs on the gills, liver and intestine of Caspian trout.

In this study, 126 fish (27.46±4.3 g) were tested in six concentrations of TiO2NPs (0, 0.01, 0.1, 1, 10 and 100 mg/L) for 4 days. At the end of the experiment, tissues were evaluated to determine the effects of tissue damage caused by TiO2NPs.

The 96-h exposure to TiO2NPs did not cause fish mortality. Accordingly, investigated TiO2NPs are classified as "relatively non-toxic". The most important tissue changes caused by short-term exposure to TiO2NPs were hyperplasia and hypertrophy, lamellar fusion, necrosis in gills; foci of melanomacrophage deposits, aggregation of blood cell, hepatocytes with pycnotic nuclei, vacuolation, necrosis in liver; thickening of lamina propria, erosion of villi and necrosis in intestine.

Although TiO2NPs are relatively non-toxic,  due to the tissue damage observed, these nanoparticles can be harmful to Caspian trout.

Parasite effects on biometric characteristics of common carp, C. carpio from Anzali Wetland.

Identifying parasites in C. carpio and evaluating their effects on biometric characteristics of fish.

A total of 78 individuals were collected on the seasonal basis (from spring through winter 2016) from the wetland, transported to the laboratory and after biometry, dissected to recover parasites. Cestodes and trematodes were stained with alum carmine and nematodes were cleared with glycerin alcohol, then their prevalence, abundance and mean intensity were determined.

Thirteen parasite species including Ichthyophthirius multifiliis, Trichodina sp., Epistilis sp., Gyrodactylus sp., Dactylogyrus extensus,  Diplozoon nipponicum, Diplostomum spathaceum, Posthodiplostomum cuticola, Asymphlodora sp., Caryophyllaeus fimbericeps, Raphidascaris acus, Pseudocapillaria tomentosa and Lernea cyprinacea were identified. Epistylis sp., P. cuticola, Asymphlodora sp. and P. tomentosa are reported for the first time from C. carpio in Anzali Wetland. The average weight in healthy and infected fish were recorded to be from 23.68 ± 3.54g to 686.73 ± 100.28 g, and from 32.47 ± 4.51 to 633.62g ± 64.64 g respectively. The condition factor in healthy and infected fish was from 1.09 ± 0.50 to 1.17±0.03, and from 1.24 ± 0.13 through 1.19 ± 0.03 respectively. It was also true for gonadosomatic index which was recorded in healthy and infected fish from 0.45 ± 0.16 through 3.56 ± 3.54, and from 1.78±0.67 through 2.74 ± 0.62. The instantaneous growth rate was 1.25 in healthy  2+ and 1+ year old individuals, and 0.72 in 3+ and 2+ year olds, while it was 0.94 and 0.65 in the same-aged infected fish, respectively.

Parasites could induce some negative influences on the biometric characteristics of infected fish, decreasing their growth rate. So that, it is necessary to monitor the parasite communities continuously in the native and commercially important fish species in Anzali Wetland to protect them and prevent introducing infected fish into the adjacent fish farms.

Diarrhea syndrome is associated with irrecoverable damages in the husbandry industry worldwide due to losses resulted from fatality, weight loss, growing weak calves and treatment costs. Hence, investigation of diarrhea causes in different areas is important to attempt management strategies to prevent and control it.

Present study was carried to investigate prevalence of some important entropathogens in diarrheic calves until three months old, in Shahrekord suburb husbandries.

Fecal samples were taken from 82 female calves in first day of diarrhea and were examined for isolation of salmonella, Escherichia coli, clostridium, cryptosporidium, and coccidia through common microbiological and parasitological methods.

In general, prevalence of isolated organisms were: salmonella 36.6%, Escherichia coli 24.4%, clostridium 9.8%, cryptosporidium 9.8%, and coccidian 7.31%, and Escherichia coli K99 were isolated from four calves. The most prevalent pathogens were Escherichia coli and Salmonella.

The calves are unavoidably exposed to infectious causes of diarrhea during their whole lifespan, because they acquire organisms from environment immediately after birth. Therefore, attempts at efficient management methods, hygienic principles and receiving enough colostrum, particularly in cold seasons, may be efficient in the control, prevention and decrease of diarrhea and its subsequent losses.

Bordetella bronchiseptica is a gram negative pathogen of the respiratory tract in dogs, pigs, cats, horses, laboratory animals and human beings.

The goal of this study was detection of Bordetella bronchiseptica in oropharynx region of pet and kenneled dogs by PCR and culture and evaluation of antibiotic susceptibility of the isolates in Iran.

The samples were collected by sterile swabs from oropharynx region of 62 pet dogs (including 31 dogs with clinical respiratory disease signs and 31 dogs without clinical respiratory disease signs) and 62 kenneled dogs (including 31 dogs with clinical respiratory disease signs and 31 dogs without clinical respiratory disease signs). Bordetella bronchiseptica was detected by PCR and culture and antibiotic susceptibility of the isolates were evaluated.

Based on the PCR results, Bordetella bronchiseptica was detected in 16.1% of pet dogs with clinical respiratory disease signs, 9.6% of pet dogs without clinical respiratory disease signs, 22.5% of kenneled dogs with clinical respiratory disease signs and 16.1% of kenneled dogs without clinical respiratory disease signs. On bacterial culture, Bordetella bronchiseptica was isolated from 3.2% pet dogs with clinical respiratory disease signs, 3.2% kenneled dogs with clinical respiratory disease signs and 6.4% kenneled dogs without clinical respiratory disease signs, none of the pet dogs without clinical respiratory disease signs was positive on bacterial culture. The isolates tested by the agar dilution method were susceptible to tetracycline, enrofloxacin, co-trimoxazole and doxycycline, moderately susceptible to ceftriaxone and resistant to ampicillin.

This study has shown the high prevalence of Bordetella bronchiseptica infection in dogs in Iran. Bordetella bronchiseptica can infect the people who have contact with the affected pet dogs and those kept in overcrowded shelters.

Flufenamic acid is a member of the fenamates and is used as an analgesic and NSAID drug. According to the ability of this drug on blocking connexin and preventing leakage of substances such as ATP from cells, it seems to be beneficial in healing diabetic wounds.

Evaluation of the effects of topical flufenamic acid as a connexin-channel blocker on skin wound healing in alloxan-induced diabetic rats.

In this study diabetics was induced in 40 male rats by IP injection of 150mg/kg of alloxan and they were divided to 4 groups. After anesthesia, 2×2 cm incision was made on the back of the rats and the skin was separated completely. Three groups were treated by 2, 5 and 10 percent concentration of flufenamic acid ointment separately, and one group was treated by Vaseline and ucerine ointment as control. Bandage and ointment were changed daily and the procedure was carried out for 21 days. The wound surface was measured on odd days. Half of the rats of each group on day five and half of them on day 21 were euthanized to get pathologic slides.

Process of healing, fibroblast concentration, epithelialization, angiogenesis, collagen formation and wound closure in 2 percent group were better than other groups and in control, 5 and 10 percent groups had a decreasing trend respectively and had a significant difference. In the last two groups, the healing process was disrupted.

The 2 percent concentration of drug not only did not show potent anti-inflammatory effects, but also improved the process of healing by blocking the connexin 43 and inhibition of ATP release, while in the concentration of 5 and 10 percent, anti-inflammatory effects of the drug predominated and delayed the healing process.

Estrus synchronization is a valuable tool in ewe reproductive management.

This study was performed to evaluate the efficiency and determine the best time of eCG injection in short-term synchronization program based on GnRH-PGF 2α in Shal ewes during the breeding season.

One hundred and sixty non-pregnant Shal ewes, aged 2-6 years old were selected and randomly stratified to four equal groups. 25µg Alarelin acetate (GnRH analogue) and 75µg D-cloprostenol (PGF 2α analogue) were injected to all ewes, on days 0 and 5, respectively. The first group (control) did not receive any other treatment. Groups 2 to 4 received 400 IU of eCG, 48 hours before, 24 hours before and concurrent with PGF2α, respectively. Ewes were exposed to fertile rams during 96 hours post PGF2α injection. Blood serum progesterone concentrations were measured just before PGF2α injection and 10 days later.

No difference was observed in the first serum progesterone evaluation among experimental groups (P>0.05). However, progesterone had significantly higher concentrations 10 days after PGF 2α injection in groups 2 and 3 in comparison with groups 1 and 4 (P<0.05). Simultaneous use of eCG with PGF2α led to a higher estrus response in comparison with other groups (P<0.05). During the first day after PGF2α, a higher percentage of ewes in group 2 and 3 exhibited estrus compared with groups 1 and 4 (P<0.05). Conversely, estrus expression was higher 24-48 hours after prostaglandin injection in groups 1 and 4 than the other two (P<0.05). Thus, the interval to estrus was earlier in group 2 and 3 than groups 1 and 4 (P<0.05). No significant differences were detected in terms of conception rate, lambing rate, prolificacy and fecundity among study groups (P>0.05).

Use of eCG in different times (48 and 24 hours before and concurrent with PGF2α) in short-term synchronization program based on GnRH-PGF2α during the breeding season can be effective on estrus indices. Regarding the diversity of sheep's masses in Iran, it seems that acceptable results may be achieved when eCG is used concurrently with PGF2α in short-term protocol.

Rotavirus Group A is one of the most important causes of gastroenteritis as it is isolated from 30 to 50% of infant diarrhea from humans and other animals. G genotype of the virus is determined by gene sequence of a surface protein of the virus (VP7), one of the most important factors in inducing immunity against the virus which acts very specific to each genotype.

In the present study the presence of common bovine rotavirus genotypes A was examined in human rotavirus population.

A total of 100 stool samples from children under 2 years of age in Tehran and Varamin were collected and to track the presence of rotavirus A, were evaluated using ELISA method. Positive samples were isolated and cultured on the MA-104 cell line after several passages. The positive samples (49 samples) were determined to be the G type using semi-nested RT-PCR and primers specific for bovine common genotype.

From 100 samples, 49 were positive in ELISA. Eight samples in the first semi nested RT-PCR showed the desired rotavirus bands and in the second round, the results were positive for the presence of bovine VP7 in two samples taken from Varamin, in one sample, G6, and in another sample, two genotypes of VP7, G6 and G8 were detected, indicating infection with at least two strains of human rotavirus reassortant. Six of the ELISA selected positive samples that were taken to the cell line MA104, showed effects of cell damage (CPE) after 4-5 consecutive passages, demonstrating proliferation of the rotaviruses of this study and so, their viability was confirmed.

The results of this study indicate reassortment between bovine and human rotaviruses and show that in case of occurrence of bovine and human rotavirus infection and the emergence of new human type, due to reassortment strain differences in protein immunogen it is possible to overcome due to lack of maternal immunity in the human population and low efficiency of current vaccines and, ultimately, epidemic and considerable losses may occur. Hence, more research is warranted.

Cardiac thrombosis normally occurs in old Syrian hamsters and according to the research it has a higher incidence rate in females than males. The most frequent site of thrombus formation has been reported to be the left atrium and it usually occurs secondary to degenerative cardiomyopathy and amyloidosis. In this study during a period of 2 years, 22 pet Syrian hamsters aged between 1-3 years-old with signs of cardiovascular disease and referred to the small animal Veterinary Teaching Hospital of University of Tehran were examined in order to evaluate for cardiac diseases as well as atrial thrombosis. During the examinations and observations clinical signs such as lethargy, anorexia, hyperpnoea, reduced daily activity, tachycardia, cyanosis, and vaginal discharge were observed. Based on the clinical sings, the initial diagnosis of cardiac disease was made and for more accurate evaluation of cardiac disease, the cases were referred to the radiology department. For detection of specific signs of cardiac disease echocardiography was performed on all patients. in some cases, sampling of vaginal discharge was taken as well and transferred to the lab for bacterial culture. Cardiac thrombosis and especially atrial thrombosis in all cases were diagnosed by echocardiography so that 9 cases showed pyometra concurrently.