BACKGROUND: Toxocara canis is a zoonotic disease that commonly infects canids. Mammals and birds are sometimes infected with this disease as paratenic hosts. It can also cause accidental infection in humans. The increase in the number of stray dogs, the expansion of urban gardens, and the proximity of dogs to humans increase the risk of human infection with Toxocara canis.OBJECTIVES: This study aims to determine the prevalence of Toxocara canis infection in dogs and foxes in Zanjan province, Iran.METHODS: A total of 484 fecal samples of stray dogs (n=355), rescue dogs (n=49), guard dogs (n=50), and foxes (n=30) in Zanjan were randomly collected from June 2021 to February 2022. The microscopic examination was done following formalin-ethyl acetate sedimentation procedures. Finally, the PCR method was used to confirm the presence of Toxocara canis in positive samples.RESULTS: Microscopic study revealed that, out of 484 samples, 21 (4.3%) were positive for Toxocara/ Toxascaris eggs. Between these positive samples of dogs and foxes, only 6 samples from dog feces were confirmed as a Toxocara canis infection by the PCR method.CONCLUSIONS: There is an increase in the prevalence of Toxocara canis infection in stray dogs in Zanjan, Iran. Given the presence of dogs in parks and residential areas, there is a risk of human infection with Toxocara canis, emphasizing the importance of adhering to treatment and prevention protocols in dealing with stray dogs.

BACKGROUND: Polycystic kidney disease is the most prevalent inherited genetic disease in Persian cats, which is caused by mutations in PKD1 and PKD2 genes. Due to the accumulation of fluids inside the cysts and their pressure on the renal parenchym, the patient is prone to developing symptoms of chronic renal failure.OBJECTIVES: The present study aimed to compare ultrasonography and molecular tests in diagnosis of autosomal dominant polycystic kidney disease.METHODS: This study was performed on 97 Persian cats, including 46 male and 51 female cats, with an average age of 6 years (minimum 2 months and maximum 14 years). All the cats were evaluated for the presence of disease using ultrasound and molecular methods.RESULTS: Among 97 females, 32 (33 %) were found to be positive for PKD on the basis of presence of anechoic cysts. In molecular tests, all the cases with cysts in the ultrasonography had mutation in PKD1 gene and 13 cases (13 %) without cysts in ultrasonography were diagnosed to be positive through molecular technique. Among 97 studied cats, 45 (46 %) showed mutated genes. The degree of agreement between the two methods of ultrasonography and PCR was determined by calculating Kapa 0.725 (Cl: 0.592-0.895). The sensitivity and specificity of the ultrasonography were calculated to be 77.11 % and 100 %, respectively.CONCLUSIONS: Imaging and molecular methods were utilized to diagnose the disease. The more frequent use of the molecular methods for the diagnosis of the disease compared to the use of ultrasound could be attributed to the higher sensitivity of the molecular technique, the small size of the cysts, the low number of cysts, the low age of the animal, and the presence of cysts in the medula of the kidney. Therefore, the molecular method could be recommended for screening the disease in the early stages. It can also be employed in breeding programs and the removal of cats with this mutated gene.

BACKGROUND: 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. OBJECTIVES: The aim of this study was the differential detection of Theileria species in sheep using PCR method. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

BACKGROUND: 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. OBJECTIVES: Molecular and hematologic survey on A. marginale infection in apparently healthy buffaloes referring to Ahvaz abattoir. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

BACKGROUND: Salmonella are endemic on most large intensive dairy farms and salmonellosis is a common cause of neonatal morbidity and mortality. Disease and mortality usually reflect a variety of management events and environmental stressors that contribute to compromised host immunity and increased pathogen exposure. OBJECTIVES: In this study, PCR method was used to identify Salmonella Enteritidis, Infantis, Dublin and serovars isolated from diarrhea samples and aborted fetuses of Tehran and Alborz provinces dairy Farms. Further observation showed that the isolation of S. Enteritidis and S. Infantis is closely related to the consumption of contaminated poultry meat powder in diet of cows. METHODS: Forty-one Salmonella were isolated from diarrhea and aborted fetus samples in Tehran and Alborz provinces Farms and were confirmed by biochemical assays, then the isolates were identified by serological methods by polyvalent and monovalent Salmonella antisera. DNA of samples was extracted by Boiling method and was tested by PCR. Salmonella serovars were identified according to the presence of specificgenes for Salmonella Enteritidis, Infantis and Dublin.  RESULTS: All samples were tested by PCR were positive. 32 samples were identified as Salmonella Enteritidis (78/04 %), 4 samples were identified as Salmonella Infantis (9/77 %) and 5 samples were identified as Salmonella Dublin (12/19 %). CONCLUSIONS: According to the results, it seems that PCR can be used as a alternative method to the expensive and time consuming biochemical and serological methods for identifying Salmonella serovars. As Salmonella Enteritidis was usually isolated from poultry, isolation from cows may be due to has been used chicken meat powder in diet of the dairy farms.

BACKGROUND: Brucellosis is one of the most dangerous worldwide infectious zoonotic diseases that are common between ruminants and human. Consumption of infected milk and by-products is the major transmission source to human. In Iran, sheep compared to cow, has a higher rate of contamination with brucellosis. Therefore, early detection and precision could be a starting point for any efficient program to control the disease in human and animals. For brucellosis monitoring, milk ring test (MRT) is recommended but the test is not reliable in sheep herds. Perhaps a more realistic outcome could be achieved by changing the antigen used in MRT. OBJECTIVES: Comparison of two Brucella abortus and Brucella melitensis antigens in MRT for detection of Brucella antibodies in milk, as well as monitoring contamination of  ewe’s milk in Dezful region by detection of B. abortus and B. melitensis genes using PCR. METHODS: In this research, 220 milk samples from 16 different herds were collected from Dezful region’s nomadic at Khuzestan province. As the first step, MRT by two antigens, B. abortus and B. melitensis, were conducted on the samples. Next, the samples were subjected to detect Brucella genes using PCR technique. RESULTS: Results showed that 47 (21/3 %) out of 220 cases were positive by MRT test, in terms of both antigens of B. abortus and B. melitensis. In PCR, out of 220 samples, only 9 (4%) samples were positive for specific genes of B. melitensis which were MRT positive as well. CONCLUSIONS: A significant difference between B. abortus and B. melitensis antigens was not observed in MRT. Although the nature and basis of PCR and MRT methods for the diagnosis of brucellosis is different but a significant difference between the results obtained by PCR and MRT showed that MRT even by changing of antigens is still not authentic. Considering that various methods of identification have their limitations, it is recommended that in ewe’s milk samples, in addition to using a serological method as screening, PCR and culture methods should be used for definitive diagnosis.

BACKGROUND: Neospora caninum is one of the most important pathogenic protozoan parasites causing bovine abortion around the world. Objectives: The aim of this study was to detect the presence of Neospora caninum in the brain, cerebellum and medulla oblongata of aborted fetuses in cattle in Arak by means of molecular method. Methods: 38 samples of brain, cerebellum and medulla oblongata from aborted fetuses in dairy cattle of Arak were tested for the presence of Neospora with nested-PCR. Results: Survey findings indicated the presence of DNA in 26.3 % of aborted fetal brains. In the cerebellum and medulla oblongata samples no Neospora caninum  DNA was detected. There was a significant relationship between neosporosis and maternal age (number of calvings), abortion history and the presence of dogs in the herd. Conclusions: The results showed a significant association between the infection and the number of abortions in the examined cows; As a result it seems that neosporosis could be an important factor in epidemic abortions in Arak city’s dairy farms which requires continuous monitoring and implementation of prevention programs in the dairy industry.

Background: Haemoproteus is a parasitic protozoa that over 120 species of it has been reported from wild aquatic birds, sparrows and other birds orders. So far, no study has been performed to determine the species of this protozoa in the north of Iran.Objectives: The aim of this study was to investigate the molecular and structural properties of Heamoproteus protozoa in the blood of infected pigeons in Mazandaran province.Methods: In the present study molecular investigation of Haemoproteus infection was carried out in domestic pigeons of Mazandaran province. For this purpose, samples obtained randomly from 150 pigeons in different regions of Mazandaran. At first, blood samples were stained with Gimsa stain and examined for presence of Haemoproteus gametocytes. Then, positive samples were used for PCR by Cytochrome b genes.. Results: Obtained results after morphological survey showed that 17 samples were positive indicating infection rate of 11.33%. Molecular investigation and analysis of PCR products showed that all of the samples belonged to Haemoproteus columbae species.Conclusion: So, being precisely familiar with this kind of protozoan and its species can limit many mistakes and be helpful in differential diagnosis of different species. This study has revealed that the most common species of Haemoproteus in Mazanadran province is Haemoproteus columbae.

BACKGROUND: Yersinia ruckeri is the etiological agent of enteric red mouth (ERM) or yersinioisis disease, one of the important bacterial diseases in the cultured salmonids. OBJECTIVES: The purpose of present study was detection of gyrA gene (quinolone resistance) in the Y. ruckeri bacterium. METHODS: In this study fish were evaluated in average size 8-12 cm from six rainbow trout farms in Chahar Mahal va Bakhtiyari province (Iran). In each farm 10 fish (totally 60) suspected to yersinioisis were randomly selected; sampling was done from lower part of intestine and cultured on Trpticase Soy Agar (TSA). The mediums were transferred to incubator and kept at 22 °C for 48 hours. Pure colonies which are grown on the mediums were tested by catalase, oxidase and gram staining, then those of gram-negative, catalase positive and  oxidase negative were diagnosed, and cultured on Waltman- Shots medium (as specific medium for Y. ruckeri). These mediums were incubated at 22 °C for 48 h. Colonies that were grown were tested by PCR method for Y.ruckeri detection. Then, in the identified strains of Y.ruckeri gyrA gene were detected by PCR test. RESULTS: The results of bacteriological, biochemical and molecular tests showed that three cases out of total isolates were identified as Y. ruckeri. In all isolates of Y. ruckeri, gyrA gene was identified by molecular test. CONCLUSIONS: Identification of quinolone resistance gene in Y. ruckeri isolates can be the reason of low efficacy of these classes of antibiotics in the aquaculture. ِTherefore, the policy of treatment should be changed specially in enteric red mouth disease.

BACKGROUND: Brucellosis is one of the most common zoonosis in Middle East and Iran. OBJECTIVES: The purpose of this study was genomic detection of Brucella spp. in sero-positive dairy cattle. METHODS: We have collected 28,519 blood samples from cows during 2012-2013. Samples were screened by Slide and tube agglutination and 2-Mercaptoethanol tests. Samples with anti-Brucella antibodies titer ≥ 1:80 and ≥1:40 in tube agglutination and 2-ME tests were considered as positive respectively. Tissue samples include: lymph nodes, liver, testicle and kidney from 122 samples of slaughtered cows were collected. The Sero-positive samples were examined by a collection of specific primers for Brucella abortus, Brucella melitensis, vaccinal strains included RB51 and Rev1 using PCR tests. RESULTS: Results showed that 450 samples were positive in slide agglutination test and 447 samples had anti-brucella antibodies titer equal to or more than 1:80. So they were positive by tube agglutination test. Three hundred eighty nine samples were positive by 2- mercaptoethanol test. PCR test results showed that 46 samples (37.7%) out of 122 samples had a specific sequence of Brucella or otherwise they have an active infection with Brucella species, whereas 62.3% of samples were negative. The PCR results showed that 2 samples (4.35%) were infected by B. melitensis, 2 samples (4.35%) infected by Rev1 strain and 42 samples (91.3%) were infected by B. abortus. CONCLUSIONS: The results showed that, as we had expected, the majority of cows were infected by B. abortus. Animals who infected by B. melitensis and Rev1 strain may be a result of contact with sheep or goats. We couldn’t find Brucella genome in 76 samples (62.3%) of sero-positive cows. It may be caused by cross reaction of sera with Brucella species in tests or activation of immune system response and elimination of organism from internal organs.