BACKGROUND: Neosporosis is a disease caused by the protozoan Neospora caninum, which is characterized by abortion in cattle and neuromuscular paralysis of various organs, particularly the hind limbs of dogs. The diagnosis of neosporosis is often made by serological molecular tests.OBJECTIVES: This study was conducted to investigate the presence of N. caninum oocysts in the feces of dogs. METHODS: A total of 100 fecal samples were collected from indoor and outdoor dogs during 2018-2019 around Tabriz. Information about age, location, and history of antiparasitic treatment of the dogs were recorded in a questionnaire. Primarily, fecal samples were examined microscopically for Neospora ocysts. After breaking the collected oocysts through freeze-thaw and sonication, DNA contents of the oocysts were extracted and analyzed via PCR.RESULTS: In a light microscopic study, oocysts were observed in 45 (45 %) of the fecal samples. In the PCR study, 21 of the 45 cases tested positive for Neospora infection (21 %). All the positive cases of infection were observed in molecular examination in dogs older than one year. The positive cases were observed in 2 % of the domestic dogs, 8 % of the stray dogs, 6 % of the kennel dogs, and 5 % of the rural dogs. Furthermore, 19 % of the infected dogs had no history of antiparasitic treatment; only 2% had a history of antiparasitic treatment. The results of statistical analysis showed that the rate of infection in dogs around Tabriz with Neospora caninum was significantly (P<0.05) related to the animal's living environment and history of antiparasitic treatment. However, this rate was found to have no significant relationships with the age of the animals.CONCLUSIONS: Due to the high rate of infection with Neospora caninum in dogs in Tabriz, it is necessary to apply preventive methods in traditional and industrial farms around this city and use rapid diagnosis methods in them.

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: Over the recent years, Neospora caninum has been one of the most important causes of abortion in dairy cattle. OBJECTIVES: We conducted the present study in order to investigate the seroprevalence of N. caninum in dairy cattle in Semnan province and its effect on abortion. METHODS: 237 blood samples were obtained from various Semnan dairy farms and 104 bulk dairy samples from four milk collection centers in Semnan, Garmsar, Damghan, and Shahrood were tested for sera and milk utilizing ELISA (Svanova Biotech AB) test kits. RESULTS: The results revealed that 87.27 % of bovine serum was positive. The percentage of opacity density (OD) of positive sample (PP) ranged from 72.17 to 137.3 (114.21±24.65). In addition, the average rate of milk seroprevalence to the parasite was 95.23 % in Semnan province. CONCLUSIONS: The frequency of Neospora caninum infection in blood and milk was high in Semnan, yet no significant relationships were observed with abortion (p < /em>>0.05).

BACKGROUND: Neospora caninum is a protozoanintracellular parasite which is considered as one of the main factors forrecurrent abortions of dairy cattle in various countries such as Iran. Thisparasite leads to negative economic impacts such as decline in reproduction,reduced amount of milk, and long calving intervals. OBJECTIVES: Therehave been numerous tests to determine the cause of abortion. PCR test isconsidered as a suitable method to specify Neospora caninum DNA and itcan determine the DNA in tissue samples and body fluids of the aborted fetus.This study aims to use PCR to evaluate parasites in the tissues of abortedfetuses so as to detect the best tissue for determining the parasite. METHODS:In this study, 82 aborted fetuses in the first six months of 2015 were studied.The tissues were selected from brain, liver, lungs, spleen, kidneys and rennetfluids. The NP21plus primer was used to detect the presence of Neosporacaninum in samples. After conducting the PCR Test, samples with 340bp bandin Gel electrophoresis were considered as positive. Statistical data from thesurvey of Neospora caninum’s presence in selected tissues were evaluatedby SAS (version 9.2) software. RESULTS: Contamination with this parasitewas found in 34 brain samples (41.5%) of aborted fetuses. In 2 (2.4%) and 4(4.9%) of the aborted fetuses, parasite DNA was found in lung and liver tissuesalong with brain tissues, respectively. CONCLUSIONS: Due to significantdifference of infection of brain tissues in comparison to other tissues, ourstudy considers brain tissue as the most appropriate sample for detecting Neosporacaninum infection in aborted fetuses in PCR method

Little is known about latent infection and molecular characterisation of Neospora caninum in sheep (Ovis aries). In this study, 330 sheep samples (180 hearts and 150 brains) were analysed for N. caninum DNA by nested polymerase chain reaction (PCR) targeting the Nc-5 gene. Neospora caninum DNA was detected in 3.9% (13/330) of sheep samples. The parasite’s DNA was detected in 6.7% of heart samples (12/180) and 0.7% (1/150) of brain samples. No clinical signs were recorded from infected or uninfected animals. Sequencing of the genomic DNA revealed 96% – 99% similarity with each other and 95.15% – 100% similarity with N. caninum sequences deposited in GenBank. To our knowledge, this is the first report on the use of PCR to identify latent neosporosis in sheep in Iran. The results of this study have the potential to contribute to our understanding of the role of N. caninum-infected sheep in the epidemiology of neosporosis.

A murine monoclonal antibody (MAB) 6G7 generated against tachyzoites of Neospora caninum recognized 8 major and several minor antigens, as observed by western blot analysis. Relative rate of migration of the 8 major antigens ranged from 31 to 97.4 kd. In addition, MAB 6G7 recognized a Toxoplasma gondii tachyzoite antigen with a relative rate of migration of 107 kd. Immunogold labeling of N caninum tachyzoites grown in human foreskin fibroblast cells indicated that MAB 6G7 binds to micronemes, dense granules, basal portions of rhoptries, and intravacuolar tubules within the parasitophorous vacuole. Monoclonal antibody 6G7 also bound to micronemes and basal portions of rhoptries within tachyzoites of T gondii. Monoclonal antibody 6G7 did not significantly inhibit development of tachyzoites in vitro.

Neospora caninum causes serious disease in dogs, and it, or a similar parasite, is a major cause of abortion in cattle. Little is known about the susceptibility of this protozoan to antimicrobial agents. We studied several antimicrobial agents to determine which classes might have activity against this parasite. We also determined whether activity of such agents was coccidiocidal or coccidiostatic. A 2-day of treatment, monoclonal antibody-based enzyme immunoassay and a 5-day of treatment, cell culture flask (CCF), lesion-based assay were developed to examine the ability of test agents to inhibit tachyzoite multiplication. Seven sulfonamides were examined, with the following activities observed: sulfathiazole greater than or equal to sulfamethoxazole > sulfadiazine > sulfaquinoxaline greater than or equal to sulfamethazine > sulfadimethoxine > sulfamerazine. Dapsone, a sulfone, had little activity. Six dihydrofolate reductase/thymidylate synthase inhibitors were examined, with the following activities observed: piritrexim > pyrimethamine > ormetoprim > trimethoprim = diaveridine > methotrexate. Six ionophorous antibiotics were examined; lasalocid, maduramicin, monensin, narasin, and salinomycin had equivalent activities, but alborixin was toxic for host cells at the lowest concentration examined. Three macrolide antibiotics--azithromycin, clarithromycin, and erythromycin--were examined and had equivalent activities. Two tetracycline antibiotics, doxycycline and minocycline, were examined and had equivalent activities. Three lincosamide antibiotics were examined, with the following activities observed: clindamycin hydrochloride > clindamycin phosphate > lincomycin hydrochloride. Pentamidine and 6 of its analogs were examined, and only hexamidine and 1,4-Di[4-(2-imidazolinyl)-2-methoxy-phenoxylbutane had activity. Eight miscellaneous antiprotozoal agents were examined for activity. Amprolium, metronidazole, paromomycin, and roxarsone had little activity. Arprinocid, diclazuril, nitrofurazone, and robenidine had good activity. Eleven agents were examined in both assays, whereas 32 agents were examined in the CCF assay only. The enzyme immunoassay and CCF assay provided similar results for agents that rapidly killed tachyzoites. However, agents that inhibited development, but were not rapidly fatal for tachyzoites, had better activity in the CCF assay. Of the classes of agents examined, the dihydrofolate reductase/thymidylate synthase inhibitors, 2 of the 6 pentamidine analogs, and the ionophores were coccidiocidal and the sulfonamides, macrolides, tetracyclines, and lincosamides were coccidiostatic. Of the miscellaneous agents examined, arprinocid, nitrofurazone, and robenidine were coccidiocidal and diclazuril was coccidiostatic.

This study was performed to detect Neospora caninum in blood of 61 Korean native cattle and 50 dairy cows in Chungnam province. All of them were healthy and did not show any clinical signs. DNA was isolated from blood samples and a 328 bp fragment was amplified by PCR using primer pair Np21 and Np6. The PCR positive rate was 14.8% in Korean native cattle and 0% in dairy cows. Cows with 15.6% were a little higher than bulls with 12.5% in gender. The detection rate of over 3-year-old Korean native cattle was 28.6% in age. The results demonstrate that N. caninum DNA can be detected in blood by PCR. PCR analysis in blood may be useful to annually screening test for N. caninum infection in clinically healthy cattle.

Neospora caninum-induced abortion is a major production problem in the daily cattle industry in the United States and worldwide. Abortions attributable to naturally acquired N caninum infection also have been observed in pygmy goats. We studied experimentally induced infections with N caninum in pregnant pygmy does to determine whether abortions attributable to N caninum infection would occur after inoculation. Seven pregnant pygmy does (1 control doe and 6 inoculated with N caninum) were studied. The control doe remained clinically normal throughout the study and delivered 2 healthy kids. Abortion, fetal death, and stillbirths were observed in some pregnant does inoculated with N caninum. Two pregnant pygmy does inoculated with N caninum early in gestation (day 51) had fetuses that died and were aborted, or died and were reabsorbed. Neospora caninum tachyzoites and lesions were observed in the brain, spinal cord, and heart of aborted fetuses; parasites also were isolated from the placenta. Four additional pregnant pygmy does (2 inoculated at mid-gestation [day 85], and 2 at late gestation [day 127]) did not abort after inoculation. However, 1 doe inoculated during mid-gestation delivered a stillborn fetus that had died about 1 week prior to parturition. This kid was congenitally infected with N caninum. Neospora caninum was isolated from the placentas of all inoculated does examined. Neonatal neosporosis was not observed in live-born kids, nor were stages of N caninum isolated from any live-born kid. Does did not undergo abortion or have congenitally infected kids when they were rebred and evaluated for neosporosis.