Neospora caninum in birds: A review

Serosurvey and associated risk factors for Neospora caninum infection in Egyptian water buffaloes (Bubalus bubalis)

Neosporosis is a parasitic disease that causes reproductive disorders in animals, making it a barrier to maximum efficiency. The purpose of this study was to determine the seroprevalence of Neospora caninum (N. caninum) antibodies in water buffaloes from four governorates in northern Egypt. A commercial indirect-ELISA test was used to detect antibodies against N. caninum in the serum of 450 water buffaloes. The total seroprevalence of N. caninum in water buffaloes from Egypt was 31.3%, and the highest prevalence was observed in Gharbia governorate. The identified risk factors for N. caninum infections in water buffaloes were sex (OR = 1.96, 95%CI: 1.22-4.17), buffaloes more than 4 years of age ( OR = 5.80, 95%CI: 2.26-14.86), abortion in second trimester (OR = 16.48, 95%%CI: 2.99-34.03), history of abortion (OR = 3.45, 95%CI: 1.58-7.52) and contact with dogs (OR = 2.55, 95%CI: 1.51-4.32). Thus, more studies are needed to determine the role of buffaloes in the epidemiology of neosporosis in Egypt.

Pathological characteristics and congenital immunological responses of pigeons-infected with Neospora caninum

Pigeons are natural intermediate host of Neospora caninum (N. caninum). In comparison to ruminants, N. caninum causes milder clinical symptoms and less financial loss to pigeons. Natural infectious rates and high prevalence of N. caninum in pigeons, and death cases of N. caninum-infected pigeons under experimental conditions have been reported, but the detailed pathological characteristics and congenital immunological responses of pigeons-infected with N. caninum remain not well described. In this study, pigeons were infected intraperitoneally with 107 N. caninum tachyzoites. N. caninum in tissues was detected by qPCR. Pathological changes of tissues were examined by hematoxylin-eosin staining. Blood smears were prepared for counting eosinophils changes in blood. Heterophil extracellular traps (HETs) in vivo and in vitro were quantified by Pico Green. N. caninum-induced HETs structures were observed by immunofluorescence staining. The model of pigeons-infected with N. caninum was successfully established. Lung and duodenum were the main target organs of pigeons-infected with N. caninum. N. caninum caused hemorrhage, edema and inflammatory cell infiltration in liver, pulmonary congestion and hemorrhage, organizational destruction in lung, and shorter villi or even disappear in duodenum. N. caninum also increased the number of eosinophils in blood of pigeons. Moreover, N. caninum-induced HETs release in the congenital immunological system of pigeons were first demonstrated, and the HETs structures were consisted of DNA as the skeleton and modified with citH3 and elastase. N. caninum-induced HETs release was related with NADPH oxidase, TLR 2 and 4, ERK1/2 and p38 MAPK signaling pathways, and glycolysis. In summary, it is the first report on the detailed pathological characteristics and congenital immunological responses of pigeons-infected with N. caninum, which may provide theoretical basis for the prevention and control of Neosporosis in pigeons.

An Antibody-Based Survey of Toxoplasma gondii and Neospora caninum Infection in Client-Owned Cats from Portugal

Toxoplasma gondii and Neospora caninum are obligate intracellular protozoan parasites infecting a wide range of hosts worldwide. However, information on the epidemiology of toxoplasmosis and neosporosis in cats from Portugal is limited. Thus, this study aims to evaluate anti-T. gondii and anti-N. caninum seroprevalence in client-owned cats from Portugal and to identify risk factors using a panel of well-characterized sera. A total of 183 domestic cats were sampled and screened for antibodies against T. gondii and N. caninum using commercial ELISA assays, and their owners answered an online questionnaire designed to obtain background information. The overall anti-T. gondii and anti-N. caninum seroprevalences were 13.1% (CI: 8.97-18.77) and 3.8% (CI: 1.87-7.68), respectively. Univariate analysis revealed that living strictly indoors was a significant protection factor (cOR: 0.053; CI: 0.005-0.627), and the presence of a chronic disease a significant risk factor (cOR: 3.106; CI: 1.062-9.082) to T. gondii seroprevalence. When performing multivariate analysis, only chronic disease (aOR: 57.527; CI: 1.7-1976.7) and seropositivity to N. caninum (aOR: 7.929; CI:0.8-82.9) were found to be a significant risk factor to anti-T. gondii antibodies. To the best of our knowledge, this is the first report of N. caninum seropositivity in cats from Portugal.

Molecular detection of Neospora caninum in chicken meat and eggs in Iran

Neospora caninum is an obligatory intracellular protozoan parasite, phylum Apicomplexa. Canids are definitive hosts and different animals can be intermediate hosts. Neospora DNA has been also detected in humans, recently. This study aimed to understand the infection rate of N. caninum in chicken meat because consumption of raw and undercooked meat can be the main risk factor for canine neosporosis. Investigation of Neospora vertical transmission to the eggs is also important. One hundred chicken legs, and fifty eggs from free-range chickens, and fifty eggs from industrial chickens were collected from different stores in Semnan city, Iran. Deoxyribonucleic acid (DNA) of samples was extracted, and the Nested-PCR (polymerase chain reaction) on Neospora internal transcribed spacer (ITS-1) gene was performed. Neospora caninum DNA was detected in eight out of one hundred (8%) chicken legs, and no eggs were infected. These results revealed that N. caninum infection in chicken meat for the first time in Iran. For the investigation of Neospora vertical transmission to eggs, more studies will be necessary. Indoor carnivores should be fed, and humans should be consumed well-cooked chicken meat to prevent infection.

The Dangerous Side of Being a Predator: Toxoplasma gondii and Neospora caninum in Birds of Prey

Toxoplasma gondii and Neospora caninum are apicomplexan protozoa of major concern in livestock and T. gondii is also considered one of the major threats and a public health concern. These protozoa have a wide range of intermediate hosts, including birds. The present work aimed to assess the prevalence of these cyst-forming parasites in migratory and sedentary birds of prey. The skeletal muscle and myocardium of 159 birds of prey from Central Italy, belonging to 19 species and recovered across 6 Wildlife Recovery Centers/Care structures along the Italian migratory route, were collected specifically for molecular (PCR) and for histopathological analysis to detect T. gondii and N. caninum. For the molecular analysis, genomic DNA was extracted. The DNA was tested by sequence typing, targeting GRA6, 529 bp repeated element, B1, PK1, BTUB, SAG2, alt.SAG2, and APICO genes for T. gondii and to end-point PCR targeting NC5 gene for N. caninum. Thirty-seven out of the one hundred and fifty-nine analyzed samples tested positive for T. gondii with a prevalence of 23.27% and nine for N. caninum, with a prevalence of 5.66%. Thirty-two sequences were obtained from the thirty-seven isolates of T. gondii. Among these, 26 presented alleles compatible with type I strain in 1 or more loci, 4 with type II strain and 2 consisted of atypical strains. Toxoplasma gondii genetic variability in birds of prey confirms previous findings of wildlife as reservoirs of atypical strains. Results from the histology showed few protozoal tissue cysts in skeletal muscle (n. 4) and hearts (n. 2).

Natural infection with Toxoplasma gondii, Neospora caninum and Sarcocystis species in domestic pigeons (Columba livia domestica) in Iran

Pigeons are common birds around the world and may act as intermediate hosts of the tissue cyst-forming apicomplexan parasites Toxoplasma gondii, Neospora caninum and Sacrocystis spp. This study aimed to provide an overview on the prevalence of and exposure to these parasites in Iranian domestic rock pigeon (Columba livia domestica) through molecular, serological and histopathological examination. Blood and tissue samples (i.e., brain, heart, gizzard, neck, thigh, and pectoral muscles) were taken from 100 pigeons. Sera were screened by agglutination tests for detection of anti- T. gondii and N. caninum antibodies, genomic DNA from tissue samples were assessed by respective species-specific PCRs, and histopathological examination of tissues was carried out. A seroprevalence of 45 % to anti-T. gondii and 35 % to anti-N. caninum IgG was recorded. PCR detected T. gondii DNA in 28 pigeons. Sacrocystis spp. was detected in one animal, but sequencing of the 28 S rRNA gene product did not reveal the identity of the species. Histopathology revealed myocarditis, myositis, and gliosis in the heart, skeletal muscles, and brain, respectively. No Sarcocystis tissue-cysts were detected, but T. gondii tissue cyst-like structures in the brain (i.e., 4 %) and heart (i.e., 3 %) were found by histology. Data reported herein demonstrate that pigeons from Iran are infected with tissue cyst-forming apicomplexans, particularly T. gondii. Since domestic pigeons are in close contact with human populations, and consumption of their meat and egg is popular in different societies, control strategies for minimizing the risk of infection in both pigeons and humans are suggested.

Switzerland-wide Neospora caninum seroprevalence in female cattle and identification of risk factors for infection

INTRODUCTION

Neospora caninum is an important cause of abortion in cattle worldwide. Infection in cattle occurs horizontally by ingestion of oocysts shed by canids or vertically, from an infected dam to the fetus, and may result in abortion, stillbirth, or birth of seropositive offspring. The control of bovine neosporosis is difficult and costly. The objectives of this study were to estimate the current nationwide seroprevalence of N. caninum infections in Swiss cattle and to assess risk factors for infection with this parasite.

METHODS

We conducted a cross-sectional study with cattle farms randomly selected and stratified according to population size, resulting in a sample of 780 female cattle. The cattle originated from 161 farms distributed over all Switzerland. The serum samples were tested for antibodies against N. caninum using a commercial ELISA and if inconclusive, retested using an in-house immunoblot technique. To collect farm parameters relevant to N. caninum transmission and prevention, farm owners were mailed a questionnaire which addressed topics putatively related to N. caninum infection such as husbandry, history of abortion, and presence of dogs on farm. Univariate analysis by generalized linear mixed model (with animal seropositivity as outcome variable) and logistic regression modeling (with farm seropositivity as outcome variable) was conducted on farm parameters investigated in the questionnaire.

RESULTS

By ELISA and immunoblot, 4.2% (33/780) of cattle sera yielded positive results. At the farm level, 16.2% (26/161) of the sampled farms had at least one seropositive animal. The return rate of the valid questionnaires was 54.0%. At the animal level, odds for farm seropositivity were 3.8 times higher when rodents had been recorded by the farmer as a problem on the farm. At the farm-level, two protective factors were identified: rearing of replacement heifers and feeding of concentrated feed.

CONCLUSION

We recorded a low seroprevalence of N. caninum in a random sample of Swiss cattle representative for the years 2017-2018. Based on a questionnaire survey, we could identify risk and protective factors for infection with N. caninum, however their biological relevance needs to be confirmed in further studies.

Seroprevalence and risk factors of Toxoplasma gondii and Neospora caninum infection in black goats in Yunnan Province, Southwestern China

Toxoplasma gondii and Neospora caninum are two obligate intracellular protozoan parasites that can cause reproductive failure and production losses. To date, there is no data of T. gondii and N. caninum seroprevalence in black goats in Yunnan Province, southwestern China. In the present study, a total of 734 serum samples were collected from black goats in four different counties of Yunnan Province. 734 and 590 serum samples were examined for antibodies against T. gondii and N. caninum by using MAT and indirect ELISA, respectively. A total of 123 and 76 samples were T. gondii-positive and N. caninum-positive, respectively. The overall seroprevalence of T. gondii in black goats was 16.76% (123/734, 95% CI: 14.06-19.46) with the titer ranged from 1:25 to 1:3200. The seroprevalence of N. caninum was 12.88% (76/590, 95% CI: 10.18-15.58). There was significant difference in seroprevalence of N. caninum in different regions (P < 0.01, χ² = 30.63) and age groups (P < 0.05, χ² = 11.85). Significant differences in seroprevalence of T. gondii were observed in different regions (P < 0.05, χ² = 9.21) and different gender groups (P < 0.01, χ² = 12.29). Results of seroprevalence of T. gondii and N. caninum indicated that T. gondii and N. caninum were prevalent parasites in black goats in Yunnan Province. This is the first report of seroprevalence of T. gondii and N. caninum in black goats in Yunnan Province. The results of this study indicated that some measures should be taken to control these two parasites and to reduce economic losses to the livestock industry in Yunnan Province.

Detection of Anti-Neospora caninum Antibodies on Dairy Cattle Farms in Southern Italy

Neosporosis is recognized as one of the major causes of bovine abortion worldwide. Canids are the main definitive host for this parasite and the presence of dogs in the farm is an important factor for the Neospora caninum infection in bovines. Since, in the province of Lecce, located in the Apulia region of Southern Italy, there are no studies showing the presence of the infection in farm animals, the objective was to perform a serological evaluation for anti-N. caninum antibodiesin serum from 706 dairy cattle and 21 farm dogs located in 40 farms uniformlydistributed over the territory.The presence of N. caninum infection was confirmed in 90.0% (36/40) of the 40 farms examined. The results obtained on all serum samples by an enzyme-linked immunosorbent assay (ID Screen^®Neospora caninum competition ELISA kit) for anti-N. caninum antibodies showed a seropositivity rate of 21.1% (149/706) among dairy cows, with a statistically significant higher percentage of positive subjects in the animals over two years old and a positivity rate of 42.9% (9/21) in tested dogs. The obtained data confirmed the presence of neosporosis even in the Lecce area, where it could therefore represent an important cause of abortion and economic losses.

Neospora caninum infection and reproductive problems in dairy cows from Brazil: A case-control study

Neosporosis, an infectious disease caused by the protozoan Neospora caninum, has been associated with economic losses in cattle rearing worldwide. However, previous studies have not presented any evidence regarding the association between serological status of neosporosis and alteration of the reproductive parameters. Thus, this study aimed to determine whether N. caninum is associated with reproductive disorders and to evaluate the possible risk factors of the infection. Blood samples from 202 dairy cows, 51 with a history of reproductive disorders (case group) and 151 without (control group), were collected from different farms in Brazil. Epidemiological questionnaires were conducted with all the farmers. Serum samples were subjected to an indirect fluorescent antibody test to detect antibodies against the parasite. In total, 28.22% (57/202) of the cows were seropositive: 47.06% (24/51) from the case group and 21.85% (33/151) from the control group. By logistic regression, cows aged ≥48 months and cows with history of abortion were 4.8 (95% confidence interval [CI] = 1.91-12.05; p = 0.001) and 2.3 (95% CI = 1.06-5.1; p = 0.034) times more likely to be seropositive, respectively. Furthermore, our results show an association between N. caninum seropositivity and abortion in dairy cows from Brazil with poor management conditions and N. caninum seropositivity risk factors for reproductive disorders.

Seroprevalence and risk factors for Neospora caninum and Toxoplasma gondii in goats of Maranhão State, Brazil

We estimated the seroprevalence and possible risk factors for neosporosis and toxoplasmosis in goats in the state of Maranhão, Brazil. In addition, the variables related to these animals and the management of the farm were investigated in terms of the significance of the associations. In total, 383 serum samples from goats, of both sexes and different ages, were collected from 15 farms in four municipalities. The indirect immunofluorescence test was used for antibody detection against Neospora caninum and Toxoplasma gondii. The overall seroprevalence of N. caninum in goats was 26.4% (101/382; IC 95% 22.3-31.1), and 114 out of 383 serum samples were T. gondii-seropositive (29.8%, IC 95% 25.4-34.5). In addition, the seroprevalence of coinfection of T. gondii and N. caninum in goats was 8.6% (33/382; IC 95% 6.2-11.8). The risk factors significantly associated with the seroprevalence of N. caninum were age, type of sheepfold floor, rearing system, feeding, pasture area cultivated, cats having access to the feed deposits, worming, slaughter place of the animals, history of abortion and the presence of dogs and cats. Regarding the seroprevalence of T. gondii infection, age, category, presence of other species and purpose of breeding were the risk factors. To our knowledge, this is the first report of the seroprevalence and risk factors for N. caninum and T. gondii in goats in the state of Maranhão, Brazil, which provides basic data for the implementation of strategies and control measures against neosporosis and toxoplasmosis.

Molecular detection and phylogenetic analysis of Neospora caninum in various hosts from Iran

Different N. caninum strains with distinct biological characteristics and pathogenicity have been introduced from various areas of the world. This study aimed to detect Neospora-infection in different hosts from Iran using the nested-Polymerase Chain Reaction (PCR) technique and to perform the phylogenetic analysis of N. caninum isolates using the Nc-5 gene. Different species of parasite hosts (cattle, dogs, rodents, cats, and birds) from the dairy farms with history of abortion with intensive breeding systems in Hamedan Province, Iran were included for sampling. The stillbirth fetuses of cattle, sheep, and goats were also collected from the slaughterhouse. The nested-PCR technique was used to identify the Neospora-DNA in the aborted fetal materials. The PCR products of the positive samples were sequenced and compared with other isolates in GenBank. Antibodies to N. caninum was found in 19.1% of dogs. Also, 11.4% of dogs were positive for Neospora-like oocysts using microscopy method. The molecular prevalence of N. caninum was 10.6% in dogs, 13.6% in cattle, 35.4% in the aborted fetuses of cows, 31.9% in rodents, 7.6% in pigeons, 1.9% in sparrows, 5.1% in cats, and 7% in the semen sample of bulls. A sampled coyote was positive while the stillbirth fetuses of sheep and goats were negative. The multiple sequence alignments indicated that 34 sequences of N. caninum bore a 94.9-99.3% similarity to each other. Hence, these sequences were classified into two major clusters (clusters A and B) and seven sub-groups (isolates 1-7). The sequence of coyote had a high similarity to the sequences derived from dogs and cows. Also, root diagram showed the isolates of current study and previous reported from Iran have a similar origin. This study provided a phylogenetic analysis of Neospora-infection in different hosts, and for the first time, explored Neospora-infection in coyotes from Iran. Different isolates were detected in the studied population in the region. Comparison of the sequences showed the farm dogs play an important role in the life cycle and distribution of the parasite; so the relationship of dogs with the herd and their access to aborted materials should be restricted. Also, regular control of rodents' population and culling of seropositive cows with a history of abortion is essential for cutting the chain of transmission.

Epidemiology of Neospora caninum infection in free-range chickens (Gallus gallus domesticus) in north central Mexico

The objective of the present study was to investigate the epidemiology of natural infection by N. caninum in free-range chickens from Aguascalientes, Mexico, through identifying the presence of antibodies, its association with certain risk factors, and estimate the frequency of parasite DNA detection in the brain. The study included 150 clinically healthy chickens from 81 small family farms distributed throughout the state, from which blood and brain samples were taken. Serum samples were processed by indirect immunofluorescence considering a dilution of 1:50 as a positive reaction, while the DNA detection was done by PCR; the association between the presence of antibodies and the potential risk factors was estimated through logistic regression. The general anti-N. caninum presence of antibodies in the studied population was 46% (69/150, CI 95% 38-54), with titers of 1:50 in 38, 1:100 in 24, and 1:200 in 7, finding positive cases in 49% of the farms and in 91% of the municipalities that integrate the state. The presence of antibodies found in the municipalities was estimated in a range of 20 to 75%. The frequency of DNA detection was 6% (9/150, CI 95% 2-11). The grain supplementation was identified as the unique risk factor for infection (OR = 2.82; 95% CI, 1.18-6.73, p < 0.019).

Biosurveillance of Selected Pathogens with Zoonotic Potential in a Zoo

Monitoring of infectious diseases is one of the most important pillars of preventive medicine in zoos. Screening for parasitic and bacterial infections is important to keep animals and equipment safe from pathogens that may pose a risk to animal and human health. Zoos usually contain many different animal species living in proximity with people and wild animals. As an epidemiological probe, 188 animals (122 mammals, 65 birds, and one reptile) from a zoo in Slovenia were examined for selected pathogens. Antibodies to Toxoplasma gondii and Neospora caninum were detected by ELISA in 38% (46/122) and 3% (4/122) of mammals, and in 0% (0/64) and 2% (1/57) of birds, respectively; the reptile (0/1) was negative. A statistically significant difference in T. gondii prevalence was found in Carnivora compared to Cetartiodactyla and primate antibodies to Encephalitozoon cuniculi were detected by IFAT in 44% (52/118) of mammals and 20% (11/56) of birds, respectively; the reptile (0/1) was negative. Herbivores had a higher chance of being infected with E. cuniculi compared to omnivores. Antibodies to Chlamydia abortus and Coxiella burnetii were not detected in any of the 74 tested zoo animals. The sera of 39 wild rodents found in the zoo were also examined; they were negative for all three parasites. The parasite T. gondii was detected by PCR in the tissue of two mute swans (Cygnus olor), three eastern house mice (Mus musculus), one yellow-necked field mouse (Apodemus flavicollis), and one striped field mouse (A. agrarius). Positive samples were genotyped by a single multiplex PCR assay using 15 microsatellite markers; one sample from a mute swan was characterized as type II. This micro-epidemiological study offers a better understanding of pathogens in zoo animals and an understanding of the role of zoos in biosurveillance.

Molecular Survey on Toxoplasma gondii and Neospora caninum Infection in Wild Birds of Prey Admitted to Recovery Centers in Northern Italy

Toxoplasma gondii and Neospora caninum (Apicomplexa, Sarcocystidae) are protozoan parasites infecting a wide range of intermediate hosts worldwide, including birds. Raptors acquire the infections through the ingestion of both infected preys and oocysts in the environment suggesting they might be used as indicators of the spread of these pathogens. Here, we report an epidemiological survey with the aim of determining the prevalence of T. gondii and N. caninum infections in wild birds of prey, hospitalized in two Wildlife Recovery Centres (WRCs) in Northern Italy. Genomic DNA extracted from brain tissue samples was submitted to Real Time PCR targeting T. gondii B1 and N. caninum Nc5 genes. T. gondii genotyping was then performed by multilocus sequence typing (MLST) analysis, targeting three polymorphic genes (GRA6, BTUB, and altSAG2). T. gondii DNA was found in 35 (62.5%) out of 56 examined samples; concerning genotyping, it was possible to amplify at least one gene for 26 animals, and obtained sequences belonged to Type II. N. caninum DNA was only detected in two (3.6%) common kestrels (Falco tinnunculus), adding a new species to the list of suitable intermediate hosts for this pathogen. Data obtained in the present study thus confirmed the spread of both T. gondiiand N. caninum in wild bird of prey, endorsing the role of WRCs in the epidemiological surveillance of wildlife.

Serosurvey of Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in raptors and risk factor analysis

Raptors are carnivorous birds with great hunting ability. Toxoplasma gondii, Neospora caninum and Sarcocystis spp. are intracellular Apicomplexan protozoans which infect a wide range of intermediate hosts, including birds. The aims of this study were to evaluate the serological reactivity of captive raptors serum to T. gondii, N. caninum and S. neurona antigens and identify possible risk factors associated with the infection. From August 2014 to September 2015, blood samples from 72 raptors were collected and serum samples were tested by immunofluorescence antibody test (IFAT). Antigen slides were prepared using tachyzoites of T. gondii and N. caninum and using merozoites of S. neurona. Serum samples were tested at the following cut-off dilutions: 1:16 for T. gondii and 1:50 for N. caninum and S. neurona. An anti-chicken IgY antibody conjugated with FITC was used as a secondary antibody at 1:50 dilution. Out of the 72 raptors serum tested by IFAT, 2.7% reacted to N. caninum, 8.3% to T. gondii and 11.1% to S. neurona antigens. The region in which the sample was collected, the reason the raptors were kept in captivity and diet were statistically associated with seropositivity to T. gondii and the use of the birds and diet were statistically associated with seropositivity to N. caninum and S. neurona (p ≤ 0.05). We highlight the occurrence of these protozoans in birds of prey and the importance of good hygiene and feeding management of these birds in captivity to reduce the risk of protozoal infections.

Neospora caninum in free-range chickens (Gallus gallus domesticus) from southern Brazil

Neospora caninum is an obligate intracellular parasite that can infect many domestic and wild animals, including birds. These animals are important sources for monitoring of environmental contamination, as they could become infected through sporulated oocysts; however, the real role of birds in the biological cycle of N. caninum remains uncertain. This study aimed to determine the prevalence of anti-N. caninum antibodies, evaluate associated factors, detect the parasite by molecular testing of free-range chickens from Brazil, and evaluate different techniques for its serological diagnosis. Blood samples of 366 chickens from 25 farms were collected for serological assays. The indirect fluorescent antibody test (IFAT) and the indirect enzyme-linked immunosorbent assay (ELISA) were used to detect anti-N. caninum antibodies. Chickens that tested seropositive by IFAT had their brain tissues and a pool of organs (heart, lung, and liver) submitted to PCR for molecular detection of the parasite. Out of 366 chickens, 65 (17.8%) and 163 (44.6%) were seropositive by IFAT and ELISA, respectively. Brain tissues (n=60) and the pools of organs (n=65) were negative in the PCR. Our results showed a high prevalence of antibodies in free-range chickens and that IFAT is the more sensitive technique for the detection of anti-N. caninum antibodies.

Neospora caninum infection in Iran (2004-2020): A review

Knowledge on neosporosis and associated risk factors in different species of animals are so important for designing the control programs and reduce the economic losses globally. This literature review targeted for evaluating the infection rate of Neospora caninum in animals in Iran. Until April 2020, all of published documents in the main English and Persian-language databases were searched. A total number of 110 documents (English = 85 and Persian = 25) were extracted. Most of reports were sero-epidemiological studies using ELISA in Iranian cattle population. The range of Neospora infection was 3.8–76.2% in cattle, 0–54.6% in dogs, 0.9–9.9% in sheep, 6.2% in goats, 19.2–55.9% in buffaloes, 20–42.2% in horses, 52% in donkeys, 3.2–27% in camels, 14% and 19% in cats, and 0–20.4% in rodents. This rate in birds was 17.3% in chicken, 9.8% and 30.4% in pigeons, 2.8% and 3.7% in sparrows, and 9.9% in hooded crows. This is a comprehensive literature review on Neospora infection in Iran at the first time. The infection of N. caninum is widespread in Iran especially in dogs and cattle population. This review can provide baseline information for future research. Study on other hosts especially on wild and exotic animals is recommended for exact estimate of neosporosis in Iran. Investigations into molecular diagnosis and genotyping of N. caninum strains are also needed; this will be helpful for developing vaccines and finding the connection among wild and domestic cycles of disease. Education on the risk factors associated with N. caninum infection for is suggested farmers and rural public.

A Review of Toxoplasmosis and Neosporosis in Water Buffalo (Bubalus bubalis)

Toxoplasmosis and neosporosis are diseases with worldwide distribution that are associated with reproductive problems in livestock and responsible for economic losses. This review presents an overview of the current knowledge relative to these diseases in water buffalo (Bubalus bubalis). In general, buffalo are considered resistant to clinical toxoplasmosis because there are studies only reporting serological evidence of natural infection in these animals. Studies have described age, poor hygienic status of the farm, and presence of cats as risk factors for the development of Toxoplasma gondii infection in buffalo. It must be highlighted that buffalo meat, which does not receive adequate freezing treatment, could be a potential source for toxoplasmic human infection as well as the importance of raw buffalo milk in the transmission of toxoplasmosis to human beings. Neospora caninum is considered one of the major causes of abortion and responsible for huge economic losses in cattle. Vertical transmission is the main route to infect calves, and is responsible for maintaining the parasite within a herd. In buffalo, vertical transmission is also described; moreover, although there are indications that N. caninum may be associated with abortion in dairy buffalo, the reproductive importance of neosporosis is apparently lower in buffalo relative to cattle. Most studies have identified a higher time of exposition to N. caninum oocysts relative to age. The household system was also described as a risk factor for infection, possibly due to persistent contact between the home-raised buffalo and canids. The fetal immune competence of buffalo is similar to bovine, and buffalo fetus are highly susceptible to infection during the first trimester of pregnancy, indicating that N. caninum may be an abortigenic agent in buffaloes. Alternatively, it is interesting to note there is evidence that the inflammatory response in pregnant buffalo infected with N. caninum is mild enough to avoid abortion in most cases. It is proposed that the possible transmission of toxoplasmosis through unprocessed milk and buffalo meat may occur, which is important in terms of public health. Additionally, there is strong evidence to suggest that N. caninum may be associated with abortion in buffalo.

Survey of Toxoplasma gondii, Neospora caninum and Sarcocystis neurona antibodies in wild red-tailed Amazon parrots (Amazona brasiliensis)

Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are obligate intracellular parasites within the phylum Apicomplexa. The red-tailed Amazon parrot (Amazona brasiliensis) is a near-threatened species of psittacine that is endemic to the Atlantic Forest of Brazil and has been designated as a bioindicator because of its sensitivity to environmental qualitative status and changes. The aim of this study was to evaluate the presence of antibodies against T. gondii, N. caninum and S. neurona in wild red-tailed Amazon parrot nestlings on Rasa Island, Brazil. Blood samples were collected from 51 parrots and plasma samples were stored at - 20 °C until immunofluorescence antibody tests (IFAT) were performed. Antigen slides were prepared using tachyzoites of T. gondii (RH strain) and, N. caninum (NC-1 strain) and using merozoites of S. neurona (SNR37 strain). Plasma samples were tested at initial dilutions of 1:16 for T. gondii, 1:50 for N. caninum and 1:5 for S. neurona. An anti-chicken antibody conjugated with FITC was used as a secondary antibody at 1:50 dilution. No antibodies for any of these three protozoa were found, thus suggesting that these wild red-tailed Amazon parrot nestlings had not been exposed to these parasites.

Serological evidence of exposure to Toxoplasma gondii and Neospora caninum in free-ranging Orinoco goose (Neochen jubata) in Brazil

Toxoplasma gondii and Neospora caninum are Apicomplexan intracellular protozoan parasites that affect numerous animal species, thus leading to severe diseases and economic losses, depending on the vertebrate species involved. The role of the avian species in maintaining and transmission of these coccidia has been studied for several years as they tend to serve as a potential source of infection for mammals and humans. The present study aimed to assess the serological exposure of Orinoco goose (Neochen jubata) to T. gondii and N. caninum. Between 2010 and 2013, 41 free-ranging Orinoco geese were captured in the Araguaia River, Brazil. The presence and titration of IgY antibodies to both coccidia were assayed via indirect immunofluorescent antibody test (IFAT). While IgY antibodies for N. caninum were present in 5 animals, with titers of 20, the antibodies for T. gondii were found in 35 animals, with titers ranging from 20 to 640. Considering that the Orinoco goose's meat is consumed by the local population in the studied area, it may represent an important source of T. gondii infection for humans. Due to its migratory behavior, this goose may play a pivotal role in the natural dispersion of both parasites. Furthermore, molecular studies are required for genotyping the isolates of T. gondii that occurs in this avian species.

Toxoplasma gondii And Neospora caninum In Brain Tissue Of Rodents In North-West Iran

Purpose

Rodents live in proximity to humans and domestic animals. These creatures can serve as reservoir hosts for many zoonotic parasites; therefore, they increase the risk of human infections. The aim of this study was to investigate Toxoplasma gondii and Neospora caninum in rodents caught in Meshgin-Shahr District, Iran.

Patients and methods

In a cross-sectional study, brain samples were collected from 70 rodents caught in Meshgin-Shahr District during March and December 2015. The specimens were examined for exposure to T. gondii and N. caninum with molecular methods.

Results

Seventy rodents were caught, including 50 Meriones persicus, 11 Mus musculus and 9 Cricetulus migratorius. Thirty rodents were female and 40 were males. Using PCR (B1 gene), T. gondii was detected in 7.1% (5/70) of the rodents while N. caninum was not detected. The prevalence of Toxoplasma infection was higher in female rodents (4.28%) compared to male rodents (2.86%), but the difference was not significant.

Conclusion

The results showed a low risk of T. gondii and N. caninum among rodents. Finally, further research is needed to understand the role of these rodent species in the transmission of the above protozoan pathogens to humans and livestock in this area.

Detection of Neospora Caninum DNA in Wild Birds from Italy

The role of avian species in the Neospora caninum life cycle has not been completely elucidated, and epidemiological data from Europe are scant. The aim of the present report was to evaluate the presence of N. caninum DNA in the tissues of 302 birds belonging to different avian species, along with IFAT titers. Forty-two out of the 302 birds (13.9%) showed low serological titers (1/50 and 1/100) against N. caninum. These data, positive for 31 animals (10.3%), were corroborated by PCR. Twenty-two hearts and eighteen brains scored positive, while nine subjects resulted had parasite DNA both in their hearts and brains. Serological data showed significantly higher results in waterfowl in respect to non-waterfowl avian species. This finding indicates a higher exposure of water birds to the parasite. These avian species, in fact, which feed directly from soil and/or water, are prone to ingest oocysts excreted by final canid hosts. The present study adds information to the state of art of N. caninum epidemiology in Italy, even if more investigations using bio-assays are needed to allow for a serological/parasitological follow-up to evaluate the real impact of the avian species in maintaining the parasite in main reservoirs.

Molecular detection of Neospora caninum from naturally infected four passeriforme birds in China

Neospora caninum is an intracellular protozoan infecting many domestic and wild animals. In the present study, the brain tissues of wild birds collected in Hunan province of China were examined by N. caninum specific nested PCR, targeting the Nc-5 gene and the internal transcribed spacer 1 (ITS-1) region of the nuclear ribosomal DNA. The prevalence of N. caninum was detected in 15.5% (37/239) of wild birds, including 20.5% (9/44) of the examined olive-backed pipit Anthus hodgsoni, 18.3% (24/131) of the examined tree sparrows Passer montanus, 7.9% (3/38) of the examined chestnut bunting Emberiza rutila and 3.8% (1/26) of the examined yellow-breasted bunting E. aureola. Phylogenetic analyses showed that N. caninum from different hosts and geographical origins are genetically diverse and can be further classified into two distinct groups. Our findings indicated that wild birds are potential source of N. caninum for other animals. To our knowledge, this is the first report of N. caninum infection in wild birds in China, which provides a foundation for the prevention and control of this parasite in China and elsewhere.

Experimental inoculation of Neospora caninum tachyzoites in eared doves (Zenaida auriculata)

Neospora caninum is an apicomplexan parasite distributed worldwide. Although a positive association between the presence of birds and abortions in cattle associated to N. caninum has been reported, the role of the birds in the epidemiologic cycle of the parasite is unknown. To the best knowledge, no experimental studies have evaluated N. caninum in the eared dove, Zenaida auriculata. Therefore, we aimed to determine whether Z. auriculat can act as intermediate host for N. caninum. Eighteen birds were divided into four groups, G1, G2, G3, and G4 (control); G1, G2 and G3 received 2 × 10⁶ tachyzoites of NC-1 strain via different routes: subcutaneous, intramuscular, and intraperitoneal, respectively. G4 composed of three birds. Serum samples were collected weekly, and one bird each from G1, G2 and G3 was euthanized on the 7th and 14th day post-inoculation (dpi). The remaining birds were euthanized after the 28th dpi. Tissues from the doves were evaluated using histopathological analysis, PCR and dog bioassay to detect the parasite. Dogs were fed with tissues from the birds and monitored for 30 days. Serum samples were collected weekly from the dogs for serological analysis, and feces samples were collected daily until the end of the experiment for coproparasitological examinations. No dove showed clinical signs of the infection; however, all of them seroconverted after the inoculation, with stronger immunological response in the G3 birds. The lung tissue of one G3 bird showed positive PCR results; it was euthanized on the 7th dpi, and an inflammatory infiltrate was observed in the lung and kidney from this dove. The dogs did not shed oocysts or seroconverted. Our results indicate that the intraperitoneal route induced infection in the doves; however, the parasite may have been eliminated by the host, and the doves may be resistant to chronic infection.

Prevalence and risk factors of Neospora caninum infection in ovine flocks of central-western Mexico

This study, carried out in 13 sheep flocks of central-western Mexico, aimed to identify the prevalence of anti-N. caninum antibodies, to develop a risk analysis of the infection and to estimate the prevalence of parasite DNA in blood. A total of 368 serum and blood samples were subjected to ELISA and PCR tests, respectively, and the association between the prevalence of antibodies and some management factors was estimated. The overall prevalence of anti-N. caninum antibodies was 13.5% [50/368; 95% confidence interval (CI) 10-17], ranging from 2.7 to 90% per flock, and 92% of the farms had seropositive animals. In ewes the prevalence was 14% (48/348, 95% CI 10-17) and in rams 10% (2/20; 95% CI 1- 33). The mean prevalence of Neospora DNA in blood was 27% (99/368, 95% CI 22-31), implying a range between 16 and 82%. In rams, the prevalence was 5% (1/20 95% CI 2-26), while in ewes it was 28% (98/348, 95% CI 23-33). The agreement between the tests was k = 0.19. The presence of other domestic animal species in the farms [odds ratio (OR) 4.4] and the consumption of placental debris, fetuses and stillborn lambs by dogs living in the farms (OR 5.8) were demonstrated to be risk factors.

Vertical transmission of Neospora caninum in bovine fetuses from a slaughterhouse in Brazil

Neospora caninum is considered as one of the main causes of reproductive failure in cattle. Vertical transmission is the main route of infection in the bovine host and plays an important role in maintaining the parasite in the herd. Molecular detection of N. caninum is important to determine the occurrence of the disease and to evaluate the genetic diversity of the parasite. The present study aimed at assessing the vertical transmission of N. caninum using molecular techniques to detect the parasite in tissue samples from bovine fetuses collected in a slaughterhouse in the state of São Paulo, Brazil. Seventy fetuses and 70 blood samples from pregnant cows were collected in a slaughtering line. Fresh samples of heart and brain tissue from fetuses were analyzed using molecular assays. Serum samples from fetuses and cows were subjected to an indirect fluorescent antibody test (IFAT) to detect antibodies against N. caninum. Nested PCR targeting the internal transcriber 1 (ITS1) region of the protozoan organism was used in the molecular testing. From the total of fetuses examined, 71.42% were positive for N. caninum by PCR. A higher number of heart samples (47.1%) were positive for the parasite using this technique. Antibodies against the protozoa were detected in 12.9% of serum samples of cows; 2.8% of fetuses were seropositive for this pathogen. Our results show that vertical transmission of N. caninum occurs in cattle from this region of Brazil, and that the use of different diagnostic techniques contributes to successful diagnosis of congenital transmission of the parasite in cattle.