Review of Neospora caninum and neosporosis in animals

In vitro and in vivo efficacy of aurintricarboxylic acid against Neospora caninum infection

Bovine neosporosis, a protozoal disease caused by Neospora caninum ( N. caninum), poses a significant threat to the global cattle industry, resulting in substantial economic losses that are difficult to quantify. The current lack of effective commercial vaccines and specific treatments highlights the urgent need for the development of potent drugs against N. caninum. In this study, we investigate the efficacy of aurintricarboxylic acid (ATA), a derivative of polyaromatic carboxylic acid, against N. caninum both in vitro and in vivo. Cell cytotoxicity is evaluated using CCK-8 kits. N. caninum proliferation within cells is assessed by qPCR analysis. Transmission electron microscopy (TEM) is employed to examine the ultrastructures of N. caninum tachyzoites. The efficacy of ATA against N. caninum infection is validated in a mouse model. Our findings indicate that ATA not only inhibits N. caninum proliferation but also reduces parasite loads within individual cells. Furthermore, ATA (20 and 40 μM) has immunomodulatory effects by downregulating the mRNA expressions of N . caninum-induced cytokines, including tumor necrosis factor-α (TNF-α), interferon (IFN-α, -β, and -γ), and β-defensin 5 (BNBD5). ATA treatment directly targets and eliminates N. caninum by disrupting its ultrastructure. The in vivo study confirms the potential of ATA to increase body weight, decrease parasite loads in the lungs and duodenum, and ameliorate the pathological effects induced by N . caninum infection in mice. In conclusion, this study represents the first evidence of the anti- N. caninum ability of ATA and provides compelling data to support its potential as a candidate for developing anti- N. caninum drugs.

Review of neosporosis: Disease insights and control approaches

The protozoan parasite Neospora caninum is a cause of infectious disease neosporosis. Neospora caninum is a major parasite affecting dogs and livestock worldwide. Neosporosis is a major cause of abortion in cattle, particularly in cattle raised in intensive agriculture. For diagnosis, the indirect enzyme-linked immunosorbent assay and immunofluorescence antibody test are employed. Neospora caninum goes through three different stages in its life cycle: sporozoites, tachyzoite, and bradyzoite. The primary method of N. caninum transmission in cattle is believed to be transplacental. Dogs are the definitive hosts of N. caninum, and the organisms in dogs and cattle are indistinguishable from one another. A high prevalence of N. caninum infection in animals was linked to the presence of dogs that tested positive for the parasite. Although exact statistics on the financial losses resulting from neosporosis in the global livestock sector are unavailable, losses are estimated to be millions of dollars. A number of medications have been investigated against N. caninum. In infected cell cultures, piritrexim, monensin, pyrimethamine, and trimethoprim stop N. caninum from growing intracellularly. Taking action to stop vertical transmission is the most practical way to control neosporosis in cattle herds, considering the current state of knowledge.

Serological survey of antibodies against Toxoplasma gondii and Neospora caninum in pigs from various regions of Poland

BACKGROUND

Pigs are prone to infections with several protozoa species. Although infection with Toxoplasma gondii rarely results in clinical symptoms in pigs, consuming pork-containing cysts represents a potential threat to human health, especially in immunocompromised individuals, pregnant women, and fetuses. It is estimated that around 2 billion people are infected with Toxoplasma gondii worldwide, making toxoplasmosis one of the most damaging zoonoses. Due to the coincidence of several factors, the meat from infected pigs can, however, frequently reach the consumer. In cattle, infection with Neospora caninum can cause considerable economic losses. The consequences of this infection for pigs remain unclear. However, infection in sows was linked with the development of some clinical signs, and transplacental transmission of the parasite was observed. Therefore, it should be considered a potential threat to pigs' health. Due to the above reasons, the data regarding the epidemiology of the mentioned parasites seems desirable. Since Poland represents one of the major pig producers in the European Union, and pork is the most commonly consumed type of meat, the present study aimed to determine the seroprevalence of Toxoplasma gondii and Neospora caninum in the Polish pig population. 1034 serum samples were collected from 16 commercial farms localised in 9 different provinces (voivodeships) of Poland from pigs belonging to the following age categories: piglets (259), weaners (220), fatteners (243), gilts (70), and sows (242) were subjected to ELISA assay with the use of commercially available kits.

RESULTS

The overall seroprevalence of Toxoplasma gondii was 11.3% (117/1034), and it was significantly higher in sows compared to other age categories (28.1%; p < 0.05). Regarding the province of Poland, the highest proportion of seropositive pigs was found in Kujawsko-Pomorskie and Podlaskie; meanwhile, in Łódzkie, Pomorskie, and Warmińsko-Mazurskie observed seroprevalence was 0%. Among tested samples, only one (1/1034; 0.097%) was positive for Neospora caninum antibodies, and it was collected from gilt maintained on the farm in Zachodniopomorskie.

CONCLUSIONS

This study updates the data on Toxoplasma gondii epidemiology in pigs reared in Poland, showing relative stability in the infection with this parasite. It also provides the first data on Neospora caninum circulation in the Polish pig population.

A longitudinal study on the effects of maternal and offspring seropositivity for Neospora caninum on birth weight, survival, reproductive performance and abortion in the offspring

Neospora caninum (N. caninum) is known as a source of economic losses due to causing abortion in cows. Additionally, it is well-established that this parasite can be vertically transmitted from the dam to the fetus through placenta. There is, however, little and contradictory information about whether transplacental infection of the offspring during prenatal period could impair its survival and reproductive performance during postnatal period, and the current study was conducted to address this issue. To this end, seropositivity of heifer dams (n = 430) and their offspring were ascertained at the age of 12 and 3 months, respectively. Based on the serologic results, there were four categories of female offspring including: 1) seronegative offspring born to seronegative dams (n = 183), 2) seropositive offspring born to seronegative dams (n = 59), 3) seronegative offspring born to seropositive dams (n = 29), and 4) seropositive offspring born to seropositive dams (n = 30). The birth weight, survival, reproductive performance and abortion of these offspring were studied from birth to culling. Maternal seropositivity was positively associated with offspring seropositivity (P < 0.05). Birth weight did not differ among offspring in various categories (P > 0.05). Seropositive offspring born to seronegative dams and seronegative offspring born to seropositive dams had inferior cumulative reproductive performance over life as compared to seronegative offspring born to seronegative dams (P < 0.05). Seropositive offspring had greater cumulative abortion risk and shorter lifespan than seronegative offspring regardless of their maternal serologic condition (P < 0.05). In conclusion, the present study showed that maternal seropositivity for N. caninum increased the risk of seropositivity in the offspring, and seropositive offspring had increased abortion risk and decreased longevity. Maternal seropositivity for N. caninum could have developmental effects on cumulative reproductive performance of the offspring that were not vertically infected.

Vertical and Horizontal Transmission of Neosporosis in Three Consecutive Pregnancies of Naturally Infected Pregnant Cows and the Effect of Vaccination on Abortion Rates

BACKGROUND/OBJECTIVES

Neosporosis is a major cause of abortions in cattle worldwide. Primary results showed that the administration of a live attenuated vaccine during the mid-pregnancy stage of naturally infected cows may assist in preventing abortions. In this study, the effect of vaccination was evaluated in five dairy herds, with a follow-up of three consecutive pregnancies and re-vaccination during the subsequent pregnancies of some of the cows.

METHODS

A total of 1059 heifers were serologically tested during their first pregnancy, and 260 and 21 of them were re-tested during their second and third pregnancies. Vaccination was administered to 193 of 420 cows with antibody titers of 1:800 or higher, and 23 of them were re-vaccinated. Data were collected regarding the outcome of each pregnancy, the number of inseminations required and removal from the herd. Vertical transmission was evaluated in 136 pre-colostral calves born from 29 vaccinated and 107 unvaccinated dams.

RESULTS

The total seroprevalence using a cutoff titer of 1:800 was 33.1, 36.5 and 85.7% during the three consecutive pregnancies. The antibody titers of individual cows fluctuated over time. Abortion rates and the rate of removal from the herd were significantly higher in seropositive cows. The rate of vertical transmission increased in correlation with the dam's antibody titer. Immunization resulted in lower abortion rates at two of the farms. Vaccine efficacy ranged from a negative effect to 54% at different farms, with an overall efficacy of 10.4%. The effect of vaccination on abortions, reproductive performance, antibody titers, vertical transmission and removal from the herd was not significant.

CONCLUSIONS

These results demonstrate varying vaccine efficacies among farms and suggest that neosporosis is a multifactorial disease that cannot be solely controlled by vaccination.

Socio-economic assessment of dog population management systems: a scoping review

Introduction

Dog Population Management (DPM) systems primarily aim to reduce the free-roaming dog population, improve the health and welfare of humans and dogs, and foster their peaceful coexistence. A key challenge to resource allocation and evidence-based policy making in DPM is the rare evaluation of the associated socio-economic impacts. This scoping review identifies, maps, and summarizes published parameters and methods on the socio-economic aspect of DPM systems.

Methods

Following PRISMA-ScR guidelines, and with a protocol registered on the Open Science Framework, this review explores (i) types of DPM services, (ii) types of parameters (intervention, impact, monetized, or non-monetized), (iii) methodological approaches (such as cost-benefit or cost-effectiveness analysis), and (iv) gaps and challenges in socio-economic DPM assessments. Relevant publications were identified through a systematic search of PubMed, Embase, Scopus, and Web of Science.

Results

Our review identified 14 out of more than 7,200 studies indicating the limitation of socio-economic data associated with DPM systems. The studies revealed diverse approaches to DPM, sterilization being the most frequently used service, often combined with vaccination and community awareness. Culling was also used by several studies as a DPM intervention, though considered unethical. The review highlighted a range of intervention, impact, and monetary parameters to evaluate the economics of DPM systems, demonstrating the complexity and varied scope of the services. Varied categorizations of the dog population were observed, making comparative evaluation challenging. Economic methods such as cost-benefit and cost-effectiveness analyses were observed, identifying several associated economic metrics. Studies highlighted gaps mostly related to data availability and accessibility.

Conclusion

The limitations of socio-economic data arise from a lack of standardized methodologies across regions and contexts and limited data collection efforts. Prioritizing systematic collection of data on costs, benefits and social impacts allows for a more robust analysis of DPM systems. Developing tools and standardized reporting methods would further facilitate consistent evaluation of impacts, efficient resource allocation and evidence-based policy making to implement the most cost-effective DPM systems.

Systematic review registration

DOI: 10.17605/OSF.IO/NHE3X.

Seroepidemiological study of Neospora caninum in equids using c-ELISA in Erbil Province, Iraq

Equine neosporosis is an intracellular protozoan disease with a global distribution, affecting a diverse range of warm-blooded animals. Neospora caninum Dubey, Carpenter, Speer, Topper et Uggla, 1988 is associated with foetal loss, neurological disease and abortion in equids. No information was available regarding equine N. caninum infection among equids in Iraq. Thus, the aim of this study was to determine the prevalence rate of N. caninum in equines by using a competitive enzyme-linked immunosorbent assay (c-ELISA). A total of 329 blood samples randomly selected from equines, comprising 268 horses and 61 donkeys were examined. The seroprevalence rate of N. caninum was determined as 46% (28/61) for donkeys and 24% (64/268) for horses. The prevalence of N. caninum indicated a significantly higher risk of infection in donkeys compared to horses (P < 0.001). However, the odds of N. caninum infection in draught equids were 8.2 times greater than other equids with a significant difference (P < 0.001). The current study revealed no significant differences in the prevalence of N. caninum across various genders, breeds, clinical statuses, disease histories and among equids that had contact with dogs. While outdoor feeding and mixed (grazing), showed a significant difference (P = 0.003) and (P = 0.75), respectively, in the presence of antibodies against N. caninum compared to indoor feeding (stable). Moreover, the odds of infection in equids with a history of late abortion were 4.8 times higher than those without such a history of abortion (2.20-10.56) with statistical significance (P < 0.001).

Characterization and functional analysis of Toxoplasma Golgi-associated proteins identified by proximity labeling

Toxoplasma gondii possesses a highly polarized secretory pathway that contains both broadly conserved eukaryotic organelles and unique apicomplexan organelles, which play essential roles in the parasite's lytic cycle. As in other eukaryotes, the T. gondii Golgi apparatus sorts and modifies proteins prior to their distribution to downstream organelles. Many of the typical trafficking factors found involved in these processes are missing from apicomplexan genomes, suggesting that these parasites have evolved unique proteins to fill these roles. Here, we identify a Golgi-localizing protein (ULP1), which is structurally similar to the eukaryotic trafficking factor p115/Uso1. We demonstrate that depletion of ULP1 leads to a dramatic reduction in parasite fitness that is the result of defects in microneme secretion, invasion, replication, and egress. Using ULP1 as bait for TurboID proximity labeling and immunoprecipitation, we identify 11 more Golgi-associated proteins and demonstrate that ULP1 interacts with the T. gondii-conserved oligomeric Golgi (COG) complex. These proteins include both conserved trafficking factors and parasite-specific proteins. Using a conditional knockdown approach, we assess the effect of each of these 11 proteins on parasite fitness. Together, this work reveals a diverse set of T. gondii Golgi-associated proteins that play distinct roles in the secretory pathway. As several of these proteins are absent outside of the Apicomplexa, they represent potential targets for the development of novel therapeutics against these parasites.

IMPORTANCE

Apicomplexan parasites such as Toxoplasma gondii infect a large percentage of the world's population and cause substantial human disease. These widespread pathogens use specialized secretory organelles to infect their host cells, modulate host cell functions, and cause disease. While the functions of the secretory organelles are now better understood, the Golgi apparatus of the parasite remains largely unexplored, particularly regarding parasite-specific innovations that may help direct traffic intracellularly. In this work, we characterize ULP1, a protein that is unique to parasites but shares structural similarity to the eukaryotic trafficking factor p115/Uso1. We show that ULP1 plays an important role in parasite fitness and demonstrate that it interacts with the conserved oligomeric Golgi (COG) complex. We then use ULP1 proximity labeling to identify 11 additional Golgi-associated proteins, which we functionally analyze via conditional knockdown. This work expands our knowledge of the Toxoplasma Golgi apparatus and identifies potential targets for therapeutic intervention.

Serological and molecular detection of Toxoplasma gondii and Neospora caninum in ruminants from Somalia

Toxoplasma gondii and Neospora caninum infect a wide range of domestic and wild animals, including humans, in the case of T. gondii, and cause economic losses in livestock due to abortion and neonatal mortality. In Somalia, zoonotic diseases are concerning due to cultural practices and livestock's economic importance, but surveillance is limited. This study aimed to determine the seroprevalence and molecular prevalence of T. gondii and N. caninum in Somali sheep, goats, and cattle. A cross-sectional study was conducted between December 2018 and January 2020 in Benadir and Lower Shabelle regions of Somalia. Blood samples were collected from 128 cattle, 184 goats, and 46 sheep. Serum samples were tested for anti-T. gondii and anti-N. caninum antibodies using IFAT, and PCR was performed on extracted DNA to detect T. gondii and N. caninum DNA. Overall, 106/358 (29.6%) animals tested positive for anti-T. gondii antibodies, with the highest prevalence in sheep (62.5%), followed by goats (30.4%) and cattle (15.6%) (P < 0.001). For anti-N. caninum antibodies, 13/358 (3.6%) animals tested positive, with cattle showing the highest prevalence (6.2%), followed by goats and sheep (both 2.2%). Co-seropositivity for both antibodies was found in cattle and sheep. Molecular detection of T. gondii DNA revealed a prevalence of 9/358 (2.5%), primarily in sheep (15.2%) and cattle at 1.6% while all goat samples tested negative. No samples were positive for the N. caninum Nc5 gene. This study reveals T. gondii and N. caninum prevalence in Somali ruminants, highlighting the need for better surveillance and control.

Occurrence of antibodies and epidemiological significance of Toxoplasma Gondii and Neospora caninum infections in canine populations of Laguna, State of Santa Catarina

Toxoplasma gondii and Neospora caninum are two species of protozoa that belong to the Apicomplexa phylum and are distributed worldwide. T. gondii is one of the most extensively studied parasites due to its significant health implications. In this study, an investigation on the occurrence of T. gondii and N. caninum antibodies in dogs from a municipality on the southern coast of Santa Catarina, Brazil, and its associated risk factors were conducted. Blood samples were collected from 238 dogs, and a questionnaire was used to gather relevant information about the dogs, including their age, gender, breed, housing and habits. The serum samples were then subjected to indirect fluorescent antibody test (IFAT) using a cutoff of 1:64 and 1:50 to detect antibodies against T. gondii and N. caninum, respectively. The study's findings revealed that the frequency of T. gondii was 23.1% (55/238), and no factors associated with infection in these animals were identified. However, the frequency of N. caninum was 4.2% (10/238), and the study identified the type of housing and environment in which the dogs lived as the factors that were associated with the infection. Stray animals and those that lived exclusively outdoors had a greater frequency of N. caninum. These results indicate that dogs from Laguna, Santa Catarina, Brazil, are exposed to T. gondii and N. caninum. As such, further studies are necessary to enhance the understanding of the nature of these protozoan infections in the municipality.

First report of Neospora caninum from aborted fetuses of cattle, sheep, and goats in Bangladesh

Objectives

The study aimed to detect Neospora caninum by nested PCR (nPCR) in aborted fetuses of cattle, sheep, and goats in Bangladesh.

Materials and Methods

The head portion of each aborted fetus (111) was dissected at each sampling site and transferred to the laboratory in an ice box. Data on risk factors associated with N. caninum infection were simultaneously collected. Deoxyribonucleic acid was extracted from brain tissue to perform nPCR targeting the internal transcribed spacer 1 (ITS1) ribosomal DNA (rDNA) gene of N. caninum and sequencing was performed from the representative positive samples.

Results

By nPCR, N. caninum was found in 16.0% of aborted fetuses of cattle, followed by sheep (14.81%) and goats (11.78%). The highest prevalence was found in aborted fetuses of animals during the second trimester (27.78%) of pregnancy aged 2 to 4 years (18.75%). Obtained sequences showed they were completely matched with N. caninum ITS1 rDNA gene deposited in GenBank. Univariate analysis demonstrated that pregnancy stages (trimesters), abortion history of the animals, and access to dogs in animal farms were significantly (p ≤ 0.05) correlated with N. caninum infection.

Conclusion

This study represents the first investigation into the molecular detection, phylogenetic characterization, and analysis of risk factors associated with N. caninum in livestock in Bangladesh. According to the research findings, N. caninum infection may have a role in abortion cases and the ensuing financial losses in the nation's livestock industry.

Alveolin proteins in the Toxoplasma inner membrane complex form a highly interconnected structure that maintains parasite shape and replication

Apicomplexan parasites possess several specialized structures to invade their host cells and replicate successfully. One of these is the inner membrane complex (IMC), a peripheral membrane-cytoskeletal system underneath the plasma membrane. It is composed of a series of flattened, membrane-bound vesicles and a cytoskeletal subpellicular network (SPN) comprised of intermediate filament-like proteins called alveolins. While the alveolin proteins are conserved throughout the Apicomplexa and the broader Alveolata, their precise functions and interactions remain poorly understood. Here, we describe the function of one of these alveolin proteins in Toxoplasma, IMC6. Disruption of IMC6 resulted in striking morphological defects that led to aberrant invasion and replication but surprisingly minor effects on motility. Deletion analyses revealed that the alveolin domain alone is largely sufficient to restore localization and partially sufficient for function. As this highlights the importance of the IMC6 alveolin domain, we implemented unnatural amino acid photoreactive crosslinking to the alveolin domain and identified multiple binding interfaces between IMC6 and 2 other cytoskeletal IMC proteins-IMC3 and ILP1. This provides direct evidence of protein-protein interactions in the alveolin domain and supports the long-held hypothesis that the alveolin domain is responsible for filament formation. Collectively, our study features the conserved alveolin proteins as critical components that maintain the parasite's structural integrity and highlights the alveolin domain as a key mediator of SPN architecture.

Frequency of Besnoitia besnoiti and Neospora caninum antibodies in cattle and small ruminants from greater Cairo and Beni Suef governorates, Egypt

Livestock industry is a pivotal sector for providing food, work places and monetary support for Egyptian people. Besnoitia besnoiti and Neospora caninum are protozoan parasites that are responsible for significant economic losses in ruminants, particularly in cattle. Besnoitia besnoiti can cause fertility problems and a general loss in productivity, while N. caninum is a major cause of abortion and neonatal abnormalities in infected animals. There is little information on the existence of these protozoa in Egypt, thus we conducted this study to reveal the current situation in cattle (n = 264), sheep (n = 151), and goats (n = 25). Serum samples were collected from governorates of Cairo, Giza, and Beni Suef, representing the most densely populated regions in Egypt. Using commercial ELISAs, an overall estimation among all tested animals (n = 440) revealed 7.7%, 13.2%, and 0.9% as seropositive rates for B. besnoiti, N. caninum, and mixed infection, respectively. Animal species (cattle vs sheep vs goat) and age of cattle (less than vs >1 year old) were analyzed as risk factors for infection. Regarding B. besnoiti, the seroprevalence was significantly higher in cattle than in sheep and goats and in adult cattle than calves. For N. caninum infection, no significant differences were recorded, although the seropositive rates were higher in cattle, and in adult cattle. This study provides the first seroprevalence data for B. besnoiti in all surveyed animals in the regions included, and in sheep and goats from Egypt, and supports the current knowledge for the occurrence of N. caninum in Egypt.

A first insight into seropositivity of Neospora caninum and associated risk factors in free-roaming dogs from Ecuador

Neosporosis is a worldwide parasitic disease caused by the protozoan Neospora caninum. It can cause economic losses to farmers due to its relationship with abortions and neonatal mortality in cows. Dogs play a key role in its spread as they are considered definitive hosts. In this study, we determined for the first time the seropositivity of N. caninum infection in dogs from Ecuador and evaluated potential risk factors. A total number of 339 free-roaming dogs from the three main regions of Ecuador (Coastal, Andean, and Amazonian regions) were included in the study and classified either as urban or rural dogs. Serum samples were collected from November 2018 to May 2019, and analyzed with a commercial ELISA test. An overall seropositivity of 6.8 % (CI: 95 %, 2.8 % - 11.7 %) was found in N. caninum infection with no statistical differences among regions or urban/rural dogs. This is the first surveillance of N. caninum in Ecuador, confirming a country-wide distribution of this pathogen. Considering the large populations of free-roaming dogs in Ecuador, a One Health approach for surveillance and managing N. caninum in dogs is needed to protect either livestock or wildlife.

BCC0 collaborates with IMC32 and IMC43 to form the Toxoplasma gondii essential daughter bud assembly complex

Toxoplasma gondii divides by endodyogeny, in which two daughter buds are formed within the cytoplasm of the maternal cell using the inner membrane complex (IMC) as a scaffold. During endodyogeny, components of the IMC are synthesized and added sequentially to the nascent daughter buds in a tightly regulated manner. We previously showed that the early recruiting proteins IMC32 and IMC43 form an essential daughter bud assembly complex which lays the foundation of the daughter cell scaffold in T. gondii. In this study, we identify the essential, early recruiting IMC protein BCC0 as a third member of this complex by using IMC32 as bait in both proximity labeling and yeast two-hybrid screens. We demonstrate that BCC0's localization to daughter buds depends on the presence of both IMC32 and IMC43. Deletion analyses and functional complementation studies reveal that residues 701-877 of BCC0 are essential for both its localization and function and that residues 1-899 are sufficient for function despite minor mislocalization. Pairwise yeast two-hybrid assays additionally demonstrate that BCC0's essential domain binds to the coiled-coil region of IMC32 and that BCC0 and IMC43 do not directly interact. This data supports a model for complex assembly in which an IMC32-BCC0 subcomplex initially recruits to nascent buds via palmitoylation of IMC32 and is locked into the scaffold once bud elongation begins by IMC32 binding to IMC43. Together, this study dissects the organization and function of a complex of three early recruiting daughter proteins which are essential for the proper assembly of the IMC during endodyogeny.

The seasonality as a relevant aspect to be considered for differential diagnosis of Trypanosoma vivax infection and co-infections in female cattle

Bovine Trypanosomiasis and other infectious diseases cause relevant loss for the livestock industry impacting productive/reproductive indices. This study intended to better understand the frequency, seasonality, and profile of infections associated with Bovine Trypanosomiasis. A total of 1443 serum samples were screened for T. vivax infection and other infectious diseases: Neosporosis, Leptospirosis, Bovine Leukosis Virus infection/(BLV), Infectious Bovine Rhinotracheitis/(IBR) or Bovine Viral Diarrhea/(BVD). Distinct methods were used for screening and diagnosis: immunofluorescence assay (Trypanosomiasis), ELISA (Neosporosis,BLV,IBR,BVD) and microscopic agglutination test (Leptospirosis). Our findings demonstrated that the seropositivity for Trypanosomiasis=57% was similar to Neosporosis=55%, higher than Leptospirosis=39% and BVL=34%, but lower than IBR=88% and BVD=71%. The seropositivity for Trypanosomiasis was higher in the autumn and lower in the winter. Regardless the season, the IBR seropositivity (min=73%;max=95%) was higher than Trypanosomiasis (min=48%;max=68%). Moreover, Neosporosis (min=71%;max=100%) and BVD (min=65%;max=76%) were more frequent than Trypanosomiasis in the summer, winter and spring. The diagnosis outcome revealed that Trypanosomiasis&IBR=43% and Trypanosomiasis&Neosporosis=35% were the most frequent co-infections with higher seropositivity in the autumn (58%) and summer (80%), respectively. Noteworthy, high seropositivity to Trypanosomiasis&BVD was registered in the autumn (46%). Together, our data re-enforce the relevance of differential diagnosis between Trypanosomiasis with other bovine infectious diseases and that differences in the seasonality profile is a relevant aspect to be considered while selecting the differential diagnosis to be applied.

Neospora caninum antibodies in bulk tank milk from dairy cattle herds in Italy in relation to reproductive and productive parameters and spatial analysis

Among the available diagnostic techniques, antibody detection in bulk tank milk (BTM) represents a useful tool to estimate and monitor Neospora caninum herd prevalence. To evaluate the prevalence of N. caninum and the effect of parasite infection on herd performances, BTM samples collected from 586 dairy herds located in one of the largest dairy production areas in Italy (Lombardy) were analyzed by an indirect ELISA to detect anti-N. caninum specific antibodies. Generalized linear models (GLMs) were developed. A purely spatial analysis scanning for clusters with high or low rates for N. caninum using the Bernoulli model was performed. A maximum entropy approach was used to estimate the probability of distribution of the parasite based on occurrence records together with environmental variables. Overall, 180 herds resulted positive for N. caninum antibodies on bulk tank milk (P = 30.7 %). A higher risk of seropositivity was evidenced in the provinces of Milano, Cremona, Brescia, and Bergamo (P = 32-40 %); a lower risk was evidenced in Lodi, Pavia, and Mantova (P = 13-24 %). A higher risk of seropositivity was revealed for small-medium farms (101-300 animals) (O.R.=2.8) and for older animals with more than 4 years (O.R.=4.4). Regarding the effect of N. caninum infection on herd performances, the number of inseminations for conception was higher (> 3 inseminations), and the period from calving to conception was longer (> 150 days) for positive farms (O.R.=2.0 and O.R.=2.3, respectively); besides, lower head daily milk production (<20 kg and 21-25 kg) and mature equivalent milk yield (<11,000), and somatic cell counts higher than 300,000 cells/ml were observed for N. caninum positive herds (O.R.=0.4, O.R.=0.4 and O.R.=1.9 respectively). The geographical distribution of N. caninum positive farms with the highest level of probability covers the central sector of the Po Plain where a significant cluster for high risk of parasite infection was shown by spatial scan statistic and Maximum entropy ecological niche modelling. A further significant cluster of low risk occurred in the southern. The climatic and environmental variables with the highest training gain when used in isolation resulted altitude, land use/land cover, and other variables related to temperature and precipitation. Neosporosis is widely distributed in Italian dairy herds and an impact of the parasite on herd performances could be hypothesized. Even if the role of N. caninum in alterations of reproductive and productive parameters should be further explored, veterinarians and farmers should be aware of neosporosis, and control plans should be adopted.

Characterization and functional analysis of Toxoplasma Golgi-associated proteins identified by proximity labelling

Toxoplasma gondii possesses a highly polarized secretory pathway that contains both broadly conserved eukaryotic organelles and unique apicomplexan organelles which play essential roles in the parasite's lytic cycle. As in other eukaryotes, the T. gondii Golgi apparatus sorts and modifies proteins prior to their distribution to downstream organelles. Many of the typical trafficking factors found involved in these processes are missing from apicomplexan genomes, suggesting that these parasites have evolved unique proteins to fill these roles. Here we identify a novel Golgi-localizing protein (ULP1) which contains structural homology to the eukaryotic trafficking factor p115/Uso1. We demonstrate that depletion of ULP1 leads to a dramatic reduction in parasite fitness and replicative ability. Using ULP1 as bait for TurboID proximity labelling and immunoprecipitation, we identify eleven more novel Golgi-associated proteins and demonstrate that ULP1 interacts with the T. gondii COG complex. These proteins include both conserved trafficking factors and parasite-specific proteins. Using a conditional knockdown approach, we assess the effect of each of these eleven proteins on parasite fitness. Together, this work reveals a diverse set of novel T. gondii Golgi-associated proteins that play distinct roles in the secretory pathway. As several of these proteins are absent outside of the Apicomplexa, they represent potential targets for the development of novel therapeutics against these parasites.

Importance

Apicomplexan parasites such as Toxoplasma gondii infect a large percentage of the world's population and cause substantial human disease. These widespread pathogens use specialized secretory organelles to infect their host cells, modulate host cell functions, and cause disease. While the functions of the secretory organelles are now better understood, the Golgi apparatus of the parasite remains largely unexplored, particularly regarding parasite-specific innovations that may help direct traffic intracellularly. In this work, we characterize ULP1, a protein that is unique to parasites but shares structural similarity to the eukaryotic trafficking factor p115/Uso1. We show that ULP1 plays an important role in parasite replication and demonstrate that it interacts with the conserved oligomeric Golgi (COG) complex. We then use ULP1 proximity labelling to identify eleven additional Golgi-associated proteins which we functionally analyze via conditional knockdown. This work expands our knowledge of the Toxoplasma Golgi apparatus and identifies potential targets for therapeutic intervention.

The seroprevalence and risk factors for exposure to Neospora caninum and Neospora hughesi in Ontario broodmares

The seroprevalence and risk factors for exposure to Neospora caninum and Neospora hughesi in broodmares in Ontario were investigated. Sixty of the 219 (27.4%) study broodmares were seropositive for N. caninum and 65/219 (29.7%) for N. hughesi with cut-offs of ≥1:40 and ≥1:160, respectively. Thirty-one of 63 participating farms (49.2%) had at least 1 broodmare seropositive for N. caninum. Thirty-three of the 63 (52.4%) participating farms had at least 1 broodmare positive for N. hughesi. Risk factors for N. caninum included presence of farm dogs (OR = 6.70; 95% CI = 2.14-20.97; p = 0.001), and high stocking density (OR = 2.83; 95% CI = 1.27-6.30; p = 0.011). Presence of livestock, excluding cattle, was associated with reduced risk of exposure (OR = 0.17; 95% CI = 0.06-0.53; p = 0.002). The only risk factor for exposure to N. hughesi was feeding hay on the ground in the paddock (OR = 4.31; 95% CI = 1.65-11.22; p = 0.003). This study demonstrated widespread exposure to Neospora spp. in broodmares in Ontario.

Construction of luciferase-expressing Neospora caninum and drug screening

BACKGROUND

Neospora caninum is an apicomplexan parasite that is particularly responsible for abortions in cattle and neuromuscular disease in dogs. Due to the limited effectiveness of currently available drugs, there is an urgent need for new therapeutic approaches to control neosporosis. Luciferase-based assays are potentially powerful tools in the search for antiprotozoal compounds, permitting the development of faster and more automated assays. The aim of this study was to construct a luciferase-expressing N. caninum and evaluate anti-N. caninum drugs.

METHODS

Luciferase-expressing N. caninum (Nc1-Luc) was constructed using clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (CRISPR/Cas9). After testing the luciferase expression and phenotype of the Nc1-Luc strains, the drug sensitivity of Nc1-Luc strains was determined by treating them with known positive or negative drugs and calculating the half-maximal inhibitory concentration (IC50). The selective pan-rapidly accelerated fibrosarcoma (pan-RAF) inhibitor TAK-632 was then evaluated for anti-N. caninum effects using Nc1-Luc by luciferase activity reduction assay and other in vitro and in vivo studies.

RESULTS

The phenotypes and drug sensitivity of Nc1-Luc strains were consistent with those of the parental strains Nc1, and Nc1-Luc strains can be used to determine the IC50 for anti-N. caninum drugs. Using the Nc1-Luc strains, TAK-632 showed promising activity against N. caninum, with an IC50 of 0.6131 μM and a selectivity index (SI) of 62.53. In vitro studies demonstrated that TAK-632 inhibited the invasion, proliferation, and division of N. caninum tachyzoites. In vivo studies showed that TAK-632 attenuated the virulence of N. caninum in mice and significantly reduced the parasite burden in the brain.

CONCLUSIONS

In conclusion, a luciferase-expressing N. caninum strain was successfully constructed, which provides an effective tool for drug screening and related research on N. caninum. In addition, TAK-632 was found to inhibit the growth of N. caninum, which could be considered as a candidate lead compound for new therapeutics for neosporosis.

Establishment of an ultrasensitive and visual detection platform for Neospora caninum based-on the RPA-CRISPR/Cas12a system

Neospora caninum is a protozoan parasite that causes neosporosis in cattle, and leads to a high rate of abortion and severe financial losses. Rapid and accurate detection is particularly important for preventing and controlling neosporosis. In our research, a highly effective diagnostic technique based on the RPA-CRISPR/Cas system was created to successfully identify N. caninum against the Nc5 gene, fluorescent reporter system and the lateral flow strip (LFS) biosensor were exploited to display results. The specificity and sensitivity of the PRA-CRISPR/Cas12a assay were evaluated. We discovered that it was highly specific and did not react with any other pathogens. The limit of detection (LOD) for this technology was as low as one parasite per milliliter when employing the fluorescent reporter system, and was approximately ten parasites per milliliter based on the LFS biosensor and under blue or UV light. Meanwhile, the placental tissue samples were detected by our RPA-CRISPR/Cas12a detection platform were completely consistent with that of the nested PCR assay (59.4 %, 19/32). The canine feces were detected by our RPA-CRISPR/Cas12a detection platform were completely consistent with that of the nested PCR assay (8.6 %, 6/70). The RPA-CRISPR/Cas12a detection procedure was successfully finished in within 90 min and offers advantages of high sensitivity and specificity, speed and low cost. The technique was better suitable for extensive neosporosis screening in non-laboratory and resource-constrained locations. This study provided a new strategy for more rapid and portable identification of N. caninum.

Evaluation of Immunodiagnostic Performances of Neospora caninum Peroxiredoxin 2 (NcPrx2), Microneme 4 (NcMIC4), and Surface Antigen 1 (NcSAG1) Recombinant Proteins for Bovine Neosporosis

Bovine neosporosis is among the main causes of abortion in cattle worldwide, causing serious economic losses in the beef and dairy industries. A highly sensitive and specific diagnostic method for the assessment of the epidemiology of the disease, as well as it surveillance and management, is imperative, due to the absence of an effective treatment or vaccine against neosporosis. In the present study, the immunodiagnostic performance of Neospora caninum peroxiredoxin 2 (NcPrx2), microneme 4 (NcMIC4), and surface antigen 1 (NcSAG1) to detect IgG antibodies against N. caninum in cattle were evaluated and compared with that of the indirect fluorescent antibody test (IFAT). The results revealed that NcSAG1 had the highest sensitivity and specificity, with values of 88.4% and 80.7%, respectively, followed by NcPrx2, with a high sensitivity of 87.0% but a low specificity of 67.0%, whereas NcMIC4 showed sensitivity and specificity of 84.1% and 78.9%, respectively, when compared with IFAT. A high degree of agreement was observed for NcSAG1 (k = 0.713) recombinant protein, showing the highest diagnostic capability, followed by NcMIC4 (k = 0.64) and NcPrx2 (k = 0.558). The present study demonstrates that NcSAG1 is helpful as an antigen marker and also demonstrates the potential immunodiagnostic capabilities of NcPrx2 and NcMIC4, which could serve as alternative diagnostic markers for detecting N. caninum infection in cattle. These markers may find utility in future treatment management, surveillance, and risk assessment of neosporosis in livestock or other animal host species. Further research should be directed toward understanding the in vivo immune response differences resulting from immunization with both recombinant proteins.

Serological and molecular detection of Toxoplasma gondii and Neospora caninum in free-ranging rats from Nagpur, India

Toxoplasma gondii and Neospora caninum are cyst-forming coccidian parasites that infect both wild and domestic non-felids as intermediate hosts, with rodents serving as important reservoir hosts during their life cycles. This study was aimed at investigating T. gondii and N. caninum infections and identifying factors favouring T. gondii infection in free-ranging rats from India. A total of 181 rodents were trap-captured, and blood and brain samples were subsequently collected for serological and molecular examination of T. gondii and N. caninum. Antibodies against T. gondii and N. caninum were detected by MAT/NAT and IFAT in 13.8% (25/181) and 1.65% (3/181) of rodents, respectively. All three N. caninum samples positive by NAT/IFAT were also positive for ELISA, while for T. gondii, 19 of 25 MAT/IFAT positive samples were also positive for ELISA. The antibody titers (MAT/NAT/IFAT) of rodents seropositive for T. gondii ranged from 25 to 400, while those of rats seropositive for N. caninum ranged from 25 to 100. Also, using PCR, DNA from T. gondii (B1 gene) and N. caninum (NC5 gene) was found in 2.76% (5/181) of brain samples and 0.55% (1/181) of brain samples. All PCR positive samples were also seropositive. No mixed infections were observed in the serological and molecular detections. A Chi-square analysis revealed that older rats and rats living in urban areas are significantly associated with T. gondii infection; however, rodent species, gender, location, habitat types, and seasonality were statistically nonsignificant. Overall, this study demonstrated that T. gondii was widely distributed while N. caninum was less prevalent among free-ranging rats in the studied area.

Transcriptome profiling of Madin-Darby bovine kidney cells uncover differences in the susceptibility of cattle to Toxoplasma gondii and Neospora caninum

Toxoplasma gondii and Neospora caninum are two major apicomplexan protozoan parasites with heteroxenous life cycles and worldwide distributions. The transplacental transmission of N. caninum causes bovine abortion, which resulting in serious economic losses to the dairy industry. Although T. gondii was also reported to cause abortions in pregnant woman and small ruminants, scarce cases about the symptom to the host cattle and the causality remains unknown. In this study, transcriptome analysis of Madin Darby bovine kidney (MDBK) cells infected with T. gondii and N. caninum was performed to uncover the differences in susceptibility of cattle to the two parasites. The results showed that 256 and 2225 differentially expressed genes (DEGs) were detected in cells infected with N. caninum and T. gondii, respectively. Moreover, significant biological differences were revealed by the functional analysis including GO and KEGG enrichment. One serpin peptidase inhibitor (SEPRINA14), which is associated with immunosuppression during pregnancy, was found to significantly decrease in cells infected with N. caninum and increase in cells infected with T. gondii-infected cells. Pattern recognition receptors TLR3 and NOD2 were also significantly upregulated in N. caninum-infected MDBK cells, but not in T. gondii. They could induce an increased inflammatory response leading to severe tissue damage. In addition, the interleukin 12 receptor subunit beta 2 (IL12β2), which plays an essential role in Th1 and Th2 cell differentiation and inflammatory bowel disease, was also markedly upregulated in the N. caninum infected cells, which led to an imbalance in the Th1 and Th2 cells by promoting the Th1 cellular response. Altogether, our findings recognized a new understanding on the differences between T. gondii and N. caninum infection of MDBK cells, where SEPRINA14, TLR3, NOD2, and IL12β2 may be the key genes that affect the difference in susceptibility of cattle to T. gondii and N. caninum, especially in pregnant animals. This study provides more clues as to why N. caninum is more likely to cause abortions in cattle.

Molecular detection and phylogenic characterization of Neospora caninum in naturally infected sheep in Alborz and Qazvin provinces, the north of the central region of Iran

Neospora caninum is a protozoan coccidian parasite that can act as a cause of abortion in sheep. The aim of this study was to investigate the presence of this parasitic agent and its role in causing abortion in sheep of Iran. Between June 2019 and February 2022, 100 samples [brain (n = 39), placenta (n = 8), embryonic membrane (n = 7), cotyledon (n = 7), umbilical cord (n = 2), homogenate mixture of tissues (heart, liver, spleen and digestive track) (n = 37)] that were collected following the necropsies of 39 aborted ovine fetuses from different parts of the Alborz and Qazvin provinces, the north of the central region of Iran were employed for DNA extraction. Nc-5 was selected as the target gene sequence for amplification of DNA by using four pairs of primers in two semi-nested PCR. Samples considered positive for the presence of the NC-5 gene were examined to further confirm the presence of the ITS1 gene. Sequence of NC-5 gene was detected from the 27 tissue samples of 23 aborted ovine fetuses. The ITS1 gene sequence was detected in all of the 27 tissue samples that were positive for the NC-5 gene analysis. Brain tissue was the most studied tissue, and the highest number of positive cases was observed in this tissue. The present study updated the situation of ovine neosporosis in the central region of Iran and confirmed the presence of the N. caninum among sheep flocks' abortion.

Seroprevalence and risk factors for Neospora spp. infection in equine in Egypt

Neospora infections in equine are associated with reproductive disorders and neurological diseases. Nevertheless, Egypt has no epidemiological information on this parasite in equine. This study determined the prevalence of Neospora spp. infection in 325 equines from three Egyptian governorates located at Northern Egypt using cELISA. The prevalence of antibodies against Neospora spp. was 19% (95% CI: 14.09-25.05) in horse, 34.1% (95%CI: 24.92-44.69) in donkey and 26.7% (95% CI: 15.97-41.04) in mule. In comparison to horse, donkey had a considerably higher chance of contracting Neospora spp. infection (OR = 1.80, 95% CI: 0.78-4.13; P = 0.016). The risk was also higher in freely grazing animals (OR = 3.49, 95% CI: 0.95-12.78; P = 0.059). Moreover, yearling animals (12-24 months) (OR = 5.03, 95% CI: 1.51-16.80; P = 0.009) and those with natural breeding (OR = 11.80, 95% CI: 3.24-42.99, P < 0.0001) and a history of early abortion (OR = 7.04, 95% CI: 3.01-16.47; P < 0.0001) also showed a greater risk of seropositivity. The risk of Neospora infection increased significantly in equines contacted with dogs (OR = 5.16, 95% CI: 1.76-15.10; P = 0.003). This the first serological study to determine the seroprevalence of Neospora spp. in equine in Egypt. Further studies are necessary to identify the species of Neospora and to understand the role of above-mentioned risk factors in spreading of infection.

Prevalence of intestinal parasites in street dogs (Canis lupus familiaris) with highlights on zoonosis in Lalitpur, Nepal

BACKGROUND

The presence of intestinal parasites influences the growth and well-being of canids. Additionally, infected dogs and their faeces with considerably higher eggs/oocysts released per gram (epg/opg) of zoonotic parasites contribute to parasitic spillover to humans, domestic animals and sympatric wildlife.

OBJECTIVES

The current study aimed to reveal the prevalence of intestinal parasites (protozoa and helminths) and to list the zoonotically significant parasites in free-roaming street dogs in Lalitpur Metropolitan City, Nepal.

METHODS

Fresh faecal samples (n = 332) were collected from feral dogs of varying ages and sexes and transported to the research laboratory. The copro microscopic examination was carried out via direct wet mount, formalin ethyl acetate sedimentation, saturated salt flotation, acid-fast staining and sporulation techniques.

RESULTS

Coproscopy revealed an overall 95.7% (318/332) prevalence rate with 23 diverse species of intestinal parasites (10 protozoa and 13 helminths). Among them, 5 protozoa and 11 helminths possessed zoonotic potential, and their overall prevalence was 92.5%. Helminth's overall prevalence was double that of the protozoa (87.7% vs. 43%). Polyparasitism was dominant over mono parasitism (79.5% vs. 16.3%), and co-infection of up to seven species of parasites at a time was recorded.

CONCLUSIONS

Urban street dogs harboured a higher prevalence of intestinal parasites that varied with age and sex. Since most of the reported parasites are zoonotic, dog density and parasitic richness indicate a greater spillover risk to humans and domestic animals. Furthermore, this study also provides appropriate 'baseline' data for assessing effective control measures against parasitic infestations among street dogs and controlling their transmission to humans.

Serosurvey of selected reproductive pathogens in domestic ruminants from Upper Egypt

Toxoplasmosis, neosporosis, and Q fever are among the most important abortifacient diseases in ruminants worldwide. These diseases result in huge economic losses in livestock besides the fact that some of are of public health concern. The present study aimed to update the data about the current seroepidemiological situation of these diseases in Upper Egypt. A total of 411 blood samples were collected from small and large ruminants and serologically tested against the presence of T. gondii, N. caninum, and C. burnetii. Generalized estimating equation (GEE) models were performed to assess the potential risk factors associated with the exposure to these pathogens. The overall seroprevalence of T. gondii was 47.9% (197/411) with an individual seropositivity of 59.4% (63/106), 58.6% (17/29), 38.8% (54/139) and 46% (63/137) in cattle, buffalo, sheep and goats, respectively. Meanwhile, 9.7% (38/411) of the examined animals were tested positive for anti-N. caninum antibodies, with an individual seropositivity of 13.2% (12/106), 34.5% (10/29), 8.6% (12/139) and 2.9% (4/137) in cattle, buffalo, sheep and goats, respectively. Furthermore, the overall prevalence of antibodies against C. burnetii was 17.3% (63/411), and exposure to this pathogen was detected in 4.7% (5/106) of cattle, 19.3% (20/129) of sheep, 29.2% (38/130) of goats but none of the examined buffalo were found to be seropositive. A total of 12.1% (50/411) of the examined animals showed co-exposure to at least two of the tested pathogens. Regarding the potential risk factors, there were statistically significant differences among species in the frequency of exposure to the three tested pathogens. Age (> 6 months) was also shown to be a significant risk factor associated with T. gondii exposure. The results obtained provided updated information about the occurrence of three of the main reproductive pathogens in Upper Egypt. The high seropositivity values found for the tested zoonotic pathogens in most of the analyzed ruminant species suggest the necessity of performing additional in-depth studies to evaluate the epidemiology of these pathogens in the study area.

Identification of IMC43, a novel IMC protein that collaborates with IMC32 to form an essential daughter bud assembly complex in Toxoplasma gondii

The inner membrane complex (IMC) of Toxoplasma gondii is essential for all phases of the parasite's life cycle. One of its most critical roles is to act as a scaffold for the assembly of daughter buds during replication by endodyogeny. While many daughter IMC proteins have been identified, most are recruited after bud initiation and are not essential for parasite fitness. Here, we report the identification of IMC43, a novel daughter IMC protein that is recruited at the earliest stages of daughter bud initiation. Using an auxin-inducible degron system we show that depletion of IMC43 results in aberrant morphology, dysregulation of endodyogeny, and an extreme defect in replication. Deletion analyses reveal a region of IMC43 that plays a role in localization and a C-terminal domain that is essential for the protein's function. TurboID proximity labelling and a yeast two-hybrid screen using IMC43 as bait identify 30 candidate IMC43 binding partners. We investigate two of these: the essential daughter protein IMC32 and a novel daughter IMC protein we named IMC44. We show that IMC43 is responsible for regulating the localization of both IMC32 and IMC44 at specific stages of endodyogeny and that this regulation is dependent on the essential C-terminal domain of IMC43. Using pairwise yeast two-hybrid assays, we determine that this region is also sufficient for binding to both IMC32 and IMC44. As IMC43 and IMC32 are both essential proteins, this work reveals the existence of a bud assembly complex that forms the foundation of the daughter IMC during endodyogeny.

Neospora caninum infection in dairy cattle in Egypt: a serosurvey and associated risk factors

Neospora caninum (N. caninum) is one of the causative agents that causing cattle abortion, and severe economic losses. Due to the scarcity of data on N. caninum infection in Egyptian cattle, the purpose of this study was to estimate the seroprevalence and determine the risk factors for parasite infection. In four governorates in northern Egypt, 540 blood samples from cattle were taken, and tested using a commercial ELISA kit. The overall seroprevalence of N. caninum in examined cattle was 28.89%. A multivariate logistic regression model determined that age (OR = 2.63, P < 0.001), manual milking (OR = 1.39, P = 0.14), abortion history (OR = 2.78, P < 0.0001), repetition of estrus (OR = 2.31, P < 0.0001), and contact with dogs (OR = 2.57, P < 0.0001) were significant risk factors. The findings proved that N. caninum infection was one of the factors contributing to abortion and financial losses in dairy cattle in Egypt. Therefore, the application of sanitary security and control programs is very important in dairy farms.

Evidence of Australian wild deer exposure to N. caninum infection and potential implications for the maintenance of N. caninum sylvatic cycle

Infections with the coccidian parasite Neospora caninum affect domestic and wild animals worldwide. In Australia, N. caninum infections cause considerable losses to the cattle industry with seroprevalence of 8.7% in beef and 10.9% in dairy cattle. Conversely, the role of wild animals, in maintaining the parasite cycle is also unclear. It is possible that native or introduced herbivorous species could be reservoir hosts of N. caninum in Australia, but to date, this has not been investigated. We report here the first large-scale screening of N. caninum antibodies in Australian wild deer, spanning three species (fallow, red and sambar deer). Consequently, we also assessed two commercial cELISA tests validated for detecting N. caninum in cattle for their ability to detect N. caninum antibodies in serum samples of wild deer. N. caninum antibodies were detected in 3.7% (7/189, 95% CI 1.8 - 7.45) of the wild deer serum samples collected in south-eastern Australia (n = 189), including 97 fallow deer (Dama dama), 14 red deer (Cervus elaphus), and 78 sambar deer (Rusa unicolor). Overall, our study provides the first detection of N. caninum antibodies in wild deer and quantifies deer's potential role in the sylvatic cycle of N. caninum.

Seroprevalence of Neospora caninum antibodies in dogs, cows, and humans in Assiut province, Egypt: a pilot study

Neospora caninum is an intracellular coccidian parasite infecting a broad range of hosts globally. Despite the existence of several epidemiological studies on neosporosis, there is a limited knowledge regarding the prevalence of N. caninum infection among dogs, cows, and humans in Egypt. To address this knowledge gap, we conducted an epidemiological investigation in the Assiut province of Egypt to determine the seropositivity of N. caninum infection among cows, dogs, and pregnant women, as well as the associated risk factors. By employing an indirect enzyme linked immunosorbent assay, we found specific N. caninum IgG antibodies in 6% (6 of 100) and 2.33% (1 of 43) of cows and dogs' sera, respectively. However, we are unable to detect antibodies in the 48 tested human sera. Moreover, no statistical significance was observed among the analyzed risk factors associated with seropositive cows and dogs. Our study highlights the presence of N. caninum in cows and dogs in the Assiut province, Egypt. Further, it underscores the need for improved comprehensive surveillance of N. caninum infection in a large population of cattle across various locations to obtain a better understanding of the economic burden associated with the disease.

Graphical abstract

The Toxoplasma subpellicular network is highly interconnected and defines parasite shape for efficient motility and replication

Apicomplexan parasites possess several specialized structures to invade their host cells and replicate successfully. One of these is the inner membrane complex (IMC), a peripheral membrane-cytoskeletal system underneath the plasma membrane. It is composed of a series of flattened, membrane-bound vesicles and a cytoskeletal subpellicular network (SPN) comprised of intermediate filament-like proteins called alveolins. While the alveolin proteins are conserved throughout the Apicomplexa and the broader Alveolata, their precise functions and interactions remain poorly understood. Here, we describe the function of one of these alveolin proteins, TgIMC6. Disruption of IMC6 resulted in striking morphological defects that led to aberrant motility, invasion, and replication. Deletion analyses revealed that the alveolin domain alone is largely sufficient to restore localization and partially sufficient for function. As this highlights the importance of the IMC6 alveolin domain, we implemented unnatural amino acid photoreactive crosslinking to the alveolin domain and identified multiple binding interfaces between IMC6 and two other cytoskeletal proteins - IMC3 and ILP1. To our knowledge, this provides the first direct evidence of protein-protein interactions in the alveolin domain and supports the long-held hypothesis that the alveolin domain is responsible for filament formation. Collectively, our study features the conserved alveolin proteins as critical components that maintain the parasite's structural integrity and highlights the alveolin domain as a key mediator of SPN architecture.

Serological Prevalence of Toxoplasma gondii, Neospora caninum, and Sarcoptes scabiei var. suis in Wild Boars (Sus scrofa) Hunted in a Highly Anthropized Area in Italy

Due to the increasing expansion into urban and rural areas, wild boars represent a potential source of infection with zoonotic and animal-specific parasites for both humans and animals. Therefore, the aim of this study was to investigate the serological prevalence to Toxoplasma gondii, Neospora caninum, and Sarcoptes scabiei var. suis in blood samples from wild boars (Sus scrofa) hunted in an anthropized area in Italy. Enzyme-linked immunosorbent assay (ELISA) tests were used to detect antibodies anti-T. gondii and anti-S. scabiei and an immunofluorescence antibody test (IFAT) for antibodies anti-N. caninum. 81 out of 128 wild boars (P = 63.3%) resulted positive for at least one of the three parasites. 68 of them were seropositive to T. gondii (P = 53.1%) and 14 to N. caninum (P = 10.9%). 9 wild boars resulted seropositive to S. scabiei var. suis (P = 7.0%). Sampling season was the only significant risk factor related to S. scabiei var. suis seroprevalence (OR = 7.8). The high occurrence of T. gondii supports the role of this species as a source of infection for other animals and humans. Furthermore, the serological prevalence of N. caninum and S. scabiei var. suis in wild boars from the study area characterized by the presence of numerous dairy cattle and pig farms is relevant to demonstrate its suitability for the circulation of these parasites both in domestic and wild species.

Herd and animal level prevalences and risk factors for Neospora caninum infection in cattle in the state of Paraíba, northeastern Brazil

Bovine neosporosis is a globally important disease, causing abortions and significant economic losses. In Brazil, studies on neosporosis in cattle are few and based on limited samples and/or from limited areas. We aimed to determine the herd and animal levels seroprevalence and associated factors for Neospora caninum infections in cattle from the state of Paraíba, Northeastern Brazil, using a planned sampling. Herds (n = 434) and cows aged ≥24 months (n = 1891) were randomly selected, and serum samples were tested with the immunofluorescence antibody test (IFAT) using as cut-off point the antibody titer 200. Herd-level and animal-level seroprevalences were 17.8% (95% CI = 14.3%-21.8%) and 18.1% (95% CI = 14.7%-22.1%), respectively. The factors associated with N. caninum infection were farm located in the Sertão mesoregion (Prevalence ratio [PR] = 2.37), mixed production (PR = 1.64), herd size of 34-111 animals (PR = 3.50) and herd size >111 animals (PR = 6.14). The results indicate high N. caninum circulation in the bovine population of the state of Paraíba, semiarid of Brazil, mainly in the Sertão mesoregion, where the highest apparent herd and animal-level prevalences of positive herds were identified. Control strategies should be adopted to mitigate the impact of disease on cattle production, as well as it's suggested the encouragement of conducting surveys in wildlife from Caatinga biome, mainly canids, to provide information on the importance of these animals on the epidemiology of bovine neosporosis.

Seroepidemiological Survey of Anti-Toxoplasma gondii and Anti-Neospora caninum Antibodies in Domestic Cats (Felis catus) in Rolim de Moura, State of Rondônia, North Brazil

Epidemiological studies on infections by Toxoplasma gondii and Neospora caninum in cats in the North Region of Brazil are scarce. We intended to assess the seroprevalence in cats of anti-T. gondii and anti-N. caninum antibodies, as well as the associated risk factors that may lead them to contract these infections in Rolim de Moura, state of Rondônia, North Brazil. For this, blood serum samples of 100 cats from different regions of the city were evaluated. To assess possible factors associated with infections, epidemiological questionnaires were applied to tutors. The Immunofluorescence Antibody Test (IFAT) was performed for anti-T. gondii (cutoff 1:16) and anti-N. caninum (cutoff 1:50) antibodies. After identifying the positive samples, antibody titration was performed. The results showed the prevalence of 26% (26/100) of anti-T. gondii antibodies, with titration varying between 1:16 to 1:8192. There were no factors associated with the prevalence of anti-T. gondii antibodies in the multivariate analysis in this study. There was no occurrence of seropositive cats for anti-N. caninum. It was concluded that there was a high prevalence of anti-T. gondii antibodies in cats in Rolim de Moura, state of Rondônia, North Brazil. However, the evaluated animals did not present anti-N. caninum antibodies. Therefore, knowing that T. gondii has different transmission forms, we emphasize the importance of spreading more information to the population about cat's relevance in the T. gondii life cycle and how to avoid the parasite transmission and proliferation.

IMC29 Plays an Important Role in Toxoplasma Endodyogeny and Reveals New Components of the Daughter-Enriched IMC Proteome

The Toxoplasma inner membrane complex (IMC) is a unique organelle that plays critical roles in parasite motility, invasion, egress, and replication. The IMC is delineated into the apical, body, and basal regions, defined by proteins that localize to these distinct subcompartments. The IMC can be further segregated by proteins that localize specifically to the maternal IMC, the daughter bud IMC, or both. While the function of the maternal IMC has been better characterized, the precise roles of most daughter IMC components remain poorly understood. Here, we demonstrate that the daughter protein IMC29 plays an important role in parasite replication. We show that Δimc29 parasites exhibit severe replication defects, resulting in substantial growth defects and loss of virulence. Deletion analyses revealed that IMC29 localization is largely dependent on the N-terminal half of the protein containing four predicted coiled-coil domains while IMC29 function requires a short C-terminal helical region. Using proximity labeling, we identify eight novel IMC proteins enriched in daughter buds, significantly expanding the daughter IMC proteome. We additionally report four novel proteins with unique localizations to the interface between two parasites or to the outer face of the IMC, exposing new subregions of the organelle. Together, this work establishes IMC29 as an important early daughter bud component of replication and uncovers an array of new IMC proteins that provides important insights into this organelle. IMPORTANCE The inner membrane complex (IMC) is a conserved structure across the Apicomplexa phylum, which includes obligate intracellular parasites that cause toxoplasmosis, malaria, and cryptosporidiosis. The IMC is critical for the parasite to maintain its intracellular lifestyle, particularly in providing a scaffold for daughter bud formation during parasite replication. While many IMC proteins in the later stages of division have been identified, components of the early stages of division remain unknown. Here, we focus on the early daughter protein IMC29, demonstrating that it is crucial for faithful parasite replication and identifying specific regions of the protein that are important for its localization and function. We additionally use proximity labeling to reveal a suite of daughter-enriched IMC proteins, which represent promising candidates to further explore this IMC subcompartment.

Temporal transcriptomic changes in microRNAs involved in the host immune response and metabolism during Neospora caninum infection

BACKGROUND

Neospora caninum infection is a major cause of abortion in cattle, which results in serious economic losses to the cattle industry. However, there are no effective drugs or vaccines for the control of N. caninum infections. There is increasing evidence that microRNAs (miRNAs) are involved in many physiological and pathological processes, and dysregulated expression of host miRNAs and the biological implications of this have been reported for infections by various protozoan parasites. However, to our knowledge, there is presently no published information on host miRNA expression during N. caninum infection.

METHODS

The expression profiles of miRNAs were investigated by RNA sequencing (RNA-seq) in caprine endometrial epithelial cells (EECs) infected with N. caninum at 24 h post infection (pi) and 48 hpi, and the functions of differentially expressed (DE) miRNAs were predicted by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The transcriptome data were validated by using quantitative real-time polymerase chain reaction. One of the upregulated DEmiRNAs, namely chi-miR-146a, was selected to study the effect of DEmiRNAs on the propagation of N. caninum tachyzoites in caprine EECs.

RESULTS

RNA-seq showed 18 (17 up- and one downregulated) and 79 (54 up- and 25 downregulated) DEmiRNAs at 24 hpi and 48 hpi, respectively. Quantitative real-time polymerase chain reaction analysis of 13 randomly selected DEmiRNAs (10 up- and three downregulated miRNAs) confirmed the validity of the RNA-seq data. A total of 7835 messenger RNAs were predicted to be potential targets for 66 DEmiRNAs, and GO and KEGG enrichment analysis of these predicted targets revealed that DEmiRNAs altered by N. caninum infection may be involved in host immune responses (e.g. Fc gamma R-mediated phagocytosis, Toll-like receptor signaling pathway, tumor necrosis factor signaling pathway, transforming growth factor-β signaling pathway, mitogen-activated protein kinase signaling pathway) and metabolic pathways (e.g. lysine degradation, insulin signaling pathway, AMP-activated protein kinase signaling pathway, Rap1 signaling pathway, calcium signaling pathway). Upregulated chi-miR-146a was found to promote N. caninum propagation in caprine EECs.

CONCLUSIONS

This is, to our knowledge, the first report on the expression profiles of host miRNAs during infection with N. caninum, and shows that chi-miR-146a may promote N. caninum propagation in host cells. The novel findings of the present study should help to elucidate the interactions between host cells and N. caninum.

Occurrence of IgG antibodies against Toxoplasma gondii, Neospora caninum, and Leptospira spp. in goats and sheep from an indigenous village in Pernambuco, Brazil

This study aimed to determine the occurrence of anti-Toxoplasma gondii, Neospora caninum, and Leptospira spp. antibodies in sheep and goats raised in villages of the Xukuru do Ororubá indigenous community, Pernambuco, Brazil. A total of 180 serum samples from sheep and 108 serum samples from goats of both sexes and different ages were analyzed. For antibody research, indirect immunofluorescence antibody test (IFAT) were used for the protozoa T. gondii and N. caninum, and microscopic agglutination test (MAT) for Leptospira spp., with a cutoff titer of 1:64, 1:50 and 1:100, respectively. The frequency of anti-T. gondii antibodies was 16.6% (30/180) for sheep and 11.1% (12/108) for goats. The frequency of anti-N. caninum antibodies was 10.55% (19/180) for sheep, and 20.37% (22/108) for goats, while for Leptospira spp., 2.2% (4/180) of sheep and 1.85% (2/108) of goats reacted positively. The results obtained in this study are unprecedented in indigenous communities in the country and serve as an alert for monitoring goats and sheep from the Xukuru do Ororubá indigenous village regarding the occurrence and productive impact of infections by T. gondii, N. caninum, and Leptospira spp., in addition to the occurrence of the zoonosis toxoplasmosis and leptospirosis in the indigenous community.

Development and application of an indirect ELISA to detect antibodies to Neospora caninum in cattle based on a chimeric protein rSRS2-SAG1-GRA7

Neospora caninum is an important apicomplexan parasite causing neosporosis in cattle. The disease is recognized as one of the most important cause of reproductive problems and abortion in cattle worldwide. In this context, we developed an indirect enzyme-linked immunosorbent assays (ELISA) with chimeric protein rSRS2-SAG1-GRA7 to diagnose antibodies to Neospora-infection. This indirect ELISA was compared to indirect fluorescent antibody test (IFAT) and western blotting (WB), and the sensitivity and specificity results of ELISA were calculated to be 86.7 and 96.1%, respectively. The overall coincidence rate was 92.6% using IFAT and WB. Additionally, 329 aborting dairy cattle serum samples were tested using this ELISA to evaluate the prevalence of N. caninum in Ningxia, China. The positive rate of N. caninum in these farms was from 19.05 to 57.89%, and the mean rate was 41.64% (±11.01%), indicating that infection with N. caninum may be one of the important causes of cattle abortion in this region. This established rSRS2-SAG1-GRA7 indirect ELISA is capable for detecting the antibodies against N. caninum, and it could be a useful screening tool for monitoring the epidemiology of neosporosis in cattle.

Exploiting the Macrophage Production of IL-12 in Improvement of Vaccine Development against Toxoplasma gondii and Neospora caninum Infections

Toxoplasmosis and neosporosis are major protozoan diseases of global distribution. Toxoplasma gondii is the cause of toxoplasmosis, which affects almost all warm-blooded animals, including humans, while Neospora caninum induces neosporosis in many animal species, especially cattle. The current defective situation with control measures is hindering all efforts to overcome the health hazards and economic losses of toxoplasmosis and neosporosis. Adequate understanding of host-parasite interactions and host strategies to combat such infections can be exploited in establishing potent control measures, including vaccine development. Macrophages are the first defense line of innate immunity, which is responsible for the successful elimination of T.gondii or N. caninum. This action is exerted via the immunoregulatory interleukin-12 (IL-12), which orchestrates the production of interferon gamma (IFN-γ) from various immune cells. Cellular immune response and IFN-γ production is the hallmark for successful vaccine candidates against both T. gondii and N. caninum. However, the discovery of potential vaccine candidates is a highly laborious, time-consuming and expensive procedure. In this review, we will try to exploit previous knowledge and our research experience to establish an efficient immunological approach for exploring potential vaccine candidates against T. gondii and N. caninum. Our previous studies on vaccine development against both T. gondii and N. caninum revealed a strong association between the successful and potential vaccine antigens and their ability to promote the macrophage secretion of IL-12 using a murine model. This phenomenon was emphasized using different recombinant antigens, parasites, and experimental approaches. Upon these data and research trials, IL-12 production from murine macrophages can be used as an initial predictor for judgment of vaccine efficacy before further evaluation in time-consuming and laborious in vivo experiments. However, more studies and research are required to conceptualize this immunological approach.

Retrospective Molecular Survey on Bacterial and Protozoan Abortive Agents in Roe Deer (Capreolus capreolus) from Central Italy

Bacterial and protozoan agents can determine abortion and other reproductive disorders in domestic ruminants, but data regarding their occurrence in wild ruminants are scanty worldwide, including in Italy. The aim of this retrospective study was to verify the occurrence of the main bacterial and protozoan abortive agents in 72 spleen samples previously collected from roe deer (Capreolus capreolus) living in mountain areas of Central Italy. All samples were collected and submitted to DNA extraction for other investigations. Molecular analyses were carried out on the DNA samples to detect Brucella spp., Chlamydia abortus, Coxiella burnetii, Salmonella enterica, Listeria monocytogenes, Neospora caninum, and Toxoplasma gondii. Three (4.16%) roe deer resulted PCR positive for C. burnetii and one (1.38%) for T. gondii. These findings suggest that roe deer living in the investigated areas do not act as important reservoirs of the searched agents. However, the tested animals lived in a closed area without contact with domestic animals that are usually involved in the epidemiology of the investigated pathogens. Monitoring of wild ruminants is pivotal to verify changes in the epidemiological scenario from a One Health perspective, too.

Seroprevalence of Toxoplasma gondii and Neospora caninum in camels recently imported to Egypt from Sudan and a global systematic review

INTRODUCTION

Toxoplasma gondii and Neospora caninum are closely related intracellular protozoan parasites of medical and veterinary concern by causing abortions and systemic illness. Limited or ambiguous data on the prevalence of T. gondii and N. caninum in camels triggered us to conduct this study.

METHODS

Camels (n = 460) recently imported from Sudan and destined mainly for human consumption, were tested for specific antibodies against these protozoans using commercially available ELISAs. From the two only quarantine stations for camels from Sudan, 368 camels were sampled between November 2015 and March 2016 in Shalateen, Red Sea governorate, and 92 samples were collected between September 2018 and March 2021 from Abu Simbel, Aswan governorate.

RESULTS & DISCUSSION

Overall, seropositive rates in camels were 25.7%, 3.9% and 0.8% for T. gondii, N. caninum and mixed infection, respectively. However, marked differences were found between the two study sites and/or the two sampling periods: For T. gondii, a higher rate of infection was recorded in the Red Sea samples (31.5%, 116/368; odds ratio 20.7, 5.0-85.6; P<0.0001) than in those collected in Aswan (2.2%, 2/92). The opposite was found for N. caninum with a lower rate of infection in the Red Sea samples (0.82%, 3/368; odds ratio 23.7, 6.7-83.9; P<0.0001) than in the samples from Aswan (16.3%, 15/92). Additionally, our systematic review revealed that the overall published seroprevalence of T. gondii and N. caninum was 28.6% and 14.3% in camels worldwide, respectively. To the best of our knowledge, this study provides the first record of seroprevalence of both T. gondii and N. caninum in recently imported camels kept under quarantine conditions before delivery to other Egyptian cities and regions. In addition, our review provides inclusive data on the prevalence of T. gondii and N. caninum in camel globally. This knowledge provides basic data for the implementation of strategies and control measures against neosporosis and toxoplasmosis.

Prevalence of Neospora caninum and Toxoplasma gondii Antibodies and DNA in Raw Milk of Various Ruminants in Egypt

The prevalence of Neospora caninum and Toxoplasma gondii antibodies in raw milk samples was estimated in different ruminants and Egyptian governorates. Of 13 bulk milk samples tested by ELISA, five (38.5%) were positive for antibodies to N. caninum, and two samples were additionally positive for antibodies to T. gondii, resulting in a seroprevalence of 15.4% for both T. gondii and co-infection. In individual milk samples (n = 171) from the same bulks, antibodies to N. caninum were detected in 25.7%, to T. gondii in 14%, and 3.5% had antibodies to both parasites. A strong correlation between the OD values of the bulk samples and of the relevant individual milk samples was found for T. gondii (Pearson r = 0.9759) and moderately strong for N. caninum (Pearson r = 0.5801). Risk factor assessment for individual milk samples revealed that antibodies to T. gondii were significantly influenced by animal species, while no risk factors were detected for N. caninum antibodies. Additionally, DNA of N. caninum was detected in a bulk milk sample of cattle for the first time in Egypt, and DNA of T. gondii was found in bulk milk samples of cattle, sheep and goats. This is the first study in Egypt in which bulk milk samples of different ruminants were tested for the presence of N. caninum and T. gondii antibodies and DNA. Both individual and bulk milk samples are useful tools for monitoring antibody response to N. caninum and T. gondii infections in different ruminants in Egypt.

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.

Molecular detection and identification of three intracellular parasites of retail mutton products in Beijing, China

Sarcocystis spp., Neospora caninum and Toxoplasma gondii are globally ubiquitous pathogens, and domestic sheep are considered to be one of the intermediate hosts. 83 myocardial samples of sheep were collected from 12 retail stores in Beijing, China. Sarcocystis spp., N. caninum and T. gondii were identified by PCR amplification of the 18S rRNA gene, Nc-5 gene and 529bp DNA fragment with a prevalence of 86.7% (95% CI: 77.5–93.2) and 43.4% (95% CI: 32.5–54.7) for Sarcocystis spp. and N. caninum infections, respectively, and no T. gondii was detected. The co-infection prevalence of Sarcocystis and N. caninum was 38.6% (95% CI: 28.1–49.9). Two Sarcocystis species were subtyped by analyzing 18SrRNA sequences and were identified as Sarcocystis tenella and Sarcocystis arieticanis. The prevalence of S. tenella and S. arieticanis infections was 84.3% (95% CI: 74.7–91.4) and 56.6% (95% CI: 45.3–67.5), respectively. This study shows that sheep have a high risk of infection with Sarcocystis and N. caninum, suggests that effective prevention measures are needed to avoid the spread of these parasites in sheep. Toxoplasmosis in sheep poses a threat to human and animal health and requires monitoring and preventing continuously.

Microcephaly and hydrocephalus in a sheep fetus infected with Neospora caninum in Southern Brazil - Short communication

A case of non-communicating hydrocephalus and microcephaly in a sheep fetus infected with Neospora caninum from Lages, Santa Catarina, Brazil, is reported. Macroscopically, there was moderate flattening and narrowing of the skull, and the portion of the cerebral hemispheres was markedly reduced in size, measuring 3.5 × 3.5 × 0.5 cm, with marked diffuse flattening of the brain gyri and dilation of the lateral ventricles. Cerebrospinal fluid samples were positive to N. caninum detection by PCR. Histologically, there was discrete focal lymphoplasmacytic necrotising encephalitis on the floor of the lateral ventricle, discrete multifocal gliosis and discrete multifocal lymphoplasmacytic myositis. Through the molecular detection of N. caninum in the cerebrospinal fluid, it was possible to report what appears to be the first case of non-communicating hydrocephalus and microcephaly in an ovine fetus infected with N. caninum.

Seroprevalence of Neospora caninum in Goats from Korkuteli District of Antalya

OBJECTIVE

This study aimed to determine the seroprevalence of Neospora caninum in goats from the Korkuteli district of Antalya.

METHODS

During the study, sera samples were obtained from 184 female goats and analyzed for the presence of antibodies against N. caninum using a commercial ELISA kit.

RESULTS

Seroprevalence of N. caninum was determined as 4.89%. Seropositivity of N. caninum in goats was not statistically significant (p>0.05) in terms of study centers, age groups, and abort situation.

CONCLUSION

This study reports the first data on the presence and seroprevalence of N. caninum in the goats in the region.

First molecular detection of Neospora caninum from naturally infected slaughtered camels in Tunisia

Background

Neosporacaninum has been documented to infect most domestic wildlife but is known to primarily infect dogs and cattle and is considered an important cause of abortion in camels.

Objective

The aim of this study was to estimate the molecular detection of Neospora caninum in tissues of naturally infected camelids.

Methods

Brain, tongue (bottom and tip) and masseter muscles from 35 slaughtered camelids from Tataouine and Médenine regions were collected (n = 140 samples). PCR was used to amplify and detect N. caninum DNA in tissues samples followed by sequencing of some PCR products. A phylogenetic tree was then constructed to compare the partial sequences of the ITS1 gene with GenBank sequences. Histopathology examination was used to detect Neospora spp. cysts, but no lesions were observed.

Results

The overall molecular detection of N. caninum in camelids was 34.3% (12/35).

The highest molecular detection of N. caninum was recorded in animals of more than 3 years old (6/9) and in animals aged between 1 and 3 years old (4/12). Whilst, the lowest molecular detection (2/14) was observed in animals 1 year or younger (p = 0.035).

There were no significant differences in molecular detection of N. caninum according to both locality and gender (p > 0.05). Similarly, there was no difference of prevalence between different anatomical locations. Comparison of the partial sequences of the ITS1 gene revealed 100–95.5% similarity among our N. caninum amplicon (MW551566) and those deposited in GenBank.

Conclusion

These results highlight the presence of a risk infection by N. caninum in camels. For preventing N. caninum infection further studies are needed to improve our knowledge about the epidemiology of neosporosis in North Africa.