PCR detection of Neospora caninum, Toxoplasma gondii and Encephalitozoon cuniculi in brains of wild carnivores

Neospora caninum, Toxoplasma gondii and Encephalitozoon cuniculi are important pathogens with affinity to the central nervous system of many animals. 240 brains of wild carnivores were examined by PCR-based diagnosis. The presence of N. caninum DNA was confirmed in 4.61% (7/152) red foxes (Vulpes vulpes). DNA of T. gondii was found in 4.92% (3/61) martens (Martes sp.) and in 1.32% (2/152) red foxes. DNA of E. cuniculi was determined in 3.28% (2/61) martens and in one examined European otter (Lutra lutra). There were no co-infections found. These results provide the first evidence of E. cuniculi in the European otter, the first report of N. caninum in foxes in the Czech Republic and confirm the presence of T. gondii in wild carnivores in the Czech Republic.     

Toxoplasma gondii infection in Polish farmed mink

The aim of this study was to determine the seroprevalence of Toxoplasma gondii antibodies in Polish farmed mink according to way of feeding as well as to confirm the role of toxoplasmosis in reproductive losses in mink farms. The serological examinations were carried out on 961 mink randomly selected from 12 Polish farms. Blood sera were examined for the presence of T. gondii antibodies with the use of the latex agglutination test. The examinations for the presence of T. gondii in organ tissues were performed on five neonatal mink kits with the use of immunofluorescence method. In total 133 (13.9%) out of 961 examined mink had T. gondii antibodies. In large farms the seropositivity was lower (2.9%), than in small farms (26.33%) (P < 0.001). Significant difference was found in seroprevalence according to way of feeding. In farms feeding fish, percentage of seropositivity was lower (2.2%), than in farms based on non-frozen slaughter offal (43.4%). Titres of T. gondii antibodies were usually lower than 120 IU/ml. Using the immunofluorescence method, T. gondii was detected in impression smears from liver and brain of two neonatal mink kits derived from one seropositive female.     

Serological survey and first finding of Neospora caninum in Taiwan, and the detection of its antibodies in various body fluids of cattle

A serological survey for antibodies against Neospora caninum in cattle, goats and farm dogs in Taiwan was carried out. Sera of 613 cattle from 25 dairy farms, 24 goats from six goat farms and 13 dogs from six dairy cattle farms were tested for antibodies against N. caninum using indirect fluorescence antibody test (IFAT). The same sera were also tested for antibodies against Toxoplasma gondii using latex agglutination test. Of the 613 cattle sera, 44.9% (275/613) were found to have antibodies against N. caninum. Among these 275 positive cattle, 77 also possessed antibodies against T. gondii. Nevertheless, 92 cattle which were negative for N. caninum showed antibodies against T. gondii. Of the 24 goat sera tested, none was found to be positive for N. caninum but 50% (12/24) were positive for T. gondii. Of the 13 farm dogs tested, three were found to possess antibodies against N. caninum, two of which tested negative for T. gondii antibodies. Besides sera, antibodies to N. caninum in cattle could be observed in the milk, vaginal secretion and saliva. However, the order of higher frequency of antibodies detection is in sera, milk, vaginal secretion and saliva. This is the first demonstration of the presence of antibodies to N. caninum in vaginal secretion and saliva of cattle. A 50microm cyst was observed in the brain of one of the 13 prednisolone-treated SPF ICR mice which had been peritoneally inoculated 4 months earlier with the brain homogenate of a serologically N. caninum positive but T. gondii negative cattle. Thus, we have confirmed for the first time the presence of N. caninum in Taiwan and also observed that it is widespread among dairy cattle and farm dogs.     

Investigations with enzyme-linked immunosorbent assays for Trichinella spiralis and Toxoplasma gondii in the Dutch 'Integrated Quality Control for finishing pigs' research project.

In the framework of the Dutch field trial 'Integrated Quality Control (IQC) for finishing pigs' ELISA (screening) techniques were used to detect animals seropositive for Toxoplasma gondii and/or Trichinella spiralis. The aim was to determine whether farms which consistently delivered seropositive pigs could be detected and monitored (defined as 'problem farms'). The investigation involved 120 farms and three slaughterhouses, and a total of 23,348 serum samples were examined. In addition, all pigs were also screened for the presence of Trichinella spiralis with the digestion method (pooled samples). The prevalence of seropositivity for Trichinella spiralis and Toxoplasma gondii was 0.3% and 2.1% respectively. Parasitological examinations concerning T. spiralis were negative. Considering the characteristics of the used methodology, the conclusion was drawn that there were no parasitological or serological indications for T. spiralis infections, and that with respect to T. gondii the infection rate seemed to be equally low for all farms involved. In addition, a longitudinal pilot study during a whole finishing period was undertaken at two finishing farms. Animals seropositive for Toxoplasma gondii were found from the earliest days of the finishing period. Housing and management may (still) play an important role in the prevention of contact with this parasite.     

Detection of specific antibodies to Neospora caninum and Toxoplasma gondii in naturally infected alpacas (Lama pacos), llamas (Lama glama) and vicunas (Lama vicugna) from Peru and Germany

Sera of an experimentally Neospora caninum infected llama and a non-infected control llama were used to establish an immunoblot, an ELISA and an IFAT to detect antibodies against N. caninum tachyzoites. Subsequently, serum samples collected from a total of 871 South American Camelids (SAC: Lama glama, Lama pacos, Lama vicugna) of two farms in Peru and from 32 SAC of a farm in central Germany were examined for antibodies against N. caninum and Toxoplasma gondii. Based on the recognition of specific bands in the immunoblot, sera of SAC from Peru were differentiated into N. caninum-positive (n = 18) and T. gondii-positive (n = 30) samples and into samples negative or inconclusive for both parasites. Using the immunoblot results as the reference, a modified version of the p38-ELISA and the IFAT were evaluated for detecting N. caninum antibodies in SAC sera. Applying a cut-off as determined by two graph-receiver operating characteristic analysis both, the ELISA and the IFAT, exhibited a sensitivity and specificity of about 95% in the SAC sera from Peru. Serological testing confirmed that SAC may become infected with N. caninum under field conditions in Peru. In addition to alpacas and llamas also 114 wild living vicunas had been examined for antibodies against N. caninum. However, only the alpacas and llamas but no vicunas were found N. caninum-positive. In contrast, T. gondii-seropositive animals were detected in all three SAC species. The lack of N. caninum-seropositive vicunas indicates that in the study area in Peru wild canids might not serve as definitive hosts of N. caninum while for T. gondii a life cycle including wild felids is likely. On the German farm no N. caninum- but only T. gondii-seropositive SAC (n = 14) were detected. The seroprevalence of T. gondii infection was significantly higher in adult SAC (alpacas in Peru, llamas in Germany) than in crias (i.e. < 12 months old foals) indicating that the predominant route of infection is post natal. Since the present study was restricted to a few farms, the seroprevalences determined are not representative. However, our results confirm natural infections with N. caninum and T. gondii in SAC. Whether these infections are linked to any disease, e.g. reproductive losses, has to be clarified in further studies.     

Seroprevalence of Toxoplasma gondii, Sarcocystis neurona, and Encephalitozoon cuniculi in three species of lemurs from St. Catherines Island, GA, USA

In the current study, we determined the seroprevalence of Toxoplasma gondii, Sarcocystis neurona, and Encephalitozoon cuniculi in three species of lemurs from St. Catherines Island, Georgia. Serum samples were tested from 52 ring-tailed lemurs (Lemur catta), six blue-eyed black lemurs (Eulemur macaco flavifrons), and four black and white ruffed lemurs (Varecia variegata variegata) using an agglutination assay. Three ring-tailed lemurs (5.8%) were positive for T. gondii (titer of 1:50); one ring-tailed lemur (1.9%) and one black and white ruffed lemur (25%) were positive for S. neurona (titers of 1:1000); and one ring-tailed lemur (1.9%) was positive for E. cuniculi (titer of 1:400). All blue-eyed black lemurs were negative for antibodies to T. gondii, S. neurona, and E. cuniculi. This is the first detection of antibodies to T. gondii in ring-tailed lemurs and antibodies to S. neurona and E. cuniculi in any species of prosimian.     

Prevalence of IgG antibodies to Encephalitozoon cuniculi and Toxoplasma gondii in cats with and without chronic kidney disease from Virginia

Kidney disease is a common and serious condition in domestic cats. There are numerous causes of kidney disease including parasitic infection. Encephalitozoon cuniculi is a microsporidian parasite that develops in the kidneys of rabbits and causes chronic renal disease. Little has been reported concerning E. cuniculi in cats and no serological studies on this parasite in cats have been conducted in the United States to date. The present study explored the possibility that E. cuniculi is an unrecognized contributor to the high prevalence of kidney disease observed in cats. A serological survey was conducted to determine the prevalence of IgG antibodies to spores of E. cuniculi in cats with and without a diagnosis of chronic kidney disease (CKD) according to the International Renal Interest Society (IRIS) staging system. Likewise, samples were examined for IgG antibodies to Toxoplasma gondii, a common well studied protozoan of cats. Plasma and sera were obtained from 232 feline patients at the Virginia-Maryland Regional College of Veterinary Medicine teaching hospital. With the investigators blinded to the renal status of test subjects, samples were screened via indirect immunofluorescent antibody assay (IFA). Thirty-six of the 232 cats met the IRIS staging system criteria for CKD. Antibodies to E. cuniculi were found in 15 of the 232 samples, which included 4 of the 36 cats with CKD. Sera from cats serologically positive to E. cuniculi did not react to spores of E. intestinalis or E. hellem when examined in the IFA. Antibodies to T. gondii were found in 63 of the 232 samples, which included 10 of the 36 cats with CKD. The prevalence of antibodies in cats with CKD to either protozoan was not significantly different (P>0.05) from the cats without CKD in the study. Collectively the results do not support the hypothesis that either E. cuniculi or T. gondii play a significant etiologic role in the occurrence or progression of CKD in cats.     

Serological survey and risk factors for Toxoplasma gondii in domestic ducks and geese in Lower Saxony, Germany

To obtain estimates for the prevalence of Toxoplasma gondii infection in ducks and geese in Germany, enzyme-linked immunosorbent assays (ELISA) were established based on affinity-purified T. gondii tachyzoite surface antigen 1 (TgSAG1) and used to examine duck and goose sera for T. gondii-specific antibodies. The results of 186 sera from 60 non-infected ducks (Anas platyrhynchos) and 101 sera from 36 non-infected geese (Anser anser) as well as 72 sera from 11 ducks and 89 sera from 12 geese inoculated experimentally with T. gondii tachyzoites (intravenously) or oocysts (orally) and positive in a T. gondii immunofluorescent antibody test (IFAT) were used to select a cut-off value for the TgSAG1-ELISA. Sera obtained by serial bleeding of experimentally inoculated ducks and geese were tested to analyze the time course of anti-TgSAG1 antibodies after inoculation and to assess the sensitivity of the assays in comparison with IFAT. In ducks, IFAT titres and ELISA indices peaked 2 and 5 weeks p.i with tachyzoites, respectively. Only three of six geese inoculated with tachyzoites at the same time as the ducks elicited a low and non-permanent antibody response as detected by the IFAT. In the TgSAG1-ELISA, only a slight increase of the ELISA indices was observed in four of six tachyzoite-inoculated geese. By contrast, inoculation of ducks and geese with oocysts led to an increase in anti-TgSAG1 antibodies within 1 or 2 weeks, which were still detectable at the end of the observation period, i.e. 11 weeks p.i. Inoculation of three ducks and three geese with oocysts of Hammondia hammondi, a protozoon closely related to T. gondii, resulted in a transient seroconversion in ducks and geese as measured by IFAT or TgSAG1-ELISA. Using the newly established TgSAG1-ELISA, sera from naturally exposed ducks and geese sampled in the course of a monitoring program for avian influenza were examined for antibodies to T. gondii; 145/2534 (5.7%) of the ducks and 94/373 (25.2%) of the geese had antibodies against TgSAG1. Seropositive animals were detected on 20 of 61 duck and in 11 of 13 goose farms; the seroprevalences within positive submissions of single farms ranged from 2.2% to 78.6%. Farms keeping ducks or geese exclusively indoors had a significantly lower risk (odds ratio 0.05, 95% confidence interval 0.01-0.3) of harboring serologically positive animals as compared with farms where the animals had access to an enclosure outside the barn.     

Serological survey for antibodies to Encephalitozoon cuniculi in pet rabbits in Italy

Pet rabbits (n = 125) from Southern Italy were submitted to a serological screening for Encephalitozoon cuniculi, using an enzyme-linked immunosorbent assay (ELISA) and a carbon immunoassay (CIA). Seventy-eight examined rabbits showed clinical signs suggestive of encephalitozoonosis (head tilt, ataxia, paralysis, cataracts, uveitis, polyuria and polydipsia), whereas 47 were healthy rabbits. Antibodies anti-E. cuniculi were found in 84/125 (67.2%) sera analysed. The results of the chi-squared test showed that sex and health status had no significant effect (P > 0.05) on E. cuniculi seropositivity; however, rabbits older than 4 months had a seropositivity for E. cuniculi significantly (P < 0.05) higher than that of rabbits aged up to 4 months. The results of the present survey reinforce the assumption that rabbit may be indicated as the main reservoir of E. cuniculi; therefore, routine screening examinations in pet rabbits are strongly advised considering the zoonotic potential of this parasite.     

Seroprevalence of Neospora caninum in dairy cattle in Bahia, Brazil.

Sera collected from 447 dairy cattle on 14 dairy farms were tested for Neospora caninum antibodies by use of an immunofluorescent antibody technique. Positive reactions with titres > or =1:200 were found in 63 (14.09%) of animals. Neospora positive sera were also tested for Toxoplasma gondii antibodies by using a commercial latex agglutination test. Antibodies to T. gondii were detected in 3 (4.76%) of 63 N. caninum positive sera. These results indicate that N. caninum infection is widespread among dairy cattle in Bahia state.     

Soil contamination of Toxoplasma gondii oocysts in pig farms in central China

Toxoplasmosis in pigs is a large threat to pig industry as well as pork consumers. Most pigs become infected by ingestion of oocysts from contaminated environment (soil, water and feed) or infected animal tissues postnatally. In the present study, field studies were conducted to evaluate the relationship between soil contamination status of Toxoplasma gondii oocysts and T. gondii infection in pigs in 12 pig farms with different density of cats in central China. The presence of T. gondii oocysts in soil were determined by PCR and loop-mediated isothermal amplification (LAMP). T. gondii DNA was found in 11 farms with different cat density excepting one farm exposed to low cat density. Twenty (21.1%) and 36 (37.9%) of 95 soil samples were T. gondii positive by PCR and LAMP, respectively (0.01相似文献   

Farmed wild boars exposed to Toxoplasma gondii and Trichinella spp

The meat of wild boar (Sus scrofa L.) can be a source of human infections with zoonotic parasites Toxoplasma gondii and Trichinella spp. We screened 197 wild boar sera collected at slaughter from 25 Finnish farms in 2007-2008 for serological evidence of infections with these parasites. Using a commercial direct agglutination test at a serum dilution of 1:40, T. gondii-specific IgG antibodies were detected in 65 (33.0%) samples, on 14 (56.0%) farms. Females, animals older than 24 months, animals of small herds, and animals originating from south-western parts of Finland were more often T. gondii-seropositive than were males, younger animals, animals of larger herds, and animals originating from the north and east, respectively. Four (2.0%) of the sera, originating from three (12.0%) farms, tested Trichinella-seropositive with an in-house ELISA and a conservative cut-off for seropositivity. One farm had both T. gondii- and Trichinella-seropositive animals. Taken together, an infection source had been present on 16 (64.0%) farms, and 69 (35.0%) of the 197 farmed wild boars intended for human consumption had specific serological evidence of exposure to a zoonotic parasite.     

Study on the prevalence of Toxoplasma gondii and Neospora caninum and molecular evidence of Encephalitozoon cuniculi and Encephalitozoon (Septata) intestinalis infections in red foxes (Vulpes vulpes) in rural Ireland

Thoracic fluid (pleural fluid and clotted blood) from 206 foxes were examined for antibodies to Toxoplasma gondii and 220 thoracic fluid samples were tested for Neospora caninum antibodies using indirect immunofluorescent antibody tests (IFAT). A total of 115 (56%) and six (3%) foxes had antibodies to T. gondii and N. caninum, respectively. The brains from 148 foxes were examined for histological lesions and pathological changes suggestive of parasitic encephalitis were observed in 33 (22%). Two thirds of these foxes had antibodies to T. gondii and one fox had antibodies to both T. gondii and N. caninum. PCR assays carried out on DNA extracted from the 33 brains with histological lesions were negative for N. caninum but one of the brains was positive for T. gondii. Microsporidian DNA was also amplified from the brains of two of these foxes. Sequencing these amplicons revealed 100% homology with Encephalitozoon (Septata) intestinalis in one fox and Encephalitozoon cuniculi in the second fox. This is the first report of Encephalitozoon infections in wildlife in Ireland.     

Seroprevalence of Neospora caninum, Toxoplasma gondii and Sarcocystis sp. in llamas (Lama glama) from Jujuy, Argentina

Llamas (Lama glama) are South American camelids described as intermediate hosts of Neospora caninum, Toxoplasma gondii and Sarcocystis aucheniae. Due to the potential role of these protozoan infections as a cause of economic losses, the aim of this study was to determine the seroprevalence for T. gondii, N. caninum and Sarcocystis sp. in llamas from Argentina. Serum samples from 308 llamas (>2 years old) were collected between 2005 and 2007. A total of 55 farms located in six departments of Jujuy province, Argentina were sampled. Presence of antibodies to N. caninum, T. gondii and Sarcocystis sp. was determined by the indirect fluorescent antibody test (IFAT). For Sarcocystis, 2 different bradyzoites-based antigens were prepared using S. aucheniae and S. cruzi. Sera were tested at dilutions 1:25 and 1:50. Antibodies to N. caninum were found in 4.6% serum samples. Fifty percent of departments and 14.5% of farms had positive animals. Antibodies to T. gondii were found in 30% of samples, distributed in 66% of departments and 43.6% of farms. Antibodies to Sarcocystis sp. were detected in 96% of samples and all departments and farms had positive animals, suggesting frequent contact between llamas and canids. Co-infection with N. caninum, T. gondii and Sarcocystis sp. was also recorded. Low seroprevalence of N. caninum in llamas detected in this study could be related to climatic and geographical conditions that limit cattle breeding activity, reducing the source of infection for definitive hosts. Seroprevalence of T. gondii and the positive animal distribution suggest frequent contamination of grass with felid faeces. In conclusion, this is the first report of combined seroprevalence for N. caninum, T. gondii and Sarcocystis sp. in llamas. Further studies are needed to determine the potential role of these protozoan infections as cause of abortion in Argentina as well as presence of these protozoans in llama meat used for human consumption.     

Encephalitozoonosis in New Zealand rabbits and potential transmission risk

Encephalitozoon cuniculi is a small protozoan parasite in the phylum Microspora. It has been shown to naturally infect several host species, including humans. Encephalitozoonosis is routinely diagnosed in vivo by serological examination or post mortem by histopathology. In a conventional rabbit colony, two animals suddenly showed clinical signs (torticollis and asthenia of limbs). Serum samples of these rabbits were seropositive for E. cuniculi after definitive diagnosis (Toxoplasma gondii and Listeria monocytogenes). The animals in the same breeding facility were also clinical examined, and the present study evaluated the prevalence of specific anti-E. cuniculi antibodies using serological testing, both in animals and in people working with animals, after two clinical cases. The rabbits showed no clinical symptoms of the disease. Blood samples were taken for E. cuniculi infection from 50 clinically healthy rabbits. Anti-E. cuniculi antibodies were found in two asymptomatic and two clinically affected animals belonging to the same rabbit colony. Finally, the present study found that the 7.7% (4/52) prevalence of CIA, test positive in rabbits. E. cuniculi spores were detected in the urine of one clinically affected rabbit, and one seropositive animal caretaker after staining with the modified trichrome stain. In conclusion, the presence of seropositive, but apparently healthy rabbits indicates the need for screening examinations to detect the anti-E. cuniculi antibody in rabbits, especially considering the potential zoonotic risk. Therefore, persons should avoid contact with the urine of infected or healthy animals, and always use good personal hygiene when handling animals.     

Cross-sectional survey in pig breeding farms in Hesse, Germany: seroprevalence and risk factors of infections with Toxoplasma gondii, Sarcocystis spp. and Neospora caninum in sows

A cross-sectional survey was performed to estimate the prevalences of antibodies to Toxoplasma gondii (ELISA, IFAT), Sarcocystis spp. (ELISA, using S. miescheriana as antigen) and Neospora caninum (ELISA, immunoblotting) in sows from breeding farms in southern Hesse, Germany. A total of 2041 plasma samples of sows from 94 randomly selected farms was examined. Data on farm profiles, husbandry management and sows were collected by a questionnaire and exploratively analysed. For T. gondii the ELISA results agreed well with the results obtained by IFAT (kappa=0.71). Antibodies to T. gondii were detected by ELISA in 19% of the sows. Sixty-nine percent of the farms had at least one seropositive sow, and a within-farm seroprevalence of >or=50% was observed in 14% of all farms. The prevalence of anti-T. gondii antibodies was positively correlated with the age of sows. The within-herd seroprevalence was significantly higher in farms with reproductive disorders than in those without such problems. On the farm level, the farm type 'piglet production' (versus 'pedigree breeding' or 'farrow-to-finish') was the only risk factor associated with the presence of T. gondii-seropositive sows. Antibodies to Sarcocystis spp. were found in 29% of the sows. Seventy-two percent of the farms harboured at least one seropositive sow, and a within-farm seroprevalence of >or=50% was detected in 23% of all farms. The seroprevalence increased significantly with the age of sows. On the farm level, only the farm type 'piglet production' (versus 'pedigree breeding') and the replacement of sows by purchasing (versus raising on the own farm) were identified as risk factors for seropositivity. Antibodies to N. caninum were detected in one sow using both the screening ELISA and the confirmatory immunoblotting technique. This may indicate the first natural N. caninum infection in pigs.     

Seroprevalence of Toxoplasma gondii infection in domestic pigeons (Columba livia) in Guangdong Province of southern China

Little information on epidemiology of Toxoplasma gondii infection in pigeons was available in People's Republic of China. In the present study, sera from 275 pigeons raised in different commercial flocks in Guangdong Province of southern China were evaluated using modified agglutination test (MAT). Specific antibodies were found in sera of 8.7% of 275 pigeons (MAT titer ≥ 1:5), and the seropositivity of eight herds we surveyed varied ranging from 0 to 18.2%. The results demonstrated the circulation of T. gondii in the examined pigeon farms, which poses potential risk for human infection with T. gondii. To our knowledge, this is the first seroprevalence survey of pigeons infected by T. gondii in People's Republic of China.     

Seroprevalence of Toxoplasma gondii in sows from slaughterhouses and in pigs from an indoor and an outdoor farm in Argentina

The objective of the present study was to determine the prevalence of Toxoplasma gondii antibodies from slaughter sows and from pigs raised at an indoor and an outdoor swine farm. Serum samples were obtained from 230 slaughter sows belonging to 83 farms distributed in 5 provinces. Blood samples were collected monthly from pigs of different ages from an intensive management indoor farm (farm 1). A cross-sectional study was carried-out from an outdoor farm (farm 2). All sera were tested for T. gondii antibodies by the modified agglutination test (MAT), using formalin-fixed tachyzoites as antigen. An antibody titer > or =1:25 was considered positive. Antibodies to T. gondii were detected in 87 (37.8%) of 230 sows sera. Distribution among provinces was: 37.1% from Santa Fe, 62.8% from Buenos Aires, 3.3% from San Luis, 58.7% from La Pampa and 24% from Córdoba. Four of 88 (4.5%) serum samples from farm 1 had antibodies to T. gondii and none of the negative pigs seroconverted. However, 45 of 112 samples from farm 2 were positive (40.2%) with the following distribution: sows 100%; nursery 40%; growers 13.8% and fatteners 20%. It is concluded that the prevalence of T.gondii antibodies among sows seems to be quite variable. T. gondii prevalence was related to the facilities and management of the farm.     

Seroprevalences of Toxoplasma gondii and Neospora sp. infections in Swedish horses

Sera from 414 Swedish horses were investigated for the presence of antibodies to Toxoplasma gondii and Neospora sp. by the T. gondii direct agglutination test (DAT), and an Neospora caninum iscom-ELISA. Five sera (1%) had a titre >1:40 in DAT, but when analysed by immunoblotting against T. gondii antigens only two of them were positive, giving a seroprevalence of 0.5%. Since the Neospora iscom ELISA had not been validated for equine sera it was used for an initial screening, and all sera with an optical density exceeding 0.200 absorbance units were selected for further investigation by immunoblot analysis. Of the 39 sera tested by immunoblotting, four reacted with at least two of the immunodominant Neospora antigens recognized by the positive control sera and were judged as positive, resulting in a seroprevalence of 1%. This is the first evidence of Neospora infection in Swedish horses. The study illustrates the necessity of critically evaluating results of serological analyses performed by methods that are not validated for the animal species under investigation.     

Prevalence of specific IgG-antibodies against Toxoplasma gondii in domestic turkeys determined by kinetic ELISA based on recombinant GRA7 and GRA8

The protozoan parasite Toxoplasma (T.) gondii is one of the most common zoonotic infectious agents worldwide. Besides its sexual reproduction in cats, T. gondii can also infect a wide spectrum of other warm-blooded animals. These include animals used for human consumption such as pigs or chickens. Nevertheless, the role of turkeys for the epidemiology of T. gondii infections has not been studied thoroughly. We have established a kinetic ELISA (KELA) for the detection of T. gondii-specific IgG antibodies in turkey serum samples. The test is based on the recombinant dense granule antigens GRA7 and GRA8. These proteins were used as an antigen mixture at a concentration of 0.13 μg per well. The overall sensitivity of the assay was between 92.6% and 100% and the specificity ranged from 78.1% to 100%, depending on the method used to calculate these parameters. Using this KELA we examined 1913 turkey serum samples from 14 turkey farms from different areas of Germany. From these sera, 387 produced a signal in the KELA, corresponding to a true seroprevalence of up to 20.2%. The seropositivity rate in individual fattening cycles at individual farms ranged from 0.0% to 77.1%, whereas the rates were highly variable within the individual farms and individual fattening cycles. Consequently, conditions of animal husbandry could not be associated with particular seroprevalence rates. Although seropositivity cannot be linked directly to infectious tissue cysts in the muscle tissue of commercially produced turkey meat, we state that there is a potential risk of being infected by consuming turkey meat products that were not heat treated.