Correlation of tissue infection and serologic findings in pigs fed Toxoplasma gondii oocysts

Each of thirteen 6-week-old pigs was inoculated per os with 10,000 sporulated oocysts of Toxoplasma gondii. By postinoculation day (PID) 13, pigs were seropositive by the indirect fluorescent antibody test. Beginning on PID 13 and every 7 days thereafter through PID 97, 1 pig was killed and 6 tissues were examined for T gondii. Of the 13 pigs, 11 were infected, including the 1st pig killed on PID 13, although none of the pigs had gross lesions of toxoplasmosis. Tissues harboring T gondii most frequently were the heart and brain; organisms were detected less frequently in the longissimus muscles, diaphragm, and liver. Toxoplasma gondii was not detected in the bronchial lymph nodes. There was good correlation between antibody and presence of T gondii in these pigs. One additional pig, maintained as a noninfected control, remained seronegative and had no evidence of infection when killed on PID 97.     

Incidence of Toxoplasma gondii oocysts in cat feces

Within two years and a half, the faeces of 620 cats coming from Brno and the area around the city were subjected to parasitological examination with special regard to the occurrence of the oocysts of Toxoplasma gondii. Sucrose solution at the specific weight of 1,150 was used as flotation medium. Oocysts of Toxoplasma gondii were eliminated by eight cats (1.29%) at the age from 16 days to 1.5 years. Six of the eight cats were younger than seven months. The Toxoplasma gondii oocysts were eliminated by the cats for 1-16 days while exhibiting signs of short-term scours and swelling of lymph nodes. In all cases the oocysts of Toxoplasma gondii were produced in the summer and autumn seasons (June-December). During the patent period, other coccidia (Isospora felis and Isospora rivolta) were also present in the cats.     

Antibody response in goats experimentally infected with Toxoplasma gondii

Serum samples of five goats inoculated with Toxoplasma gondii were analyzed using the enzyme linked immunosorbent assay (ELISA), indirect hemagglutination (IHA) and western blotting (WB). Antibodies detected by ELISA peaked between 19 and 62 days after inoculation and persisted throughout the experiment with no association to parasitaemia. Using WB, the main antigens detected had molecular weights of approximately 68, 62, 50, 48, 42, 34, 28, 26, 22 and 19 kDa. Antibody titers of between 1:256 and 1:32000 were observed using IHA, with a significant drop in activity after treatment with 2-mercapto-ethanol between days 12 and 48. This coincided with the parasitaemic period that occurs between 5 and 64 days after inoculation.     

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   

Examination of cats for the elimination of Toxoplasma gondii oocysts]

Two hundred and two samples of excrements were investigated for the presence of Toxoplasma gondii oocysts. Fifty-two samples were taken from dead domestic cats and a hundred and fifty samples were obtained from wild cats living in various localities of the CSSR. The investigation was orientative and a flotation method with the Breza flotation solution of the specific weight of 1.300 was used. If the finding was positive, residues of the excrements were floated with a saccharose, solution of the specific weight of 1.150 and containing 0.8% of phenol. The oocysts were rinsed several times, then they were sporulated in Petri dishes with water with a 2.5% solution of potassium dichromate. The sporulated oocysts, after rinsing, were injected i. p. to mice. The excrements of the fifty-two domestic cats were negative. Out of a hundred and fifty samples of the excrements of wild cats, one sample with the oocysts of isospore type was found; a biological test with mice proved the oocysts of Toxoplasma gondii. It may be inferred from the results obtained that the elimination of oocysts by cats is the same as given in foreign literature, and the occurrence rate will be about 2%.     

Seroprevalence of Toxoplasma gondii infection in goats and sheep in Zimbabwe

Seroprevalence rates of Toxoplasma gondii anti-antibodies in adult goats and sheep from different parts of Zimbabwe were determined. A total of 225 (67.9%) of the 335 serum samples tested were positive for anti-T. gondii IgG antibodies with the indirect fluorescent antibody test. There were differences in antibody seroprevalences among communal land goats from the different agro-ecological zones (Natural regions llb and III: 80 and 96.7%, respectively; Natural region IV: 65.9%; Natural region V: 45%; and Natural region III had a significantly higher seroprevalence than IV and V. The highest seroprevalences found in Natural regions II b and Ill are likely to be linked to the existence of more households and hence the possibility of a higher concentration of domestic cats that increases the chances of environmental contamination with their faeces harbouring T. gondii oocysts. The seroprevalence rate in sheep from a large commercial farm (10%) was significantly lower than that of sheep reared under the communal grazing system (80%). Overall, significantly higher proportions of seropositive animals had antibody titres of 1:50 (34.2% of 225) and 1:100 (44% of 225) as compared to the 9.8% and 12% with antibody titres of 1:200 and > or =1:400, respectively.     

Sarcocystis capracanis and Toxoplasma gondii infections in range goats from Texas

Specimens of tongues, esophagi, diaphragms, or abdominal muscles of 115 range goats from San Angelo, Tex, were examined for Sarcocystis and Toxoplasma gondii infections. Sarcocystis spp zoites were found microscopically in pepsin digests of muscles of 60.8% goats and sarcocysts of S capracanis were found in histologic sections of 27.8% goats. Sarcocysts were more common in sections of tongue (19.1%) than in those of other muscles (9.9% to 10.7%). A dog fed Sarcocystis-infected tissues shed sporocysts in feces, whereas 2 cats fed the same tissues did not shed sporocysts. Toxoplasma gondii was neither seen in histologic sections of goat tissues nor found by bioassays in mice or cats. Mice inoculated with pepsin digests of muscles did not develop T gondii infection and 2 cats fed goat tissues did not shed oocysts. Also, antibody to T gondii was not found in serum samples from goats. The low prevalence of T gondii infection in range goats may be because of the relative absence of domestic cats on Texas ranges.     

Seroprevalence of Toxoplasma gondii and Neospora caninum infections in goats in Poland

In 2007 a survey on herd-level seroprevalence of Toxoplasma gondii and Neospora caninum infections in goats in Poland was carried out. Sera were collected from all 49 breeding goat herds, scattered over the entire country, with the vast majority of them located in the western, central and northern provinces. Only adult females (≥12 months of age) were included in the study. A herd was recorded as infected if at least one seropositive female was detected. In each herd, simple random sampling was applied and sample size was determined in a way, which allowed to evaluate serological status of a herd at expected individual-level seroprevalence 10% and level of confidence 95%. In total, 1060 sera were tested using two commercial indirect ELISA kits. Sera positive to N. caninum were subsequently confirmed with IFAT. The true herd-level seroprevalence was 100% for T. gondii and 9.0% for N. caninum infection. Three herds positive to T. gondii infection were randomly selected and all adult goats were tested with an ELISA. Individual-level true seroprevalence in these herds ranged from 30.2% to 100%. This is the first time that antibodies to N. caninum have been detected in goats in Poland.     

Seroprevalence of Toxoplasma gondii and Neospora caninum in dairy goats from Romania

Little information is available about the seroprevalence of Toxoplasma gondii and Neospora caninum infections in goats in Romania and even in Europe. During 2007-2010, 735 serum samples were collected from dairy goats located in 4 historical regions (Cri?ana, Maramure?, Transylvania and Muntenia) of Romania. Sera were analyzed for T. gondii and N. caninum antibodies (IgG type) by enzyme-linked immunosorbent assay (ELISA) using two commercial kits (Chekit Toxotest Antibody ELISA and Chekit Neospora caninum Antibody ELISA; Idexx-Bommeli, Switzerland). Three hundred and eighty-eight out of 735 (52.8%) goats presented T. gondii antibodies and 12 out of 512 (2.3%) goats had N. caninum antibodies. The high seroprevalence of T. gondii suggests that infection with this parasite is common in dairy goats in Romania, and less common the infection with N. caninum. This is the first time that infection with N. caninum in goats has been reported in Romania and the first extended study on seroepidemiology of T. gondii.     

Seroprevalence of Toxoplasma gondii infection in domestic goats in Satun Province, Thailand

Goats are important domestic animals in the south of Thailand due to the minimal cost of rearing and maintaining them, and their production of both meat and milk. Toxoplasmosis is one of the most threatening parasitic zoonoses and the causative agent Toxoplasma gondii uses a wide range of warm-blooded intermediate hosts including the goat. The objective of this study was to assess the seroprevalence of antibodies to T. gondii in goats of Satun Province in Thailand. A total of 631 goat sera were examined for antibodies against toxoplasmosis with commercial latex agglutination test kits (Toxocheck-MT 'Eiken'). Of these, 176 (27.9%) were found to be positive to T. gondii; antibody titers ranged from 1:64 to 1:4096 (1:64 cut-off). Female goats were 1.73 times more likely than male to be seropositive (odds ratio [OR]=1.73; 95% confidential interval [CI]=1.11, 2.73). Dairy goats were more likely to be seropositive than meat goats (OR=1.36; 95% CI=0.84, 2.20). Goats were infected with T. gondii with acquisition of age because older goats were more likely to be seropositive than young goats under 1-year-old (for 1-2 years, OR=19.6; 95% CI=0.92, 4.15, for >2 years, OR=2.70; 95% CI=1.26, 5.80). The high seroprevalence of T. gondii antibodies found in the present study suggested widespread exposure of goats in Satun Province to T. gondii.     

Comparison of different commercial DNA extraction kits to detect Toxoplasma gondii oocysts in cat faeces

The cat is the definitive host of Toxoplasma gondii and plays an important role in the transmission of this and other coccidian parasites, e.g. Hammondia hammondi, a protozoon closely related and morphologically similar to T. gondii. A number of techniques to detect T. gondii nucleic acids in feline faeces are described and several extraction kits for isolating pathogen DNA from faeces or soil are commercially available. To compare the performance of such kits with regard to isolating oocyst DNA, a feline sample that had tested negative for coccidian parasites including T. gondii and H. hammondi was spiked with 10(4), 10(3), 10(2), 50 and 10 H. hammondi oocysts. Several ready-to-use stool or soil kits and an in-house method were then used to extract parasite DNA from these spiked faecal samples. Of six kits tested, two were found suitable for the detection of H. hammondi oocysts DNA by the polymerase chain reaction (PCR) in faecal samples with a detection limit of 250 oocysts per 1 g of faecal sample. These two kits revealed a similar, even slightly lower detection limit (50 oocysts per 1 g of sample) when tested with faecal samples spiked with T gondii oocysts.     

Effects of ozone and ultraviolet radiation treatments on the infectivity of Toxoplasma gondii oocysts

Clinical toxoplasmosis in humans has been epidemiologically linked to the consumption of drinking water contaminated by Toxoplasma gondii oocysts. We evaluated killing of T. gondii oocysts after ultraviolet (UV) or ozone treatments by bioassay in mice and/or cell culture. A 4-log inactivation of the oocyst/sporozoite infectivity was obtained for UV fluences >20 mJ cm(-2). In contrast, oocysts were not inactivated by ozone with an exposure (Ct) up to 9.4 mg min l (-1) in water at 20 degrees C. In conclusion, UV treatment can be an effective disinfection method to inactivate T. gondii oocysts in drinking water, but ozone did not show promise in this research.     

Analysis of IgG response to experimental infection with RH Toxoplasma gondii in goats.

The IgG response of goats experimentally infected with RH Toxoplasma gondii has been analysed using an indirect ELISA and Western-blot analysis. Specific IgG antibodies were first detected at 14 days post-inoculation (p.i.), reaching a peak by day 35 p.i. and showing slight fluctuations until the end of the experiment (91 p.i.). Specific IgG showed a reactivity over a whole range of peptides (125-24 kDa approximately), but the highest reactivity was observed against a group of antigens with a molecular weight between 34 and 28 kDa, in particular against a 30 kDa fraction which is considered to represent the major surface protein of T. gondii named p30 or SAG-1.     

Titration of Toxoplasma gondii oocysts in non-pregnant sheep and the effects of subsequent challenge during pregnancy

Fifty-nine ewes, seronegative to Toxoplasma gondii, were allocated to four groups which received 2000, 200, 20 or no M1 strain toxoplasma oocysts 56 days before mating. Fifty-one of them subsequently became pregnant and were challenged with 10,000 oocysts between 78 and 83 days of gestation. Infection with 2000 oocysts induced a pyrexia, seroconversion and protective immunity in all the recipient animals. Ewes that received either 20 or no oocysts before pregnancy were susceptible to subsequent challenge and severe fetal mortality occurred. In this study 200 oocysts was the threshold value for the induction of toxoplasma infection in sheep, although not all the ewes that seroconverted to this dose were protected against further challenge.     

Seroprevalence of Toxoplasma gondii infection in domestic sheep and goats in Borno state,Nigeria

Serum samples were collected from 372 sheep and same number of goats from the three geopolitical zones of Borno state, Nigeria. The samples were tested for the presences of Toxoplasma gondii antibodies by enzyme-linked immunosorbent assay. Of these, 6.7% (25/372) and 4.6% (17/372) of sheep and goats, respectively, were found to be seropositive to T. gondii antibodies, both far less than the estimated global average of 31%. Results were statistically analyzed by chi-square (χ²) test. The results showed that age, environmental conditions, and farm location are the main determinants of prevalence of antibodies against T. gondii in the study area. Older animals (>3 years) are significantly more infected than younger animals (between 6 months and 1 year).The prevalence of anti T. gondii antibodies is significantly higher (P < 0.05) in both sheep and goats sampled from the southern zone than the northern zone. Animals from the southern zones are about four times more likely to be exposed to T. gondii infection than those in the northern zone, (sheep; odds ratio (OR) = 4.25, 95% confidence interval (CI) = 1.177–15.36, P = 0.018), (goats; OR = 4.38, 95% CI = 0.925–20.73, P = 0.04). Farm location in urban area was identified as a risk factor for sheep (OR = 6.06, 95% CI = 2.53–14.54, P = 0.000), and goats (OR = 4.99, 95% CI = 1.59–15.62, P = 0.004). Current data on prevalence of ovine and caprine T. gondii in Borno state are provided by the study as well as identifying the main risk factors associated with T. gondii infection in the area.     

Serologic response of red-legged partridges (Alectoris rufa) after oral inoculation with Toxoplasma gondii oocysts

Thirty 5-month-old red-legged partridges (Alectoris rufa) reared in battery were divided into five groups: 4 birds in group A, 14 birds in group B, 4 birds in group C, 4 birds in group D and 4 birds in group E, and were inoculated orally with 10, 50, 10(2), 10(3) and 10(4) oocysts of the OV-51/95 strain of Toxoplasma gondii, respectively. During the experiment, blood samples from all birds were drawn every 3-7 days and at necropsy. Serologic response was measured by the modified agglutination test (MAT) and the latex agglutination test (LAT). One bird from each group was killed at 44, 58, 65 and 72 days after inoculation (DAI). From 72 DAI to the end of the experiment, surviving partridges from group B were killed at weekly intervals. The last partridges were sacrified 100 DAI. MAT was the most sensitive and specific test for detecting T. gondii antibodies in the birds. First positive titers were detected by MAT in all sera on 7 DAI, but titers by LAT did not appear until 13 DAI. Antibody titers detected by MAT on 7 DAI were higher in the partridges with the largest inocula (10(3) or 10(4) oocysts) than those inoculated with 10, 50 or 10(2) oocysts. All surviving birds developed a serologic response to T. gondii, with maximum titers of 512-32,768 in the MAT on 13-17 DAI, and positive titers persisted at least until 100 DAI. To the contrary, LAT reveals only very low antibody titers even in partridges inoculated with the highest dose of T. gondii.     

Isolation of Toxoplasma gondii from goats with history of reproductive disorders and the prevalence of Toxoplasma and chlamydial antibodies

The prevalence of antibodies to Toxoplasma gondii and Chlamydia psittaci was assessed in goats with a history of abortion, stillbirth and neonatal mortality. Antibodies were detected in 540 (30%) and 57 (3.2%) goats out of 1799 tested by indirect haemagglutination and complement fixation tests, respectively. Toxoplasma gondii was isolated for the first time in Botswana from 22 out of 81 sets (27.2%) of foetal tissues, maternal and foetal cotyledons and uterine tissues of goats which had previously aborted or given birth to stillborn or weak kids that died within two days of birth. These results implicate T. gondii and C. psittaci, but especially the former, to be associated with caprine reproductive problems and require appropriate control measures.     

Development of lesions and tissue distribution of parasite in lambs orally infected with sporulated oocysts of Toxoplasma gondii

The host-pathogen interaction is as a key feature during the formation of tissue cysts of Toxoplasma gondii within intermediate hosts. In this study, we investigated whether oral infection of lambs with T. gondii oocysts may be used as an experimental model in sheep to study this interaction, with the main objective being to detect the presence and distribution of lesions and parasite within different organs at different time points after oral infection. Lambs were infected with 5 × 10(3) and 5 × 10(5) sporulated T. gondii oocysts and culled at 2, 3, 5 and 6 weeks post-infection (WPI). During the infection, rectal temperature of the animals and serological antibodies against T. gondii were monitored. The presence of inflammatory lesions and parasite were evaluated through histological and immunohistochemical methods at different organs (brain, liver, lung, heart and lymph nodes). The lambs showed no clinical signs other than fever, and lesions appeared mainly in the brain, characterized by glial foci and perivascular cuffs, and in the heart, denoted by foci of interstitial myositis. Tissue cysts and tachyzoite-like structures were observed at all time points studied in the brain, where together with the glial foci they appeared mainly in the cerebral cortex of the forebrain and in the midbrain, but also in the heart, lung and lymph nodes. This study shows that oral infection with sporulated oocysts in lambs may provide a model for investigating the host-parasite interaction in situ during the development of tissue cysts.