• Parasites, Hosts and Diseases
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• v.31 no.1
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• pp.31-36
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• 1993

This study was performed to evaluate differences of T cell subsets according to the injection period of recombinant mouse $interferon-{\gamma}{\;}(IFN-{\gamma}$ in acute Toxoplasma gondii infection. Each mouse was infected intraperitoneally with 100 cysts of Beverley strain T. gondii, and injuten with $5{\;}{\times}{\;}10^4$ units of $IFN-{\gamma}$ every other day two tares. The percentage of Thy-1, 2 cells and L3T4/Ly-2 cell ratio were significantly increased in the mice that received two doses of $IFN-{\gamma}$ on days 2 and 0 before infection, or days 0 and 2 after infection. The percentage of Ly-2 cells decreased in the $IFN-{\gamma}$ injected groups at th\ulcorner 3rd and 4th week after infection. The results suggest that administration of $IFN-{\gamma}$ to T gonnii-infected mice improves the changed population of T cell subsets to a normal state, especially when $IFN-{\gamma}$ was infected just after the infection.

• Parasites, Hosts and Diseases
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• v.50 no.4
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• pp.287-293
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• 2012

Knowledge of the prevalence of human Toxoplasma gondii infection is required in the Republic of Korea. In this study, we surveyed the seroprevalence of T. gondii infection and analyzed the risk factors associated with seropositivity among residents in 2 administrative districts; Seoul and the island of Jeju-do, which have contrasting epidemiologic characteristics. Sera and blood collected from 2,150 residents (1,114 in Seoul and 1,036 in Jeju-do) were checked for IgG antibody titers using ELISA and for the T. gondii B1 gene using PCR. In addition, participants completed a questionnaire that solicited information on gender, age, occupation, eating habits, history of contact with animals, and travel abroad. The T. gondii B1 gene was not detected in all residents examined. However, ELISA showed 8.0% (89 of 1,114 sera) positive for IgG antibodies against T. gondii in Seoul and 11.3% (117 of 1,036 sera) in Jeju-do. In both districts, the positive rates were higher in males than in females, and those 40-79 years of age showed higher rates than other ages. In Seoul, residents older than 70 years of age showed the highest positive rate, 14.9%, whereas in Jeju-do the highest prevalence, 15.6%, was in those in their sixties. The higher seropositive rate in Jeju-do than in Seoul may be related to eating habits and occupations. The present results and a review of related literature are indicative of an increased seroprevalence of T. gondii in Korea in recent years.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.641-647
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• 1992

This study was conducted to determine the serum antibodies against toxoplasma in the artificially infected dogs, pet and street dogs by latex agglutination (LA) and indirect fluorescent antibody (IFA) test. LA test was carried out with commercial Toxo-MT kit (Eiken chemical Co.) and IFA test was carried out with rabbit-anti-dog IgG labelled with FITC (Cappel Co.) and toxo-antigen slides prepared in laboratory. The results obtained were as follows ; 1. Antibodies to Toxoplasma gondii in the artificially infected dogs were detected firstly at the Day 8 in IFA and Day 9 in LA test after inoculation. Positive antibody reactions by these tests were declined gradually afterward but maintained up to 12 weeks. 2. In LA test serum antibody titers in 310 test sera were shown as 10 cases(32%) in 1 : 32.5(1.0%) in 1 : 64, 4(1.3%) in 1 : 128 and 2(0.7%) in 1 : 256. In IFA test serum antibody titers 310 test sera were shown as 17 cases(5.5%) in 1 : 64, 8(2.6%) in 1 : 128 and 5(1.6%) in 1 : 256. 3. In the total of 310 sera from pet and street dogs toxoplasma antibody positive rates were 21 cases (6.8%) by LA and 30 cases (9.7%) by IFA test and the positive detection rates between these two groups by LA and IFA test were not significant(p<0.05). 4. In the total of 115 sera from pet dogs toxoplasma antibody positive rates were 12 cases(10.4%) by LA and 15(13.0%) by IFA test. And in the 195 street dogs the positive rates were 9 cases(4.6%) by LA and 15(7.7%) by IFA test. Also, the positive detection rates between these two groups by LA and IFA test were not significant(p<0.05). 5. Agreement of reactivity between LA and IFA test for 310 sera was 91.3% in total of 283 cases consisting of 12 cases(3.9%) of both LA and IFA positive and 271 cases(87.4%) of LA and IFA negative. 6. LA test was almostly equivalent to the IFA test in producibility and proved to be a simple tool for the screening of toxoplasma antibody in laboratory.

• Parasites, Hosts and Diseases
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• v.31 no.4
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• pp.363-370
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• 1993

This study was performed to evaluate the prophylactic effects of trimethoprim- sulfamethoxazole (TMP-SMZ) In mice experimentally infected with virulent RH strain and avirulent Beverley strain of T dognii. The mice infected with $1{\times}10^5$ tachyzoltes were used In the measurement of mean survival days, and the mice infected with 10 cysts were used In the tltratlons of specific antibodies and enumeration of brawn cysts. Mean survival days of mice were significantly increased In mice treated with TMP-SMZ as compared with splramycln-treated and untreated control group. Mean survival days and survival rates of mice were Increased according to the Increment of dosages, and TMP-SMZ protected 100% of mice after fifteen daily dose of 24 mg/mouse or more admlnlsted orally. Toxoplasma-specific serum IgG and IgM antibody titers were slgnlflcantly lower in mice treated with TMP-SMZ than those of splramycln-treated and untreated control group. Toxoplosma cysts were not found In mice treated with TMP-SMZ at a dose of 24 mg/mouse or more per day but the group of splramycin treatment and untreated controls were found in the brain from 20 days after Infection. The present results revealed that TMP-SMZ can be used as a prophylactic agent against murine toxoplasmosls after Intraperitoneally challenges with the virulent or avlrulent strain of T. gondii.

• Parasites, Hosts and Diseases
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• v.53 no.2
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• pp.155-162
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• 2015

Toxoplasma gondii is a protozoan parasite with a broad range of intermediate hosts. Chickens as important food-producing animals can also serve as intermediate hosts. To date, experimental studies on the pathogenicity of T. gondii in broiler chickens were rarely reported. The objective of the present study was to compare the pathogenicity of 5 different T. gondii strains (RH, CN, JS, CAT2, and CAT3) from various host species origin in 10-day-old chickens. Each group of chickens was infected intraperitoneally with $5{\times}10^8$, $1{\times}10^8$, $1{\times}10^7$, and $1{\times}10^6$ tachyzoites of the 5 strains, respectively. The negative control group was mockly inoculated with PBS alone. After infection, clinical symptoms and rectal temperatures of all the chickens were checked daily. Dead chickens during acute phage of the infection were checked for T. gondii tachyzoites by microscope, while living cases were checked for T. gondii infection at day 53 post-inoculation (PI) by PCR method. Histopathological sections were used to observe the pathological changes in the dead chickens and the living animals at day 53 PI. No significant differences were found in survival periods, histopathological findings, and clinical symptoms among the chickens infected with the RH, CN, CAT2, and CAT3 strains. Histopathological findings and clinical symptoms of the JS (chicken origin) group were similar to the others. However, average survival times of infected chickens of the JS group inoculated with $5{\times}10^8$ and $1{\times}10^8$ tachyzoites were 30.0 and 188.4 hr, respectively, significantly shorter than those of the other 4 mammalian isolates. Chickens exposed to $10^8$ of T. gondii tachyzoites and higher showed acute signs of toxoplasmosis, and the lesions were relatively more severe than those exposed to lower doses. The results indicated that the pathogenicity of JS strain was comparatively stronger to the chicken, and the pathogenicity was dose-dependent.

• Parasites, Hosts and Diseases
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• v.58 no.5
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• pp.487-492
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• 2020

Toxoplasmosis is caused by an obligate intracellular protozoan parasite; Toxoplasma gondii, which is one of the most important zoonotic parasite worldwide. In dogs, the sexual reproductive cycle of T. gondii is lacking, and the animals are not widely consumed as food, but they are vital in the mechanical transmission of the parasite. However, there is no present data on the exposure of stray dogs to T. gondii in Malaysia. The objective of this serological survey was to determine the prevalence of T. gondii antibodies (IgG) and associated factors in stray dogs in East and West Malaysia. Antibodies to T. gondii were determined in serum samples from 222 stray dogs from 6 different states in East and West Malaysia (Peninsular Malaysia) using an Indirect ELISA. The seroprevalence for T. gondii was 23.4% (Confidence interval: CI 17.8-29.2%). Stray dogs from Selangor and Kuala Lumpur had the highest seroprevalence (32.4%; CI 13.2-45.5%) and lowest in those from Penang and Kedah (12.5%; CI 1.3-23.5%). Gender and breed were not associated with T. gondii seropositivity. However, adult dogs were more likely to be seropositive for T. gondii (OR=2.89; CI 1.1-7.7) compared with younger dogs. These results revealed that T. gondii is prevalent in stray dogs in the studied areas in Malaysia, and indicative of the level of environmental contamination of this parasite especially in urban areas.

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.249-258
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• 1994

Recently, the importance of toxoplasmosis is raised as a complication in immunosuppressed or AIDS patients. Our study focused on the identification of a variety of Toxoplasma antigens by immunoblotting. Rabbits and BALB/c mice were immunized with Toxoplosmo Iysate (RH strain) , frozen tachyzoites (RH strain) or cysts (Beverly and Fukaya strain) . Blood were collected from ear vein, heart or orbital plexus for detecting the serum antibody levels. For excretory-secretory (E.S) antigens, T gondii (RH) tachyzoite were cultured in CHL (Chinese hamster lung) cells with MEM containing of 5% FCS. After 72hrs, culture supernatant was collected. BALB/c mice were inoculated with RH tachyzoite intraperitoneally and peritoneal fluids were extracted three days later. E.S antigens were detected in culture supernatant and infected mouse peritoneal fluid by EITB. Serum IgG levels in rabbit were 1 :512 of 10 days after primary immunization, 1 : 2,048 of 10 days after secondary immunization, 1: 1,024 of 20 days after secondary immunization by IFAT, respectively. Serum IgG levels of immunized mice were 1:128 after 7 weeks. Tachyzoite antigens of the RH strain were detected 25 protein bands ranging 10 kDa-220 kDa of molecular weights with Coomassie blue stain. Toxoplcsma major antigens corresponding to n of 24 kDa, 27 kDa,30 kDa, 35 kDa, 38 kDa were recognized by IgG and IgM antibodies. Excretory-secretory antigens present in culture supernatant with M. W. of 20, 30 kDa and in infected mouse peritoneal fluid with M.W. of 33 (P30), 45 kDa. When RH tachyzoite antigen was probed with different mice sera immunized with 2 strains of T gondii, the IgG antibody bud of Fukaya and Beverly strain (8 week-serum) is identical to those of RH strain. It is considered that the 30 kDa polypeptide detected in excretory- secretory materials and Iysate was important major antigen of T gondii (RH).