Displaying publications 61 - 80 of 141 in total

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  1. Evaluation of Toxoplasma gondii-recombinant dense granular protein (GRA2) for serodiagnosis by western blot
    Ching XT, Lau YL, Fong MY, Nissapatorn V
    Parasitol Res, 2013 Mar;112(3):1229-36.
    PMID: 23274488 DOI: 10.1007/s00436-012-3255-5
    Toxoplasma gondii infects all warm-blooded animals including humans, causing serious public health problems and great economic loss in the food industry. Commonly used serological tests involve preparation of whole Toxoplasma lysate antigens from tachyzoites which are costly and hazardous. An alternative method for better antigen production involving the prokaryotic expression system was therefore used in this study. Recombinant dense granular protein, GRA2, was successfully cloned, expressed, and purified in Escherichia coli, BL21 (DE3) pLysS. The potential of this purified antigen for diagnosis of human infections was evaluated through western blot analysis against 100 human serum samples. Results showed that the rGRA2 protein has 100 and 61.5 % sensitivity towards acute and chronic infection, respectively, in T. gondii-infected humans, indicating that this protein is useful in differentiating present and past infections. Therefore, it is suitable to be used as a sensitive and specific molecular marker for the serodiagnosis of Toxoplasma infection in both humans and animals.
    Matched MeSH terms: Toxoplasmosis/diagnosis*; Toxoplasmosis/immunology
  2. Fulltext Toxoplasmosis in HIV/AIDS patients in Malaysia
    Nissapatorn V, Lee CK, Cho SM, Rohela M, Anuar AK, Quek KF, et al.
    Southeast Asian J. Trop. Med. Public Health, 2003;34 Suppl 2:80-5.
    PMID: 19238664
    Three hundred and one sera of HIV/AIDS patients were tested for anti-Toxoplasma IgG antibody by ELISA technique. The seroprevalence of toxoplasmosis was 41.2% (95% CI: 35.5-46.9) in HIV/AIDS patients. The seroprevalence was significantly higher in the Malay (57.9%) than the Chinese (38.7%), followed by the Indian patients (29.6%) (p<0.05). No possible risk factor, such as contact with cats, consumption of uncooked meat, and history of blood transfusions was found to have any significant association with the presence of anti-Toxoplasma antibody in the study sample (p>0.05). Multivariate analysis was employed to find any association between Toxoplasma seroprevalence and a single subject having single or multiple risk factors. It was found that the association was not statistically significant (p>0.05). Among the HIV/AIDS study samples, 124 (41.2%) samples were found to have positive anti-Toxoplasma antibody, the association between the presence of anti-Toxoplasma antibody and CD4 cell count was determined but no statistically significant association was found (p>0.05). During the study period, only one case of active CNS toxoplasmosis was registered and the diagnostic criteria included: clinical presentations, CT scan finding, serological evidence of anti-Toxoplasma IgG antibody, and respose to anti-Toxoplasma therapy.
    Matched MeSH terms: Toxoplasmosis/complications*; Toxoplasmosis/epidemiology*
  3. Fulltext Distribution of anti-Toxoplasma gondii antibodies among Orang Asli (aborigines) in Peninsular Malaysia
    Hakim SL, Radzan T, Nazma M
    Southeast Asian J. Trop. Med. Public Health, 1994 Sep;25(3):485-9.
    PMID: 7777912
    The distribution of anti-toxoplasma antibodies among the aborigines in Malaysia and its association with other soil transmitted infections and eosinophilia were studied. A total of 415 serum samples were collected and tested by IFA test. Overall prevalence was 10.6%, lower than previously reported. The antibody titers showed a unimodal distribution peaking at 1:8 dilution. There was a higher proportion of high antibody titer (> 1:128) in the adult compared to the children with no significant difference in prevalence rate by sex. The pattern of infection does not differ from other soil transmitted infections and there was no association between raised Toxoplasma antibodies with eosinophilia.
    Matched MeSH terms: Toxoplasmosis/complications; Toxoplasmosis/epidemiology*
  4. Fulltext Review on human toxoplasmosis in Malaysia: the past, present and prospective future
    Nissapatorn V, Abdullah KA
    Southeast Asian J. Trop. Med. Public Health, 2004 Mar;35(1):24-30.
    PMID: 15272740
    We reviewed various studies regarding human toxoplasmosis in Malaysia. They showed a varying prevalence of specific Toxoplasma antibodies among the Malaysian population. The Malays have shown the highest seroprevalence of toxoplasmosis, by most studies, when compared to other races. Demographic profiles have shown that Toxoplasma seropositivity is higher in males than females, lower in people with higher incomes, higher in the unemployed and tends to increase with age. In general, the route of transmission, such as contact with a cat, consumption of undercooked meat and blood transfusion were shown to have no significant association with Toxoplasma seropositivity (p > 0.05). The immune status (CD4 cell count < 200 cell/mm3) was strongly associated with toxoplasmic encephalitis (p < 0.05).
    Matched MeSH terms: Toxoplasmosis/diagnosis*; Toxoplasmosis/epidemiology*
  5. Fulltext IgG avidity assay: a tool for excluding acute toxoplasmosis in prolonged IgM titer sera from pregnant women
    Emelia O, Rahana AR, Mohamad Firdaus A, Cheng HS, Nursyairah MS, Fatinah AS, et al.
    Trop Biomed, 2014 Dec;31(4):633-40.
    PMID: 25776588 MyJurnal
    An accurate diagnosis for toxoplasmosis is crucial for pregnant women as this infection may lead to severe sequelae in the fetus. The value of IgG avidity assay as a tool to determine acute and chronic toxoplasmosis during pregnancy was evaluated in Universiti Kebangsaan Malaysia Medical Centre (UKMMC). In this study, 281 serum samples from 281 pregnant women in various trimesters were collected. These samples were assayed using specific anti-Toxoplasma IgM and IgG antibodies, followed by IgG avidity test. The overall seroprevalence of toxoplasmosis in pregnant women was 35.2% (33.5% for anti-Toxoplasma IgG and 1.8% for both anti-Toxoplasma IgG and IgM antibodies). Of 5 (1.8%) serum samples positive for IgM ELISA, 4 had high-avidity antibodies, suggesting past infection and one sample with borderline avidity index. Two samples with low avidity were from IgM negative serum samples. The IgG avidity assay exhibited an excellent specificity of 97.6% and a negative predictive value (NPV) of 95.6%. The study also demonstrated no significant correlation between avidity indexes of the sera with IgG (r=0.12, p=0.24) and IgM (r=-0.00, p=0.98), suggesting the complementary needs of the two tests for a better diagnosis outcome. These findings highlight the usefulness of IgG avidity assay in excluding a recently acquired toxoplasmosis infection in IgM-positive serum sample.
    Matched MeSH terms: Toxoplasmosis/diagnosis*; Toxoplasmosis/epidemiology
  6. Fulltext Unusual manifestation of cutaneous toxoplasmosis in a HIV-positive patient
    Fong MY, Wong KT, Rohela M, Tan LH, Adeeba K, Lee YY, et al.
    Trop Biomed, 2010 Dec;27(3):447-50.
    PMID: 21399585 MyJurnal
    We report a case of unusual cutaneous toxoplasmosis manifestation in a HIV-positive patient. He presented with hard and painful nodular lesions on the arms, hands and chest. Serology tests for anti-Toxoplasma antibody were negative. However, histopathologic examination of the lesion revealed foci of macrophages containing crescent-shaped organisms resembling the zoites of the protozoan parasite Toxoplasma gondii. Ultrastructure examination under electron microscopy and PCR confirmed the organism as T. gondii.
    Matched MeSH terms: Toxoplasmosis/diagnosis*; Toxoplasmosis/pathology*
  7. Fulltext Identification, production and assessment of two Toxoplasma gondii recombinant proteins for use in a Toxoplasma IgG avidity assay
    Teh AY, Amerizadeh A, Osman S, Yunus MH, Noordin R
    Pathog Glob Health, 2016 Oct-Dec;110(7-8):277-286.
    PMID: 27697019
    The IgG avidity assay is an important tool in the management of suspected toxoplasmosis in pregnant women. This study aimed to produce new Toxoplasma gondii recombinant proteins and to assess their usefulness in an IgG avidity assay. Toxoplasma positive and negative serum samples were used, the former were categorized into low (LGA) and high (HGA) IgG avidity samples. Immunoblots were performed on 30 T. gondii cDNA clones to determine the reactivity and IgG avidity to the expressed proteins. Two of the clones were found to have diagnostic potential and were analyzed further; AG12b encoded T. gondii apical complex lysine methyltransferase (AKMT) protein and AG18 encoded T. gondii forkhead-associated (FHA) domain-containing protein. The His-tagged recombinant proteins, rAG12b and rAG18, were expressed and tested with LGA and HGA samples using an IgG avidity western blot and ELISA. With the IgG avidity western blot, rAG12b identified 86.4% of LGA and 90.9% of HGA samples, whereas rAG18 identified 81.8% of both LGA and HGA samples. With the IgG avidity ELISA, rAG12b identified 86.4% of both LGA and HGA samples, whereas rAG18 identified 77.3% of LGA and 86.4% of HGA serum samples. This study showed that the recombinant antigens were able to differentiate low avidity and high avidity serum samples, suggesting that they are potential candidates for use in the Toxoplasma IgG avidity assay.
    Matched MeSH terms: Toxoplasmosis/immunology*; Toxoplasmosis/parasitology
  8. Fulltext Seroprevalence of Toxoplasma gondii Infection in Refugee and Migrant Pregnant Women along the Thailand-Myanmar Border
    van Enter BJD, Lau YL, Ling CL, Watthanaworawit W, Sukthana Y, Lee WC, et al.
    Am J Trop Med Hyg, 2017 Jul;97(1):232-235.
    PMID: 28719309 DOI: 10.4269/ajtmh.16-0999
    Toxoplasma gondii primary infection in pregnancy is associated with poor obstetric outcomes. This study aimed to determine the seroprevalence of Toxoplasma infection in pregnant migrant and refugee women from Myanmar attending antenatal care in Thailand. A random selection of 199 residual blood samples from first antenatal screen in 2014-2015 was tested for Toxoplasma IgG and IgM antibodies. Seroprevalence of Toxoplasma infection was 31.7% (95% confidence interval = 25.6-38.4). Avidity testing in the three positive IgM cases indicated all were past infections. Multiparity (≥ 3 children) was significantly associated with higher Toxoplasma seropositivity rates. Seroprevalence of T. gondii infection in this pregnant population is similar to the only other report from Myanmar, where multiparity was also identified as a significant association. Toxoplasma infection is important in pregnant women. Nevertheless, in this marginalized population, this infection may be given less priority, due to resource constraints in providing the most basic components of safe motherhood programs.
    Matched MeSH terms: Toxoplasmosis/blood*; Toxoplasmosis/epidemiology
  9. Fulltext Occurrence of Toxoplasma gondii antibodies and associated risk factors in women in selected districts of Punjab province, Pakistan
    Ali S, Amjad Z, Khan TM, Maalik A, Iftikhar A, Khan I, et al.
    Parasitology, 2020 Sep;147(10):1133-1139.
    PMID: 32517832 DOI: 10.1017/S0031182020000967
    Toxoplasmosis is a parasitic zoonotic disease caused by Toxoplasma (T.) gondii. Limited data are available on the occurrence of T. gondii in women especially pregnant women in Pakistan. The present study aimed to determine the occurrence and risk factors associated with T. gondii in pregnant and non-pregnant women in Punjab Province, Pakistan. A cross-sectional study was conducted and 593 samples were collected from pregnant (n = 293) and non-pregnant (n = 300) women of District Headquarter Hospitals of Chiniot, Faisalabad, Jhang and Okara, Pakistan. Data related to demographic parameters and risk factors were collected using a pretested questionnaire on blood sampling day. Serum samples were screened for antibodies (IgG) against T. gondii using ELISA. A univariant and binomial logistic regression was applied to estimate the association between seropositive and explanatory variables considering the 95% confidence interval. P value ⩽0.05 was considered statistically significant for all analysis. Out of 593, 44 (7.42%) women were seropositive for T. gondii IgG antibodies. Occupation, age, sampling location, socioeconomic status, contact with cat, pregnancy status and trimester of pregnancy were significantly associated with seropositivity for T. gondii antibodies. Location and trimester of pregnancy were identified as potential risk factors for T. gondii seropositivity based on binomial logistic regression. Toxoplasma gondii is prevalent in pregnant and non-pregnant women. Therefore, now a necessitated awareness is required to instruct the individuals about these infectious diseases (toxoplasmosis) and their control strategies to maintain the health of human population. Moreover, health awareness among public can help the minimization of T. gondii infection during pregnancy and subsequent risk of congenital toxoplasmosis.
    Matched MeSH terms: Toxoplasmosis/epidemiology*; Toxoplasmosis/parasitology
  10. Fulltext Seropositivity and serointensity of Toxoplasma gondii antibodies and DNA among patients with schizophrenia
    Omar A, Bakar OC, Adam NF, Osman H, Osman A, Suleiman AH, et al.
    Korean J Parasitol, 2015 Feb;53(1):29-34.
    PMID: 25748706 DOI: 10.3347/kjp.2015.53.1.29
    The aim of this cross sectional case control study was to examine the serofrequency and serointensity of Toxoplasma gondii (Tg) IgG, IgM, and DNA among patients with schizophrenia. A total of 101 patients with schizophrenia and 55 healthy controls from Sungai Buloh Hospital, Selangor, Malaysia and University Malaya Medical Center (UMMC) were included in this study. The diagnosis of schizophrenia was made based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The presence of Tg infection was examined using both indirect (ELISA) and direct (quantitative real-time PCR) detection methods by measuring Tg IgG and IgM and DNA, respectively. The serofrequency of Tg IgG antibodies (51.5%, 52/101) and DNA (32.67%, 33/101) among patients with schizophrenia was significantly higher than IgG (18.2%, 10/55) and DNA (3.64%, 2/55) of the controls (IgG, P=0.000, OD=4.8, CI=2.2-10.5; DNA, P=0.000, OD=12.9, CI=2.17-10.51). However, the Tg IgM antibody between patients with schizophrenia and controls was not significant (P>0.005). There was no significant difference (P>0.005) in both serointensity of Tg IgG and DNA between patients with schizophrenia and controls. These findings have further demonstrated the strong association between the active Tg infection and schizophrenia.
    Matched MeSH terms: Toxoplasmosis/immunology; Toxoplasmosis/epidemiology*; Toxoplasmosis/parasitology*
  11. Fulltext Seroepidemiology of toxoplasmosis in renal patients
    Nissapatorn V, Leong TH, Lee R, Init-Ithoi, Ibrahim J, Yen TS
    Southeast Asian J. Trop. Med. Public Health, 2011 Mar;42(2):237-47.
    PMID: 21710842
    Toxoplasmosis is an important parasitic disease in immunosuppressed patients. This prospective study was conducted to determine the seroprevalence, associated risk factors and the incidence of clinically confirmed toxoplasmosis among renal patients at the University of Malaya Medical Center, Kuala Lumpur, Malaysia. We interviewed 247 renal patients, each of whom answered an epidemiological questionnaire, and collected blood samples for measurement of anti-Toxoplasma IgG and IgM antibodies by ELISA. Overall seroprevalence of latent toxoplasmosis was observed in 126 (51%) renal patients. Race (Malays), marital status (married) and primary level of education, were all factors associated with a greater chance of Toxoplasma infection. A case of clinically confirned toxoplasmosis was diagnosed in a renal transplant recipient as a result of immunosuppression. Based on the findings obtained, this preliminary study shows a high prevalence of latent toxoplasmosis in renal patients. Risk factors may have significantly contributed to Toxoplasma acquisition in these patients. We recommend further studies be carried out to monitor for trends in toxoplasmosis among immunosuppressed patients.
    Matched MeSH terms: Toxoplasmosis/complications*; Toxoplasmosis/epidemiology*; Toxoplasmosis/parasitology
  12. Isolation and genotyping of Toxoplasma gondii from free-range ducks in Malaysia
    Puvanesuaran VR, Noordin R, Balakrishnan V
    Avian Dis, 2013 Mar;57(1):128-32.
    PMID: 23678741
    Toxoplasma gondii is a parasitic protozoan that infects nearly one-third of humans. The present study was performed to isolate and genotype T. gondii from free-range ducks in Malaysia. Sera, heads, and hearts from 205 ducks were obtained from four states in Peninsular Malaysia, and 30 (14.63%) sera were found to be seropositive when assayed with the modified agglutination test (MAT > or = 1:6). All the positive samples were inoculated into mice, and T. gondii was successfully isolated from four individual duck samples (1.95%), which were initially found to be strongly seropositive (MAT > or = 1:24). The isolates were subjected to PCR-RFLP analysis, and two T. gondii strains were identified: type I and type II. This is the first reported study on the genetic characterization of T. gondii isolates from free-range farm animals in Southeast Asia.
    Matched MeSH terms: Toxoplasmosis, Animal/blood; Toxoplasmosis, Animal/epidemiology*; Toxoplasmosis, Animal/parasitology
  13. Fulltext Performance of 2 Polymerization Protocols Targeting Cloned Toxoplasma Parasites
    Hanafy NA, Badr MS, Nasr GM
    Open Access Maced J Med Sci, 2018 Sep 25;6(9):1577-1580.
    PMID: 30337968 DOI: 10.3889/oamjms.2018.400
    BACKGROUND: Toxoplasma gondii is a common parasitic infection of humans. Infection is usually mild. Serious complications can occur in pregnant and immunocompromised patients.

    AIM: The present study aims to investigate the performance of 2 different PCR protocols; real-time quantitative molecular assays (qPCR) and conventional molecular assays (cPCR), using 2 different sets of primers and by using cloned purified Toxoplasma genomic substances to be evaluated as reference samples.

    METHODS: The target DNA was provided in 8 different quantities.

    RESULTS: Amplification failure was reported only with the cPCR in samples of low concentrations using both primer sets. Quantitative PCR detected the 8 different dilutions of the purified Toxoplasma gondii using the 2 sets of primers while cPCR was sensitive to detect only 6 different dilutions.

    CONCLUSION: Generally real-time quantitative molecular assays, is easy to use method compared to conventional PCR assay and produces more reliable results within only one hour time but still the possible application of qPCRs in routine diagnosis necessitates analysis of a large number of clinical samples in further studies to make the proper choice.

    Matched MeSH terms: Toxoplasmosis
  14. Fulltext Recent advances in Toxoplasma gondii immunotherapeutics
    Lim SS, Othman RY
    Korean J Parasitol, 2014 Dec;52(6):581-93.
    PMID: 25548409 DOI: 10.3347/kjp.2014.52.6.581
    Toxoplasmosis is an opportunistic infection caused by the protozoan parasite Toxoplasma gondii. T. gondii is widespread globally and causes severe diseases in individuals with impaired immune defences as well as congenitally infected infants. The high prevalence rate in some parts of the world such as South America and Africa, coupled with the current drug treatments that trigger hypersensitivity reactions, makes the development of immunotherapeutics intervention a highly important research priority. Immunotherapeutics strategies could either be a vaccine which would confer a pre-emptive immunity to infection, or passive immunization in cases of disease recrudescence or recurrent clinical diseases. As the severity of clinical manifestations is often greater in developing nations, the development of well-tolerated and safe immunotherapeutics becomes not only a scientific pursuit, but a humanitarian enterprise. In the last few years, much progress has been made in vaccine research with new antigens, novel adjuvants, and innovative vaccine delivery such as nanoparticles and antigen encapsulations. A literature search over the past 5 years showed that most experimental studies were focused on DNA vaccination at 52%, followed by protein vaccination which formed 36% of the studies, live attenuated vaccinations at 9%, and heterologous vaccination at 3%; while there were few on passive immunization. Recent progress in studies on vaccination, passive immunization, as well as insights gained from these immunotherapeutics is highlighted in this review.
    Matched MeSH terms: Toxoplasmosis/therapy*
  15. Fulltext Recombinant dense granular protein (GRA5) for detection of human toxoplasmosis by Western blot
    Ching XT, Lau YL, Fong MY, Nissapatorn V, Andiappan H
    Biomed Res Int, 2014;2014:690529.
    PMID: 24987700 DOI: 10.1155/2014/690529
    Toxoplasma gondii infects all warm-blooded animals, including humans, causing serious public health problems and great economic loss for the food industry. Commonly used serological tests require costly and hazardous preparation of whole Toxoplasma lysate antigens from tachyzoites. Here, we have evaluated an alternative method for antigen production, which involved a prokaryotic expression system. Specifically, we expressed T. gondii dense granular protein-5 (GRA5) in Escherichia coli and isolated it by affinity purification. The serodiagnostic potential of the purified recombinant GRA5 (rGRA5) was tested through Western blot analysis against 212 human patient serum samples. We found that rGRA5 protein was 100% specific for analysis of toxoplasmosis-negative human sera. Also, rGRA5 was able to detect acute and chronic T. gondii infections (sensitivities of 46.8% and 61.2%, resp.).
    Matched MeSH terms: Toxoplasmosis/blood*
  16. Fulltext Genotyping of Toxoplasma gondii isolates from wild boars in Peninsular Malaysia
    Puvanesuaran VR, Noordin R, Balakrishnan V
    PLoS One, 2013;8(4):e61730.
    PMID: 23613920 DOI: 10.1371/journal.pone.0061730
    Toxoplasma gondii is a parasitic protozoan that infects nearly one-third of the world population. The present study was done to isolate and genotype T. gondii from wild boar from forests of Pahang, Malaysia. A total of 30 wild boars' blood, heads and hearts were obtained for this study and 30 (100.0%) were found to be seropositive when assayed with modified agglutination test (MAT ≥ 6). The positive samples were inoculated into mice and T. gondii was only isolated from samples that had strong seropositivity (MAT ≥ 1:24).The isolates were subjected to PCR-RFLP analysis and all the Peninsular Malaysia isolates of T. gondii are of clonal type I.
    Matched MeSH terms: Toxoplasmosis, Animal/parasitology*
  17. Cloning and expression of Toxoplasma gondii dense granule antigen 2 (GRA2) gene by Pichia pastoris
    Lau YL, Fong MY, Idris MM, Ching XT
    Southeast Asian J. Trop. Med. Public Health, 2012 Jan;43(1):10-6.
    PMID: 23082548
    Detection of Toxoplasma gondii infection is essential in pregnant women and immunosuppressed patients. Numerous studies have shown that the recombinant production of several Toxoplasma antigens, including dense granule antigens (GRAs) has high potential as diagnostic reagents. In the present study, we produced GRA2 using Pichia pastoris system. RNA of T. gondii RH strain tachyzoite was used as a template to produce cDNA clones of full-length GRA2 via reverse transcriptase PCR. Amplicons were inserted into pPICZalpha A and the recombinant plasmid transformed into P. pastoris, X-33 strain. The expressed recombinant protein was identified by SDS-PAGE and Western blotting. A recombinant protein of -28 kDa was produced, which could be detected by toxoplasmosis positive human sera indicating that the recombinant protein retained its antigenicity. The present study indicates that P. pastoris-expressed GRA2 should be useful for detection of Toxoplasma infection.
    Matched MeSH terms: Toxoplasmosis/diagnosis
  18. Isolation of viable Toxoplasma gondii cysts from brain samples for oral infection
    Puvanesuaran VR, Ibrahim N, Noordin R, Balakrishnan V
    Eur Rev Med Pharmacol Sci, 2012 Sep;16(9):1179-83.
    PMID: 23047500
    AIM: A method was developed to separate contaminant-free viable Toxoplasma gondii cysts from brain samples of infected mice for molecular biology studies and reinfection.
    MATERIALS AND METHODS: The mice brains were homogenized and washed with phosphate buffered saline (PBS) Tween 80 prior to fractionation using 19-22% dextran solution. Finally, the supernatant was purified by two-step membrane filtration (100-160 microm and < 10 microm) to obtain pure T. gondii cyst. The isolates were analyzed through microscopic observation, qPCR and by reinfection of new batch of mice.
    RESULTS: T. gondii cysts were best isolated with 21% dextran solution and two step filtration.
    CONCLUSIONS: The method was observed not to disrupt the integrity of the cysts containing bradyzoites. In addition, the isolated cysts in the filtrate were found to be contaminant-free, viable and able to infect healthy mice when introduced orally; which, mimics the natural infectivity pathway.
    Matched MeSH terms: Toxoplasmosis, Animal/parasitology*
  19. Optimization for high-level expression in Pichia pastoris and purification of truncated and full length recombinant SAG2 of Toxoplasma gondii for diagnostic use
    Ling LY, Ithoi I, Yik FM
    Southeast Asian J. Trop. Med. Public Health, 2010 May;41(3):507-13.
    PMID: 20578535
    SAG2 is one of the major surface antigens of the intracellular protozoan parasite Toxoplasma gondii. In the present study, truncated recombinant SAG2(S) and full length recombinant SAG2(T) of T. gondii were optimally produced (approximately 15 mg/liter) in Pichia pastoris expression system using BMMY medium at pH 3, 25 degrees C in 0.5-1% methanol and a time-course of 1-2 days. The recombinant proteins were purified using a commercial gel filtration purification system obtaining approximately 33% recovery. The purified SAG2(S) and SAG2(T) showed molecular masses of 45 and 36 kDa by SDS-PAGE, respectively. The recombinant proteins were evaluated by Western blotting with patients' sera and demonstrated 90% sensitivity and 100% specificity for detection of toxoplasmosis. This study provided a means for large-scale expression and purification of SAG2, which should be useful for diagnosis of toxoplasmosis.
    Matched MeSH terms: Toxoplasmosis/diagnosis*
  20. Comparison of three forms of antigens in the demonstration of cell-mediated immune response in murine toxoplasmosis
    Rahmah N, Khairul Anuar A
    Biochem Biophys Res Commun, 1992 Dec 15;189(2):640-4.
    PMID: 1472034
    Mice were chronically infected with cysts of ME49 strain of Toxoplasma gondii. At different periods post-infection, their spleens were removed and single cell suspensions were made. Lymphocyte transformation experiments were performed on the lymphocyte suspensions using three different kinds of antigens of ME49 strain of T. gondii, namely soluble, excretory/secretory and cystic forms. The results showed that the pattern of lymphocyte responsiveness was dependent on the kind of antigen employed for induction of the blastogenesis. Using soluble and cystic forms of the antigen, different periods of lymphocyte suppression and lymphocyte proliferation were demonstrated. However, with the use of excretory/secretory antigen, no significant suppression of lymphocyte stimulation was noted throughout the course of infection. Thus excretory/secretory antigen may be the best form of antigen for stimulation of the cell-mediated immune response and hence it appears to be a good candidate for vaccine in toxoplasmosis.
    Matched MeSH terms: Toxoplasmosis, Animal/immunology*
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