Displaying publications 1 - 20 of 71 in total

Abstract:
Sort:
  1. Zeehaida M, Zairi NZ, Tan ZN, Wong WK, Lim BH
    Trop Biomed, 2009 Dec;26(3):366-8.
    PMID: 20237453
    The screening for anti-amoebic antibody among a group of donors was to obtain negative control serum samples for an on-going antigen development assay in diagnosis of amoebic liver abscess. Out of 200 samples, 125 (62.5%) were negative, whereas 44 (21.5%) had IHA titer of less than 1:128 and 31 (16.0%) of the samples had significant IHA titers of 1:128 or more, in which 2 serum samples gave titers of 1:4096.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  2. Andiappan H, Nissapatorn V, Sawangjaroen N, Nyunt MH, Lau YL, Khaing SL, et al.
    Parasit Vectors, 2014;7:564.
    PMID: 25498432 DOI: 10.1186/s13071-014-0564-9
    Toxoplasma gondii, an obligate intracellular protozoan parasite, causes a disease called toxoplasmosis which can sometimes be acquired congenitally by a newborn from an infected mother. This study aimed to determine the seroprevalence of Toxoplasma infection and its associated risks among 219 and 215 pregnant women from Malaysia and Myanmar, respectively.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  3. Noordin R, Smith HV, Mohamad S, Maizels RM, Fong MY
    Acta Trop, 2005 Jan;93(1):57-62.
    PMID: 15589798
    Diagnosis of human toxocariasis, caused by Toxocara canis or Toxocara cati, normally relies on a combination of the presence of clinical signs and symptoms backed by positive serology. The use of Toxocara excretory-secretory antigen (TES) in ELISA assays increases the test specificity. However, in tropical countries where soil-transmitted helminths are endemic, cross-reactivity from antibodies to these intestinal parasites poses a significant limitation for Toxocara serodiagnosis. To increase the specificity of serodiagnosis, we compared the use of IgG-ELISA to the use of IgG4-ELISA using commercially manufactured TES-coated plates. The sensitivity of the IgG-ELISA was 97.1%, while that of the IgG4-ELISA was 45.7%; the specificities were 36.0 and 78.6%, respectively. The study shows that employing both assays can improve the serodiagnosis of toxocariasis. An IgG4 immunoassay would also be useful in the secondary screening of antigen clones in the effort to develop improved serological tests for toxocariasis.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  4. Yahaya N
    PMID: 1822863
    Various studies on toxoplasmosis in Malaysia have shown that specific antibodies to Toxoplasma gondii are common among Malaysians. Among the ethnic groups, the Malays have the highest prevalence rate followed by Indians, Orang Aslis (aborigines) and Chinese. Antibody is acquired early in life and increases with age. There is no significant difference in the prevalence rate between males and females. The disease is apparently more prevalent among rural dwellers and those in the lower socioeconomic group. It appears that the prevalence rate is also influenced by environmental conditions, occupation, diet and cultural habits. Studies with animals have shown the presence of antibody to T. gondii, but this does not seem to be the source of infection since Malaysians normally cook their meat well.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  5. Suresh K, Mak JW, Yong HS
    PMID: 1822869
    Thirty in vitro serial passages of Toxoplasman gondii cultures in Vero cell line performed once in every five days had a mean increase in parasite count of 74.4 +/- 14.8 times from that of initial counts. Long term cultures in Vero cell line did not alter the virulence of the parasite. The good correlation (r = 0.99) between the IFA titer and ELISA OD values using the parasite antigens from in vitro sources indicates that long term maintenance of T. gondii in culture does not affect significantly the ability to recognize antibodies to surface and soluble antigens. The results also show that soluble antigens containing host cells can be directly used for immunodiagnostic purposes without purification. The in vitro maintenance of T. gondii is safer and cheaper when compared to the in vivo method.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  6. Deshpande PS, Kotresha D, Noordin R, Yunus MH, Saadatnia G, Golkar M, et al.
    Rev Inst Med Trop Sao Paulo, 2013 4 9;55(2):79-83.
    PMID: 23563759
    Toxoplasmosis is an important cause of congenital infection. The present study was performed to evaluate the usefulness of recombinant (r) GRA-7 cloned from nucleotides (n) 39-711 in discriminating between acute and chronic toxoplasmosis. First, commercial IgM, IgG and IgG avidity ELISAs were used to determine the serological profile of the sera. Serum samples were from 20 symptomatic patients with acute infection (low IgG avidity, IgM positive), 10 with chronic infection (high IgG avidity, IgM negative) and 10 with indeterminate IgG avidity (IgM positive) which were tested for IgG avidity status with an in-house developed IgG avidity Western blot using the rGRA-7 recombinant antigen. All 20 sera from cases of probable acute infection showed bands which either faded out completely or reduced significantly in intensity after treatment with 8 M urea, whereas the band intensities of the 10 serum samples from chronic cases remained the same. Of the 10 sera with indeterminate IgG avidity status, after treatment with 8 M urea the band intensities with six sera remained the same, two sera had completely faded bands and another two sera had significantly reduced band intensities. Discrimination between acute and chronic toxoplasmosis was successfully performed by the in-house IgG avidity Western blot.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  7. Kan SP, Pathmanathan R
    PMID: 1822870
    Sarcocystis is a tissue coccidian with an obligatory two-host life cycle. The sexual generations of gametogony and sporogony occur in the lamina propria of the small intestine of definitive hosts which shed infective sporocysts in their stools and present with intestinal sarcocystosis. Asexual multiplication occurs in the skeletal and cardiac muscles of intermediate hosts which harbor Sarcocystis cysts in their muscles and present with muscular sarcocystosis. In Malaysia, Sarcocystis cysts have been reported from many domestic and wild animals, including domestic and field rats, moonrats, bandicoots, slow loris, buffalo, and monkey, and man. The known definitive hosts for some species of Sarcocystis are the domestic cat, dog and the reticulated python. Human muscular sarcocystosis in Malaysia is a zoonotic infection acquired by contamination of food or drink with sporocysts shed by definitive hosts. The cysts reported in human muscle resembled those seen in the moonrat, Echinosorex gymnurus, and the long-tailed monkey, Macaca fascicularis. While human intestinal sarcocystosis has not been reported in Malaysia so far, it can be assumed that such cases may not be infrequent in view of the occurrence of Sarcocystis cysts in meat animals, such as buffalo. The overall seroprevalence of 19.8% reported among the main racial groups in Malaysia indicates that sarcocystosis (both the intestinal and muscular forms) may be emerging as a significant food-borne zoonotic infection in the country.
    Matched MeSH terms: Antibodies, Protozoan/blood
  8. Lau YL, Cheong FW, Chin LC, Mahmud R, Chen Y, Fong MY
    Trop Biomed, 2014 Dec;31(4):749-59.
    PMID: 25776601 MyJurnal
    Malaria causes high global mortality and morbidity annually. Plasmodium knowlesi has been recognised as the fifth human Plasmodium sp. and its infection is widely distributed in Southeast Asia. Merozoite surface protein-119 (MSP-119) appears as a potential candidate for malaria blood stage vaccine as it could induce protective immunity. In this study, codon optimized P. knowlesi MSP-119 (pkMSP-119) was expressed and purified in yeast Pichia pastoris expression system. The purified recombinant protein was further evaluated using Western blot assay using knowlesi malaria, non-knowlesi human malaria, non-malarial parasitic infections and healthy serum samples (n = 50). The sensitivity of purified pkMSP-119 towards detection of knowlesi infection was as 28.6% (2/7). pkMSP-119 did not react with all non-malarial parasitic infections and healthy donor sera, yet reacted with some non-knowlesi human malaria sera, therefore lead to a specificity of 86.0% (37/43).
    Matched MeSH terms: Antibodies, Protozoan/blood*
  9. Saadatnia G, Ghaffarifar F, Khalilpour A, Amerizadeh A, Rahmah N
    Trop Biomed, 2011 Dec;28(3):606-14.
    PMID: 22433890 MyJurnal
    Toxoplasmosis can cause serious disease in immunocompromised patients and to congenitally infected foetuses. Appropriate laboratory investigations in potential cases of acute Toxoplasma infection are important. Excretory secretory antigen (ESA) is immunogenic during both human and experimental infections, therefore is considered as a good candidate for investigation into new infection markers. In this study, ESA was prepared from in vitro cultures of Toxoplasma gondii to identify T. gondii ESA antigenic component(s) that is/are most reactive with serum samples from probable acute cases of toxoplasmosis. Serum samples were obtained from several categories of individuals with the following Toxoplasma serology: Group I: IgM+ IgG+ (low IgG avidity) or IgM+ IgG- from sera of patients who had clinical query of toxoplasmosis (n=35). Group II: IgM- IgG+ (high IgG avidity) from chronically infected individuals (n=30). Group III: normal/healthy individuals with anti-Toxoplasma IgMIgG- (n=20). Group IV: individuals with other infections who had anti-Toxoplasma IgM- IgG- (n=10). The ESA was subjected to SDS-PAGE, followed by Western blot analysis using the above sera and probed with peroxidase conjugated anti-human IgM and IgA antibodies. The blots were then developed using chemiluminescence substrate. The selected antigenic band was excised from the gel after two dimensional electrophoresis and sent for mass spectrometry analysis using MALDI TOF-TOF. The most promising antigenic band was a 10 kDa protein which showed sensitivity of 80% in both IgM and IgA blots, and specificity of 96.7% with sera from other infections and healthy controls. The two best identifications for the 10 kDa band were ubiquitin (ribosomal protein CEP52 fusion protein) and polyubiquitin.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  10. Rahman WA, Fong S, Chandrawathani P, Nurulaini R, Zaini CM, Premalaatha B
    Trop Biomed, 2012 Mar;29(1):65-70.
    PMID: 22543604 MyJurnal
    A comparative seroprevalence study on bovine trypanosomiasis and anaplasmosis was conducted. Sera of adult cattle and buffaloes of different breeds from farms from five different states in Malaysia were collected and tested for the presence of Trypanosoma evansi antibodies by CATT and Anaplasma marginale antibodies by c-ELISA. Of the 116 samples, 14.7% tested positive for bovine trypanosomiasis and 77.6% for bovine anaplasmosis.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  11. Chandrawathani P, Nurulaini R, Zanin CM, Premaalatha B, Adnan M, Jamnah O, et al.
    Trop Biomed, 2008 Dec;25(3):257-8.
    PMID: 19287367
    Antibodies to the protozoan parasite, Toxoplasma gondii were assayed in sera of 200 goats, 100 pigs, 126 cattle from various states of Malaysia, and 135 dogs and 55 cats around Ipoh region using an indirect fluorescence antibody test (IFAT, cut-off titer 1:200); antibodies were found in 35.5% of goats, 14.5% cats, 9.6% dogs, 7.9% local cattle and 4% yellow cattle but not in pigs. Results indicate that infection is most prevalent in goats.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  12. Lau YL, Shamilah H, Fong MY
    Trop Biomed, 2006 Dec;23(2):186-93.
    PMID: 17322821 MyJurnal
    A truncated form of surface antigen 2 (SAG2) of the protozoan parasite Toxoplasma gondii was cloned and expressed in the methylotrophic yeast Pichia pastoris. This recombinant antigen, designated as recSAG2-N, contained only the N-terminal half of the native SAG2. The recSAG2-N was secreted by the Pichia pastoris into the culture supernatant, and it was harvested by using the trichloroacetic acid precipitation method. Specificity of recSAG2-N was evaluated in western blot assays. Fifty human serum samples, including 32 from confirmed cases of toxoplasmosis, were tested. Results from the assays showed that recSAG2-N reacted with sera from the toxoplasmosis cases only. In vivo experiments showed that serum from mice which received recSAG2-N reacted with the native SAG2 of T. gondii.
    Matched MeSH terms: Antibodies, Protozoan/blood
  13. Ngui R, Hassan NA, Chang LY, Teh SJC, Chua KH, Kee BP, et al.
    Trop Biomed, 2020 Mar 01;37(1):155-164.
    PMID: 33612726
    Toxoplasma gondii is an obligate intracellular protozoan parasite that causes toxoplasmosis in humans. To date, little is known about T. gondii infection among the indigenous community, particularly in East Malaysia. This study was conducted to determine the status of T. gondii infection and to investigate associated risk factors among the indigenous community of Sarawak, East Malaysia. The sociodemographic data was obtained using a pretested questionnaire. A serological test was done to detect the presence of specific IgM and IgG antibodies against T. gondii in serum samples. A nested polymerase chain reaction (PCR) was used to determine acute infection among seropositive individuals. The overall seroprevalence of T. gondii infection was 50% (95% CI = 43.3 - 56.7). From this subset, 40.1%, 5.7%, and 4.2% were positive for anti-T. Gondii IgG antibodies, IgM, and both IgG and IgM, respectively. Four seropositive samples were amplified through PCR. None of the pregnant women tested positive for T. gondii infection based on the serological and PCR assays. A significant association was found between age, low monthly household income, unemployment, usage of untreated water and close contact with T. gondii seropositive cats. These results provide basic information on T. gondii infection and may be useful for policymakers to initiate prevention and control programs, especially amongst pregnant women and women of childbearing age in the indigenous community.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  14. Shen ZZ, Li K, Li ZJ, Shang XL, Hu F, Zhou WJ, et al.
    Trop Biomed, 2020 Jun 01;37(2):452-457.
    PMID: 33612814
    Toxoplasma gondii is a world-widely spread zoonotic parasite. However, scarce knowledge is known about the prevalence of T. gondii infection in people in Hubei province, China. This study herein was to perform epidemiological investigation of T. gondii infection in people in this region. A total 12527 blood samples were obtained during 2015-2018, and were assayed for T. gondii antibodies of IgG and IgM, respectively by employing an indirect hemagglutination test (IHA). The results discovered that the prevalence of T. gondii in people was 2.44% and 6.1%, respectively based on antibodies of IgG and IgM, respectively. The prevalence was ranged from 0.3% to 5.4% during 2015-2018 based on IgM antibodies. For genders, the prevalence was 0.7% and 2.6% in males and females, respectively based on IgM antibodies. In different years, the prevalence was ranged from 4.9% to 14.0% based on IgG antibodies. The prevalence of T. gondii was 4.9% and 6.6% in males and femalesy based on IgG antibodies. The current results may be helpful for the implementation of preventive measures against Toxoplasma infection among people living in this region.
    Matched MeSH terms: Antibodies, Protozoan/blood
  15. Xia NB, Lu Y, Zhao PF, Wang CF, Li YY, Tan L, et al.
    Trop Biomed, 2020 Jun 01;37(2):489-498.
    PMID: 33612818
    Toxoplasma gondii, a ubiquitous pathogen that infects nearly all warm-blooded animals and humans, can cause severe complications to the infected people and animals as well as serious economic losses and social problems. Here, one local strain (TgPIG-WH1) was isolated from an aborted pig fetus, and the genotype of this strain was identified as ToxoDB #3 by the PCR RFLP typing method using 10 molecular markers (SAG1, SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, C22-8, C29-2 and Apico). A comparison of the virulence of this isolate with other strains in both mice and piglets showed that TgPIG-WH1 was less virulent than type 1 strain RH and type 2 strain ME49 in mice, and caused similar symptoms to those of ME49 such as fever in piglets. Additionally, in piglet infection with both strains, the TgPIG-WH1 caused a higher IgG response and more severe pathological damages than ME49. Furthermore, TgPIG-WH1 caused one death in the 5 infected piglets, whereas ME49 did not, suggesting the higher virulence of TgPIG-WH1 than ME49 during piglet infection. Experimental infections indicate that the virulence of TgPIG-WH1 relative to ME49 is weaker in mice, but higher in pigs. This is probably the first report regarding a ToxoDB #3 strain from pigs in Hubei, China. These data will facilitate the understanding of genetic diversity of Toxoplasma strains in China as well as the prevention and control of porcine toxoplasmosis in the local region.
    Matched MeSH terms: Antibodies, Protozoan/blood
  16. Kholib-Jati AK, Wan-Ahmad WMA, Mohamad S, Wan-Mahmood WH, Husin A, Wan-Ab-Rahman WS
    Trop Biomed, 2020 Mar 01;37(1):218-226.
    PMID: 33612733
    Toxoplasmosis is a zoonotic disease caused by Toxoplasma gondii that is prevalent in humans and animals. This study was aimed to determine the seroprevalence of T. gondii infection among hemato-oncology patients and its association with sociodemographic and behavioural characteristics. This cross-sectional study was conducted at the Hospital Universiti Sains Malaysia (USM) involving 56 blood samples from hemato-oncology patients. Anti-T. gondii IgG and IgM antibodies and IgG avidity were determined using enzyme-linked immunosorbent assays (ELISA). The association of T. gondii exposure, sociodemographic, and behavioural characteristics were assessed by a questionnaire and face-to-face interviews. Twenty-eight (50%) patients were seropositive for T. gondii antibodies, where 27 (48.21%) patients were IgG+/IgM- and one patient (1.79%) was IgG+/IgM+ with high avidity index, indicating infection of more than 20 weeks. A univariate analysis showed that age, gender, ethnicity, marital status, educational level, employment status, stem cell transplant, blood transfusion, close contact with cats, water supply, and consumption of undercooked meat were not significantly associated with Toxoplasma seropositivity (p < 0.05). Our study has demonstrated, for the first time, the serological evidence of T. gondii exposure among hemato-oncology patients in Hospital USM. Our findings indicated that latent toxoplasmosis was relatively prevalence among our patients. Therefore, serological screening tests should be considered for immunocompromised patients as well as the implementation of health education programmes to encourage a healthy lifestyle and the consumption of healthy food among them.
    Matched MeSH terms: Antibodies, Protozoan/blood
  17. Khan K, Khan W, Khan T, Naaz G, Naheda A, Aqeel S
    Trop Biomed, 2020 Dec 01;37(4):1038-1049.
    PMID: 33612756 DOI: 10.47665/tb.37.4.1038
    Toxoplasma gondii is a protozoan parasite that can infect all mammals, serving as intermediate hosts. The cause of congenital toxoplasmosis is transplacental transmission of the parasite to the foetus, resulting in wide range of manifestations from mild chorioretinitis to miscarriage. Its frequency can be reduced by early screening of pregnant women which is based mainly on tests for anti-Toxoplasma antibodies. We collected serum samples of 594 pregnant women (subjects) after taking their consent over a period of two years (2016-2018) and analyzed them for anti-Toxoplasma IgG by ELISA. The positive samples were then analyzed for IgG avidity test which could differentiate between recent and past infections. The seroprevalence was also correlated with the age of the subjects and their contact with cats. 162 subjects were found positive out of which only three showed a recent infection. After following up until delivery, one of them delivered a baby who had jaundice and was diagnosed with anti-Toxoplasma IgM at birth. The foetus of the second subject died in-utero, while the third woman delivered a normal baby after being given spiramycin when diagnosed with toxoplasmosis in the first trimester. It was found that most of the positive subjects had frequent contact with cats. Invasion of the parasite during third trimester resulted in death in-utero and jaundice. Most common cause of pregnancy wastage during our study was spontaneous abortions while pregnancy loss due to congenital anomalies was rare.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  18. Noordin R, Yunus MH, Saidin S, Mohamed Z, Fuentes Corripio I, Rubio JM, et al.
    Am J Trop Med Hyg, 2020 12;103(6):2233-2238.
    PMID: 32996457 DOI: 10.4269/ajtmh.20-0348
    Independent evaluations of XEh Rapid®, an IgG4-based rapid dipstick test, were performed to assess its diagnostic performance to detect amebic liver abscess (ALA) using 405 samples at seven laboratories in four countries. The test showed high diagnostic specificity (97-100%) when tested with samples from healthy individuals (n = 100) and patients with other diseases (n = 151). The diagnostic sensitivity was tested with a total of 154 samples, and the results were variable. It was high in three laboratories (89-94%), and moderate (72%) and low (38%) in two other laboratories. Challenges and issues faced in the evaluation process are discussed. Nevertheless, XEh Rapid is promising to be developed into a point-of-care test in particular for resource-limited settings, and thus merits further confirmation of its diagnostic sensitivity.
    Matched MeSH terms: Antibodies, Protozoan/blood*
  19. Sonaimuthu P, Fong MY, Kalyanasundaram R, Mahmud R, Lau YL
    Parasit Vectors, 2014;7:297.
    PMID: 24986686 DOI: 10.1186/1756-3305-7-297
    Toxoplasma gondii infects all warm-blooded animals, including humans. Early diagnosis and determining the infective stage are critical for effectively treating immunosuppressed individuals and pregnant women with toxoplasmosis. Among the rhoptry proteins of the parasite, Rhoptry protein 8 (ROP8), is known to be expressed during the early stages of T. gondii infection and is involved in parasitophorous vacuole formation. In this study, we have investigated the diagnostic efficacy of recombinant ROP8 (rROP8).
    Matched MeSH terms: Antibodies, Protozoan/blood
  20. Syed-Hussain SS, Howe L, Pomroy WE, West DM, Smith SL, Williamson NB
    Vet Parasitol, 2014 Jun 16;203(1-2):21-8.
    PMID: 24582279 DOI: 10.1016/j.vetpar.2014.01.003
    Recent reports indicate Neospora caninum has a possible role in causing abortions in sheep in New Zealand. Knowledge about the epidemiology of neosporosis in sheep is limited. This study aimed to adapt and validate a commercially available ELISA assay as an IgG avidity assay to discriminate between acute (primary and re-inoculated) and chronic N. caninum infections in sheep. In addition, it was used to compare the antibody avidity values between lambs from ewes inoculated with N. caninum either during the pregnancy or in the previous year. The avidity assay was undertaken by using 6M urea for the first wash after incubation with the primary antibody in the commercial ELISA (Chekit* Neospora antibody test kit, IDEXX Laboratories, Australia). Sequential serum samples were obtained from naïve ewes (n=16) experimentally inoculated with live N. caninum tachyzoites. All ewes were seropositive by two weeks post-inoculation and remained seropositive for 20 weeks post-inoculation. There was a linear relationship between time after inoculation and avidity values (p<0.05) over the first 24 weeks. In Week 4, all animals had avidity values <35% and by Week 8, 8/16 animals had avidity values of >35%. These results suggest that an avidity value of <35% indicates a recent primary infection while a value of >35% is indicative of a chronic infection. The assay was then validated using samples from other groups of experimentally inoculated sheep as well as samples from naturally infected ewes. When comparing sample to positive ratio (S/P) and avidity values from lambs born from recently inoculated ewes with those from ewes inoculated the previous year and re-inoculated in the current year, it was possible to differentiate the lambs at 2 weeks of age. Lambs from recently inoculated ewes had low S/P and avidity values at 2 weeks of age which increased by 12 weeks of age. In comparison, lambs from re-inoculated ewes had high S/P and avidity values at 2 weeks of age, due to maternal antibody influence but values were similar to those from lambs that were born from recently inoculated ewes at 12 weeks of age. Avidity values for four naturally infected ewes were all >60% indicating chronic infection. These results suggest that the assay is able to discriminate between recent and chronic infection in sheep as well as able to differentiate lambs with maternal immunity compared to their own de novo immunity. As such it can be utilized to understand the kinetics of N. caninum infection in sheep.
    Matched MeSH terms: Antibodies, Protozoan/blood
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links