Displaying publications 1 - 20 of 48 in total

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  1. Generation of human scFv-IgG1Fc antibodies for detection of lymphatic filarial recombinant antigens, BmR1 and BmSXP
    Abdo AIK, Ngoh YY, Lew MH, Dass SA, Rahumatullah A, Noordin R, et al.
    Biotechnol Appl Biochem, 2022 Feb;69(1):70-76.
    PMID: 33258152 DOI: 10.1002/bab.2082
    Lymphatic filariasis is a neglected parasitic disease that affects millions in tropical and subtropical countries and is caused by Wuchereria and Brugia species. Specific and sensitive detection methods are essential in mapping infected areas where rapid tests are needed to cover underdeveloped and remote regions, which facilitates eliminating the disease as a public health problem. A few commercialized rapid tests based on antigen or antibody detection are available, but the former only detects infection by Wuchereria species and cross-reacts with nonlymphatic filaria, whereas antibody detection might provide positive results of previous infection. Here, we report the production of three different recombinant immunoglobulin gamma (IgG)1 antibodies based on scFvs previously generated via human antibody phage display technology, that is, anti-BmR1 clone 4, anti-BmXSP clone 5B, and anti-BmXSP clone 2H2. The scFv sequences were cloned into a pCMV-IgG1 vector, then transfected into a HEK293F cell line. The generated antibodies were found to be able to bind to their respective targets even at relatively low concentration. Conjugation of Fc to scFv induces binder stability and provides multiple labeling sites for probes and signaling molecules that can be used in rapid tests.
    Matched MeSH terms: Antigens, Helminth*
  2. Detection of circulating antigens and parasite specific antibodies in filariasis
    Abdullah WO, Oothuman P, Yunus H
    Southeast Asian J. Trop. Med. Public Health, 1993;24 Suppl 2:31-6.
    PMID: 7973943
    In Peninsular Malaysia, only Wuchereria bancrofti and Brugia malayi are reported to cause human filariasis. Brugia pahangi infects many of the same animal hosts as the zoonotically transmitted subperiodic B. malayi. There is a well-recognized need for improved diagnostic techniques for lymphatic filariasis. Parasite antigen detection is a promising new approach, and it will probably prove to be more sensitive and specific than clinical, microscopic and antibody-based serological methods. We recently generated monoclonal antibodies (MAb XC3) from in vitro culture products of adult B. pahangi (B.p. IVP). Filarial antigenemia was quantitated in various hosts including the sera from 6 Malaysian Aborigines with acute lymphatic filariasis. In hosts infected with brugian filariasis and dirofilariasis, antigenemia was scored ranging from 90 ng/ml to 960 ng/ml. None of the control animal and human sera had antigenemia above 90 ng/ml. In addition, MAb XC3 and B.p. IVP were applied in several seroepidemiological surveys among household cats in Kuala Selangor in order to correlate information gathered for future studies of possible cases of human infection. Out of the 81 cats surveyed, 10 (12.35%) and 5 (6.17%) were parasitologically positive for B. pahangi and B. malayi, respectively. However, 21 (25.92%) were antigenemia positive when serologically investigated with MAb XC3. Antifilarial antibodies to B.p. IVP by direct ELISA showed very high cross-reactivity with non-filarial gut worm infections. 16 (19.75%) cats had reciprocal titers ranging from 320 to 2,560. Only 1 (1.23%) cat from this group was antigenemic.
    Matched MeSH terms: Antigens, Helminth/analysis*; Antigens, Helminth/immunology
  3. Detection of Angiostrongylus malaysiensis circulating antigen using monoclonal antibody-based enzyme-linked immunosorbent assay (MAb-ELISA)
    Ambu S, Rain AN, Mak JW, Maslah D, Maidah S
    Southeast Asian J. Trop. Med. Public Health, 1997;28 Suppl 1:143-7.
    PMID: 9656366
    Three MAbs 1C4.2D8, 1C4.2C4 and 1C4.1F5 were produced using sonicated adult worm antigens of Angiostrongylus malaysiensis and they were found to be secreters of IgG1. The MAbs 1C4.2C4 and 1C4.2D8 were found to react with antigens of A. malaysiensis and cross-react with the closely related A. cantonensis but not with other helminths. A total of 108 human sera collected from Orang Asli (aborigenes) from Grik, in the State of Perak were tested for A. malaysiensis infection using the MAb-ELISA. MAb 1C4.1F5 and 25 (23%) were positive. Twenty of these positive samples were tested with the MAb 1C4.2D8 and none was found to be positive.
    Matched MeSH terms: Antigens, Helminth/blood*; Antigens, Helminth/immunology
  4. Direct detection of Strongyloides infection via molecular and antigen detection methods
    Balachandra D, Ahmad H, Arifin N, Noordin R
    Eur J Clin Microbiol Infect Dis, 2021 Jan;40(1):27-37.
    PMID: 32729057 DOI: 10.1007/s10096-020-03949-x
    Laboratory diagnosis of Strongyloides infections can be grouped into direct and indirect detection methods, and a combination of the two methods is often needed to reach an accurate and timely diagnosis. This review focuses on non-conventional direct detection via molecular and antigen detection assays. Conventional PCR is the most commonly used molecular diagnostic for Strongyloides. Real-time PCR is accurate and highly sensitive for quantitative and qualitative analysis. Meanwhile, PCR-RFLP can efficiently distinguish human and dog isolates of S. stercoralis, S. fuelleborni (from monkey), and S. ratti (from rodent). Loop-mediated isothermal amplification (LAMP) amplifies DNA isothermally with high specificity, efficiency, and rapidity, and has potential for point-of-care (POC) translation. As for antigen detection assay, coproantigen detection ELISAs for strongyloidiasis traditionally relied on raising rabbit polyclonal antibodies against the parasite antigens for use as capture or detection reagents. Subsequently, hybridoma technology using animals has enabled the discovery of monoclonal antibodies specific to Strongyloides antigens and was utilised to develop antigen detection assays. In recent times, phage display technology has facilitated the discovery of scFv antibody against Strongyloides protein that can accelerate the development of such assays. Improvements in both direct detection methods are being made. Strongyloides molecular diagnostics is moving from the detection of a single infection to the simultaneous detection of soil-transmitted helminths. Meanwhile, antigen detection assays can also be multiplexed and aptamers can be used as antigen binders. In the near future, these two direct detection methods may be more widely used as diagnostic tools for strongyloidiasis.
    Matched MeSH terms: Antigens, Helminth/immunology
  5. A new antigen detection ELISA for the diagnosis of Strongyloides infection
    Balachandra D, Rahumatullah A, Lim TS, Mustafa FH, Ahmad H, Anuar NS, et al.
    Acta Trop, 2021 Sep;221:105986.
    PMID: 34058161 DOI: 10.1016/j.actatropica.2021.105986
    Serodiagnosis is an essential component of the laboratory diagnosis of Strongyloides infection and is usually performed using an indirect IgG antibody test. A direct antigen detection method can complement the IgG assay, particularly for detecting early infection and post-treatment follow-up. In the present study, a recombinant scFv monoclonal antibody against NIE recombinant protein (rMAb23) that we had previously produced was used to develop a Strongyloides antigen detection ELISA (SsAg-ELISA). The assay is based on detecting immune complexes of circulating NIE antigens bound to Strongyloides-specific IgG antibodies. The optimized ELISA parameters were 10 µg/mL of rMAb23 coated on microtitre plate wells, 2% skim milk as blocking reagent, 1:100 serum dilution, and 1:1000 goat anti-human IgG F(ab')2 conjugated to horseradish peroxidase. Four groups of serum samples were used, i.e., Strongyloides-positive serum samples categorized into Groups IA and IB; the former were from probable chronic infections and the latter from probable early/acute infections. Strongyloides-negative samples comprising Groups II (healthy samples) and III (other infections); the latter were from eleven different types of other parasitic infections. The receiver operating characteristic (ROC) curve showed an area under the curve (AUC) of 1.00, cut-off optical density (OD405) of 0.5002, and 100% diagnostic sensitivity and specificity. The results of the commercial IgG-ELISA and SsAg-ELISA from Group IA were found to be moderately correlated (r = 0.416; p 
    Matched MeSH terms: Antigens, Helminth
  6. Epidemiology of Trypanosoma evansi infection in crossbred dairy cattle in Malaysia
    Cheah TS, Sani RA, Chandrawathani P, Bahri S, Dahlan I
    Trop Anim Health Prod, 1999 Feb;31(1):25-31.
    PMID: 10399814
    An investigation into the epidemiology of Trypansoma evansi infection in crossbred dairy cattle was conducted for a period of 12 months on a dairy cattle farm in Penninsular Malaysia. The prevalence of parasitaemia was highest in lactating animals (13.4%), followed by those in the dry herd (8.8%), late pregnant animals (8.1%), early pregnant animals (4.7%), calves (0.3%) and heifers (0.2%). The prevalence of antigenaemia was highest in the lactating animals (54.7%), followed by that in dry animals (53.7%), heifers (51.1%), late pregnant animals (47.7%), early pregnant animals (46.5%) and calves (24.2%).
    Matched MeSH terms: Antigens, Helminth/blood
  7. Biotechnology research on cestodes in the Philippines, Malaysia, and Indonesia
    Cross JH
    Southeast Asian J. Trop. Med. Public Health, 1988 Mar;19(1):41-5.
    PMID: 3043701
    There are essentially no reports on the use of modern biotechnological methods on the study of cestode parasites in the Philippines, Indonesia or Malaysia. The only recent reports of cestode studies in these countries have been on reports of new species in animals and on prevalence rates of cestode parasites in humans; Taenia solium and cysticercosis, Taenia saginata and Hymenolepis nana, etc. Reports on the use of biotechnology has emanated from outside the area on cestodes of humans and animals, and some of these methods could be used to study cestodes in this part of the world.
    Matched MeSH terms: Antigens, Helminth/isolation & purification
  8. Fulltext Pro-fibrinolytic potential of the third larval stage of Ascaris suum as a possible mechanism facilitating its migration through the host tissues
    Diosdado A, Simón F, Morchón R, González-Miguel J
    Parasit Vectors, 2020 Apr 20;13(1):203.
    PMID: 32312291 DOI: 10.1186/s13071-020-04067-5
    BACKGROUND: Ascaris roundworms are the parasitic nematodes responsible for causing human and porcine ascariasis. Whereas A. lumbricoides is the most common soil-transmitted helminth infecting humans in the world, A. suum causes important economic losses in the porcine industry. The latter has been proposed as a model for the study of A. lumbricoides since both species are closely related. The third larval stage of these parasites carries out an intriguing and complex hepatopulmonary route through the bloodstream of its hosts. This allows the interaction between larvae and the physiological mechanisms of the hosts circulatory system, such as the fibrinolytic system. Parasite migration has been widely linked to the activation of this system by pathogens that are able to bind plasminogen and enhance plasmin generation. Therefore, the aim of this study was to examine the interaction between the infective third larval stage of A. suum and the host fibrinolytic system as a model of the host-Ascaris spp. relationships.

    METHODS: Infective larvae were obtained after incubating and hatching fertile eggs of A. suum in order to extract their cuticle and excretory/secretory antigens. The ability of both extracts to bind and activate plasminogen, as well as promote plasmin generation were assayed by ELISA and western blot. The location of plasminogen binding on the larval surface was revealed by immunofluorescence. The plasminogen-binding proteins from both antigenic extracts were revealed by two-dimensional electrophoresis and plasminogen-ligand blotting, and identified by mass spectrometry.

    RESULTS: Cuticle and excretory/secretory antigens from infective larvae of A. suum were able to bind plasminogen and promote plasmin generation in the presence of plasminogen activators. Plasminogen binding was located on the larval surface. Twelve plasminogen-binding proteins were identified in both antigenic extracts.

    CONCLUSIONS: To the best of our knowledge, the present results showed for the first time, the pro-fibrinolytic potential of infective larvae of Ascaris spp., which suggests a novel parasite survival mechanism by facilitating the migration through host tissues.

    Matched MeSH terms: Antigens, Helminth/metabolism*
  9. Fulltext Dirofilaria immitis possesses molecules with anticoagulant properties in its excretory/secretory antigens
    Diosdado A, Simón F, Morchón R, González-Miguel J
    Parasitology, 2020 Apr;147(5):559-565.
    PMID: 31992384 DOI: 10.1017/S0031182020000104
    Dirofilaria immitis is a parasitic nematode that survives in the circulatory system of suitable hosts for many years, causing the most severe thromboembolisms when simultaneous death of adult worms occurs. The two main mechanisms responsible for thrombus formation in mammals are the activation and aggregation of platelets and the generation of fibrin through the coagulation cascade. The aim of this work was to study the anticoagulant potential of excretory/secretory antigens from D. immitis adult worms (DiES) on the coagulation cascade of the host. Anticoagulant and inhibition assays respectively showed that DiES partially alter the coagulation cascade of the host and reduce the activity of the coagulation factor Xa, a key enzyme in the coagulation process. In addition, a D. immitis protein was identified by its similarity to the homologous serpin 6 from Brugia malayi as a possible candidate to form an inhibitory complex with FXa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and mass spectrometry. These results indicate that D. immitis could use the anticoagulant properties of its excretory/secretory antigens to control the formation of blood clots in its immediate intravascular habitat as a survival mechanism.
    Matched MeSH terms: Antigens, Helminth/metabolism; Antigens, Helminth/chemistry
  10. Fulltext Detection of circulating antigens of Parastrongylus cantonensis in human sera by dot-blot ELISA and sandwich ELISA using monoclonal antibody
    Eamsobhana P, Yong HS, Mak JW, Wattanakulpanich D
    Southeast Asian J. Trop. Med. Public Health, 1997 Sep;28(3):624-8.
    PMID: 9561620
    A dot-blot ELISA was compared with a previously performed sandwich ELISA for the detection of Parastrongylus cantonensis antigens in sera from patients. Using the same monoclonal antibody and the same sera, 6 of 10 sera (60%) from parastronglyiasis patients were positive in dot-blot ELISA, whereas with sandwich ELISA, 5 of the same patient sera (50%) were positive. The specificity in both assays was 100% using 50 sera from patients with other parasitic diseases; of these, 10 each were from patients with cysticercosis, filariasis, gnathostomiasis, malaria and toxocariasis. The control group consisted of 53 sera from normal health Thais and Malaysians. The sensitivity of the assays was, however, slightly better with dot-blot ELISA and because it is simple, quick and cost-effective, it may be a test of choice for specific diagnosis of human parastrongyliasis.
    Matched MeSH terms: Antigens, Helminth/blood*
  11. Detection of circulating antigens of Parastrongylus cantonensis in human sera by sandwich ELISA with specific monoclonal antibody
    Eamsobhana P, Mak JW, Yong HS
    Southeast Asian J. Trop. Med. Public Health, 1995 Dec;26(4):712-5.
    PMID: 9139382
    A specific monoclonal antibody (AW-3C2) as revealed by ELISA was produced against the adult worm antigens of Parastrongylus cantonensis and used in a sandwich ELISA for the detection of circulating antigens in the sera of parastrongyliasis patients and those with other parasitic diseases. A total of 60 sera was used in this study. Of these, 10 each were from patients with parastrongyliasis, cysticercosis, filariasis, gnathostomiasis, malaria and toxocariasis. The control group consisted of 53 serum samples from normal healthy Thais and Malaysians. The mean +/- optical density (OD) values for the normal Thai and Malaysian groups were 0.126 +/- 0.028 and 0.124 +/- 0.029, respectively. The mean OD values of the parastrongyliasis patient group differed significantly from that of the normal groups as well as those of other parasitic infections. Using a cut-off point of OD +/- 3SD of the control groups as indicating a positive reading, the specificity of the assay with this monoclonal antibody was 100% while the sensitivity was 50%.
    Matched MeSH terms: Antigens, Helminth/blood*
  12. Fulltext Evaluation of dot immunogold filtration assay (DIGFA) for rapid serodiagnosis of eosinophilic meningitis due to Angio-strongylus cantonensis (Nematoda: Metastrongyloidea)
    Eamsobhana P, Prasartvit A, Gan XX, Yong HS
    Trop Biomed, 2015 Mar;32(1):121-5.
    PMID: 25801261
    Angiostrongylus cantonensis is the most frequent cause of eosinophilic meningitis in humans in Thailand and worldwide. Because of difficulty of recovering the Angiostrongylus larvae from infected patients, detection of parasite-specific antibodies is used to support clinical diagnosis. This study tested serum samples from eosinophilic meningitis patients and individuals at risk of infection with A. cantonensis to evaluate a recently developed simple and rapid dot-immunogold filtration assay (DIGFA) for detection of specific antibodies against A. cantonensis. Purified 31-kDa glycoprotein of A. cantonensis and protein A colloidal gold conjugate were employed to detect the 31-kDa anti-A. cantonensis antibody in patients sera from the parasite endemic areas of northeast Thailand. The results were compared with those obtained by dot-blot enzyme-linked immunosorbent assay (ELISA) with 31-kDa A. cantonensis antigen. The overall positivity rate of DIGFA and dot-blot ELISA for A. cantonensis infection in 98 clinically diagnosed cases from three highly endemic districts in Khon Kaen province were 39.79% and 37.75%, respectively. Among 86 sera of subjects at risk of infection with A. cantonensis, 24.41% were positive by DIGFA and 23.25% by dot-blot ELISA. There were good correlation between the visual grading of DIGFA and dot-blot ELISA in both groups of defined sera. DIGFA is as sensitive and specific as dot-blot ELISA for confirming eosinophilic meningitis due to A. cantonensis infection, with advantages of simplicity, rapidity and without the use of specific and expensive equipment, and can be used in field settings.
    Matched MeSH terms: Antigens, Helminth/immunology
  13. Recombinant expression of the larval excretory-secretory antigen TES-120 of Toxocara canis in the methylotrophic yeast Pichia pastoris
    Fong MY, Lau YL
    Parasitol Res, 2004 Jan;92(2):173-6.
    PMID: 14655048
    A gene encoding the larval excretory-secretory antigen TES-120 of the dog ascarid worm Toxocara canis was cloned into the methylotrophic yeast Pichia pastoris. Specificity of the recombinant TES-120 antigen produced by the yeast was investigated. Forty-five human serum samples from patients infected with different()parasitic organisms, including 8 cases of toxocariasis, were tested against the recombinant antigen in immunoblot assays. Results from the assays showed that the recombinant TES-120 antigen reacted with sera from toxocariasis patients only. This highly specific recombinant TES-120 antigen can potentially be used for the development of an inexpensive serodiagnostic assay for human toxocariasis.
    Matched MeSH terms: Antigens, Helminth/genetics; Antigens, Helminth/immunology*; Antigens, Helminth/metabolism
  14. Fulltext Lateral flow test using Echinococcus granulosus native antigen B and comparison of IgG and IgG4 dipsticks for detection of human cystic echinococcosis
    Khalilpour A, Sadjjadi SM, Moghadam ZK, Yunus MH, Zakaria ND, Osman S, et al.
    Am J Trop Med Hyg, 2014 Nov;91(5):994-9.
    PMID: 25200268 DOI: 10.4269/ajtmh.14-0170
    Cystic echinococcosis (CE) caused by infection with Echinococcus granulosus is of major concern for humans in many parts of the world. Antigen B was prepared from E. granulosus hydatid fluid, and Western blots confirmed eight batches showing a band corresponding to the 8-/12-kDa subunit with positive serum and no low-molecular mass band (< 15 kDa) with negative serum. The batches were pooled and used to prepare lateral flow immunoglobulin G4 (IgG4) and IgG dipsticks. Diagnostic sensitivity was determined using serum samples from 21 hydatidosis patients, and diagnostic specificity was established using sera from 17 individuals infected with other parasites and 15 healthy people. IgG4 dipstick had a diagnostic sensitivity of 95% (20 of 21) and a specificity of 100% (32 of 32). The IgG dipstick had a sensitivity of 100% (21 of 21) and a specificity of 87.5% (28 of 32). Thus, both IgG and IgG4 dipsticks had high sensitivities, but IgG4 had greater specificity for the diagnosis of human CE.
    Matched MeSH terms: Antigens, Helminth/blood; Antigens, Helminth/immunology
  15. Purification of recombinant antigen BmSXP used in panLF rapid kit for lymphatic filariasis
    Khoo TK, Noordin R, Santhanam A
    Indian J Exp Biol, 2012 Apr;50(4):256-64.
    PMID: 22611913
    A rapid antibody detection test is very useful for the detection of lymphatic filariasis, especially for certification and surveillance of post-mass drug administration. panLF Rapid kit is suitable for this purpose since it can detect all species of lymphatic filaria. It is based on the detection of anti-filarial IgG4 antibodies that react with recombinant B. malayi antigens, BmR1 and BmSXP. There is an increase demand for the test due to its attributes of being rapid, sensitive and specific results, as well as its field-applicability. The main aim of this paper is to obtain high recovery and purity of recombinant antigen BmSXP via a modified method of immobilized metal affinity chromatography (IMAC). The highest product yield of 11.82 mg/g dry cell weight (DCW) was obtained when IMAC was performed using the optimized protocol of 10 mM imidazole concentration in lysis buffer, 30 mM imidazole concentration in wash buffer, and 10 column volume wash buffer containing 300 mM salt concentration. This gave a 54% protein recovery improvement over the manufacturer's protocol which recorded a product yield of only 7.68 mg/g DCW. The recovered BmSXP recombinant antigen showed good western blot reactivity, high sensitivity (31/32, 97%) and specificity (32/32, 100%) in ELISA, thus attesting to its good purity and quality.
    Matched MeSH terms: Antigens, Helminth/analysis*; Antigens, Helminth/isolation & purification
  16. The design of target specific antibodies (scFv) by applying de novo workflow: Case study on BmR1 antigen from Brugia malayi
    Khor BY, Lim TS, Noordin R, Choong YS
    J Mol Graph Model, 2017 09;76:543-550.
    PMID: 28811153 DOI: 10.1016/j.jmgm.2017.07.004
    De novo approach was applied to design single chain fragment variable (scFv) for BmR1, a recombinant antigen from Bm17DIII gene which is the primary antigen used for the detection of anti-BmR1 IgG4 antibodies in the diagnostic of lymphatic filariasis. Three epitopes of the BmR1 was previously predicted form an ab initio derived three-dimensional structure. A collection of energetically favourable conformations was generated via hot-spot-centric approach. This resulted in a set of three different scFv scaffolds used to compute the high shape complementary conformations via dock-and-design approach with the predicted epitopes of BmR1. A total of 4227 scFv designs were generated where 200 scFv designs produced binding energies of less than -20 R.E.U with shape complementarity higher than 0.5. We further selected the design with at least one hydrogen bond and one salt bridge with the epitope, thus resulted in a total of 10, 1 and 19 sFv designs for epitope 1, 2 and 3, respectively. The results thus showed that de novo design can be an alternative approach to yield high affinity in silico scFv designs as a starting point for antibody or specific binder discovery processes.
    Matched MeSH terms: Antigens, Helminth/immunology; Antigens, Helminth/chemistry*
  17. Immunogenicity, antibody responses and vaccine efficacy of recombinant annexin B30 against Schistosoma mansoni
    Leow CY, Willis C, Chuah C, Leow CH, Jones M
    Parasite Immunol., 2020 03;42(3):e12693.
    PMID: 31880816 DOI: 10.1111/pim.12693
    AIMS: Schistosomes infect approximately 250 million people worldwide. To date, there is no effective vaccine available for the prevention of schistosome infection in endemic regions. There remains a need to develop means to confer long-term protection of individuals against reinfection. In this study, an annexin, namely annexin B30, which is highly expressed in the tegument of Schistosoma mansoni was selected to evaluate its immunogenicity and protective efficacy in a mouse model.

    METHODS AND RESULTS: Bioinformatics analysis showed that there were three potential linear B-cell epitopes and four conformational B-cell epitopes predicted from annexin B30, respectively. Full-length annexin B30 was cloned and expressed in Escherichia coli BL21(DE3). In the presence of adjuvants, the soluble recombinant protein was evaluated for its protective efficacy in two independent vaccine trials. Immunization of CBA mice with recombinant annexin B30 formulated either in alum only or alum/CpG induced a mixed Th1/Th2 cytokine profile but no significant protection against schistosome infection was detected.

    CONCLUSION: Recombinant annexin B30 did not confer significant protection against the parasite. The molecule may not be suitable for vaccine development. However, it could be an ideal biomarker recommended for immunodiagnostics development.

    Matched MeSH terms: Antigens, Helminth/immunology*
  18. Brugia malayi infection in Meriones unguiculatus: antibody response to recombinant BmR1
    Lim BH, Noordin R, Nor ZM, Rahman RA, Abdullah KA, Sinnadurai S
    Exp Parasitol, 2004 Sep-Oct;108(1-2):1-6.
    PMID: 15491542
    BmR1 recombinant antigen has previously been shown to demonstrate high sensitivity and specificity in the serological diagnosis of brugian filariasis in humans. In this study, the pattern of recognition of antibody to BmR1 during Brugia malayi infection was investigated by employing Meriones unguiculatus as the experimental model. Thirty two gerbils were infected subcutaneously with 120 L(3); and two control groups each comprising 25 animals were employed. ELISA using BmR1 was used to detect filaria-specific IgG antibodies elicited by the gerbils; using sera collected from the day 1 until day 150 post-inoculation (p.i.). The results showed that BmR1 detected B. malayi infection in gerbils harboring adult worms irrespective of the presence of circulating microfilaria, and was exemplified by positive ELISA results in nine a microfilaraemic animals that harbored live adult worms. The initial time of the antibody recognition was at day 8 p.i. and the antibody titre showed some correlation with adult worm burden.
    Matched MeSH terms: Antigens, Helminth/immunology*
  19. Recent advances in diagnostic techniques in filariasis
    Lim PK
    Southeast Asian J. Trop. Med. Public Health, 1993;24 Suppl 2:45-50.
    PMID: 7973946
    Accurate diagnosis of human filarial infections still remains a problem for clinicians and co-ordinators of filariasis control programs. Diagnosis of filariasis is based on parasitological, histopathological, clinical and immunological approaches. No significant advances have been made for the first three approaches although some refinements in their use and interpretation of results have occurred. For the immunological approach, intradermal tests and antibody detection assays using crude parasite extracts generally lack specificity and/or sensitivity to discriminate between past and present filarial infections in humans. Antigen detection assays would therefore provide a more accurate indication of active filarial infections. Several monoclonal antibodies to various stages of lymphatic filarial parasites have been developed and appear potentially useful for filarial antigen detection.
    Matched MeSH terms: Antigens, Helminth/immunology
  20. A filtration-based rapid test using a partially purified third-stage larval antigen to detect specific antibodies for the diagnosis of gnathostomiasis
    Ma A, Wang Y, Liu XL, Zhang HM, Eamsobhana P, Yong HS, et al.
    J Helminthol, 2019 Jan;93(1):26-32.
    PMID: 29144215 DOI: 10.1017/S0022149X17001080
    Human gnathostomiasis is an emerging food-borne parasitic disease caused by nematodes of the genus Gnathostoma. Currently, serological tests are commonly applied to support clinical diagnosis. In the present study, a simple and rapid filtration-based test, dot immune-gold filtration assay (DIGFA) was developed using a partially purified antigen of Gnathostoma third-stage larvae (L3). A total of 180 serum samples were tested to evaluate the diagnostic potential of DIGFA for gnathostomiasis. The diagnostic sensitivity and specificity were 96.7% (29/30) and 100% (25/25), respectively. The cross-reactivity with sera from other helminthiasis patients ranged from 0 to 4%, with an average of 1.6% (2/125). DIGFA using a partially purified L3 antigen was not only simple and rapid, but also more accurate than standard assays for the diagnosis of human gnathostomiasis. DIGFA may represent a promising tool for application in laboratories or in the field, without requiring any instrumentation.
    Matched MeSH terms: Antigens, Helminth/immunology*; Antigens, Helminth/isolation & purification
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