Displaying publications 1 - 20 of 116 in total

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  1. Yahaya ML, Zakaria ND, Noordin R, Abdul Razak K
    Biotechnol Appl Biochem, 2021 Oct;68(5):1095-1106.
    PMID: 32935878 DOI: 10.1002/bab.2029
    Salmonella and Shigella genera are common pathogens that contaminate foods and beverages. Lateral flow assays (LFA) are commonly used to detect these pathogens. However, most of the developed LFAs are for single detection. Simultaneous detection of pathogens is required to reduce cost and time. In this work, 40 nm gold nanoparticles (AuNPs) were synthesized using the seeding growth method as labeling agent. The AuNPs were characterized and conjugated with mouse anti-Gram negative endotoxin antibody. The nitrocellulose membrane HF135 was immobilized with anti-mouse IgG antibody as a control line and two separate test lines with either anti-Shigella or anti-Salmonella antibody, respectively. Color intensity of test lines was observed for positive samples. A milk sample was used as proof of concept to mimic actual contamination. The limit of detection of the LFA was 3.0 × 106 CFU/mL for multiplex detection of Shigella flexneri and Salmonella Typhi and for both single detections. The result was comparable with the enzyme-linked immunosorbent assay (ELISA) analysis. The produced LFA could differentiate between Shigella flexneri, Shigella boydii, Salmonella Enteritidis, and Salmonella Typhi. The developed LFA was able to identify Shigella flexneri and Salmonella Typhi with good sensitivity in milk samples, thus, beneficial to ensure the safety of food before entering the market.
  2. Noordin R, Osman E, Anuar NS, Juri NM, Rahumatullah A, Ahmad Hilmi NA
    Am J Trop Med Hyg, 2021 08 30;105(5):1214-1217.
    PMID: 34460427 DOI: 10.4269/ajtmh.21-0674
    A lateral flow rapid test for strongyloidiasis will greatly facilitate the control and elimination of the disease. Previously SsRapid prototype rapid test showed high diagnostic specificity to detect Strongyloides infection, determined using non-Strongyloides sera negative by IgG-ELISAs. Since high specificity is crucial before a test is used for public health control activities, further validation of its specificity is needed. Also, it needs to be ascertained whether non-Strongyloides sera positive by IgG-ELISAs and SsRapid are truly positive for Strongyloides or are cases of cross-reactivity. We performed 84 rapid tests (two types of dipsticks and cassettes) using 34 serum samples. They were divided into four groups based on Strongyloides infection and coinfection with other parasites and the availability of recombinant proteins and rapid tests for the latter. Sera was adsorbed using polystyrene microspheres beads separately coated with four recombinant parasite proteins. The small sample size is a limitation of this study; however, the overall results showed that the sera adsorption procedure was successful, and the SsRapid test is specific.
  3. Mohd Hanafiah K, Arifin N, Bustami Y, Noordin R, Garcia M, Anderson D
    Diagnostics (Basel), 2017 Sep 07;7(3).
    PMID: 28880218 DOI: 10.3390/diagnostics7030051
    Lateral flow assays (LFAs) are the mainstay of rapid point-of-care diagnostics, with the potential to enable early case management and transform the epidemiology of infectious disease. However, most LFAs only detect single biomarkers. Recognizing the complex nature of human disease, overlapping symptoms and states of co-infections, there is increasing demand for multiplexed systems that can detect multiple biomarkers simultaneously. Due to innate limitations in the design of traditional membrane-based LFAs, multiplexing is arguably limited to a small number of biomarkers. Here, we summarize the need for multiplexed LFA, key technical and operational challenges for multiplexing, inherent in the design and production of multiplexed LFAs, as well as emerging enabling technologies that may be able to address these challenges. We further identify important areas for research in efforts towards developing multiplexed LFAs for more impactful diagnosis of infectious diseases.
  4. Noordin R, Yunus MH, Tan Farrizam SN, Arifin N
    Adv Parasitol, 2020;109:131-152.
    PMID: 32381194 DOI: 10.1016/bs.apar.2020.01.003
    Toxocariasis is a human infection primarily caused by larvae of Toxocara canis from dogs, and also by T. cati from cats. Children have a more significant risk of acquiring the infection due to their closer contact with pets, and greater chances of ingesting soil. Diagnosis of toxocariasis is based on clinical, epidemiological, and serological data. Indirect IgG ELISA is a widely used serodiagnostic method for toxocariasis, with native T. canis TES most commonly used as the antigen. Western blots, using the same antigen, can be used to confirm positive ELISA findings to reduce false-positive results. Improvements in Toxocara serodiagnosis include the use of recombinant TES antigens, simpler and more rapid assay formats, and IgG4 subclass detection. Also, incorporation of recombinant T. cati TES protein increases the diagnostic sensitivity. Development of antigen detection tests using polyclonal and monoclonal antibodies, nanobodies, or aptamers can complement the antibody detection assays, and enhance the effectiveness of the serodiagnosis.
  5. Mohd-Hassan NH, Noordin R, Arifin N
    Trop Biomed, 2020 Sep 01;37(3):578-586.
    PMID: 33612773 DOI: 10.47665/tb.37.3.578
    Strongyloidiasis is a mysterious yet important parasitic disease that is hard to diagnose. While microscopic examination remains a "controversial" gold standard method, improved diagnosis is achieved through confirmatory assays with serological and/or molecular diagnostic approaches. In the current serodiagnosis of strongyloidiasis, recombinant proteins have been adopted in place of the use of native parasite antigens, although the availability of diagnostically potential proteins are still limited. Here, we introduce a novel Strongyloides recombinant protein that is uniquely attached to two different short peptide tags as a potential diagnostic biomarker for serodiagnosis of strongyloidiasis, namely lysine (7K) and aspartic acid (7D). The work presented focus on improving the yield and purity of the previously unexpressed recombinant protein. Preliminary diagnostic evaluation of the recombinant favors Ss3a7K protein owing to its higher antigenicity performance with 80% sensitivity and 100% specificity, respectively.
  6. 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.
  7. Puvanesuaran VR, Nowroji K, Sreenivasan S, Noordin R, Balakrishnan V
    Eur Rev Med Pharmacol Sci, 2012 Aug;16(8):1028-32.
    PMID: 22913152
    AIM: To determine the usefulness of prednisolone in increasing the number of Toxoplasma (T.) gondii tachyzoites and bradyzoites in mice.
    MATERIALS AND METHODS: The mice were water-fasted prior to being immunosuppressed with oral inoculation of prednisolone. Tachyzoites of 7T gondii RH strain were inoculated into mice and the number of the parasites in the intraperitoneal fluids was then determined at 96 hs post-infection. In addition, tachyzoites of T. gondii ME49 strains were orally introduced into mice and the number of brain cysts formed was observed by microscopic observation at 45 days post-infection.
    RESULTS: T. gondii propagation was found to be significantly improved by introduction of the prednisolone (p = 0.0004); and the number of parasite showed positive correlation with the increment in dosage of prednisolone (r = 0.9051).
    CONCLUSIONS: The use of prednisolone greatly improved the number of parasite formed in mice: both tachyzoite and cyst forms.
  8. 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.
  9. 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.
  10. Tan AA, Azman SN, Abdul Rani NR, Kua BC, Sasidharan S, Kiew LV, et al.
    Trop Biomed, 2011 Dec;28(3):620-9.
    PMID: 22433892 MyJurnal
    There is a great diversity of protein samples types and origins, therefore the optimal procedure for each sample type must be determined empirically. In order to obtain a reproducible and complete sample presentation which view as many proteins as possible on the desired 2DE gel, it is critical to perform additional sample preparation steps to improve the quality of the final results, yet without selectively losing the proteins. To address this, we developed a general method that is suitable for diverse sample types based on phenolchloroform extraction method (represented by TRI reagent). This method was found to yield good results when used to analyze human breast cancer cell line (MCF-7), Vibrio cholerae, Cryptocaryon irritans cyst and liver abscess fat tissue. These types represent cell line, bacteria, parasite cyst and pus respectively. For each type of samples, several attempts were made to methodically compare protein isolation methods using TRI-reagent Kit, EasyBlue Kit, PRO-PREP™ Protein Extraction Solution and lysis buffer. The most useful protocol allows the extraction and separation of a wide diversity of protein samples that is reproducible among repeated experiments. Our results demonstrated that the modified TRI-reagent Kit had the highest protein yield as well as the greatest number of total proteins spots count for all type of samples. Distinctive differences in spot patterns were also observed in the 2DE gel of different extraction methods used for each type of sample.
  11. 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.
  12. Khor BY, Tye GJ, Lim TS, Noordin R, Choong YS
    Int J Mol Sci, 2014 Jun 19;15(6):11082-99.
    PMID: 24950179 DOI: 10.3390/ijms150611082
    Brugia malayi is a filarial nematode, which causes lymphatic filariasis in humans. In 1995, the disease has been identified by the World Health Organization (WHO) as one of the second leading causes of permanent and long-term disability and thus it is targeted for elimination by year 2020. Therefore, accurate filariasis diagnosis is important for management and elimination programs. A recombinant antigen (BmR1) from the Bm17DIII gene product was used for antibody-based filariasis diagnosis in "Brugia Rapid". However, the structure and dynamics of BmR1 protein is yet to be elucidated. Here we study the three dimensional structure and dynamics of BmR1 protein using comparative modeling, threading and ab initio protein structure prediction. The best predicted structure obtained via an ab initio method (Rosetta) was further refined and minimized. A total of 5 ns molecular dynamics simulation were performed to investigate the packing of the protein. Here we also identified three epitopes as potential antibody binding sites from the molecular dynamics average structure. The structure and epitopes obtained from this study can be used to design a binder specific against BmR1, thus aiding future development of antigen-based filariasis diagnostics to complement the current diagnostics.
  13. Tommy YB, Lim TS, Noordin R, Saadatnia G, Choong YS
    BMC Struct Biol, 2012 Nov 27;12:30.
    PMID: 23181504 DOI: 10.1186/1472-6807-12-30
    BACKGROUND: Toxoplasma gondii is an intracellular coccidian parasite that causes toxoplasmosis. It was estimated that more than one third of the world population is infected by T. gondii, and the disease is critical in fetuses and immunosuppressed patients. Thus, early detection is crucial for disease diagnosis and therapy. However, the current available toxoplasmosis diagnostic tests vary in their accuracy and the better ones are costly.

    RESULTS: An earlier published work discovered a highly antigenic 12 kDa excretory-secretory (ES) protein of T. gondii which may potentially be used for the development of an antigen detection test for toxoplasmosis. However, the three-dimensional structure of the protein is unknown. Since epitope identification is important prior to designing of a specific antibody for an antigen-detection based diagnostic test, the structural elucidation of this protein is essential. In this study, we constructed a three dimensional model of the 12 kDa ES protein. The built structure possesses a thioredoxin backbone which consists of four α-helices flanking five β-strands at the center. Three potential epitopes (6-8 residues) which can be combined into one "single" epitope have been identified from the built structure as the most potential antibody binding site.

    CONCLUSION: Together with specific antibody design, this work could contribute towards future development of an antigen detection test for toxoplasmosis.

  14. Makhsin SR, Razak KA, Noordin R, Zakaria ND, Chun TS
    Nanotechnology, 2012 Dec 14;23(49):495719.
    PMID: 23164811 DOI: 10.1088/0957-4484/23/49/495719
    This study describes the properties of colloidal gold nanoparticles (AuNPs) with sizes of 20, 30 and 40 nm, which were synthesized using citrate reduction or seeding-growth methods. Likewise, the conjugation of these AuNPs to mouse anti-human IgG(4) (MαHIgG(4)) was evaluated for an immunochromatographic (ICG) strip test to detect brugian filariasis. The morphology of the AuNPs was studied based on the degree of ellipticity (G) of the transmission electron microscopy images. The AuNPs produced using the seeding-growth method showed lower ellipticity (G ≤ 1.11) as compared with the AuNPs synthesized using the citrate reduction method (G ≤ 1.18). Zetasizer analysis showed that the AuNPs that were synthesized using the seeding-growth method were almost monodispersed with a lower polydispersity index (PDI; PDI≤0.079), as compared with the AuNPs synthesized using the citrate reduction method (PDI≤0.177). UV-visible spectroscopic analysis showed a red-shift of the absorbance spectra after the reaction with MαHIgG(4), which indicated that the AuNPs were successfully conjugated. The optimum concentration of the BmR1 recombinant antigen that was immobilized on the surface of the ICG strip on the test line was 1.0 mg ml(-1). When used with the ICG test strip assay and brugian filariasis serum samples, the conjugated AuNPs-MαHIgG(4) synthesized using the seeding-growth method had faster detection times, as compared with the AuNPs synthesized using the citrate reduction method. The 30 nm AuNPs-MαHIgG(4), with an optical density of 4 from the seeding-growth method, demonstrated the best performance for labelling ICG strips because it displayed the best sensitivity and the highest specificity when tested with serum samples from brugian filariasis patients and controls.
  15. Huat LB, Garcia AO, Ning TZ, Kin WW, Noordin R, Azham SS, et al.
    Asian Pac J Trop Biomed, 2014 Jun;4(6):446-50.
    PMID: 25182945 DOI: 10.12980/APJTB.4.2014C1169
    To characterize the Entamoeba histolytica (E. histolytica) antigen(s) recognized by moribound amoebic liver abscess hamsters.
  16. Supali T, Djuardi Y, Bradley M, Noordin R, Rückert P, Fischer PU
    PLoS Negl Trop Dis, 2013;7(12):e2586.
    PMID: 24349595 DOI: 10.1371/journal.pntd.0002586
    The lymphatic filarial parasite Brugia timori occurs only in eastern Indonesia where it causes high morbidity. The absence of an animal reservoir, the inefficient transmission by Anopheles mosquitoes and the high sensitivity to DEC/albendazole treatment make this species a prime candidate for elimination by mass drug administration (MDA).
  17. 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.
  18. 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.
  19. Berizi M, Babaie J, Fard-Esfahani P, Enshaeieh M, Noordin R, Saadatnia G, et al.
    Iran J Parasitol, 2022 1 28;16(4):621-630.
    PMID: 35082891 DOI: 10.18502/ijpa.v16i4.7875
    Background: Toxoplasmosis is a worldwide-distributed infection that can cause serious diseases, mainly in congenitally infected and immunodeficient individuals. PCR assays play an indispensable role in the detection of Toxoplasma gondii in different biological samples.

    Methods: This study was conducted in the Parasitology Department at Pasteur Institute of Iran (Tehran) during 2016-2018. We designed a highly sensitive quantitative real-time PCR (RT-qPCR) targeted REP-529, a noncoding repetitive DNA. We cloned the amplicon in a plasmid (pTZREP-529) and used it to generate the standard curve. The Toxoplasma RT-qPCR characteristics, i.e., detection limit, specificity, linear dynamic range, linearity, intra-, and inter-assay precisions, were determined. The detection limit of the assay was one plasmid copy number (PCN) per reaction (about 0.004 T. gondii genome), and the linear dynamic range was equal to 6 logs (1× 101 to 1× 107 PCN per reaction).

    Results: The assay showed no signal when genomic DNA of Plasmodium falciparum, Leishmania major, and Trichomonas vaginallis were used. The standard curve was drawn using dilutions of pTZREP-529 plasmid spiked with genomic DNA from a mouse brain, and test characteristics were shown unaffected. Applying the Toxoplasma RT-qPCR, we showed brain cysts were significantly decreased in mice vaccinated with GRA2 antigen of Toxoplasma formulated in Monophosphoryl Lipid A (MPL) adjuvant.

    Conclusion: We have developed a quantitative, specific, and highly sensitive PCR for detecting T. gondii in biological samples.

  20. Ning TZ, Kin WW, Noordin R, Cun ST, Chong FP, Mohamed Z, et al.
    BMC Infect Dis, 2013;13:144.
    PMID: 23514636 DOI: 10.1186/1471-2334-13-144
    Amoebic liver abscess (ALA) is the most frequent clinical presentation of extra-intestinal amoebiasis. The diagnosis of ALA is typically based on the developing clinical symptoms, characteristic changes on radiological imaging and serology. Numerous serological tests have been introduced for the diagnosis of ALA, either detecting circulating amoebic antigens or antibodies. However those tests show some pitfalls in their efficacy and/or the preparation of the tests are costly and tedious. The commercial IHA kit that used crude antigen was reported to be useful in diagnosis of ALA, however high antibody background in endemic areas may cause problems in its interpretation. Thus, discovery of well-defined antigen(s) is urgently needed to improve the weaknesses of current serodiagnostic tests.
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