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  1. Development of a slide latex agglutination test for rotavirus antigen detection
    Yap KL
    Malays J Pathol, 1994 Jun;16(1):49-56.
    PMID: 16329576
    The aim of this study was to optimize the conditions for the passive adsorption of polyclonal antibody onto plain surface polystyrene latex particles and its performance in a slide latex agglutination test for rotavirus antigen detection. Cleaning of latex particles by washing through repetitive centrifuging, decanting and resuspending in distilled water was adequate in removing surfactants from the particles' surfaces to enable coating. A study of antibody concentration, incubation temperature and buffer pH revealed that optimum coating was achieved with a 3-fold excess of antibody to the calculated total particle surface capacity for the antibody in a glycine-saline buffer of pH 9.2 at 40 degrees C for 4 hours. The ionic strength and pH of the latex suspending buffer and the sample buffer were critical factors determining the sensitivity of the test and the appearance of non-specific agglutination. Ultrasonication, addition of glycerol and Tween 20, either individually or in combination, were able to suppress non-specific agglutination in some batches of latex reagents. Polyethylene glycol 6000 enhanced the quality of agglutination as well as reduced the time of its appearance, especially in reagents that produced poor agglutination.
    Matched MeSH terms: Latex Fixation Tests/methods*
  2. Fulltext Conventional rapid latex agglutination in estimation of von Willebrand factor: method revisited and potential clinical applications
    Mahat M, Abdullah WZ, Hussin CM
    J Immunol Res, 2014;2014:850810.
    PMID: 25759835 DOI: 10.1155/2014/850810
    Measurement of von Willebrand factor antigen (VWF : Ag) levels is usually performed in a specialised laboratory which limits its application in routine clinical practice. So far, no commercial rapid test kit is available for VWF : Ag estimation. This paper discusses the technical aspect of latex agglutination method which was established to suit the purpose of estimating von Willebrand factor (VWF) levels in the plasma sample. The latex agglutination test can be performed qualitatively and semiquantitatively. Reproducibility, stability, linearity, limit of detection, interference, and method comparison studies were conducted to evaluate the performance of this test. Semiquantitative latex agglutination test was strongly correlated with the reference immunoturbidimetric assay (Spearman's rho = 0.946, P < 0.001, n = 132). A substantial agreement (κ = 0.77) was found between qualitative latex agglutination test and the reference assay. Using the scoring system for the rapid latex test, no agglutination is with 0% VWF : Ag (control negative), 1+ reaction is equivalent to <20% VWF : Ag, and 4+ reaction indicates >150% VWF : Ag (when comparing with immunoturbidimetric assay). The findings from evaluation studies suggest that latex agglutination method is suitable to be used as a rapid test kit for the estimation of VWF : Ag levels in various clinical conditions associated with high levels and low levels of VWF : Ag.
    Matched MeSH terms: Latex Fixation Tests/methods*
  3. Fulltext Rotavirus - A Retrospective Study of Incidence at the Hospital Universiti Sains Malaysia (HUSM)
    Ludin CM, Radzi JM, Maimunah A
    Malays J Med Sci, 2003 Jul;10(2):87-90.
    PMID: 23386803 MyJurnal
    The present study, analyzes data from 1991 to 2000 for rotavirus infection among children with diarrhoea and acute gastroenteritis admitted to the Hospital Universiti Sains Malaysia (HUSM). The Latex Slide Agglutination Test was used for the detection of rotavirus antigens. Out of 1097 stool samples tested, 207 samples or 18.8 % were found to be positive for rotavirus. The infection occurred most frequently in infants and young children from 6 months to 2 years of age. The infection was recorded highest in the year of 2000 - 48 cases (34.1%) and the lowest in 1999 - 5 cases (6.6%). Stool examination and cultures from the rotavirus positive samples revealed no parasites and enteropathogenic bacteria. These observations suggested that rotavirus could still remain as an important agent causing diarrhoea and gastroenteritis in young children admitted to HUSM.
    Matched MeSH terms: Latex Fixation Tests
  4. Legionella species and serogroups in Malaysian water cooling towers: identification by latex agglutination and PCR-DNA sequencing of isolates
    Yong SF, Goh FN, Ngeow YF
    J Water Health, 2010 Mar;8(1):92-100.
    PMID: 20009251 DOI: 10.2166/wh.2009.002
    In this study, we investigated the distribution of Legionella species in water cooling towers located in different parts of Malaysia to obtain information that may inform public health policies for the prevention of legionellosis. A total of 20 water samples were collected from 11 cooling towers located in three different states in east, west and south Malaysia. The samples were concentrated by filtration and treated with an acid buffer before plating on to BCYE agar. Legionella viable counts in these samples ranged from 100 to 2,000 CFU ml(-1); 28 isolates from the 24 samples were examined by latex agglutination as well as 16S rRNA and rpoB PCR-DNA sequencing. These isolates were identified as Legionella pneumophila serogroup 1 (35.7%), L. pneumophila serogroup 2-14 (39%), L. pneumophila non-groupable (10.7%), L. busanensis, L. gormanii, L. anisa and L. gresilensis. L. pneumophila was clearly the predominant species at all sampling sites. Repeat sampling from the same cooling tower and testing different colonies from the same water sample showed concurrent colonization by different serogroups and different species of Legionella in some of the cooling towers.
    Matched MeSH terms: Latex Fixation Tests
  5. Fulltext Rotavirus RNA electropherotype in different states in Malaysia for the year 2000 and 2001
    Zuridah H, Bahaman AR, Mohd Azmi ML, Mutalib AR
    Med J Malaysia, 2004 Jun;59(2):153-9.
    PMID: 15559163 MyJurnal
    A total of 157 stool samples were examined for Group A rotaviruses in diarrheic children admitted to 8 different major hospitals in Malaysia. The overall incidence rate in this study was 19.7% (31 of 157) with a variation of 9.5% to 39.1% in different locations. Majority of the infections detected were in those under 2 years of age and there were fewer admissions in the older age group. The stool samples were initially screened for rotavirus Group A by latex agglutination method and followed by RNA electrophoresis. The size and the characteristics wheel-shaped morphology of the viral preparations when examined by electron-microscopy further confirmed the presence of rotaviruses in the positive stool samples. Analysis of the RNA pattern showed that majority of the isolates, 51.6% (16 of 31) were Type IIC ('long' with comigration of RNA segments 7 and 8), 35.5% (11 of 31) with Type IIG ('long' with comigration of segments 7, 8, 9), 9.7% (3 of 31) with Type IG ('short' with comigration of RNA segments 7, 8, 9) and 3.2% (1 of 31) of mixed or atypical pattern. It appeared that over a 12 year interval, only one new or unusual rotavirus electropherotype was found. This is the first comprehensive report on the electropherotypes of rotaviruses covering eight different geographical locations in Malaysia and the data obtained is useful for understanding the geographic distribution and types of rotaviruses transmitting in Malaysia.
    Matched MeSH terms: Latex Fixation Tests
  6. Fulltext The use of an in-house biotin-avidin linked immunosorbent assay to detect Aspergillus antigens in sera of immunocompromised patients
    Abdul Samad S, Yusoff H, Fadilah SAW
    Med J Malaysia, 2001 Mar;56(1):32-8.
    PMID: 11503293
    A biotin-avidin-linked immunosorbent assay was developed to detect Aspergillus antigens in sera of immunocompromised patients. The assay was based on a double antibody sandwich ELISA using polyclonal antibodies raised against water-soluble antigens of Aspergillus fumigatus. Aspergillus antigens were positive in sera of 9 of 16 (56%) patients who were studied prospectively and in 13 of 73 (19%) patients studied retrospectively. The 9 prospectively studied patients who were antigen positive were febrile neutropenic hematological malignancy patients who exhibited a high risk of acquiring invasive aspergillosis.
    Matched MeSH terms: Latex Fixation Tests
  7. An evaluation of the staphylococcal co-agglutination test for the detection of group A rotavirus in human faeces
    Yap KL, Ooi YE, Khor CM, Wong SH
    Malays J Pathol, 1992 Dec;14(2):105-10.
    PMID: 1338997
    The group A rotavirus staphylococcal co-agglutination test was evaluated and its sensitivity and specificity compared with an in-house enzyme-linked immunosorbent assay (ELISA) and a commercial latex agglutination test (Rotalex). In addition, the storage stability of the staphylococcal reagents was ascertained. Examination of 136 clarified suspensions of diarrhoeal faeces by the staphylococcal co-agglutination test revealed a high proportion of false positives (26%) and uninterpretable results (34%) due to non-specific agglutination. Non-specific agglutination could be removed effectively by prior absorption of the clarified faecal specimens with unsensitized staphylococci. The staphylococcal co-agglutination test was less sensitive and specific than the in-house enzyme-linked immunosorbent assay but was comparable to the Rotalex slide latex agglutination test. The staphylococcal reagents have a shelf life of at least 29 weeks.
    Matched MeSH terms: Latex Fixation Tests
  8. Fulltext Evaluation of PCR-based approach for serotype determination of Streptococcus pneumoniae
    Shakrin NN, Balasubramaniam SD, Yusof HA, Mastuki MF, Masri SN, Taib NM, et al.
    Trop Biomed, 2013 Jun;30(2):338-44.
    PMID: 23959499 MyJurnal
    Determination of Streptococcus pneumoniae serotypes is essential for epidemiological surveillance. Therefore accurate, reliable and cost effective serotyping method is crucial. In this study, we determined the serotypes of 41 pneumococcal isolates recovered from human anterior nares by multiplex Polymerase Chain Reaction (PCR) utilizing published primers. The data was then compared with conventional serology using latex agglutination (LA) and the Quellung reaction. Based on the PCR-approach, 8 different serogroups/serotypes were detected with one isolate classified as non-typeable (cpsA-negative). In reference to the serology-based data, the results were in agreement except for one isolate. For the latter isolate, the LA and Quellung tests failed to show a reaction but the PCR-approach and sequencing identified the isolate as serogroup 15B/C. Based on this experimental setting, we found that the PCR-approach for pneumococcal serotypes determination is reliable to serve as the alternative for determining the pneumococcal serotyping.
    Matched MeSH terms: Latex Fixation Tests
  9. Seroprevalence, associated risk factors and hematological impacts of toxoplasmosis in small ruminants of Multan, Punjab-Pakistan
    Ullah MZ, Awais MM, Akhtar M, Anwar MI, Navid MT, Khan I, et al.
    Trop Biomed, 2018 Dec 01;35(4):1028-1040.
    PMID: 33601850
    Toxoplasmosis is a protozoal infection of zoonotic potential with worldwide geographical distribution which affects nearly all warm-blooded animals including mammals and birds. Keeping in view, this study was conducted to determine the seroprevalence of toxoplasmosis along with associated risk factors and its haematological impacts in small ruminants of district Multan, Pakistan. In this study, a total of 250 sera samples collected from sheep (n=125) and goats (n=125) from three tehsils of Multan were examined using commercially available Latex agglutination test kit for the presence of anti-T. gondii antibodies. The haematological profiles of Toxoplasma seropositive and seronegative animals were determined by using automated haematology analyser. Overall seroprevalence of toxoplasmosis in small ruminants was 42.80% with a higher prevalence rate (44.80%) in sheep as compared to goats (40.80%). Sex, existence of co-morbid conditions, feeding pattern and presence of pet cats and dogs were identified as significant (P<0.05) risk factors associated with the presence of antibodies against toxoplasmosis. The breed was found to be a significant (P=0.026) risk factor for the seroprevalence of toxoplasmosis in goats but not in sheep. Haematological analysis revealed significantly altered leukocytic counts (P<0.05) in seropositive sheep and goats as compared to seronegative ones. Our findings showed that small ruminants of the Multan District in Pakistan are toxoplasma seropositive and may pose a serious threat of public health concern in the region.
    Matched MeSH terms: Latex Fixation Tests
  10. Fulltext Investigation of stx 2 + eae + Escherichia coli O157:H7 in beef imported from Malaysia to Thailand
    International Food Research Journal, 2011;18(1):381-386.
    MyJurnal
    To gain insight into the microbiological safety of food products routinely traded across international borders in Southeast Asian countries, beef imported from Malaysia to southern Thailand was examined for contamination with Escherichia coli O157 and its subsequent spread into the imported areas. We screened 31 samples exported from Malaysia and 36 domestic Thai samples. Isolation methods including an O157 antigen-targeted immunomagnetic separation technique, screening on CHROMagar O157 medium, and serotype confirmation of E. coli isolates by specific agglutination tests were employed. Fourteen strains of E. coli O157:H7 were isolated from eight Malaysian samples (25.8%) and six strains from four Thai samples (11.1%). These strains were of the stx1-stx2+eae+ genotype except one Malaysian strain which was of the stx1- stx2- eae+ genotype. All 19 O157:H7 strains possessing the stx2 gene produced little or no Stx2 (reversed passive latex agglutination titer ≤ 4). Of the 19 strains, five Malaysian (38.5%) and two Thai (33.3%) strains exhibited resistance to a set of antibiotics. Finally, the results of two DNA fingerprinting
    analyses (O157 IS-printing targeted to IS629 and pulsed-field gel electrophoresis, PFGE) of the O157:H7 strains possessing the stx2 gene, indicated that the Malaysian and Thai strains are closely related. Therefore, E. coli O157:H7 might be transferred from Malaysia to southern Thailand through beef trade.
    Matched MeSH terms: Latex Fixation Tests
  11. Prevalence of Bacillus cereus in selected foods and detection of enterotoxin using TECRA-VIA and BCET-RPLA
    Rusul G, Yaacob NH
    Int J Food Microbiol, 1995 Apr;25(2):131-9.
    PMID: 7547144
    Enterotoxigenic Bacillus cereus was detected in cooked foods (17), rice noodles (3), wet wheat noodles (2), dry wheat noodles (10), spices (8), grains (4), legumes (11) and legume products (3). One hundred ninety-four (42.3%), 70 (15.3%) and 23 (5.2%) of the 459 presumptive B. cereus colonies isolated from PEMBA agar were identified as B. cereus, Bacillus thuringiensis and B. mycoides, respectively. B. cereus isolates were examined for growth temperature, pH profile and enterotoxin production using both TECRA-VIA and BCET-RPLA kits. One hundred seventy-eight (91.8%) and 164 (84%) of the strains were enterotoxigenic as determined using TECRA-VIA and BCET-RPLA, respectively. Eighty-two (50%) of the enterotoxigenic strains were capable of growing at 5 degrees C, and 142 (86.6%) grew at 7 degrees C within 7 days of incubation. The enterotoxigenic strains did not grow at pH 4.0 but 69 (42.0%) of the strains were able to grow at pH 4.5 within 7 days at 37 degrees C. The isolates were resistant to ampicillin (98.8%), cloxallin (100%) and tetracycline (61.0%), and susceptible to chloroamphenicol (87%), erythromycin (77.4%), gentamycin (100%) and streptomycin (98.7%).
    Matched MeSH terms: Latex Fixation Tests
  12. Fulltext Characterization of Burkholderia pseudomallei from spontaneous melioidosis in a Bornean orangutan
    Testamenti VA, Surya M, Saepuloh U, Iskandriati D, Tandang MV, Kristina L, et al.
    Vet World, 2020 Nov;13(11):2459-2468.
    PMID: 33363342 DOI: 10.14202/vetworld.2020.2459-2468
    Background and Aim: Melioidosis is a potentially fatal disease affecting humans and a wide range of animal species; it is often underdiagnosed and underreported in veterinary medicine in Indonesia. This study aimed to characterize morphological and molecular features of Burkholderia pseudomallei, the causative agent of melioidosis which caused the death of a Bornean orangutan.

    Materials and Methods: Pulmonary abscess samples were cultured on several types of media, including Ashdown agar, Ashdown broth, and MacConkey agar. Type three secretion system orf 2 real-time polymerase chain reaction (PCR) and latex agglutination tests were performed to identify the bacteria. Morphological characteristics were compared to all previously published morphotypes. Subsequently, the bacteria were characterized by multilocus sequence typing (MLST) and Yersinia-like flagellum/Burkholderia thailandensis-like flagellum and chemotaxis PCR. The results of the genotyping were afterward compared to all genotypes from Southeast Asia.

    Results: Multiple morphotypes of B. pseudomallei were perceived during the growth on Ashdown agar. Furthermore, it was identified by MLST that the Type I and Type II morphotypes observed in this study were clones of a single ST, ST54, which is predominantly found in humans and the environment in Malaysia and Thailand, although a very limited number of reports was published in association with animals. Moreover, the E-BURST analysis showed that the ST is grouped together with isolates from Southeast Asian countries, including Malaysia, Thailand, Singapore, and Cambodia. ST54 was predicted to be the founding genotype of several STs from those regions.

    Conclusion: B. pseudomallei ST54 that caused the death of a Bornean orangutan has a distant genetic relationship with other STs which were previously reported in Indonesia, implying a vast genetic diversity in Indonesia that has not been discovered yet.

    Matched MeSH terms: Latex Fixation Tests
  13. Genetic characterization of Escherichia coli O157: H7/- strains carrying the stx2 gene but not producing Shiga toxin 2
    Koitabashi T, Vuddhakul V, Radu S, Morigaki T, Asai N, Nakaguchi Y, et al.
    Microbiol. Immunol., 2006;50(2):135-48.
    PMID: 16490932
    Nine Escherichia coli O157: H7/- strains isolated primarily from non-clinical sources in Thailand and Japan carried the stx(2) gene but did not produce Stx2 toxin in a reversed passive latex agglutination (RPLA) assay. A strain (EDL933) bearing a stx(2) phage (933W) was compared to a strain (Thai-12) that was Stx2-negative but contained the stx(2) gene. To study the lack of Stx2 production, the Thai-12 stx(2) gene and its upstream nucleotide sequence were analyzed. The Thai-12 stx(2) coding region was intact and Stx2 was expressed from a cloned stx(2) gene using a plasmid vector and detected using RPLA. A lacZ fusion analysis found the Thai-12 stx(2) promoter non-functional. Because the stx(2) gene is downstream of the late promoter in the stx(2) phage genome, the antitermination activity of Q protein is essential for strong stx(2) transcription. Thai-12 had the q gene highly homologous to that of Phi21 phage but not to the 933W phage. High-level expression of exogenous q genes demonstrated Q antitermination activity was weak in Thai-12. Replication of stx(2) phage was not observed in Stx2-negative strains. The q-stx(2) gene sequence of Thai-12 was well conserved in all Stx2-negative strains. A PCR assay to detect the Thai-12 q-stx(2) sequence demonstrated that 30% of O157 strains from marketed Malaysian beef carried this sequence and they produced little or no Stx2. These results suggest that stx(2)-positive O157 strains that produce little or no Stx2 may be widely distributed in the Asian environment.
    Matched MeSH terms: Latex Fixation Tests
  14. Fulltext Pattern of rheumatoid arthritis in West Malaysia
    Toh BH, Sengupta S, Ang AH, White JC, Lau KS
    Ann Rheum Dis, 1973 Mar;32(2):151-6.
    PMID: 4120913 DOI: 10.1136/ard.32.2.151
    In West Malaysia RA appears to be less common than in temperate climates, but more common than in tropical Africa; furthermore, the incidence of gout and SLE is comparable. The clinical manifestations of RA are milder than those seen in more temperate climates. Subcutaneous rheumatoid nodules have not been observed. Positive serological tests for RF are significantly higher than in the general Malaysian population, but still lower than those reported for patients with RA in temperate climates. Of the three main ethnic groups, the highest incidence of positive results is found in the Chinese.
    Study site: Arthritis Clinic, University Hospital, Kuala Lumpur (University Malaya Medical Centre, UMMC, Kuala Lumpur, Malaysia)
    Matched MeSH terms: Latex Fixation Tests
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