scholarly journals Effects of Pretreating Serum Samples on the Performance of a Latex Agglutination Test for Serodiagnosis of Paracoccidioidomycosis

2011 ◽  
Vol 19 (3) ◽  
pp. 386-390 ◽  
Author(s):  
Fabíola Silveira-Gomes ◽  
Silvia Helena Marques-da-Silva
Keyword(s):  
Sensitivity And Specificity ◽  
Bacterial Infections ◽  
Paracoccidioides Brasiliensis ◽  
Latex Agglutination ◽  
Agglutination Test ◽  
Latex Agglutination Test ◽  
Serum Samples ◽  
Content Type ◽  
Human Sera ◽  
Normal Human

ABSTRACTParacoccidioidomycosis (PCM) is a fungal disease caused byParacoccidioides brasiliensis, and Brazil is one of the principal countries where it is endemic. Diagnosis is based on the observation of buddingP. brasiliensisyeast in clinical specimens from patients; however, the sensitivity of the visualization of fungi is low, indicating that serological tests are used for early diagnosis. The double-immunodiffusion test (ID) is the “gold standard” test for serology in PCM, although the execution of this test requires the availability of laboratorial infrastructure. We report the improved performance of a latex agglutination test (LAT) by pretreating 30 serum samples from PCM patients and 71 controls (histoplasmosis and aspergillosis patients, patients with bacterial infections, and normal human sera) with a dilution buffer incubated at 37°C for 30 min. The sensitivity and specificity of the LAT test in the nonpretreated samples were 73% and 79%, respectively. However, when samples were pretreated, the sensitivity and specificity of the test increased to 90%. In this study, we did not observe cross-reactivity with histoplasmosis patient sera, but some reactions to sera from patients with aspergillosis and bacterial infections were noted. Normal human sera were not reactive in our tests. These results indicate the need for the elimination of heterologous reactions so that we can adequately use this method for screening cases of PCM.

scholarly journals A rapid latex agglutination test for the detection of anti-cysticercus antibodies in cerebrospinal fluid (CSF)

2002 ◽  
Vol 44 (1) ◽  
pp. 57-58 ◽  
Author(s):  
Sérgio M. ROCHA ◽  
Lisandra A. SUZUKI ◽  
Andréa D.T. da SILVA ◽  
Gisele C. ARRUDA ◽  
Cláudio L. ROSSI
Keyword(s):  
Diagnostic Tests ◽  
Chronic Headache ◽  
Viral Meningitis ◽  
Latex Agglutination ◽  
Agglutination Test ◽  
Latex Agglutination Test ◽  
Serum Samples ◽  
Neurologic Disorders ◽  
Specific Antigens ◽  
Additional Approach

Simple and rapid latex-based diagnostic tests have been used for detecting specific antigens or antibodies in several diseases. In this article, we present the preliminary results obtained with a latex agglutination test (LAT) for diagnosing neurocysticercosis by detection of antibodies in CSF. A total of 43 CSF samples were assayed by the LAT: 19 CSF samples from patients with neurocysticercosis and 24 CSF samples from patients with other neurologic disorders (neurosyphilis, n = 8; neurotoxoplasmosis, n = 3; viral meningitis, n = 4, chronic headache, n = 9). The LAT exhibited 89.5% sensitivity and 75% specificity. The use of LAT seems to be an additional approach for the screening of neurocysticercosis with advantage of simplicity and rapidity. Further studies could be performed using purified antigens and serum samples.

scholarly journals Development and Evaluation of a Latex Agglutination Test for the Serodiagnosis of Paracoccidioidomycosis

2011 ◽  
Vol 18 (4) ◽  
pp. 604-608 ◽  
Author(s):  
Fabíola Silveira-Gomes ◽  
Dayse Nogueira Sarmento ◽  
Thifany Mendes Pinto ◽  
Rosiane Ferreira Pimentel ◽  
Lívia Barreto Nepomuceno ◽  
...  
Keyword(s):  
Latex Particle ◽  
Paracoccidioides Brasiliensis ◽  
Cross Reactivity ◽  
Latex Agglutination ◽  
Dimorphic Fungus ◽  
Double Immunodiffusion ◽  
Serum Samples ◽  
Content Type ◽  
Healthy Donors ◽  
Low Costs

ABSTRACTParacoccidioidomycosis (PCM) is the most prevalent systemic mycosis in Latin America. It is caused by the dimorphic fungusParacoccidioides brasiliensis. The immunodiffusion (ID) test is one of the most widely used techniques for PCM serologic diagnosis due to the simplicity and low costs of its execution. However, it requires trained and qualified people to execute it. The purpose of this study was to evaluate a latex particle agglutination (LA) test for the detection of anti-P. brasiliensisantibodies by using pooled crude exoantigens from the fungus. Fifty-one serum samples obtained from patients with PCM were tested. Positivity was observed in 84% (43/51) of these patients, and the agglutination patterns varied from small clumps with a cloudy background to large clumps with a clear background. The antibody titer reactivity ranged from 1:2 to 1:64. Cross-reactivity was observed in sera from patients with aspergillosis, histoplasmosis, and nonfungal disease. Serum samples obtained from healthy donors were not reactive. The sensitivity and specificity of the LA test were 84% and 81%, respectively. When comparing the LA test with the double-immunodiffusion test, we found an agreement of 92%. Further work is needed to improve the performance of the LA assay before it can be proposed as a reliable diagnostic tool, mainly in laboratories with little infrastructure.

scholarly journals Diagnostic accuracy of urinary latex agglutination test (KAtex) for the diagnosis of visceral leishmaniasis: A meta-analysis

2018 ◽  
Vol 12 (12) ◽  
pp. 1045-1051 ◽  
Author(s):  
Mohammad Fararouei ◽  
Bahador Sarkari ◽  
Samaneh Abdolahi Khabisi ◽  
Zahra Rezaei
Keyword(s):  
Middle East ◽  
Visceral Leishmaniasis ◽  
Diagnostic Accuracy ◽  
Sensitivity And Specificity ◽  
Meta Analysis ◽  
Latex Agglutination ◽  
Agglutination Test ◽  
Latex Agglutination Test ◽  
Receiver Operating Curve ◽  
Significant Difference

Latex agglutination test (KAtex) has been used in the last two decades for the diagnosis of visceral leishmaniasis (VL) in different VL-endemic areas. Here, we present a meta-analysis of studies which evaluated the KAtex for the diagnosis of VL to find out its overall diagnostic performance. A database search was performed on PubMed, Scopus, ISI Web of Science, Iranmedex and Google Scholar. The search of databases found 57 papers, of which 17 articles fulfilled our eligibility criteria. Meta-analysis of diagnostic accuracy (MADA) and Hierarchical Summary Receiver Operating Curve (HSROC) packages were used to do the meta-analysis and to obtain pooled estimates of sensitivity and specificity. Fixed effect bivariate analysis was conducted, using Mantel-Haenszel estimator, to measure the performance and diagnosis odds ratio (DOR) of the test. Heterogeneity of the test results was assessed by Chi-squared test. The sensitivity of individual studies ranged from 39.8 to 100%, and the specificity ranged from 64 to100%. The combined sensitivity and specificity estimates of KAtex were 77% (95% CI, 70-83%), and 97% (95% CI, 93-97%), respectively. Comparing the performance of the test by region suggests a significant difference where the lowest and highest sensitivities are reported from Nepal/Tunisia and Europe/Middle East respectively (p < 0.05). On the other hand, the lowest and highest rates of specificity were reported from Sudan and America/Middle East respectively. The overall specificity of KAtex is satisfactory. However, KAtex suffers from low sensitivity and this shortcoming should be improved. The test provides a rapid and simple diagnosis of VL and improvement of its sensitivity deserve further studies.

scholarly journals Syphilis Fast Latex Agglutination Test, a Rapid Confirmatory Test

2001 ◽  
Vol 8 (4) ◽  
pp. 841-842 ◽  
Author(s):  
Martha B. Fears ◽  
Victoria Pope
Keyword(s):  
Point Of Care ◽  
Transmitted Disease ◽  
Treponema Pallidum ◽  
Latex Agglutination ◽  
Agglutination Test ◽  
Latex Agglutination Test ◽  
Confirmatory Test ◽  
Serum Samples ◽  
Sexually Transmitted ◽  
Particle Agglutination

ABSTRACT Using 255 serum samples with various reactivities, we evaluated the Syphilis Fast latex agglutination test (Syphilis Fast) against theTreponema pallidum particle agglutination test (TP-PA) for confirming a diagnosis of syphilis. We found 98.8% agreement between the Syphilis Fast and the TP-PA. The Syphilis Fast, however, had a couple of advantages over the TP-PA: the test takes only 8 min to perform and produces results that are easy to read. It appears to be a good confirmatory test for syphilis, especially for point-of-care clinics such as prenatal or sexually transmitted disease clinics.

scholarly journals Efficacy of a Latex Agglutination Test for Rapid Identification of Staphylococcus aureus: Collaborative Study

1996 ◽  
Vol 79 (3) ◽  
pp. 661-670 ◽  
Author(s):  
Tsung C Chang ◽  
Su H Huang ◽  
H Y Chao ◽  
B L Chen ◽  
C Chen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Sensitivity And Specificity ◽  
Collaborative Study ◽  
False Negative ◽  
Pairwise Comparison ◽  
Latex Agglutination ◽  
Agglutination Test ◽  
Latex Agglutination Test ◽  
Official Method ◽  
Latex Test

Abstract Fifteen laboratories completed a collaborative study comparing the efficacy of a latex agglutination kit (Aureus Test) with that of AOAC Official Method 987.09 (coagulase test for identification of Staphylococcus aureus). Each laboratory analyzed 240 strains of bacteria, including 160 isolates of S. aureus and 80 isolates of other bacteria. Upon receipt of cultures, collaborators subcultured each isolate on both tryptic soy agar (TSA) and Baird-Parker agar medium (BPA) to determine whether the growth medium has any effect on either method. For cultures grown on TSA, the latex test had sensitivity and specificity rates of 99.2 and 97.1 %, respectively, whereas the coagulase test had respective rates of 98.4 and 92.5%. For cultures able to grow on BPA, the latex test had sensitivity and specificity rates of 99.2 and 96.6%, respectively, while the coagulase test had respective rates of 98.3 and 91.3%. By using the McNemar pairwise comparison test of the 2 methods, the falsepositive and false-negative rates of the latex test were significantly lower (p &lt; 0.01) than those of the coagulase test for strains grown either on TSA or BPA. The latex agglutination test for identification of S. aureus isolated from foods has been adopted by AOAC INTERNATIONAL.

scholarly journals Recombinant leptospiral immunoglobulin like B protein based latex agglutination test for serodiagnosis of human leptospirosis

2020 ◽  
Vol 6 (2) ◽  
pp. 229-236
Author(s):  
Yosef Deneke ◽  
Rajib Deb ◽  
SM Lutful Kabir
Keyword(s):  
Acute Infection ◽  
Latex Agglutination ◽  
Agglutination Test ◽  
The Body ◽  
Latex Agglutination Test ◽  
City Hospital ◽  
Indian Veterinary Research Institute ◽  
Test Kit ◽  
Human Sera ◽  
Sera Samples

Humans get leptospirosis by contact with fresh water, damp soil, or vegetation contaminated by the urine of infected animals, swallowing contaminated food or water or while working in contaminated flood plains or at wet agricultural settings. The bacteria enter the body through abrasions in the skin and mucous membranes. In the present study recombinant LigB protein is employed in latex agglutination test, which is a cross reacting lipoprotein able to detect acute infection caused by any pathogenic leptospiral serovars. It was employed for serodiagnosis of leptospirosis. The 46 KDa 6X His tagged LigB protein, obtained by IPTG induction of recombinant E. coli M15 cells containing the N-terminal region of LigB gee in PQE30 expression vector, was purified by Ni-NTA affinity chromatography and adsorbed on latex bead surface for performing latex agglutination test against leptospirosis suspected human sera. A total of 28 human sera samples were received from Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh India, which tested positive by IgM ELISA test kit were subjected to both rLigB based LAT and MAT. All the 28 sera showed seropositivity by both the tests. Icterohaemorrahigae was the predominant serovar followed by Javanica and Grippotyphosa. Six out seven sera samples received from Indian Veterinary research Institute, Human Hospital and City Hospital, Bareilly were tested positive both by rLAT and MAT. The result showed that sera were tested positive by rLigB based LAT, which were reconfirmed using microscopic agglutination test (MAT). The results from LAT were in concordance with MAT. In conclusion, rLigB based LAT is a rapid, reliable diagnostic tool at resource poor and remote diagnostic centers with high sensitivity and specificity, under laboratory and field conditions, for the detection of leptospirosis. Asian J. Med. Biol. Res. June 2020, 6(2): 229-236

scholarly journals Diagnostic Study of Toxoplasmosis in Domestic Chickens in Sulaimani Province

2013 ◽  
Vol 12 (2) ◽  
pp. 63 ◽  
Author(s):  
A. A. Mohammed
Keyword(s):  
Toxoplasma Gondii ◽  
Histopathological Examination ◽  
Latex Agglutination ◽  
Agglutination Test ◽  
Gallus Domesticus ◽  
Latex Agglutination Test ◽  
Diagnostic Study ◽  
Serum Samples ◽  
First Report ◽  
Seropositive Rate

Toxoplasma gondii causes toxoplasmosis in human and animals, a disease of cosmopolitan character. A total of 65 serum samples of domestic chickens (Gallus domesticus) from Sulaimani region were collected from May till August 2012.The overall seropositivity against T. gondii antibody was 60% based on the Latex agglutination test (LAT). The positive agglutination titers were ranged between 1:2 -1:128, and the highest seropositive rate observed at a titer 1: 128 was 25.64% . The present study demonstrated that anti-Toxoplasma antibodies were high in chickens in this study.In histopathological examination of brain samples, tissue cysts were observed in 7 samples 33.33%. About the Giemsa stained impression tissue smears of liver, kidney and spleen of all seropositive chickens tissue cysts also observed at the rate of 38.46%, 20.51% and 12.82% respectively, the results indicate that T. gondii localized in the liver more often than in other tissues of naturally infected chickens.This is the first report of T. gondii infection in domestic chickens in Sulaimani province.

scholarly journals Enzyme-Linked Immunosorbent Assay Using Recombinant SAG1 Antigen To Detect Toxoplasma gondii-Specific Immunoglobulin G Antibodies in Human Sera and Saliva

2013 ◽  
Vol 20 (4) ◽  
pp. 468-473 ◽  
Author(s):  
Nouha Chahed Bel-Ochi ◽  
Aïda Bouratbine ◽  
Mohamed Mousli
Keyword(s):  
Toxoplasma Gondii ◽  
Sensitivity And Specificity ◽  
Specific Antigen ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Native Form ◽  
Content Type ◽  
Percent Agreement ◽  
Human Sera ◽  
Commercial Kits

ABSTRACTSerologic detection ofToxoplasma gondiiIgG antibodies is widely accepted as a means to determine immune status and susceptibility toToxoplasmainfection during pregnancy. However, current commercial kits present some drawbacks, such as a requirement for whole-parasite antigen preparation or interassay variability. To address these problems, the purpose of this study was to produce a whole sequence of the recombinantT. gondiiSAG1 antigen (rSAG1) to assess its diagnostic performance inToxoplasmaIgG screening and to explore a saliva-based method as a noninvasive alternative to serum-based testing. rSAG1 was expressed in recombinant bacteria as inclusion bodies, purified through one-step affinity chromatography, and refolded in native form by dialysis. A large amount was obtained, and the specific antigen immunoreactivity was confirmed by immunoblotting. Two rSAG1-based enzyme-linked immunosorbent assays (ELISAs) applied to paired serum and saliva samples were designed. The rSAG1-based ELISA evaluation consisted of testing intrinsic sensitivity and specificity of 49 serum samples from patients immune to toxoplasmosis and 42 serum samples from nonimmune controls identified by routinely used kits. To assess agreement between serum-based and saliva-based tests, the positive percent agreement (PPA) and negative percent agreement (NPA) between the 2 tests were estimated. The rSAG1 serum-based ELISA detected specific IgG with 100% sensitivity and specificity. The PPA and NPA between the serum-based and saliva-based tests varied according to the selected optical density threshold in saliva. Thus, for a selected cutoff of 0.14, the PPA was 100% and the NPA was 88.1%, whereas for a selected cutoff of 0.29, the PPA was 67.3% and the NPA was 100%.

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