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Clinical and Diagnostic Laboratory... Jul 2001Using 255 serum samples with various reactivities, we evaluated the Syphilis Fast latex agglutination test (Syphilis Fast) against the Treponema pallidum particle... (Comparative Study)
Comparative Study
Using 255 serum samples with various reactivities, we evaluated the Syphilis Fast latex agglutination test (Syphilis Fast) against the Treponema 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.
Topics: Agglutination Tests; Humans; Latex Fixation Tests; Reagent Kits, Diagnostic; Sensitivity and Specificity; Syphilis; Time Factors; Treponema pallidum
PubMed: 11427439
DOI: 10.1128/CDLI.8.4.841-842.2001 -
Journal of Clinical Microbiology Jun 1980A method that increases the sensitivity and specificity of the direct agglutination (AG) test for diagnosis of Toxoplasma gondii infection is described. Qualitative... (Comparative Study)
Comparative Study
A method that increases the sensitivity and specificity of the direct agglutination (AG) test for diagnosis of Toxoplasma gondii infection is described. Qualitative results in the Sabin-Feldman dye test (DT) and AG test were in excellent agreement (98%). Differences in titers between these two tests often related to the length of time the individual was infected. The AG test titer was most often lower than the DT titer during acute (recent) infection; the AG test titer was most often higher than the DT titer in older or chronic infection. If the AG test antigen described here can be made available, the AG test would be ideal for use as a screening test and would provide a simple and inexpensive means for the surveillance of seronegative women during pregnancy and for detection of seroconversions.
Topics: Agglutination Tests; Animals; Antibodies; Antigens; Fluorescent Antibody Technique; Humans; Immunoglobulin M; Mice; Toxoplasmosis
PubMed: 7000807
DOI: 10.1128/jcm.11.6.562-568.1980 -
Acta Pathologica Et Microbiologica... Jun 1976A slide co-agglutination test (Phadebact Gonococcus Test) for the serological identification of Neisseria gonorrhoeae was assessed on gonococcal-like, oxidase positive... (Comparative Study)
Comparative Study
A slide co-agglutination test (Phadebact Gonococcus Test) for the serological identification of Neisseria gonorrhoeae was assessed on gonococcal-like, oxidase positive colonies from 120 cultures, originating from about 6,500 consecutive tonsillo-pharyngeal specimens received at the Neisseria Department, Statens Seruminstitut. The test was performed after subculture on a serum-free medium, since this procedure was found to reduce the number of strains showing inconclusive reactions (pseudo co-agglutination). If this pseudo co-agglutination does occur, however, the test can be repeated with the addition of trypsin to the test system. This causes the previously inconclusive reactions to be reverted to clearly positive reactions in the case of gonococci, and to clearly negative reactions in more than half of the previously inconclusive reactions with other bacterial strains. The results obtained by the Phadebact Gonococcus Test were compared with those obtained by bacteriological identification procedures. Fifty-six of the 120 cultures examined contained gonococci, and all strains were identified by the slide co-agglutination test (five strains with the addition of trypsin). The remaining 64 cultures were negative or exhibited consistently pseudo co-agglutination (eight strains). The specificity and sensitivity of the reagent was further confirmed by the examination of 53 strains of Neisseria gonorrhoeae and 50 strains representing Neisseria species commonly occurring in tonsillo-pharyngeal specimens. The Phadebact Gonococcus Test was considered to be a reliable alternative to routine bacteriological identification of Neisseria gonorrhoeae.
Topics: Agglutination Tests; Neisseria gonorrhoeae; Palatine Tonsil; Pharynx; Serotyping
PubMed: 826107
DOI: 10.1111/j.1699-0463.1976.tb01916.x -
The American Journal of Tropical... Apr 2020Currently, a significantly lower temperature (35°C) than initially established (56°C) is indicated as the maximum temperature storage for the commercial reference...
Currently, a significantly lower temperature (35°C) than initially established (56°C) is indicated as the maximum temperature storage for the commercial reference visceral leishmaniasis (VL) freeze-dried direct agglutination test (FD-DAT). Despite an approximately 50% loss in the number of promastigotes in an FD-DAT batch that expired 7 years earlier, the promastigotes maintained a similar morphology to the equivalent valid batch implying most likely that auto-agglutination, rather than aging, is the main reason for expiry. The substitution of normal saline which was initially recommended for reconstitution, by citrate-saline/formaldehyde (CSF) as an anti-clumping/preservative agent resulted in restoration of validity comparable with that of the freeze-dried original or the liquid direct agglutination test (LQ-DAT) version (Friedman ANOVA test = 1.0588; = 0.5890). Following a similar reconstitution procedure as for the 7-year expired antigen, using significantly lower promastigote concentration (1.4 × 10/mL) than in the non-expired (9.0 × 10/mL), good reliability for VL detection and stability at 4°C (> 12 months) were achieved. In comparison with the original version using normal saline ($32.0/vial), the cost-effectiveness of the FD-DAT was appreciably improved by the CSF incorporation and lowering of promastigote concentration per unit suspension medium ($12.8/vial). With diagnostic reliability comparable with the full-out titration used, FD-DAT procedure based on single sample dilution at the VL cutoff (1:3,200) permitted the use of significantly smaller antigen volumes (0.1 mL vs. > 1.5 mL), therefore contributing to a further reduction in the application cost. The successful replacement of β-mercaptoethanol (β-ME) by urea ( = 21.00; = 0.0868) provided the required safety for the test procedure similar to the widely applied LQ-DAT.
Topics: Agglutination Tests; Animals; Antigens, Protozoan; Dogs; Freeze Drying; Humans; Leishmaniasis, Visceral
PubMed: 32043445
DOI: 10.4269/ajtmh.19-0745 -
The American Journal of Tropical... Apr 2020The direct agglutination test (DAT) for visceral leishmaniasis (VL) is the serodiagnostic test for VL that has the most robust sensitivity and specificity in the field...
The direct agglutination test (DAT) for visceral leishmaniasis (VL) is the serodiagnostic test for VL that has the most robust sensitivity and specificity in the field across all endemic regions. It is based on trypsin-treated and formaldehyde-fixed whole promastigote cells from . The exact identity and nature of the epitopes on the DAT antigen that cause agglutination with VL patients' sera are currently unknown. In this study, we performed antigen-inhibition studies which revealed that lipophosphoglycan (LPG) and the DAT antigen share epitopes. Antibody inhibition with a monoclonal antibody directed against the phosphoglycan repeat epitope of LPG showed that this is not the epitope that reacts with human sera. Oxidation of carbohydrates by sodium metaperiodate did not alter the reactivity of human sera with the DAT antigen and LPG. This indicates that carbohydrates do not play a role in the reaction of the DAT antigen with antibodies in serum from VL patients, and that they also are not involved in the reaction of LPG with the same serum. We conclude that the noncarbohydrate moiety of LPG, that is, the core-anchor fragment, and potentially other noncarbohydrate epitopes on the surface of the DAT antigen are responsible for its agglutination with antibodies from VL patients. As LPG plays a role in the DAT reaction, this could facilitate the following: 1) incorporation of LPG, preferably the synthetic version of the core-anchor fragment, into an immunochromatographic test format that is more adapted as a point-of-care test (short incubation, little training, and equipment needed) than DAT and 2) enhancing the quality control for the production of the DAT antigen.
Topics: Agglutination Tests; Antibodies, Monoclonal; Antibodies, Protozoan; Antigens, Protozoan; Enzyme-Linked Immunosorbent Assay; Humans; Leishmania donovani; Leishmania infantum; Leishmaniasis, Visceral; Sensitivity and Specificity
PubMed: 32124719
DOI: 10.4269/ajtmh.19-0784 -
Clinical and Diagnostic Laboratory... Jul 1998Current serologic tests used to detect antibodies to Neospora caninum require species-specific secondary antibodies, limiting the number of species that can be tested.... (Comparative Study)
Comparative Study
A modified agglutination test for Neospora caninum: development, optimization, and comparison to the indirect fluorescent-antibody test and enzyme-linked immunosorbent assay.
Current serologic tests used to detect antibodies to Neospora caninum require species-specific secondary antibodies, limiting the number of species that can be tested. In order to examine a wide variety of animal species that may be infected with N. caninum, a modified direct agglutination test (N-MAT) similar to the Toxoplasma gondii modified direct agglutination test (T-MAT) was developed. This test measures the direct agglutination of parasites by N. caninum-specific antibodies in serum, thus eliminating the need for secondary host-specific anti-isotype sera. The N-MAT was compared to the indirect fluorescent-antibody test (IFAT) and the enzyme-linked immunosorbent assay (ELISA) with a "gold standard" serum panel from species for which secondary antibodies were available (n = 547). All positive samples tested were from animals with histologically confirmed infections. Up to 16 different species were tested. The N-MAT gave a higher sensitivity (100%) and specificity (97%) than the ELISA (74 and 94%, respectively) and had a higher sensitivity but a lower specificity than the IFAT (98 and 99%, respectively). The reduced specificity of the N-MAT was due to false-positive reactions in testing fetal fluids with particulate matter or severely hemolyzed serum. Overall, the N-MAT proved to be highly sensitive and specific for both naturally and experimentally infected animals, highly reproducible between and within readers, easy to use on large sample sizes without requiring special equipment, and useful in testing serum from any species without modification.
Topics: Abortion, Veterinary; Agglutination Tests; Animals; Antibodies, Protozoan; Cattle; Cattle Diseases; Coccidiosis; Enzyme-Linked Immunosorbent Assay; Evaluation Studies as Topic; Female; Fluorescent Antibody Technique, Indirect; Neospora; Predictive Value of Tests; Pregnancy; Sensitivity and Specificity; Species Specificity
PubMed: 9665950
DOI: 10.1128/CDLI.5.4.467-473.1998 -
Canadian Journal of Comparative... Apr 1982A microtitration agglutination test was developed and evaluated for detecting infection of swine with group E streptococci type IV, the most common causative agent of...
A microtitration agglutination test was developed and evaluated for detecting infection of swine with group E streptococci type IV, the most common causative agent of streptococcic lymphadenitis of swine. Whole cell agglutinogens representing group and type antigens of group E streptococci were tested in the microtitration agglutination test against reference antisera to Streptococcus groups A, B, C, D, E, F, G. H, K, L, M, N, O, P, Q, R, S and U, as well as specific antisera to types II, IV and V of group E. Group E specific agglutinogens were unsatisfactory in the microtitration agglutination test because of cross reactions with group P and U antisera and because of poor reproducibility of the test. Type specific agglutinogens of group E streptococci reacted only with their respective homologous antisera and not with any heterologous group antisera. None of the group E streptococci agglutinogens reacted with 52 normal swine sera. Agglutinogen made from group E streptococci type IV was selected for further evaluation in the microtitration agglutination test because group E streptococci types II and V are considered to be of minor importance in the etiology of streptococcic lymphadenitis of swine. Swine experimentally infected with a type IV strain developed significant titers in the microtitration agglutination test. All swine tested negative before exposure and seroconverted (titer >/=4) two to six weeks postexposure.The microtitration agglutination test was used by two different laboratories to test 187 duplicate samples of serum from infected swine. A total of 94.1% of the tests were read at either the same titer (48.1%) or a difference of not more than one dilution (46.0%) at the two laboratories. There was disagreement between the two laboratories in the test-positive test-negative status of 19 of the sera (10.2%). Titers of two of the sera differed by two dilutions (<4 at one laboratory and 8 at the other). The remaining 17 sera differed in titer by only one dilution (<4 at one laboratory and 4 at the other).
Topics: Agglutination Tests; Agglutinins; Animals; Antibodies, Bacterial; Cross Reactions; Epitopes; Lymphadenitis; Serotyping; Streptococcal Infections; Streptococcus; Swine; Swine Diseases
PubMed: 6178488
DOI: No ID Found -
Thorax Jun 1977A new whole cell agglutination test for active tuberculosis, for which encouraging results have recently been reported, has been carried out on the serum of 112...
A new whole cell agglutination test for active tuberculosis, for which encouraging results have recently been reported, has been carried out on the serum of 112 subjects. The results have been disappointing; the test had no predictive value in the diagnosis of active tuberculosis.
Topics: Agglutination Tests; Child, Preschool; False Positive Reactions; Female; Humans; Infant; Male; Pregnancy; Tuberculosis, Pulmonary
PubMed: 882951
DOI: 10.1136/thx.32.3.349 -
Preventive Veterinary Medicine Dec 2023When Bayesian latent class analysis is used for diagnostic test data in the absence of a gold standard test, it is common to assume that any unknown test sensitivities...
When Bayesian latent class analysis is used for diagnostic test data in the absence of a gold standard test, it is common to assume that any unknown test sensitivities and specificities are constant across different populations. Indeed this assumption is often necessary for model identifiability. However there are a number of practical situations, depending on the type of test and the nature of the disease, where this assumption may not be true. We present a case study of using a microscopic agglutination test to diagnose leptospiroris infection in beef cattle, which strongly suggests that sensitivity in particular varies among herds. We develop and fit an alternative model in which sensitivity is related to within-herd prevalence, and discuss the statistical and epidemiological implications.
Topics: Cattle; Animals; Bayes Theorem; Leptospirosis; Cattle Diseases; Agglutination Tests; Prevalence; Sensitivity and Specificity
PubMed: 37976969
DOI: 10.1016/j.prevetmed.2023.106074 -
Journal of Comparative Pathology Apr 1950
Topics: Abortion, Veterinary; Agglutination; Agglutination Tests; Agglutinins; Animals; Brucellosis; Female; Pregnancy; Sheep; Sheep, Domestic
PubMed: 15428541
DOI: 10.1016/s0368-1742(50)80008-5