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PubMed1987

Pheromone induction of agglutination in Saccharomyces cerevisiae a cells.

a-Agglutinin, the cell surface sexual agglutinin of yeast a cells, was assayed by its ability to bind its complementary agglutinin, alpha-agglutinin. The specific binding of 125I-alpha-agglutinin to a cells treated with the sex pheromone alpha-factor was 2 to 2.5 times that of binding to a cells not treated with alpha-factor. Competition with unlabeled alpha-agglutinin revealed that the increased binding was due to increased cell surface expression of a-agglutinin, with no apparent change in the binding constant. The increase in site number was similar to the increase in cellular agglutinability. Increased expression of a-agglutinin followed the same kinetics as the increase in cellular agglutinability, with a 10-min lag followed by a 15- to 20-min response time. Induction kinetics were similar in cells in phases G1 and G2 of the cell cycle. Maximal expression levels were similar in cells treated with excess pheromone and in cells exposed to pheromone after destruction of constitutively expressed a-agglutinin.

Agglutination↗
PubMed1980

2-mercaptoethanol Brucella agglutination test: usefulness for predicting recovery from brucellosis.

Ninety-two patients with brucellosis were studied for 18 months, and 15 to 29 sera from each patient were tested by the standard tube brucella agglutination test and by the 2-mercaptoethanol (2ME) brucella agglutination test. The standard tube test remained positive (greaterr than or equal to 160) for 1.5 years in 44 of the 92 patients (48%), despite adequate antibiotic treatment. The 2ME titers remained positive (greater than or equal to 160) in only 8 of 92 patients (9%) after 1 year, and in only 4 of 92 patients (4%) after 1.5 years. Positive 2ME titers 1 year after initiation of treatment were present in 3 of 10 patients (30%) with drug allergies that interfered with antibiotic treatment, in contrast to only 5 of 82 patients (6%) without any allergies (P = 0.039). None of 84 patients with negative 2ME titers after 12 months of treatment had significant signs or symptoms of brucellosis, and none developed chronic brucellosis. In contrast, four of eight patients with positive 2ME titers after 12 months of treatment still had signs and symptoms of brucellosis and required further treatment. The 2ME test is superior to the standard tube test in determining the adequacy of antibiotic therapy, and a negative 2ME test is strong evidence against a diagnosis of chronic brucellosis.

Agglutination Tests↗
PubMed1981

Typing of Haemophilus influenzae by coagglutination and conventional slide agglutination.

Coagglutination was compared with conventional slide agglutination for the typing of 297 clinical isolates of Haemophilus sp. A 100% correlation was found with the H. influenzae type b isolates. Coagglutination showed no false-positive reactions with the nontypable strains of H. influenzae and H. parainfluenzae isolates; however, conventional slide agglutination exhibited many false-positive and non-interpretable reactions.

Agglutination Tests↗
PubMed1982

Detection of Legionella antigenuria by reverse passive agglutination.

A reverse passive agglutination method was developed to detect soluble antigens of Legionella spp. By this method Legionella antigens were detected in urine specimens from 14 of 15 antigenuric patients with clinically diagnosed Legionnaires disease and in none of 263 urine samples from healthy subjects or patients with urinary tract infections. Intra-genus cross-reactivity was observed only between L. pneumophila serogroups 2, 3, and 6. The Legionella reverse passive agglutination method was also evaluated with reference to reagent concentrations, test conditions, and subjectivity of reading test results. The method is rapid and does not require special equipment.

Agglutination Tests↗
PubMed1982

Sensitivity of passive bacterial agglutination for detection of hepatitis B surface antigen.

The sensitivity of passive bacterial agglutination (PBA), i.e., the agglutination of Staphylococcus aureus coated with antibodies to hepatitis B surface antigen by hepatitis B surface antigen, was assessed by testing reference panel no. 3A sera (Bureau of Biologics, U.S. Food and Drug Administration). Of the 23 samples containing hepatitis B surface antigen, 18 were positive by PBA. Sera from 100 healthy adults were tested by PBA and reversed passive hemagglutination. Four sera were positive by both methods. One additional sample was positive only by PBA; if one assumes that it was a false-positive result, the rate of false-positive reactions was only 1%.

Agglutination↗
PubMed1983

Cross-reactivity of Haemophilus somnus antibody in agglutination and complement fixation tests and in the enzyme-linked immunosorbent assay.

The specificity and sensitivity of agglutination, complement fixation, and enzyme-linked immunosorbent assay (ELISA) procedures in the detection of antibodies to Haemophilus somnus was investigated. H. somnus rabbit immune sera were found to agglutinate Pasteurella multocida, Staphylococcus aureus, and Haemophilus agni and, in some instances, also Pasteurella haemolytica, Salmonella dublin, Streptococcus agalactiae, and Corynebacterium pyogenes. In complement fixation tests with saline extracts as antigens, only H. agni reacted with H. somnus antisera to any significant degree. In ELISA tests with sonicated or heat-extracted antigens, cross-reactions were seen with the two Pasteurella spp. and with H. agni. When whole cells and saline extracts were used as antigens in ELISAs, only H. agni showed any cross-reactivity. The greatest specificity in distinguishing homologous from heterologous reactions was achieved by ELISA with saline extracts as antigens. Escherichia coli and Brucella abortus antigens failed to react with H. somnus antibody in any of the tests. A rabbit serum containing antibody to bovine type isolates of P. multocida, P. haemolytica, S. aureus, S. agalactiae, S. dublin, C. pyogenes, and E. coli gave no positive reaction in ELISA tests with saline extract of H. somnus as antigen. It is concluded that such saline extract, which appears to consist largely of H. somnus common antigen, has the potential of being a useful diagnostic reagent in the study by ELISA of antibody response to H. somnus.

Agglutination Tests↗
PubMed1983

Comparison of Phadebact coagglutination, Bactogen latex agglutination, and counterimmunoelectrophoresis for detection of Haemophilus influenzae type b antigens in cerebrospinal fluid.

Cerebrospinal fluid specimens from patients with suspected meningitis were screened with the Phadebact Haemophilus Test (Pharmacia Diagnostics), with Bactogen (Wampole Laboratories), and by counterimmunoelectrophoresis. With culture-positive fluids, Phadebact coagglutination detected 95%, Bactogen latex agglutination detected 91%, and counterimmunoelectrophoresis detected only 79%. Both agglutination techniques were 25-fold more sensitive than counterimmunoelectrophoresis when tested with dilutions of positive fluids. To obtain specific reactions with the Phadebact reagents it was necessary to heat treat (95 degrees C, 5 min) the fluid; with Bactogen and counterimmunoelectrophoresis this was not necessary.

Agglutination Tests↗
PubMed1975

New microtechnique for the leptospiral microscopic agglutination test.

A new microtechnique has been developed for the detection of leptospiral antibodies in serum by the microscopic agglutination test. The test was set up in a microtiter transfer plate held in a transfer plate holder, resting on a transfer plate cover. Live leptospiral antigen was added and a second transfer plate cover was placed over the transfer plate during 2 h of incubation at 32 C. After incubation the bottom cover was removed and the complete unit was placed in a specially designed base plate containing microscope slides (50 by 75 mm). The serum/antigen mixture was ejected on to the microscope slides by means of a sharp tap. The agglutination was then read using a 10 X objective, 10 X eyepieces, and a dry, dark field condenser.

Agglutination Tests↗
PubMed1985

Identification of 22 Legionella species and 33 serogroups with the slide agglutination test.

We used the slide agglutination test to determine the serologic relationships of 22 Legionella spp. representing 33 serogroups. Antisera prepared against 14 of the Legionella spp. contained cross-reactive antibodies (1+ or greater) at their working dilutions. Numerous cross-reactions were observed for the blue-white fluorescing Legionella spp. With only three exceptions in the latter group, cross-reactive antibodies were removed by absorption, thereby producing serogroup-specific antisera. For screening tests or for identification only to the genus level, nine polyvalent antiserum pools were prepared. Routine use of slide agglutination test reagents should expand the number of Legionella spp. that can be identified in the clinical laboratory and, at the same time, provide a simpler, less costly test procedure.

Agglutination Tests↗
PubMed1985

Serogrouping of Bacteroides vulgatus by the agglutination test.

The agglutination technique was used to establish a serological classification scheme for Bacteroides vulgatus strains isolated from normal human feces and clinical specimens, especially from ulcerative colitis patients. Absorbed antisera to 10 strains of B. vulgatus were prepared. These 10 absorbed antisera were species specific. Of 90 B. vulgatus strains tested, 55 (61%) were agglutinated by one or more of these 10 absorbed antisera. A total of 27 serological patterns were grouped into 18 serogroups; 10 of these serogroups contained only one group component, whereas the other 8 serogroups were composed of more than one component. This serological classification could be used to study the epidemiology of this organism.

Adult↗
PubMed1988

The reason for loss of agglutinability of Pseudomonas aeruginosa cells heated to 60 degrees C.

The loss of agglutinability of live Pseudomonas aeruginosa cells by mild heating to 60 to 80 degrees C is due to denaturation of surface slime, which can no longer combine with antibodies but is still attached to the cell surface and thus prevents access of antibodies to the cell wall. Prolonged boiling or autoclaving would not only denature the slime but also detach it from cell surface and thus make the cells accessible to antibodies directed to cell wall antigens. Heated cells are, however, no longer agglutinable by antibodies directed to slime antigens. After prolonged boiling or autoclaving, a large amount of polysaccharides appeared in the supernatant, and concomitantly, total cell volume as measured by turbidity of the cell suspension was significantly reduced.

Agglutination↗
PubMed1988

Experience with the use of pronase to eliminate interference factors in the latex agglutination test for cryptococcal antigen.

Cryptococcal antigen titers of 70 cerebrospinal fluid and 57 serum specimens from patients suspected of having cryptococcosis were determined both before and after treatment with pronase. Median titers of cerebrospinal fluid specimens before and after treatment were 128 and 128, respectively; mean geometric titers of these specimens before and after treatment were 102 and 204, respectively. Median titers of the serum specimens before and after treatment were 16 and 512, respectively; mean geometric titers of these specimens before and after treatment were 19 and 631, respectively. The modified latex agglutination test did not detect antigen in any of 50 cerebrospinal fluid and 51 serum specimens from patients not suspected of having cryptococcosis. These results suggest that the pronase modification increases the sensitivity of the latex agglutination test and that the modification be routinely incorporated into it.

Agglutination Tests↗
PubMed1988

Improvement of a direct agglutination test for field studies of visceral leishmaniasis.

To increase the potential for the wide-scale application of our direct agglutination test for visceral leishmaniasis, modifications in the components and procedures were introduced. Supplementation with 0.056 M citrate of the suspension medium stabilized the antigen for 9 weeks at 37 degrees C. To circumvent the need for cooling systems in the field, 0.2% (wt/vol) gelatin was added to the serum diluent instead of fetal bovine serum, with reliable results. Specificity and sensitivity were improved by the incorporation of 0.1 M 2-mercaptoethanol in samples with borderline titers. The test could be performed on samples of whole blood; thus the difficulties of preparation and storage of serum, plasma, or filter paper blood are avoided. For mass screening programs, a single serum dilution of 1:6,400 could be employed, contributing to a further reduction in test expenses. Sera from different geographical areas showed equal reactivities in this direct agglutination test despite the nonhomologous Leishmania donovani antigens used.

Adolescent↗
PubMed1990

Detection of pYV+ Yersinia enterocolitica isolates by P1 slide agglutination.

Rabbit polyclonal antisera were raised against the pYV-encoded outer membrane protein P1 of five Yersinia enterocolitica strains belonging to serogroups O:3, O:5,27, O:8, and O:9. Analysis of these strains with the sera showed that P1 presented at least six different antigenic factors. Two of the serum specimens were chosen to test the P1 agglutinability of 797 strains isolated from various sources. This technique appeared to be more reliable than autoagglutination and Ca2+ dependency to monitor the presence of the pYV plasmid. Hence, we propose this P1-mediated agglutination as a new and easy virulence test.

Agglutination Tests↗
PubMed1990

Comparison of immunofluorescence, particle agglutination, and enzyme immunoassays for detection of human T-cell leukemia virus type I antibody in African sera.

The effectiveness of four screening tests for detecting antibody to human T-cell leukemia virus type I (HTLV-I) was determined by using 2,700 African serum specimens. The tests studied were indirect immunofluorescence, particle agglutination from Fujirebio, and two enzyme immunoassays, one from Abbott Laboratories that used virus lysate from HUT 102 cells and the other from Cambridge BioScience Corp. that used an env recombinant protein. Positive and doubtful sera were confirmed by Western immunoblot and radioimmunoprecipitation assay with Food and Drug Administration seropositivity criteria. The best results were obtained with the two enzyme immunoassays, which were more sensitive (100 and 98.6% [Abbott and Cambridge, respectively]) and more specific (98.7 and 96.5%). Indirect immunofluorescence exhibited difficulties for reading and interpretation. With particle agglutination, prozone was observed for 9 of 78 HTLV-I-positive serum specimens. False-positives in any of the tests were not linked to cross-reactions with human immunodeficiency viruses. However, confirmation tests remain necessary for HTLV-I screening.

Africa↗
PubMed1995

Comparative evaluation of microagglutination test and serum agglutination test as supplementary diagnostic methods for brucellosis.

The diagnosis of brucellosis in cattle and small ruminants requires the use of more than one serological test. The complement fixation test (CFT), the rose bengal test (RBT), and the serum agglutination test (SAT) are among the most useful tests for routine diagnosis. The microagglutination test (MAT) was developed as a simpler and more efficient test than the SAT. The relative efficacy of this test compared with that of the SAT was evaluated by using brucella-free sheep and goats prior to and after vaccination treatment. The specificities of the MAT and the SAT were 100%. Of the ewes and goats with a vaccination history, one ewe, expectedly a negative responder, had reactions in the MAT, the complement fixation test, and the rose bengal test but not in the SAT, suggesting a lower sensitivity of the SAT in this case. The calculated sensitivities of the MAT and the SAT were 93.9%. The agreement between MAT and SAT results from nonresponders was examined by using sera from unvaccinated lambs and kids (95.2% agreement), unvaccinated ewes and goats (84.4%), and ewes and goats with a vaccination history (43.9%). For the latter group higher levels of agglutination units were observed by the MAT than by the SAT in 51.5% of the samples. In testing sera from positive reactors after vaccination neither method was superior (MAT values were greater than SAT values for 23.5% of the samples, and MAT values were less than SAT values for 21.9% of the samples). Comparison of the methods on the individual sample level revealed a significant correlation between the MAT and the SAT (r = 0.96 +/- 0.005; P < 0.001). Since the MAT is simpler to perform than the SAT and can potentially be automated, the inclusion of the MAT as a supplementary test in brucellosis control programs is recommended.

Agglutination Tests↗
PubMed1995

Agglutination of Streptococcus suis by sialic acid-binding lectins.

The 35 Streptococcus suis capsular-type reference strains as well as 45 field strains of type 2 were tested with sialic acid-binding lectins from Sambucus nigra (SNA I), Triticum vulgaris, Maackia amurensis, Homarus americanus, and Limax flavus. Only types 1, 1/2, 2, 14, 15, and 16 agglutinated with SNA I and/or the T. vulgaris lectin. All field strains agglutinated only with SNA I. Reaction with SNA I was probably due to the sialic acid moiety since it disappeared after sialidase treatment. These results confirm the presence of sialic acid in S. suis with the possible terminal sequence N-acetylneuraminic acid-alpha(2,6)GalNAc.

Agglutination Tests↗
PubMed1996

Rapid method for detection of Coxiella burnetii antibodies using high-density particle agglutination.

A high-density particle agglutination test, using erythrocyte-sensitizing substance from phase II Coxiella burnetii adsorbed to high-density composite particles, was developed for rapid serodiagnosis of Q fever. The test was compared with the microimmunofluorescence test for sensitivity and specificity by using 3,036 human serum samples collected in Gifu Prefecture, Japan. An excellent agreement was found between the two tests for the acute-phase group and paired serum samples, but some discordant results were observed in the single-sample group. The sensitivity and specificity of the high-density particle agglutination test were both 100% in the former group and 81.6 and 99.9%, respectively, in the latter group. The test is a very promising tool for routine serodiagnosis of Q fever because of its simplicity, sensitivity, and specificity.

Agglutination Tests↗