Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AGGLUTINATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,063 records · Page 59Linked to original sources

Seroprevalence of Mycoplasma pneumoniae in HIV-infected patients using a microparticle agglutination test.

Mycoplasma pneumoniae is increasingly recognized as a common and important pathogen in community settings, and is responsible for various pulmonary and extrapulmonary conditions in the normal population. However, the seroepidemiology of acute M. pneumoniae infection in HIV-infected individuals is still unclear worldwide. This study examined the seroprevalence of antibodies to M. pneumoniae in HIV-infected patients admitted with respiratory complaints at a tertiary AIDS care centre in Chennai, India. A commercial gelatin microparticle agglutination test (Serodia-Myco II, Fujirebio) was used for the determination of antibodies against M. pneumoniae in acute serum specimens. Of the 200 HIV-infected patients with underlying pulmonary conditions tested, 34 (17 % positivity; 95 % CI 12-23 %) had antibodies specific to M. pneumoniae, while among the 40 patients with no underlying pulmonary symptoms, five (12.5 % positivity; 95 % CI 4-27 %) had evidence of anti-M. pneumoniae antibody. This shows that the incidence of M. pneumoniae seropositivity is greater in patients with underlying pulmonary complaints. Most positive titres were found in the age group 28-37 years in the symptomatic and symptom-free groups (64.7 and 60 %, respectively). The positive titres ranged from 40 to >20 480. High titres (> or =320) were found in 10 out of the 39 patients (25.6 %). This seroprevalence study reports a 16.2 % prevalence of M. pneumoniae infections in HIV-infected patients by a particle agglutination test.

AIDS-Related Opportunistic Infections↗

Comparison of antibody titers against borrelial strains isolated in Japan by the microcapsule agglutination test for serological studies of early Lyme disease.

Results of a passive microcapsule agglutination test using 2 Japanese strains, Borrelia garinii and Borrelia afzelii, were comparable to that of the passive microcapsule agglutination test using a Swiss strain Borrelia burgdorferi IRS in detecting antibodies of an early stage of Lyme disease patients in Japan. MCAT with microcapsule sensitized strain IRS seems likely to become one of the important tools for the early diagnosis of Lyme disease in the world. The highest titer of MCAT was detected in the serum samples of patients which were taken around 2 weeks after erythema chronicum migrants. The test is very simple and can be employed easily in diagnostic laboratories.

Agglutination Tests↗

Detection of Clostridium difficile toxin A by reversed passive latex agglutination.

A reversed passive latex agglutination (RPLA) assay for detecting Clostridium difficile toxin A is presented. Purified monoclonal antibody (mAb 37B5) was used for latex sensitization. The culture supernatants of 93 strains of C. difficile were tested by RPLA assay and the results compared with those of a commercially available latex agglutination test, PCR and cytotoxin assay with Vero cells. There was agreement between RPLA, cytotoxicity and PCR assays, but 29 strains were positive in the RPLA assay while 35 were positive in the cytotoxicity test and PCR using primer pair NK3-NK2 directed to the nonrepeating portion of the C. difficile toxin A gene. The 6 cytotoxic but RPLA-negative strains were demonstrated to be toxin A-negative/toxin B-positive strains in the PCR assay by using primer pair NK11-NK9 directed to the repeating portion of the C. difficile toxin A gene. There were no cross-reactions with culture supernatants of the other clostridial strains except for two strains of C. sordelli that produced hemorrhagic toxin (which is immunologically related to C. difficile toxin A).

Agglutination Tests↗

Distribution of Aeromonas hydrophila serogroups in different clinical samples and the development of polyclonal antibodies for rapid identification of the genus Aeromonas by direct agglutination.

We characterized a collection of 256 Aeromonas hydrophila strains isolated from blood, discharge and stool for their serogroup designation. Of these, 2.3% were untypable and 15.2% were rough strains. Among the typable strains, about 50% comprised serogroups O:11, O:16, O:18, O:34 and O:83. To develop rapid differentiation of Aeromonas from other oxidase-positive bacteria, antisera against Aeromonas were produced to establish a direct, genus-specific, agglutination test. It was found that among 105 isolates of Aeromonas, 102 showed positive results with the agglutination test. The calculated sensitivity and specificity were 97.1% and 90.7%, respectively.

Aeromonas↗

Application of in vitro mutagenesis to identify the gene responsible for cold agglutination phenotype of Streptococcus mutans.

A previously unidentified protein with an apparent molecular mass of 120 kDa was detected in some Streptococcus mutans strains including the natural isolate strain Z1. This protein was likely involved in the cold-agglutination of the strain, since a correlation between this phenotype and expression of the 120 kDa protein was found. We have applied random mutagenesis by in vitro transposition with the Himar1 minitransposon and isolated three cold-agglutination-negative mutants of this strain from approximately 2,000 mutants screened. A 2.5 kb chromosomal fragment flanking the minitransposon in one of the three mutants was amplified by PCR-based chromosome walking and the minitransposon insertion in the other two mutants occurred also within the same region. Nucleotide sequencing of the region revealed a 1617 nt open reading frame specifying a putative protein of 538 amino acid residues with a calculated molecular weight of 57,192. The deduced eight amino acid sequence following a putative signal sequence completely coincided with the N-terminal octapeptide sequence of the 120 kDa protein determined by the Edman degradation. Therefore, the 1617 nt gene unexpectedly encoded the 120 kDa protein from S. mutans. Interestingly, this gene encoded a collagen adhesin homologue. In vitro mutagenesis using the Himar1 minitransposon was successfully applied to S. mutans.

Agglutination↗

Evaluation of the human T-cell leukemia virus type I seropositivity of blood donors by the particle agglutination inhibition test.

In the HTLV-I seroscreening of blood donor sera by gelatin particle agglutination (PA), more than 50% (55.6%) of the PA-positive sera were negative by immunofluorescence assay (IF). However, when donors were divided into age groups, there were increasing numbers of IF-positive/PA-positive donors with age. Among the PA-positive donors in the 50-64 age group, 65.9% were IF-positive compared to 16.0% in the 16-19 age group. The serological specificities of the IF-negative/PA-positive specimens were tested by using a newly developed PA inhibition (PAI) test. The HTLV-I specificity of the PAI test was confirmed by the observation that agglutinations with anti-HTLV-I p19 and gp21 monoclonal antibodies as well as IF-positive sera were specifically inhibited with HTLV-I preparations or HTLV-I-positive cell extracts and not with HTLV-I-negative cell extracts. Sixty of the 104 specimens collected randomly from the IF-negative/PA-positive donors were PAI-positive. The majority (80%) of such PAI-positive sera showed more than two bands of HTLV-I gag-encoded polypeptide, p19, p24, p28 and p53 on Western blotting. Some of the PAI-positive sera were also positive by enzyme immunoassay. These results indicate that at least some of the IF-negative/PA-positive donors possess HTLV-I-specific antibody and may be potential HTLV-I carriers who will become IF-positive at a later age.

Adolescent↗

Improvement of gelatin particle agglutination test for detection of anti-HTLV-I antibody.

Partial modifications of antigen components were made to improve the gelatin particle agglutination (PA) test for the detection of antibodies against human T cell leukemia virus type-I. Envelope glycoproteins prepared by lentil lectin affinity chromatography were further added to the purified viral antigens to be coated on the gelatin particles. Comparative studies with a conventional PA test kit (Serodia ATLA) and indirect immunofluorescence assay showed that the specificity and sensitivity of the new PA test were increased and that abnormal agglutination such as the prozone phenomenon was abolished by this improvement.

Agglutination Tests↗

The detection of antisperm antibodies in serum: a comparison of the tray agglutination test, indirect immunobead test and indirect SpermCheck assay.

Testing for antisperm antibodies (ASAs) is an important part of the work-up of the sub-fertile couple, yet there is little consensus regarding the most appropriate methods. The SpermCheck assay (GSC; Bio-Rad Laboratories Inc., Diagnostics Division, Hercules, CA, U.S.A.) is supplied with wash buffer, controls and bead reagent which detects all three major classes of ASAs (IgA, IgG and IgM) in a single test. This study compared results on a bank of samples using the tray agglutination test (TAT), immunobead test (IBT), GSC and a modified SpermCheck assay to detect a single isotype in each test (SISC). The IBT and SISC showed excellent correlation, with 127/141 (90.1%) tests agreeing. There was an apparent lack of sensitivity to IgM with GSC as 8/15 (53.3%) samples testing positive with IBT and 7/15 (46.7%) testing positive with SISC were negative with GSC. Of the 24 IBT-negatives, seven (29.2%) were positive for TAT, indicating a high incidence of non-immunological agglutination, though this decreased as the TAT titre increased. The proportion of samples testing positive for IBT increased with TAT titre: 3/20 (15.0%) for TAT-negative samples, 6/10 (60.0%) for low titres and 21/24 (87.5%) for high titres. This was also observed when comparing the GSC with TAT. The TAT therefore appears useful as a first-line screen, whilst the inability of the GSC to adequately detect IgM limits its use as an indirect test. Both the IBT and SISC can be used to further investigate the type and class of ASA present.

Agglutination Tests↗

Quantitative test for Bacteroides nodosus pilus protein by an agglutination-absorption test.

A pili agglutination-absorption test (PAAT) was developed for the quantitative measurement of pilus protein in cultures of Bacteroides nodosus and to quantify pili yields during purifications. The test was calibrated by recording the amount of pilus protein required to absorb a measurable amount of anti-pili antibody from antiserum. The amount of anti-pilus antibody in absorbed and unabsorbed serum was specifically measured by a Bact. nodosus K-agglutination test. The PAAT could be calibrated using any combination of crude or pure pili preparations and specific anti-pili serum or non-specific anti-Bact. nodosus serum. This had advantages over the use of radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques for measurement of pili because they require the use of highly purified reagents for calibration. The minimum quantity of pilus protein measurable by PAAT was 0.1 microgram per test which was similar in sensitivity to that reported for RIA and ELISA. The reagents used in PAAT were stable for at least six months. The amount of pilus protein per bacterium as measured by PAAT was directly proportional to the average number of pili per bacterium as measured by electron microscopy. The test was Bact. nodosus serotype specific.

Absorption↗

Functional cooperation among human IgG-specific murine monoclonal antibodies for the detection of weak blood group antibodies in routine agglutination tests.

Seven monoclonal antibodies (MAbs) selected from a large panel of human IgG-specific murine MAbs were characterized serologically and studied for their ability to cooperate in routine antihuman globulin agglutination tests. In binding inhibition experiments, three of these MAbs were shown to bind simultaneously to immobilized human IgG molecules. Cooperation among these MAbs increased significantly the capacity of the individual MAbs to agglutinate red cells sensitized with weak blood group antibodies. These results demonstrate the usefulness of selected MAb blending for the preparation of potent antihuman IgG reagents from murine monoclonal antibodies.

Agglutination Tests↗

A simple and practical agglutination assay for human leucocyte antigen-B27 typing.

BACKGROUND AND OBJECTIVES: The human leucocyte antigen (HLA) B27 is the most frequently typed single antigen that is associated with diseases. Here, we describe a simple and rapid particle agglutination assay (PaGIA) for HLA-B27 typing. MATERIALS AND METHODS: Superparamagnetic particles were coated with a monoclonal antibody to HLA-B27 and subsequently used for testing. Anticoagulated whole-blood samples were obtained from healthy blood donors (n = 194) with known HLA patterns and from patients (n = 51) who had been typed positive for HLA-B27 by flow cytometry. RESULTS: The particles agglutinated only after incubation with HLA-27-positive blood samples, using the ID-microtyping system. Positive reactions were clearly distinguishable from negative reactions in all samples tested. Flow cytometric HLA-B27 typing revealed an indeterminate result in one patient. CONCLUSIONS: The new HLA-B27 PaGIA is suitable for rapid typing of HLA-B27. The assay is simple and easy to perform, and can be implemented in any routine laboratory.

Agglutination Tests↗

Cerastotin, a serine protease from Cerastes cerastes venom, with platelet-aggregating and agglutinating properties.

Cerastotin, a thrombin-like enzyme from the venom of the desert viper Cerastes cerastes, has been purified by gel filtration on Sephadex G-75 and two ion-exchange chromatographies on Mono S columns. It is a neutral glycoprotein (pI = 6.6), present as a single polypeptide chain of 40 kDa. Its N-terminal sequence shows strong similarity with those of other thrombin-like enzymes from snake venoms. Cerastotin possesses esterase and amidolytic activities measured with N(alpha)-tosyl-L-arginine methyl ester and the thrombin chromogenic substrate D-phenylalanyl-L-pipecolyl-L-arginine p-nitroanilide, respectively. The amidolytic activity is inhibited by phenylmethylsulfonyl fluoride, N(alpha)-tosyl-L-lysine chloromethane, N(alpha)-tosyl-L-phenylalanyl chloromethane, D-phenylalanyl-L-prolyl-L-arginyl chloromethane and benzamidine, suggesting that cerastotin is a serine protease. Cerastotin efficiently clots human plasma and cleaves preferentially the alpha chain of fibrinogen. Cerastotin did not induce aggregation of washed normal platelets, but did aggregate platelets in the presence of exogenous fibrinogen. A monoclonal antibody directed against glycoprotein (GPIb), which specifically inhibits induced agglutination by ristocetin also completely blocks platelet aggregation induced by cerastotin. However, another anti-GPIb monoclonal antibody, which specifically inhibits alpha-thrombin binding to GPIb, did not prevent this aggregation. Furthermore, platelets which were desensitised by alpha-thrombin still aggregate in the presence of cerastotin, but not alpha-thrombin. Similarly a monoclonal antibody, anti-GPIIb-IIIa, which blocks fibrinogen binding, did not inhibit cerastotin-induced platelet aggregation. This activity is abolished in the presence of 1 mM phenylmethylsulfonyl fluoride and/or 10 mM EDTA. Cerastotin also agglutinates formalin-fixed and washed platelets, only in the simultaneous presence of fibrinogen and of Von Willebrand factor.

Agglutination↗

Case report and literature review: transient Inab phenotype and an agglutinating anti-IFC in a patient with a gastrointestinal problem.

BACKGROUND: The Inab phenotype is a rare deficiency of all Cromer antigens. These antigens are carried on the decay-accelerating factor (DAF, CD55) molecule that is attached to the red blood cell (RBC) membrane by a glycosylphosphatidylinositol (GPI) anchor. Although typically inherited, an acquired and transient form of the Inab phenotype also exists. A patient with the triad of transient Inab phenotype, a direct-agglutinating anti-IFC, and gastrointestinal (GI) abnormalities is reported. CASE REPORT: An 18-month-old boy with gastroesophageal reflux disease requiring a feeding tube, milk and soy intolerance, and severe growth retardation, as well as vision and hearing deficits from cytomegalovirus infection, was identified when pretransfusion testing revealed a potent panagglutinin (titer > 2000 at 4 degrees C). This antibody did not react with Dr(a-) and IFC RBCs, and the autocontrol was negative. The patient's RBCs lacked CD55 by flow cytometric techniques but had normal levels of CD59 and antigens such as Yt(a) and Emm, carried on GPI-linked proteins, thus excluding paroxysmal nocturnal hemoglobinuria. Several months after initial detection, the anti-IFC was virtually undetectable and his cells reacted weakly with anti-IFC, anti-Dr(a), and anti-CD55. RBCs from the propositus' parents and brother demonstrated normal CD55 and CD59 expression. CONCLUSION: This is the first example of a direct-agglutinating anti-IFC. The cause of the transient depression in CD55 protein (and thus Cromer system antigens) and appearance of anti-IFC remains unknown, as does the relationship between the patient's GI system abnormalities and these serologic findings.

Agglutination↗

The effect of anti-lymphocyte serum, mitogens and enzymatic treatment on the agglutination and surface charge of lymphoid cells.

Agglutination of thymocytes and B-cells with anti-lymphocyte serum subsequent to treatment of the cells with trypsin or neuraminidase was slightly and similarly increased, independent of the effect on the surface charge shown previously. The enzymatic treatment did not increase capping of antiserum binding sites. Agglutination caused by binding of IgG antibodies of anti-lymphocyte serum was not accompanied by change in the net surface charge. Neither did binding of the mitogens phytohaemagglutinin, concanavalin A or poke-weed mitogen influence the surface charge of the cells.

Agglutination↗

Serology of Neisseria gonorrhoeae. Demonstration by co-agglutination and immunoelectrophoresis of antigenic differences associated with colour/opacity colonial variants.

Serological classification of Neisseria gonorrhoeae by co-agglutination (COA) into previously described antigen classes W and J was confirmed in the present work. Immunization of rabbits with classified organisms gave antibodies which produced the expected results when used in the preparation of COA reagents. Colour/opacity colonial variants of isogenic strains, characterized by stereomicroscopy as opaque and transparent, respectively, were found to influence immunization, absorption, co-agglutination and precipitation in immunoelectrophoresis (IE). It was shown by COA and IE that organisms of opaque colonies often contained an extra antigenic factor(s) which resisted heating at 100 degrees C but was sensitive to treatment with pronase. They were extracted by heating the organisms in saline or lithium chloride solution. Serological classification with COA in clinical isolates was reproducible with reagents for antigen classes W and J. Colony morphology dependent reactions, mostly due to organisms of opaque colonies, occurred in 7% with reagents for antigen class W and in 20% for antigen class J.

Agglutination Tests↗

Staphylococcal protein-A agglutination assay for avian viruses.

Protein-A rich staphylococci were used to develop an agglutination assay for the detection and quantitation of avian reticuloendotheliosis virus (REV) and Herpes virus of turkeys (HVT). Rabbit anti-REV or anti-HVT were used to coat the staphylococci and these reagents were mixed with REV or various other viral antigen preparations. An agglutination titer was determined for antigen preparations of varying purity and the results indicated that in addition to being rapid, this assay allows the detection of as little as 0.3 to 0.5 microgram of partially purified viral antigens. No crossreactivity was observed with the two antisera and the various antigen preparations. This study also confirmed the reports in the literature that chicken immunoglobulins do not bind to protein-A of the Cowan I strain of Staph. aureus.

Agglutination Tests↗

Evaluation of two commercial kits for rapid detection of human rotavirus in feces: Rotalex, a latex agglutination test and Rotavirus ELISA Kit.

96 fecal specimens from children with symptoms of gastroenteritis were tested with a latex agglutination test (Rotalex, Orion Diagnostica, Finland) and an enzyme-linked immunosorbent test (Rotavirus ELISA Kit, Dakopatts, Copenhagen, Denmark). Using the ELISA method as reference, the latex agglutination (LX) came out with three non-specific and two false negative results. The LX test was found to be a rapid, practical and non-expensive choice for a laboratory examinating few samples daily.

Agglutination Tests↗

Immunoglobulin class specificity of non-agglutinating antibody produced in cattle following Brucella abortus 45/20 vaccination.

The immunoglobulin class specificity of non-agglutinating antibody produced following vaccination with Br. abortus 45/20 vaccine was determined using the antiglobulin test. In previously unvaccinated cattle it was found that most of the non-agglutinating antibody was associated with the IgG1 immunoglobulin class. In cattle sensitised to Brucella antigens by prior vaccination with Brucella abortus strain 19 the majority of antibody was also associated with the IgG1 immunoglobulin class, but a significant amount of IgG2 antibody was also present. The results indicate that the significance of levels of IgG2 antibody would be difficult to determine in cattle repeatedly exposed to Brucella antigens.

Agglutination Tests↗