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PubMed1983

Agglutination tests and their modifications in the diagnosis of bovine brucellosis.

This article reviews the effects of using Yersinia enterocolitica serotype: 09 somatic antigen in diagnostic tests for brucellosis. The tests employed include the standard tube agglutination test, the microplate agglutination test, the quantitative plate agglutination test, the growth agglutination test and the indirect hemagglutination technique. Only the growth agglutination technique demonstrated an increased sensitivity over the STAT. Neither the microplate agglutination test nor quantitative plate tests offered any significant advantages over the STAT. The QPAT using Brucella O antigen was clearly subject to false negative results. The indirect hemagglutination technique showed extreme variation in results, the significance of which (if any) was unclear.

Agglutination Tests↗
PubMed1975

Cellular energy dependent agglutination of rat ascites tumor cells mediated by concanavalin A and Ricinus communis agglutinin.

Effect of various metabolic inhibitors on the agglutination of rat ascites tumor cells mediated by concanavalin A and Ricinus communis agglutinin was studied using a quantitative assay method for agglutination in which turbidity of cell suspension is measured. Cell agglutination was inhibited by low temperature, cytochalasin B and inhibitors of energy generating systems without affecting lectin binding, and agglutination was not affected by hydroxyurea, actinomycin D or cycloheximide. The inhibitors of energy generating systems decreased the cellular ATP level and inhibited macromolecular synthesis under the conditions where they inhibited the agglutinations. In contrast, cytochalasin B did not depress the cellular ATP level nor inhibit RNA and protein syntheses. These results suggest that the agglutination is associated with cellular energy dependent processes other than macromolecular synthesis; probably with some cellular surface movements participated by microfilament activity.

Agglutination↗
PubMed1993

Adherence of Escherichia coli to sperm: a mannose mediated phenomenon leading to agglutination of sperm and E. coli.

OBJECTIVE: To investigate the mechanism of adherence between Escherichia coli and sperm. DESIGN: Experimental study performed with donor sperm and male genital tract-derived E. coli. SETTING: Andrology unit of a university hospital. PATIENTS: None. INTERVENTIONS: Monitoring of sperm-E. coli agglutination; addition of sugars to block adherence; electron microscopy. MAIN OUTCOME MEASURE: Sperm-E. coli agglutination. RESULTS: Escherichia coli readily adhered to and agglutinated sperm. The phenomenon was observed at E. coli to sperm ratios as low as 1:20; maximum sperm agglutination involving approximately 90% of spermatozoa was seen with ratios of 1:5 or higher. By transmission electron microscopy, E. coli adherence was observed both on sperm heads and tails. Heteroagglutination could be blocked by D-mannose and alpha-methyl-mannopyranoside but not by other sugars. Preincubation of sperm or E. coli with mannose resulted in block of agglutination, indicating mannose-binding structures both on sperm and E. coli. CONCLUSIONS: Adherence of E. coli to sperm is mediated by mannose and mannose-binding structures present on both cell types. Agglutination of sperm by E. coli may be relevant in male and female infertility.

Bacterial Adhesion↗
PubMed1985

Agglutination and fusion of globoside GL-4 containing phospholipid vesicles mediated by lectins and calcium ions.

We have investigated the interaction of five N-acetylgalactosamine (GalNAc) specific lectins with the glycosphingolipid globoside GL-4, inserted into phospholipid vesicles composed of phosphatidyl-ethanolamine and phosphatidic acid, with respect to their ability to induce vesicle agglutination, fusion, and destabilization. The following lectins were used: soybean agglutinin (SBA); Sophora japonica agglutinin (SJA); Helix pomatia agglutinin (HPA); Ricinus communis agglutinin II (RCAII); and Codium fragile agglutinin (CFA). SBA and SJA caused rapid vesicle agglutination while HPA, CFA, and RCAII were ineffective. However, in the presence of RCAII, but not HPA and CFA, the addition of Ca2+ caused vesicle agglutination which was specifically inhibited by the haptenic sugar GalNAc, while ethylenediaminetetraacetic acid (EDTA) dissociated the vesicle complex. RCAII/Ca2+-induced vesicle agglutination was accomplished by binding of Ca2+ to RCAII after the lectin/receptor interaction. The rate of SBA-induced vesicle agglutination was increased in the presence of Ca2+, independent of the order of Ca2+ addition, and was not reversed by EDTA, indicating that the mechanism by which Ca2+ stimulated agglutination in this case was different from that observed in the presence of RCAII. In contrast to RCAII/Ca2+, SBA/Ca2+ induced of the vesicles, which occurred only when Ca2+ was added after lectin addition. Close approach of adjacent bilayers was accomplished by nonspecific interactions of SBA with the bilayer after lectin binding to the receptor as revealed by a limited extent of SBA-induced fusion and an enhanced membrane permeability upon lectin binding. The phenomena observed can be explained in terms of a Ca2+-modulated reorientation of the carbohydrate head group, causing it to adopt a more perpendicular orientation with respect to the plane of the bilayer.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylgalactosamine↗
PubMed1986

Ricinus communis agglutinin-mediated agglutination and fusion of glycolipid-containing phospholipid vesicles: effect of carbohydrate head group size, calcium ions, and spermine.

The glycolipids galactosylcerebroside (GalCer), lactosylceramide (LacCer), and trihexosylceramide (Gb3) were inserted into phospholipid vesicles, consisting of phosphatidylethanolamine and phosphatidic acid. The extent to which their carbohydrate head groups protruded beyond the vesicle surface and their interference with membrane approach were examined by determining vesicle susceptibility toward type I Ricinus communis agglutinin (RCA1) induced agglutination and Ca2+- and spermine-induced aggregation and fusion either in the presence or in the absence of the lectin. The initial agglutination rates increased in the order GalCer much less than LacCer less than Gb3, while a reversed order was obtained for Ca2+- and spermine-induced aggregation and fusion, indicating an enhanced steric interference on close approach of bilayers with increasing head group size. The lectin-mediated agglutination rates for LacCer- and Gb3-containing vesicles increased by an order of magnitude when Ca2+ was also included in the medium, at a concentration that did not induce aggregation per se. Charge neutralization could not account for this observation as the polyvalent cation spermine did not display this synergistic effect with RCA1. Addition of Ca2+ to preagglutinated vesicles substantially reduced the threshold cation concentration for fusion (micromolar vs. millimolar). Quantitatively, this concentration decreased with decreasing carbohydrate head group size, indicating that the head group protrusion determined the interbilayer distance within the vesicle aggregate. The distinct behavior of Ca2+ vs. spermine on RCA1-induced agglutination on the one hand and fusion on the other indicated that Ca2+ regulates the steric orientation of the carbohydrate head group, which appears to be related to its ability to dehydrate the bilayer. As a result, lectin agglutinability becomes enhanced while fusion will be interrupted as the interbilayer distance increases, the threshold head group size being three carbohydrate residues (Gb3). Finally, GalCer-containing vesicles were not agglutinated by RCA1 at ambient temperature, irrespective of the presence of Ca2+. Above 25 degrees C, RCA1 facilitated Ca2+-induced fusion of the vesicles, which was abolished by the haptenic sugar lactose. Since Gb3- and LacCer-containing vesicles displayed a similar behavior, a temperature-induced alteration in the supporting lipid matrix is suggested, which apparently affects lectin/glycolipid interaction.

Agglutination↗
PubMed1979

Effect of polyene antibiotics on the lectin-induced agglutination of transformed and untransformed cell lines.

Treatment of transformed Py3T3, SV101-3T3, and L1210 cells, as well as mitotic and Pronase-treated untransformed 3T3 cells, with the polyene antibiotics filipin, nystatin, and amphotericin B inhibited agglutination by wheat germ agglutinin. The effect of polyene antibiotic treatment was lectin and cell specific. Concanavalin A induced agglutination was not inhibited, wheat germ agglutination induced agglutination of untransformed 3T3 interphase cells was not influenced, and other aggregation phenomena, including those of erythrocytes with blood group specific antibodies or divalent cations, were unaffected by polyene treatments. This suggests that the formation of polyene-cholesterol complexes in transformed and erythrocyte cell membranes may specifically affect wheat germ agglutinin receptors and/or secondary events necessary for wheat germ agglutinin induced agglutination. Fluorescence studies of membrane filipin-cholesterol complexes showed that pretreating the cells with wheat germ agglutinin, but not concanavalin A, perturbed the fluorescence properties of filipin. Electron spin resonance studies with spin-labeled fatty acids revealed at best only a slight decrease in fatty acyl chain flexibility following filipin treatment. These studies indicate that there are not only quantitative differences between the agglutinability of transformed and untransformed cells with wheat germ agglutinin but that qualitative differences exist as well.

Agglutination↗
PubMed2001

Persistence of anti-leptospiral IgM, IgG and agglutinating antibodies in patients presenting with acute febrile illness in Barbados 1979-1989.

The persistence of anti-leptospiral IgM and IgG antibodies and agglutinating antibodies was studied in serologically confirmed cases of severe leptospirosis during the acute illness and over periods of several years after recovery. The antibody response in non-leptospirosis patients presenting to hospital with similar symptoms over the same period of time was used to estimate the background antibody level to leptospirosis in the community. All patients enrolled in the study had blood samples collected twice in the acute stage of illness, once during convalescence and then annually from the time of initial hospitalisation until the end of the study period. Six hundred and thirty-eight patients presented to hospital with acute febrile illness, of whom 321 were diagnosed with leptospirosis. Patients who had severe leptospirosis commonly remained seropositive, with IgM, IgG and agglutinating antibodies detectable for several years after infection. A significant proportion of cases had high titres of agglutinating antibody detectable by the microscopic agglutination test (> or = 800). There were marked differences in the magnitude and duration of persistence of agglutinating antibodies directed against different serogroups. More than 20% of cases with evidence of infection with serogroup Autumnalis retained titres of >800, 4 years after the acute illness. In one case a titre of 800 was detected 11 years after infection. Persistence of agglutinating antibody titres can create problems in interpretation of serological results and make it impossible to estimate the time of infection, given a specific titre. This study demonstrates that in endemic areas where seroprevalence is high, use of a single elevated titre is not reliable to define a current infection.

Agglutination Tests↗
PubMed1998

Effects of calcium and bicarbonate on head-to-head agglutination in ejaculated boar spermatozoa.

The present study was conducted to reveal the effects of calcium and bicarbonate on the occurrence of head-to-head agglutination in ejaculated boar spermatozoa in vitro. Boar spermatozoa were washed and incubated in a modified Krebs-Ringer bicarbonate (mKRB) in a 37 degrees C CO2 incubator (5% CO2 in air) for 1-5 h. Before and after the incubation, aliquots of each sperm sample were fixed, smeared on glass slides, and stained with a phosphate-buffered solution of Giemsa to assess the percentages of head-to-head agglutinated spermatozoa. Before the incubation, only 5-12% of the spermatozoa were agglutinated. After the 1-h incubation, however, the percentage of head-to-head agglutinated spermatozoa rose to approximately 50%, followed by only minor increases thereafter. This rise was dependent on the concentrations of calcium chloride contained in the mKRB and was attenuated by the addition of 2 mM [ethylenebis(oxyethylenenitrilo)]tetra-acetic acid (EGTA) to the medium. Moreover, the replacement of sodium bicarbonate with 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (Hepes) in the medium and treatment with ruthenium red, which have both been shown previously to inhibit calcium uptake by boar spermatozoa, significantly reduced the rise. Based on these findings, it was concluded that extracellular calcium and bicarbonate are key factors regulating head-to-head agglutination in boar spermatozoa. The possible relationship between agglutinability and the fertilizing ability of boar spermatozoa is also discussed.

Animals↗
PubMed1978

Flagellar membrane agglutination and sexual signaling in the conditional GAM-1 mutant of Chlamydomonas.

The temperature-sensitive gametogenesis-defective mutant, gam-1 is sex-limited, expressed only in mating type minus (mt-), and can sexually agglutinate but not fuse at the restrictive temperature (35 degrees C) with gametes of wild type (wt) mt+. Thin-section, freeze-cleave, and scanning electron microscopy reveal that the gam-1 phenotype is dependent on both the temperature at which the cells undergo nitrogen starvation (and therefore gamete formation) and the temperature at which the cells are maintained during the 12 h before mating. Under all conditions of gametogenesis at 35 degrees C, each gam-1 cell produces a normal-appearing membrane-associated mating structure that fails to activate in response to flagellar agglutination. Varying with the conditions of gametogenesis, on the other hand, are the agglutination and signaling properties of the gam-1 flagella. The two mutant phenotypes displayed by gam-1 have been denoted gam-1-I and gam-1-II. An agglutination reaction involving gam-1-I cells does not result in activation of the wt mt+ mating structure. A more stable agglutination reaction, which can result in activation of the wt mt+ mating structure, is characteristic of gam-1-II cells, but because the gam-1 mt- mating sturcture still fails to activate, cell fusion is precluded. We conclude that the gam-1 mutation affects flagellar component(s) involved in establishing an effective, signal-generating agglutination reaction.

Agglutination↗
PubMedDate not supplied

Genetic analysis of the aggA locus involved in agglutination and adherence of Pseudomonas putida, a beneficial fluorescent pseudomonad.

An isolate of Pseudomonas putida, which rapidly adheres to plant roots, is agglutinated by a glycoprotein from root surfaces. Agglutination is prevented and adherence to the root surface is diminished by Tn5 insertion in mutant 5123. Two cosmid clones from wild type P. putida and a 2.7-kbp EcoRI-HindIII subclone present in both cosmid clones restored agglutinable to wild type levels in transconjugants of the nonagglutinable (Agg-) Tn5 mutant 5123. These three clones increased agglutinability in transconjugants of the parental Agg+ isolate. The 2.7-kbp EcoRI-HindIII subclone restored adherence to bean root surfaces of 5123 to wild type levels in a short-term binding assay. Deletion analysis of the 2.7-kbp fragment indicated only 1.45 kbp was necessary for complementation of agglutinability in 5123. This sequence, termed the aggA locus, contains an open reading frame of 1,356 nucleotides encoding a predicted 50,509-Da protein. The distribution of the aggA locus in plant-associated bacteria, as detected through Southern hybridization, is limited to bacteria that express the agglutination phenotype.

Agglutination Tests↗
PubMed1996

A particle agglutination assay for rapid identification of heparin binding to coagulase-negative staphylococci.

The heparin-binding properties of six different species of coagulase-negative staphylococci were examined by a particle agglutination assay. Heparin (mol. wt 4000-6000), mildly treated with sodium periodate, was covalently coupled to amino-modified latex beads (0.72 micron diameter). The particle agglutination assay was validated by comparing results with the adhesion (percentage binding of adherent cells) of coagulase-negative staphylococcal strains to heparinised microtitration plates. Of 38 different coagulase-negative staphylococcal strains tested, 30 showed agglutination reactivity with heparin-coated latex beads. Strains of different coagulase-negative staphylococcal species agglutinated heparin-coated latex beads to various extents (e.g., cells of Staphylococcus haemolyticus strains reacted more strongly than cells of S. epidermidis strains). The agglutination reaction was significantly inhibited by fucoidan, suramin, lambda-carrageenan and other sulphated compounds, but not by non-sulphated carbohydrate polymers such as hyaluronic acid. Agglutination of staphylococcal cells with heparin-coated latex beads was completely blocked by a cell-surface extract. These results suggest that structures responsible for heparin binding are exposed on the cell surface.

Agglutination Tests↗
PubMed2005

Human platelet antigen genotyping by using sequence-specific primers and the particle gel agglutination assay.

BACKGROUND AND OBJECTIVES: Polymerase chain reaction using sequence-specific primers (PCR-SSP) is currently the most widely used technique for human platelet antigen (HPA) genotyping. Here, we describe a novel particle gel-agglutination technique for simplified visualization of the amplified products. MATERIALS AND METHODS: Biotinylated primers were used to amplify HPA-1, -2, -3, -4, -5, -6, and -15, and the PCR products were incubated with streptavidin particles. Fluorescein isothiocyanate (FITC)-labelled primers [amplifying a fragment of the human growth hormone (HGH) gene] and anti-FITC-coated particles were used as internal controls. Agglutination of the particles in or on top of the gel indicated specific amplification. A total of 100 samples from blood donors was tested by using this new technique and a standard PCR-SSP protocol. RESULTS: The use of biotinylated sequence-specific primers resulted in PCR products that agglutinated streptavidin particles, and the FITC-labelled HGH primers led to agglutination of anti-FITC-coated particles. Negative reactions were clearly distinguishable from positive reactions. The results of the particle gel agglutination method were in concordance with those of the electrophoretic visualization in all cases tested. CONCLUSIONS: The new particle agglutination method is reliable and easy to use.

Agglutination Tests↗
PubMed1990

Milk whey induction of agglutination in ovine and bovine mastitis Staphylococcus aureus.

A total of 59 mastitis staphylococcic strains were tested for growth agglutination upon supplementation of growth media with ovine and bovine milk whey and mammary secretions from dry cows. Differences were observed when comparing bacterial species or origins (ovine vs. bovine) of bacteria and whey. All of the ovine and bovine S. aureus strains tested, but only 4 among 22 other ovine mastitis staphylococcic strains, showed growth agglutination in Todd Hewitt broth (THB) supplemented with greater than or equal to 30% (v/v) ovine milk whey. None of the strains agglutinated during growth in regular THB medium. Ovine whey had an agglutination induction capacity higher than bovine whey (P less than 0.005), concerning the number of responsive ovine and bovine S. aureus strains. There were no differences between whey samples from different ewes with regard to their capacity to induce agglutination. Ovine S. aureus strains were more responsive than bovine strains of this bacterial species, concerning the number of responsive strains (P less than 0.001) to bovine whey (greater than or equal to 30% in THB), the proportion of responsive strains at low (10%) ovine whey concentration (P less than 0.001), and the strength of reaction (precipitation timing and clump size). Secretions from dry cows systematically induced agglutination in all of the bovine and ovine S. aureus strains tested.

Agglutination↗
PubMed1984

Different structure-function relationships for alpha-factor-induced morphogenesis and agglutination in Saccharomyces cerevisiae.

Eight synthetic analogs of the mating pheromone alpha-factor-induced morphogenesis and increased agglutinability in a cells. Most analogs induced increased agglutinability at lower concentrations than those at which they induced morphogenesis, but the ratio of the potencies for the two effects varied 140-fold among different analogs. Morphological response to pheromone required exposure for at least 90 min, but increased agglutinability followed exposures of 20 s. Two synthetic analogs induced neither response. In competition experiments, both of these analogs prevented induction of increased agglutinability and morphogenesis by active alpha factor. The inactive peptides blocked increased agglutinability at lower concentrations than those at which they blocked morphogenesis. alpha factors exhibited different structure-function relationships for morphogenesis as compared with agglutinability. Thus, response of Saccharomyces cerevisiae to alpha factor is complex and may be mediated by more than one receptor.

Agglutination↗
PubMed1984

Evaluation of three commercial agglutination tests for the identification of Staphylococcus aureus.

Three commercially available rapid slide agglutination tests for the identification of Staphylococcus aureus were evaluated with 354 recent clinical isolates (165 strains of S. aureus). The test results of two latex agglutination products, SeroSTAT Staph (Scott Laboratories, Inc.) and Staphylatex (American Micro Scan), and one hemagglutination product, Staphyloslide (BBL Microbiology Systems), were compared with the results of the tube coagulase test, which was read at 4 h (4-h tube coagulase test) and, if negative, again after overnight incubation at room temperature (24-h tube coagulase test). Discrepancies between agglutination and tube coagulase identifications were resolved by use of the thermonuclease, mannitol fermentation, and slide coagulase tests. All sensitivities, specificities, predictive values of a positive result, and predictive values of a negative result for the three agglutination tests were at least 98.8% and comparable with the 4-h tube coagulase test. Best results were obtained with the 24-h tube coagulase test, which yielded one false-negative and no false-positive tests. Agglutination identifications may be performed on organisms taken directly from a primary plate when sufficient growth is present. Kit agglutination procedures yield rapid and reliable identifications and are easy to perform. This study also demonstrates the usefulness of the 24-h tube coagulase test.

Agglutination Tests↗
PubMed1984

Improved detection of bacterial antigens by latex agglutination after rapid extraction from body fluids.

Nonspecific agglutination of antibody-coated latex particles, unrelated to the presence of specific bacterial antigens, is a major difficulty with commercial latex particle agglutination tests. Rheumatoid and other factors are known to interfere with latex tests. We studied the use of six chelating, reducing, and anticoagulatory reagents in a rapid extraction of antigen procedure to free heat-stable antigens of Haemophilus influenzae type b and group B streptococcus which had been added to human sera. We also screened sera for the incidence of nonspecific agglutination from the three following groups: 123 patients with positive serology tests, 112 hospitalized patients, and 87 blood donors. The rapid extraction of antigen procedure involved a 1:4 dilution of the sera with each of the six reagents, incubation at 100 degrees C for 3 min, and centrifugation at 13,000 X g for 5 min. Two commercial latex kits were tested (Bactigen and Wellcogen). Nonspecific agglutination was entirely eliminated by each of the six extraction reagents. Sera from 52% of the patients with positive serology tests, 29% of the hospitalized patients, and 28% of the blood donors showed nonspecific agglutination with Bactigen before extraction. Nonspecific agglutination was eliminated in all but one sample after the rapid extraction of antigen procedure. This simple, rapid extraction procedure eliminated nonspecific reactions in cerebrospinal fluids and amniotic fluids and reduced this problem in urines and sera with each commercial kit used on clinical specimens.

Agglutination↗
PubMed2006

Diagnosing human African trypanosomiasis in Angola using a card agglutination test: observational study of active and passive case finding strategies.

OBJECTIVE: To assess the operational feasibility of detecting human African trypanosomiasis by active and passive case finding using the card agglutination test with serial dilution of serum to guide treatment. SETTING: Trypanosomiasis control programme in the Negage focus, northern Angola, during a period of civil war. DESIGN: Observational study. PARTICIPANTS: 359 patients presenting themselves to health centres with symptoms (passive case finding) and 14,446 people actively screened in villages. MAIN OUTCOME MEASURES: Whole blood and serological tests at different dilutions using the card agglutination test, and detection of parasites by microscopy. RESULTS: Active case finding identified 251 people with a positive card agglutination test result, 10 of whom had confirmed parasites. In those presenting for investigation 34 of 51 with a positive card agglutination test result at the dilution of 1:8 or more used to guide treatment had parasites in blood, lymph node fluid, or cerebrospinal fluid, compared with 10 of 76 in those detected by active case finding: positive predictive values of 67% for passive case detection and 13% for active case detection. Only at a cut-off dilution more than 1:32 was the positive predictive value in active case detection reasonable (46%) and at this dilution 40% of microscopically proved cases were missed. CONCLUSIONS: The card agglutination test is useful for initial screening in active detection of cases with human African trypanosomiasis but, given the toxicity of the drugs, serology using the card agglutination test should be not used alone to guide treatment after active case finding. A second confirmatory test is needed.

Adolescent↗
PubMed2006

A meta-analysis of the diagnostic performance of the direct agglutination test and rK39 dipstick for visceral leishmaniasis.

OBJECTIVE: To compare the performance of the direct agglutination test and rK39 dipstick for the diagnosis of visceral leishmaniasis. DATA SOURCES: Medline, citation tracking, January 1986 to December 2004. Selection criteria Original studies evaluating the direct agglutination test or the rK39 dipstick with clinical visceral leishmaniasis as target condition; adequate reference classification; and absolute numbers of true positive, true negative, false positive, and false negative observations available or derivable from the data presented. RESULTS: 30 studies evaluating the direct agglutination test and 13 studies evaluating the rK39 dipstick met the inclusion criteria. The combined sensitivity estimates of the direct agglutination test and the rK39 dipstick were 94.8% (95% confidence interval 92.7% to 96.4%) and 93.9% (87.7% to 97.1%), respectively. Sensitivity seemed higher and more homogenous in the studies carried out in South Asia. Specificity estimates were influenced by the type of controls. In phase III studies carried out on patients with clinically suspected disease, the estimated specificity of the direct agglutination test was 85.9% (72.3% to 93.4%) and of the rK39 dipstick was 90.6% (66.8% to 97.9%). CONCLUSION: The diagnostic performance of the direct agglutination test and the rK39 dipstick for visceral leishmaniasis is good to excellent and seem comparable.

Agglutination Tests↗