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PubMed1975

Mating reaction in Saccharomyces cerevisiae. VIII. Mating-type-specific substances responsible for sexual cell agglutination.

The agglutination factors of a and alpha mating types of Saccharomyces cerevisiae were solubilized from isolated cell-wall fractions by treatment with snail enzyme (Glusulase) and shown to be adsorbed specifically by cells of the opposite mating type, resulting in the loss of agglutinability of these cells. The agglutination factors of a and alpha types adsorbed by cells of the opposite mating type at pH 5.5 were eluted at pH 9.0. These factors were further purified on Sepharose 4B. From the elution pattern on Sepharose 4B, the molecular weights of the solubilized agglutination factors are estimated to be about one million. Thus purified agglutination factors contained carbohydrate and protein and were considerably resistant to heat treatment. Neutral protease of Bacillus subtilis inactivated both a and alpha type agglutination factors. Trypsin inactivated the alpha type agglutination factor only.

Agglutination↗
PubMed1992

Determination of lectin characteristics by a novel agglutination technique.

A technique generally applicable for the determination of lectin characteristics is described. A sensitive light transmission/scattering method was adapted for the determination of lectin levels and lectin activity. Applying this procedure Geodia cydonium lectin-mediated agglutination was studied in an agglutimeter device using erythrocytes and even T-lymphocytes. In the Geodia lectin/T-lymphocyte system chosen, (i) a lectin concentration as low as 0.57 micrograms/ml could be measured accurately, (ii) the observed cell agglutination velocity constant with a maximal value of 0.75 min-1 was calculated, and (iii) the size of the agglutinates at a given lectin concentration and time period was estimated. The Geodia lectin activity was determined in parallel also in the erythrocyte system. Here, compared to the lectin/T-lymphocyte system the agglutination efficiency of the Geodia lectin-mediated agglutination was more than 10-fold higher and the lowest detectable lectin concentration was 0.06 micrograms/ml. Compared to the hemagglutination assay the lectin/erythrocyte system turns out to be more sensitive and to give much more information on agglutination behavior; this conclusion is supported by additional data using a second lectin isolated from Pellina semitubulosa. The superiority of the agglutination method described here over other known methods must be seen in its accuracy; moreover more lectin characteristics can be determined.

Agglutination↗
PubMed1984

Agglutinating activity of gliadin-derived peptides from bread wheat: implications for coeliac disease pathogenesis.

The PT-digest of bread wheat gliadin was very active in agglutinating undifferentiated human K562(S) cells. This activity was quantitatively, but not qualitatively, similar to that of Con A or WGA. Moreover, Con A-induced cell agglutination was inhibited by mannan and mannose, WGA-induced agglutination by NAG only, and cell agglutination induced by bread wheat gliadin peptides was inhibited by each of these three saccharides. Not only was mannan the most active saccharide in preventing cell agglutination induced by bread wheat gliadin peptides, but it was also able to dissociate agglutinated cells. As compared to the PT- digest of whole bread wheat gliadin, the digest obtained from purified A-gliadin was tenfold more active. The PT-digest of durum wheat gliadin did not show any agglutinating activity.

Agglutination Tests↗
PubMed2002

[Diagnosis of human brucellosis. Role of pH in the seroagglutination test and influence of pH on the agglutinating activity of IgM, IgG and IgA antibodies].

OBJECTIVE: To evaluate the role of pH in the seroagglutination test (SAT)and Rose Bengal (RB) test, and to determine the influence of pH on the agglutinating activity of IgM, IgG and IgA antibodies. MATERIALS AND METHODS: The SAT was performed at pH 7.2 or pH 5.0 in standard microtiter-type polystyrene plates using Ring Test antigen or the Brucella suspension (BRUCAPT) provided in the Brucellacapt kits. Specific antibodies against native hapten were determined by radial immunodiffusion. Additionally, IgG, IgA and IgM fractions were separated from 8 sera by absorption chromatography and their agglutinating capacity was studied at pH 7.2 and 5.0. RESULTS: We studied 72 sera from patients with clinical brucellosis taken at the time of hospitalization, 16 from persons in contact with infected animals, and 16 from healthy donors. SAT results at pH 5.0 correlated with those obtained with the Rose Bengal test. Four Rose Bengal-positive sera were found to be SAT-negative at pH 7.2 and SAT-positive at pH 5.0. SAT performed at pH 5.0 with BRUCAPT antigen yielded higher titers than tests performed at pH 7.2 or 5.0 with Ring Test antigen (p < 0.001), with highest titers in IDR-positive sera. Among the 8 IgG fractions, all but one agglutinated at pH 7.2, and in 4, IgG titers showed significant increases at pH 5.0. Three IgA fractions were SAT-negative at pH 7.2 and SAT-positive at pH 5.0; the other 5 agglutinated at both pH conditions and were DTT-sensitive. All IgA fractions but one were positive by Rose Bengal. Agglutinating activity of the IgM fraction was not affected by pH. CONCLUSION: The SAT performed with the buffer and antigen suspension included in the Brucellacapt kit (pH 5.0) is highly useful for detecting agglutinating and non-agglutinating antibodies at pH 7.2.

Agglutination Tests↗
PubMed1975

In vitro oncospheral agglutination given by immune sera from mice infected, and rabbits injected, with eggs of Hymenolepis nana.

Oncospheral agglutination given by sera immunized with Hymenolepis nana eggs is described as a new way of assessing H. nana infection. All sera of mice which possessed acquired protective immunity against reinfection by H. nana eggs had the potency to induce oncospheral agglutination in vitro. Only oncospheres, which had been hatched, agglutinated, no agglutination occurred in sera from uninfected mice. Oncospheral agglutination was carried out by mixing 0-1 ml of serial two-fold dilutions of serum and 0-1 ml of Hanks' balanced salt solution containing about 600 hatched oncospheres. Titre of agglutinins was indicated as a reciprocal of the final dilution capable of giving agglutination clusters made of three or more oncospheres. Agglutinins developed within 14 days after a primary infection with 500 shell-free eggs. There was no rapid increase of agglutinins within 4 days following a secondary infection. The titre increase coincided with the increase in dosages of eggs. Agglutinins were thought to be immunoglobulins, because the potency of the serum to agglutinate oncospheres was extinguished after absorption of globulins with rabbit anti-mouse globulin serum. Agglutinins were produced in rabbits by intravenous injections of shell-free eggs. The titres of the rabbit sera were much higher than those of mouse sera.

Agglutination↗
PubMed1991

Slide-agglutination for rapid serological typing of Treponema hyodysenteriae.

A slide agglutination (SA) test was developed to determine the serogroup of isolates of Treponema hyodysenteriae of serogroups A to F. Rabbit antisera which are normally used for serogrouping T. hyodysenteriae in an agarose gel double-diffusion precipitation test (AGDP) were not suitable for SA because they agglutinated isolates from more than one serogroup. The agglutination reaction was made serogroup-specific by cross-absorbing the typing sera for serogroups A to F with whole treponemes from the other 5 of these 6 serogroups of T. hyodysenteriae. The absorbed sera were reacted in slide agglutination tests with 33 isolates of T. hyodysenteriae and with four non-T. hyodysenteriae intestinal spirochaetes. None of the non-T. hyodysenteriae isolates agglutinated, but 27 of the 33 isolates of T. hyodysenteriae did. The results for 26 of the 27 agglutination reactions agreed with the serogroup as determined in AGDP. One of the 6 isolates of T. hyodysenteriae which failed to react in slide agglutination was of serogroup B, 1 of serogroup D, 1 each were from new serogroups G, H and I, and 1 was untypable in AGDP.

Agglutination Tests↗
PubMed1996

Agglutination of Leishmania promastigotes by midgut lectins from various species of phlebotomine sandflies.

Lectins which agglutinate Leishmania promastigotes were demonstrated in gut lysates from laboratory colonies of five Phlebotomus and two Lutzomyia species. In general, the highest agglutination titres were found in P. halepensis and Lu. longipalpis (Jacobina). Marked differences were found in the agglutination of promastigotes of various Leishmania species and strains and high agglutination titres were observed in some natural vector-parasite combinations, such as Phlebotomus argentipes and Le. donovani. Intraspecific variability, in agglutination of Le. major strains, could be related to the varying infectivity of the strains to laboratory animals. Similar carbohydrates, of which the most effective were D-mannosamine and N-acetyl-D-glucosamine, inhibited the agglutination of Le. major and Le. donovani promastigotes by midgut extracts from P. papatasi and Lu. longipalpis. D-Mannosamine and N-acetyl-D-glucosamine inhibited agglutination of promastigotes in all vector-parasite combinations. The results of the carbohydrate-inhibition tests indicate that the lectin specificities in Phlebotomus are similar to those in Lutzomyia.

Acetylglucosamine↗
PubMedDate not supplied

Serologic diagnosis of human brucellosis: analysis of 214 cases by agglutination tests and review of the literature.

The serum agglutination test (SAT) and 2-mercaptoethanol (2ME) agglutination were used in studies of the sera of 214 patients in whom brucellosis was suspected. On the basis of historical, epidemiologic, clinical, and serologic data, four groups were identified: group I (108 cases) had negative agglutination reactions, and brucellosis was considered unlikely; group II (57 cases) had positive agglutination reactions, and active brucellosis was diagnosed; group III (37 cases) had positive agglutination reactions, but other factors--notably, a history of prior infection--made inactive brucellosis likely; and group IV (12 cases) had positive agglutination reactions, but insufficient data were available for further classification. Most patients with active brucellosis had agglutinin titers of greater than or equal to 160; however, no single titer was always diagnostic. Although more sensitive tests are available, agglutination reactions provide data sufficient to differentiate active from inactive disease when other factors are considered and follow-up sera are tested. This article discusses individual cases and reviews the literature on the diagnosis of brucellosis.

Adolescent↗
PubMed1983

Role of DNA and bacteriophage in Campylobacter auto-agglutination.

Auto-agglutinated and non-agglutinated cells of Campylobacter jejuni and C. coli were examined by transmission electronmicroscopy in phosphotungstate negative stain. Agglutination was induced by three factors (1) extracellular DNA, (2) an aggregated protein, probably a bacteriophage precursor, and (3) free phage-tail sheaths. Auto-agglutinated cells were often "leaky," with a mantle of adhering DNA. About 80% of the auto-agglutinated cells could be resuspended after treatment with DNAase. Flagella were loosely embedded in protein aggregates, especially in phage-infected cultures. They were clumped in a side-by-side arrangement by free phage-tail sheaths. These findings suggest that auto-agglutination could be minimised in suspensions of organisms intended for use in agglutination tests by harvesting early logarithmic-phase cells containing no more than a low phage population. The most common C. jejuni phage had a contractile tail, a head diameter of 60-70 nm, and an overall length of 180-210 nm. A phage isolated from C. jejuni strain 1590 was morphologically identical with C. coli phage.

Agglutination↗
PubMed1993

Rapid diagnosis of typhoid fever by co-agglutination in an Indian hospital.

Detection of Salmonella typhi infection by a co-agglutination assay for specific O, H and Vi antigens and by blood culture were compared for 110 patients with suspected typhoid fever. Blood cultures were positive for S. typhi in 25.5% of patients. Co-agglutination tests with patients' serum and with blood culture supernates gave positive results in 70.9% and 67.3% of cases respectively. S. typhi antigens Hd and O9 were detected in patients' serum by co-agglutination in 96.4% of blood culture-positive, and 62.2% of blood culture-negative patients. Co-agglutination results were uniformly negative with serum samples from a control group of 50 healthy individuals, 20 patients with febrile non-typhoid infectious disease and 20 patients with non-infectious febrile disease. Of the 25 patients with suspected typhoid fever who had not received prior antibiotic treatment, 88% yielded positive blood cultures and 96% gave positive results in serum co-agglutination tests. By contrast, of the 85 patients who had received prior antibiotics, only 7% yielded positive blood cultures, but 63.5% gave positive results in serum co-agglutination tests. Co-agglutination tests with serum offer a simple, rapid, sensitive, specific and economical method for the early diagnosis of typhoid fever.

Agglutination Tests↗
PubMed1981

Pili mediated agglutination of Serratia marcescens in human urine.

Of 51 strains of Serratia marcescens isolated from patients with urinary or respiratory tract infections, 35 agglutinated in human urine. The agglutinating strains possessed numerous pili which were morphologically distinct from common pili or type I pili. The diameter of the pili was 3 nm and the average length was 0.3 micrometer. Electron microscopic examination showed that 80% or more of the cells of the agglutinating strains and 0 to 8% of the cells of the nonagglutinating strains were piliated. When an agglutinating strain was heated at 55 C for 10 min, it lost its agglutinating capacity and concomitantly its pili. These results suggest that the agglutination might occur because of interactions between the pili and some factors in human urine. The urinary slime appears to contain these agglutinating factors.

Agglutination↗
PubMed1978

Lectin analysis of Trypanosoma congolense bloodstream trypomastigote and culture procyclic surface saccharides by agglutination and electron microscopic technics.

Living, intact bloodstream trypomastigotes and culture procyclic forms of Trypanosoma congolense were tested for aggulination with the lectins concanavalin A (Con A), phytohemagglutinin P (PP), wheat germ agglutinin (WGA), soybean agglutinin (SBA), and fucose binding protein (FBP). Similar experiments were conducted with living bloodstream and culture forms treated with trypsin or dextranase. Parasites were incubated for 30 min at 25 C in various concentrations of each lectin, then examined for agglutination by dark-field microscopy. Control preparations consisted of parasites incubated alone or with 0.5 M of the specific competing sugar, with or without the corresponding lectin. Electron-microscopic localization of lectin binding sites on the surface of intact and dextranase-treated bloodstream and intact culture forms was accomplished with Con A, reacted with horseradish peroxidase (HRP) and then diaminobenzidine (DAB). In addition, FBP and SBA were coupled to HRP, then utilized for the localization of binding saccharides on the surface of bloodstream forms by the DAB technic. Similar studies were conducted with culture procyclics incubated with WGA-, SBA-, PP- or FBP-HRP conjugates and then reacted with DAB. Controls were utilized to confirm the sugar specificity of all positive reactions. Intact living bloodstream forms were agglutinated in a concentration-dependent manner with all the lectins tested. Agglutination levels were scored as Con A greater than FBP greater than WGA = PP = SBA. Sugars resembling alpha-D-mannose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, and alpha-L-fucose are evidently present on the surface of the parasites. No agglutination was noted in any control preparations. Identical lectin-induced agglutinations were obtained with trypsin- or dextranase-treated bloodstream forms. Trypsin disrupted but did not entirely remove the surface coat of bloodstream forms, while dextranase did not alter the ultrastructure of the parasites. Con A-, SBA- and FBP-binding saccharides were distributed uniformly on the surface coat of intact bloodstream forms; a similar distribution of Con A receptors was noted also on the surface of dextranase-treated cells. No lectin-binding saccharides were visualized by electron microscopy on any control preparations. Intact, trypsin- or dextranase-treated, procyclics were agglutinated in a concentration-dependent fashion by Con A and WGA, but not by the other lectins tested. Control preparations did not agglutinate and the enzymes did not affect the ultrastructure of the parasites. Con A- and WGA-specifically binding saccharides were uniformly distributed on intact procyclics and control preparations were lectin-negative. Thus, T. congolense procyclics retained surface saccharides resembling alpha-D-mannose and N-acetyl-D-glucosamine but lost sugars resembling N-acetyl-D-galactosamine (or D-galactose) and alpha-L-fucose...

Agglutination Tests↗
PubMed1980

Role of lipopolysaccharide in wheat germ agglutinin-mediated agglutination of Neisseria meningitidis and Neisseria gonorrhoeae.

Wheat germ agglutinin, having specificity for N-acetyl glucosamine, agglutinated known nonencapsulated Neisseria meningtidis strains, but failed to agglutinate encapsulated strains of all serogroups tested Presence of a capsule, therefore, blocked wheat germ agglutinin agglutination of N. meningitidis strains. In contrast, Neisseria gonorrhoeae strains were strongly agglutinated, providing additional evidence for nonencapsulation of N. meningitidis strains. In contrast, Neisseria gonorrhoeae strains were strongly agglutinated, providing additional evidence for nonencapsulation of N. gonorrhoeae. Purified lipopolysaccharide from a single N. meningitidis and N. gonorrhoeae strains tested. Thus, in absence of capsular polysaccharide wheat germ agglutinin agglutinates Niesseria strains through interaction with lipoplysaccharide in the outer membrane. Of 34 nongroupable throat N. meningitidis isolates, 10 failed to agglutinate in wheat germ agglutinin, suggesing that at least some nongroupable. N. meningitidis strains may possess capsule-like materials.

Agglutination↗
PubMed1975

Cell surface saccharides of Trypanosoma lewisi. I. Polycation-induced cell agglutination and fine-structure cytochemistry.

Trypanosoma lewisi bloodstream and culture forms were agglutinated differentially with low concentrations of the cationic compounds: ruthenium red, ruthenium violet, Alcian blue chloride, 1-hexadecylpyridinium chloride, lanthanum chloride, and cationized ferritin. The bloodstream form trypanosomes gave the highest agglutination levels with each of the compounds tested. Ruthenium red was the most effective inducer of cell agglutination among the several cations used. Trypsin-treated bloodstream forms were agglutinated less in the presence of ruthenium red than untreated controls. Ruthenium red-induced cell agglutination also was lowered with chondroitin sulphate and dextran sulphate, but not with alpha-D-glucose, alpha-D-mannose or with several methyl glycosides. Treatment of the bloodstream trypanosomes with alpha-amylase, dextranase, or neuraminidase had little effect on agglutination levels obtained with ruthenium red. Fine-structure cytochemical staining with ruthenium red, ruthenium violet, and Alcian blue-lanthanum nitrate was used to ascertain the presence and distribution of presumptive carbohydrates in the trypanosome cell surface. The extracellular surface coat of the bloodstream forms stained densely with each of the polycationic dyes. Trypsin treatment removed the surface coat from bloodstream trypanosomes; however, the surface membranes of the organisms were stained densely with the several dyes. Similar surface-membrane staining was obtained with the cationic compounds and the culture forms, which lack a cell surface coat. Cationized ferrin was used at the fine-structure level to visualize the negative surface charge present in the cell surface coat and external membrane of the several trypanosome stages. Results obrained from the agglutination and cytochemistry experiments indicate that complex polysaccharides are present in the surface membranes and cell surface coat of T. lewisi bloodstream forms. Similar conclusions also pertain to the surface membranes of the T. lewisi culture from trypanosomes. The carbohydrates probably represent glycopeptide and glycoprotein structural components of the surface membrane of this organism.

Agglutination↗
PubMed1976

Cell surface saccharides of Trypanosoma lewis i. II. Lectin-mediated agglutination and fine-structure cytochemical detection of lectin-binding sites.

Bloodstream (BSF) and culture forms (CF) of Trypanosoma lewisi were specifically agglutinated with the plant lectins concanavalin A (Con A), soybean agglutinin (SBA), wheat germ agglutinin (WGA), and fucose-binding protein (FBP). Lectin-mediated cell agglutination was inhibited, and reversed in the presence of specific lectin-binding saccharides. Cells were agglutinated randomly with all lectins suggesting a uniform distribution in the trypanosome cell surface of the lectin-binding saccharide ligands. The BSF and CF were not agglutinated with phytohaemagglutinin-M, phytohaemagglutinin-P, or influenza virions. Living trypsinized BSF, which lacked a surface coat, gave agglutination results with the lectins identical to those obtained with living intact BSF. Glutaraldehyde- or formalin-fixed intact and trypsinized BSF gave results similar to those obtained with living cells and SBA, WGA, and FBP. However, intact, fixed BSF gave much lower agglutination levels with Con A than trypsinized-fixed, living intact, or living trypsinized BSF cells. Intact and trypsinized living and fixed CF gave identical agglutination results with each of the lectins. Living and fixed cells treated extensively with the glycoside hydrolases alpha-amylase, dextranase, and neuraminidase gave results with the lectins identical to those obtained with untreated cells. Con A bound at the cell surface was visualized with an iron-dextran (Fe-Dex) conjugate. Dense iron marker particles were distributed randomly in the intact BSF surface coat. The Con A-bound Fe-Dex marker was present on the pellicular and flagellar membrane outer lamina of trypsinized BSF and intact CF cells. Horseradish peroxidase (HRPO)-diaminobenzidine (DAB) coupled reactions also were used to visualize surface-bound Con A. Dense Con A-HRPO-DAB deposits were present uniformly in the BSF surface coat, and on the membranes of trypsinized BSF and intact CF trypanosomes. SBA and WGA were conjugated to HRPO and these used in DAB-coupled reactions at the ultrastructure level. Results obtained with the HRPO-conjugated lectins were similar in surface localization and distribution to those obtained with the Con A-HRPO-DAB preparations. Treatment of BSF and CF with the several glycoside hydrolases produced no apparent enhanced or reduced reactivity for the lectins in any of the fine-structure cytochemistry experiments. The cumulative results indicate that ligands similar or identical to alpha-D-mannose, N-acetylgalactosamine, and N-acetylglucosamine, and alpha-L-fucose are constituents in the extracellular surface coat matrix of T. lewisi BSF. Similar conclusions also pertain to the pellicular and flagellar membrane ligands of the BSF and CF cells. Moreover, results obtained with the glycoside hydrolases and influenza virions suggest that the T. lewisi cell surface ligands are not associated directly with repetitively bonded alpha-I,4- and alpha-I,6-D-glucans or sialic acid moieties.

Acetylglucosamine↗
PubMed1977

Concanavalin A-induced agglutination of Naegleria.

Concanavalin A (Con A) agglutinated all Naegleria gruberi strains tested but did not agglutinate any N. fowleri strains tested. Agglutination was time and temperature dependent and Con A concentration and ameba concentration dependent over certain ranges. Agglutination increased to maximum up to 1 h incubation with Con A. At least 1 X 10(6) amebae/ml were needed for maximum agglutination, and Con A concentrations higher than 100 microgram/ml did not appreciably increase agglutination. Incubation of 4 degrees C or with 10 mM alpha-methyl-D-mannoside inhibited agglutination of N. gruberi. These data indicate a difference in polysaccharide structure of cell membranes of N. fowleri and N. gruberi.

Agglutination↗
PubMed1976

Patching, microvilli, and the agglutination of normal and transformed cells.

Transmission and scanning electron microscopy were used to study possible structural correlates in the process of agglutination of several types of normal and transformed cells by Concanavalin A. In parallel studies we found that post-confluence inhibition of cell division and agglutiniability of cells by Concanavalin A were not correlated with patching of surface bound lectin molecules as determined with a hemocyanin marker. Transformed cells growing in monolayer cultures were found to have many more microvilli than the corresponding normal cells. However, when cells were brought into suspension with EDTA, all cells developed numerous microvilli and we were not able to distinguish between agglutinable and nonagglutinable cells on the basis of morphological appearance. Cells agglutinated by Concanavalin A had numerous interdigitated microvilli at points of cell-cell contact. The appearance of spontaneously agglutinated cells and lectin agglutinated cells was very similar with respect to the involvement of microvilli in cell-cell attachments, and labeling studies with hemocyanin indicated that Concanavalin A bound to microvilli is rapidly cleared from these surface specializations in a manner analogous to that observed with patching of surface bound lectin. Several lines of SV-40 transformed fibroblasts were shown to be considerably more spontaneously agglutinable than untransformed cells. These results indicate that Concanavalin A may amplify an intrinsic membrane property common to many transformed cells that is expressed as an increase in the rate of adhesion of suspended cells. It is proposed that the membrane change detected by the agglutination reaction may also be involved in the loss of post-confluence inhibition of cell division and growth of transformed cells in semisolid media, due to a surface interaction that allows transformed cells to use each other as growth substrata.

Agglutination↗
PubMed1976

A serologic survey of a population of Georgia dogs for Brucella canis and an evaluation of the slide agglutination test.

In a serologic survey of stray and pet dog populations of Georgia, serums were screened for Brucella canis antibodies, using the slide agglutination test. If results were positive, B canis antibody titers were determined, using the standard tube agglutination test. The stray dogs had significantly (P less than 0.01) higher titers than did the pet dogs. The reactor rate was 58% higher for the slide agglutination test than for the tube agglutination test. The manufacturer's evaluation of the slide agglutination test was based on a comparison of the serologic results of that test with those of the tube agglutination test, using a comparative method that permitted the results to be interpreted as 99% agreement between the 2 tests. Reevaluation of the manufacturer's data by a different method indicated that the slide agglutination test is very accurate when the results are negative (99.7% specific) but less so when the results are positive (62.5% sensitive).

Agglutination Tests↗