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PubMed1967

Inhibition and agglutination of arthrobacters by psuedomonads.

The bacterial flora of water in Narragansett Bay, R.I., was observed semimonthly from 1962 to 1964. Dominant isolates were keyed to genus, and the isolates for each genus were expressed as percentage of total isolates. There was a consistent inverse relationship between arthrobacters and the dominant pseudomonads. Pseudomonad growth on agar plates markedly inhibited arthrobacter cross-streaks. Agar from inhibition zones as well as supernatant fluids from pseudomonad broth cultures inhibited arthrobacter motility and caused the cells to agglutinate. Gummy pseudomonad residues from vacuum-evaporated broth cultures readily passed a G-25 Sephadex column. This material agglutinated arthrobacter cells, but failed to cause arthrobacter inhibition in filter-pad assays. In contrast, sterile medium inside a dialysis sac, inoculated externally with a pseudomonad, was inhibitory to arthrobacters in pad assay but failed to agglutinate arthrobacter cells. Pseudomonad isolates from soil showed similar inhibiting and agglutinating activities for both soil and seawater arthrobacter isolates. The inhibitory and agglutinating activities of pseudomonad isolates appeared to diminish on prolonged laboratory cultivation.

Agglutination↗
PubMed1969

Dextran-induced agglutination of Streptococcus mutans, and its potential role in the formation of microbial dental plaques.

Glucose-grown washed cells of streptococci similar to Streptococcus mutans, which contain cell-bound dextransucrase, have been observed to agglutinate upon the addition of high molecular weight dextran. Low molecular weight dextran or unrelated polysaccharides were ineffective. Agglutination also occurred upon addition of sucrose, which can be converted into dextran, but not with other mono- and disaccharides. Other bacteria, including species capable of synthesizing dextrans, were not observed to exhibit this phenomenon. Cells of S. mutans agglutinated upon addition of dextran over a wide pH range, but maximal sensitivity to dextran occurred at pH 8.5. At this pH, such cells can be used for a simple, specific, and exquisitely sensitive qualitative assay for high molecular weight dextran, for addition of 6 ng of dextran with a molecular weight of 2 x 10(6) (i.e., approximately three molecules per cell) caused detectable agglutination. High concentrations of glucose, levan, and dextran of molecular weight of 2 x 10(4) inhibited the reaction. Fluorescein-labeled cells of S. mutans were observed to adhere to dextran-containing plaques and dextran-treated teeth, suggesting that this phenomenon may be of importance in the formation of streptococcal dental plaques. The mechanism responsible for dextraninduced agglutination appears to involve the affinity of a receptor site, possibly dextransucrase, on the surface of several cells for common dextran molecules.

Agglutination↗
PubMed1980

Screening of bacterial isolates for mannose-specific lectin activity by agglutination of yeasts.

A total of 393 clinical bacterial isolates were tested for their ability to agglutinate yeast cells of either Saccharomyces cerevisiae or Candida albicans. A positive agglutination of yeasts that could be prevented by methyl alpha-D-mannoside was taken as an indication for the possible presence of a mannose-specific lectin (carbohydrate-binding protein) on the surface of the tested bacteria. Agglutination tests on glass slides showed that 38% of all the isolates tested were positive in their capacity to agglutinate yeasts. Among the various strains tested, all isolates of Serratia marcescens, Proteus morganii, and Citrobacter diversus, as well as 94% of Klebsiella pneumoniae, were positive. On the other hand, only 46% of the Escherichia coli, 48% of the salmonellae, 44% of the Citrobacter freundii, and 71% of the Aeromonas hydrophila isolates were positive. A quantitative determination of the lectin activity done by observing the agglutination of yeasts in microtiter plates showed that S. marcescens isolates were the most avid binders to the yeast, whereas Klebsiella and Citrobacter isolates were the weakest.

Agglutination↗
PubMed1982

Serotyping of Campylobacter jejuni by slide agglutination based on heat-labile antigenic factors.

A serotyping scheme for Campylobacter jejuni was developed based on slide agglutination of live bacteria with whole cell antisera absorbed with homologous heated and heterologous unheated cross-reactive antigens. Among 815 isolates from human and nonhuman sources, 21 serogroups were recognized. Of the 615 isolates from human cases of gastroenteritis, 529 (86%) were typable; 455 strains agglutinated in 20 single antisera, whereas 74 isolates agglutinated in various pairs of antisera, allowing subdivision of some main serogroups into subserogroups. Of the 200 isolates of C. jejuni from nonhuman sources (chicken, swine, etc.), 166 (83%) were typable, 145 cultures agglutinated in various single antisera, and 21 strains agglutinated with different pairs of antisera. Among isolates from all sources, 8 serogroups (1, 2, 4, 5, 7, 8, 9, and 11) were encountered most frequently. Serogroups 1, 2, 4, 5, 7, 9, and 11 were most common among human isolates; the majority of the chicken and all of the swine isolates belonged to the same serogroups identified from human cases. Very good serological correlation was obtained in 20 family outbreaks and 4 community outbreaks.

Agglutination Tests↗
PubMed2001

A Shared noncapsular antigen is responsible for false-positive reactions by Staphylococcus epidermidis in commercial agglutination tests for Staphylococcus aureus.

Many of the commercial slide agglutination tests for Staphylococcus aureus incorporate antibodies against cell surface antigens associated with methicillin resistance, including capsular polysaccharides and an uncharacterized antigen, serotype 18. These tests are more sensitive than the first-generation agglutination procedures that detected only bound coagulase and protein A, but they suffer from false-positive reactions with some coagulase-negative staphylococci. The aim of this study was to elucidate the mechanism for false-positive agglutination by S. epidermidis in these tests. A group of methicillin-resistant S. aureus (MRSA) isolates, including a serotype 18 strain, that were not detectable in the first-generation tests were found to be of capsular polysaccharide type 8. All of these isolates were deficient in bound coagulase and/or protein A, and they possessed a heat-stable, proteinaceous antigen that was absent from a prototype capsule type 8 strain. Enzyme-linked immunosorbent assay and agarose gel immunodiffusion experiments demonstrated that this proteinaceous antigen was also present on both methicillin-sensitive and methicillin-resistant S. epidermidis clinical isolates. S. epidermidis strains that gave false-positive agglutination test results had a considerably higher level of this antigen than strains that gave the correct negative result. These findings reveal the importance of the careful selection of MRSA strains for raising anti-capsular type 8 antibodies for use in agglutination tests. Strains devoid of the antigen shared with S. epidermidis should be used to eliminate potential cross-reactions with this coagulase-negative coccus.

Agglutination Tests↗
PubMed2004

Comparison of the Denka Seiken slide agglutination method to the quellung test for serogrouping of Streptococcus pneumoniae isolates.

This study compared a slide agglutination test (Denka Seiken, Tokyo, Japan) to the "gold standard" quellung reaction (Pneumotest; Statens Serum Institut, Copenhagen, Denmark) for the serogrouping of pneumococci. Two hundred clinical isolates of Streptococcus pneumoniae were used for the comparison. Each assay was performed according to the manufacturer's instructions. There was an overall agreement of 95.7% between the two methods. Only 4 of 10 isolates of serogroup 22 were detected with the slide agglutination assay. Two isolates that were untypeable by the Pneumotest method were typed as serogroups 6 and 31 by the slide agglutination method. The Pneumotest method was unable to type 22 isolates, and the slide agglutination method was unable to type 16 isolates. The slide agglutination method compares favorably with the Pneumotest method and is easier to perform and to interpret.

Agglutination↗
PubMed1973

Agglutination of Sindbis virus and of cells infected with Sindbis virus by plant lectins.

We have examined the agglutination of Sindbis virus and of chick and hamster cells infected with Sindbis virus by two of the plant lectins, concanavalin A and Ricinus communis agglutinin. Both lectins agglutinate the virus by binding to the polysaccharide chains of the envelope glycoproteins. Both chick and hamster cells exhibit increased agglutination by the lectins after infection by Sindbis virus. In the case of chick cells infected with Sindbis virus, this increase in agglutinability occurs between 3 and 5 h after infection. Infected and mock-infected cells bind the same amount of (3)H-labeled concanavalin A, which suggests that the increase in agglutination after infection is due to rearrangements at the cell surface rather than to insertion of new lectin binding sites per se.

Agglutination↗
PubMed1972

Bacterial agglutination studies with secretory IgA prepared from human gastrointestinal secretions and colostrum.

The function of human purified colostral and gastrointestinal IgA has been studied by its ability to agglutinate common gastrointestinal organisms. Agglutinating activity was unaffected by trypsin or acid but it was abolished rapidly by pepsin. Both colostral and gastrointestinal IgA agglutinated a wide range of enteric organisms. Variations in this activity occurred between different individuals, and between different gastrointestinal sites in the same individual. In preliminary studies, saliva and IgA prepared from gastric and jejunal secretions in patients with pernicious anaemia showed a more uniform agglutination pattern than IgA prepared from the same sites in other patients. The agglutinin activity of IgA prepared from a particular site may be determined by the bacterial flora at that site. Agglutination methods for assessing the function of gastrointestinal antibody may be of value in the study of the possible roles of antibodies in inflammatory bowel disease.

Agglutination Tests↗
PubMed1980

Agglutination of granulocytes from chronic myeloid leukaemia by concanavalin A.

Peripheral blood leucocytes from chronic myeloid leukaemia (CML) patients previously untreated or in relapse are agglutinated by concanavalin A (Con A) at concentrations of 25-400 microgram/ml. Leucocytes from normal subjects, from CML patients in remission and from patients with granulocytosis are not agglutinated by Con A. Normal bone marrow cells which contain immature and mature myeloid cells are not agglutinated either by Con A. These results suggest that an alteration occurs in the cell surface of myeloid cells in CML due to leukaemic change and results in the agglutination of these cells by Con A. If peripheral blood leucocytes of CML patients in relapse are separated into immature and mature fractions, both these fractions are agglutinated by Con A suggesting that this alteration occurs in the cell surface of both the immature and the mature myeloid cells.

Agglutination↗
PubMed1981

Relationship between saliva and serum agglutination titers and post-irradiation caries activity in cancer patients.

Agglutination titers in 444 saliva and 481 serum samples from 36 head and neck cancer patients and 16 control subjects were determined against formalinized cellular antigens of Streptococcus and Lactobacillus species. Saliva agglutination titers were significantly higher in cancer patients before radiotherapy than in control subjects. Changes in specific saliva agglutination titers to oral isolates following radiotherapy reflected changes in saliva IgA and post-irradiation caries activity. Patients with no post-irradiation caries activity had significantly higher saliva agglutination titers to S. mutans, S. sanguis, and L. fermenti, lower plaque S. mutans counts, and higher saliva IgA levels than those with post-irradiation caries activity. Serum agglutination titers were unrelated to either serum immunoglobulin levels, microbial counts, or caries activity.

Adolescent↗
PubMed2006

Comparison of Brucella immunoglobulin M and G flow assays with serum agglutination and 2-mercaptoethanol tests in the diagnosis of brucellosis.

The diagnostic value of Brucella IgM/IgG flow assays was evaluated in comparison with serum agglutination and 2-mercaptoethanol tests by testing a selection of serum samples submitted to the laboratory because of clinical suspicion of brucellosis. All 39 admission and 11 follow-up samples that agglutinated in the serum agglutination test tested positive in the flow assay, whereas all 20 serum agglutination negative samples with clinical suspicion of brucellosis, 23 control samples from healthy individuals and 20 control samples from cases with chronic hepatitis tested negative in the flow assay. The Brucella IgM and IgG flow assays were slightly more sensitive than the agglutination tests in discriminating between specific IgM and IgG antibodies. The Brucella IgM and IgG flow assays are easy-to-perform and quick assays that can be used for the diagnosis of brucellosis. The flow assays are very useful, especially in rural settings where brucellosis is widespread and where well-equipped laboratories to perform the laboratory tests are not readily available.

Agglutination Tests↗
PubMed1995

Humoral defense of the nematode Ascaris suum: antibacterial, bacteriolytic and agglutinating activities in the body fluid.

Three humoral defense activities (antibacterial, bacteriolytic and agglutinating) were detected in the body fluid of the nematode Ascaris suum. Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) were more sensitive to the antibacterial activity than the Gram-negative bacteria (Escherichia coli). The antibacterial activity was heat stable and was lost by trypsin digestion. The molecular mass of the factor responsible for antibacterial activity was estimated as 6 kDa. The bacteriolytic activity against dried Micrococcus luteus was also detected. The bacteriolytic factor was 6-9 kDa in molecular mass, heat sensitive and trypsin sensitive. Both E. coli and glutaraldehyde-fixed trypsin-treated human A-type red blood cells were agglutinated in the body fluid. An analytical gel permeation HPLC revealed the agglutinating activity consists of at least two factors. Activities of both agglutinating factors were lost by heat treatment or trypsin digestion. The molecular masses estimated for the two agglutinating factors were 500 kDa and 25 kDa. Under experimental conditions, microbe-injection was not a prerequisite for the appearance of these defense activities.

Agglutination↗
PubMed2002

Surfactant protein D inhibition of human macrophage uptake of Mycobacterium tuberculosis is independent of bacterial agglutination.

The innate immune system in the lung is essential for controlling infections due to inhaled pathogens. Mycobacterium tuberculosis (M.tb) encounters components of the innate immune system when inhaled into the lung, but the consequences of these interactions are poorly understood. Surfactant protein D (SP-D) binds to and agglutinates M.tb bacilli, and reduces the uptake of the bacteria by human macrophages. In the current studies, we utilized a recombinant SP-D variant (CDM) that lacks the collagen domain to further characterize the interaction of SP-D with M.tb, and determine the effects of agglutination on bacterial uptake by human monocyte-derived macrophages. These studies demonstrate that the binding of SP-D and CDM to M.tb is saturable and inhibited by carbohydrate competition and Ca(2+) chelation, implicating the carbohydrate recognition domain in the interaction. Fluorescence microscopy reveals that dodecameric SP-D leads to agglutination of the bacilli, whereas the trimeric CDM does not, demonstrating that the multivalent nature of SP-D is essential for agglutination of M.tb. However, preincubation of M.tb with increasing concentrations of SP-D or CDM leads to a concentration-dependent reduction in the uptake of the bacteria by macrophages, indicating that agglutination does not play a direct role in this observation. Finally, the reduced uptake of M.tb by SP-D is associated with reduced growth of M.tb in monocyte-derived macrophages. These studies provide direct evidence that the inhibition of phagocytosis of M.tb effected by SP-D occurs independently of the aggregation process.

Agglutination Tests↗
PubMed1994

Diversity of agglutinating phenotype, cytoadherence, and rosette-forming characteristics of Plasmodium falciparum isolates from Papua New Guinean children.

The relationship between antigenic variation, cytoadherence, rosette formation, and the pathogenesis of malaria has led to great interest in the diversity of these properties in Plasmodium falciparum isolates from different communities. In this study, we extend previous investigations by delineating the spectrum of agglutinating phenotypes, adherence to C32 melanoma cells, human umbilical vein endothelial cells (HUVEC), CD36, and intracellular adhesion molecule-1 (ICAM-1), and rosette-forming ability of a group of 20 P. falciparum isolates from Papua New Guinean children. Agglutination phenotypes were determined by using both the children's convalescent serum and a panel of adult immune sera. The wide range of variant antigenic types in the community was demonstrated by the failure of the agglutination assays to identify any two isolates with the same agglutinating phenotype in this, the largest study of its kind. Comparison of agglutination profiles from fresh and cryopreserved isolates demonstrated the general acceptability of cryopreservation before testing, but cautioned that some isolates may undergo selection and phenotypic change during the process. Nineteen isolates were able to bind to at least one of the four ligands studied and showed marked variation in both avidity and specificity of binding. The purified proteins ICAM-1 and CD36 proved to be the most useful assay ligands for investigating field isolates, with 18 isolates binding to at least one protein and 14 to both. No correlation was found between the binding of isolates to any two ligands nor between the binding of a standardized inoculum and the level of the patient's presenting parasitemia. All isolates from the study group were found to form rosettes (at a mean rate of 14.6% of cultured trophozoites involved in rosettes). A lack of correlation between rosette formation and CD36 binding suggests that the previously reported role of CD36 as a rosette formation receptor may not be important for isolates from Papua New Guinea.

Agglutination Tests↗
PubMed2000

[Qualitative and quantitative comparison of three agglutination tests for detecting Toxoplasma gondii antibodies].

OBJECTIVE: To evaluate the diagnostic value of three agglutination tests used in three countries for detection of antibodies to Taxoplasma gondii. METHODS: A total of 288 human serum samples were assayed using modified agglutination test (MAT-1, using selfmade antigen), latex agglutination test (LAT, using Japanese Kit) and modified agglutination test (MAT-2, using French antigen). RESULTS: The positive rates of MAT-1 (> or = 1:20), LAT (> or = 1:32) and MAT-2 (> or = 1:20) were 9.7% (28/288), 8.9% (10/112) and 8.1% (17/210), respectively. No significant statistical difference was found among these positive rates (chi 2 = 0.392, P > 0.05). High agreements were found between MAT-1 and LAT (93.7%), LAT and MAT-2 (94.5%), and MAT-2 and MAT-1 (97.3%). Significant correlation were demonstrated in MAT-1 and LAT (r = 0.613), LAT and MAT-2 (r = 0.551), and MAT-2 and MAT-1 (r = 0.841), p < 0.001. CONCLUSION: The detection efficiency of the three agglutination tests is in good agreement and could alternatively be used for the diagnosis of toxoplasmosis.

Agglutination Tests↗
PubMedDate not supplied

Lysolecithin induced membrane alterations in thymocytes. Effects of lysophosphatides possessing adjuvant and immuno-suppressive activities on cell agglutination by concanavalin A.

The effects of lysolecithin and of 2 synthetic ether-desoxy lysolecithin analogs, containing alkyl residues of 16 or 12 carbon atoms, on the agglutination kinetics of calf and rabbit thymocytes by concanavalin A (Con A) were investigated. Unlike the natural lysolecithin, these synthetic analogs are resistant to metabolism by membrane associated enzymes. It was found that pretreatment of thymocytes with lysolecithin or with the C16-analog leads to slightly increased agglutination rates. The C12-analog, in contrast, significantly inhibits thymocyte agglutination by Con A. Moreover, a comparison of these results with lysophosphatide effects on the agglutinability of erythrocytes of various species revealed that the inhibitory effect of the short-chain phosphatide is rather specific for thymocytes. The finding that long- and short-chain lysophosphatides, which have previously been shown to react as adjuvants or immunosuppressants, respectively, induce adserve alterations in thymocyte membranes indicates that these substances may affect the immune response by changing the membrane properties of immune competent cells. Concerning the nature of these membrane alterations it was shown that lysolecithin did not affect the number of Con A receptors per cell nor the affinity of lectin binding. It is therefore concluded that the lysophosphatide induced alterations of Con A agglutinability can not be caused by an uncovering or covering of lectin-receptors.

Agglutination↗
PubMed1976

Effect of neuraminidase and papain treatment on lectin-induced agglutination of Novikoff tumor cells and assay of lectin receptor activity of the glycopeptides released from the cell surface by papain.

Lectins, plant proteins that bind specific saccharide determinants, have been utilized to examine the effect of neuraminidase digestion on the structure and/or expression of oligosaccharide moieties present at the periphery of Novikoff ascites hepatoma cells. Five lectins were utilized: concanavalin A (Con A), specific for alpha-D-manno- or alpha-D-glucopyranosyl residues; wheat germ agglutinin, specific for 2-acetamido-2-deoxy-D-glucopyranosyl residues; Ricinus communis agglutinin I (RCAI), specific for D-glucopyranosyl residues; R. communis agglutinin II (RCAII), specific for D-galacto- or 2-acetamido-2-deoxy-D-galactopyranosyl residues; and soybean agglutinin, specific for 2-acetamido-2-deoxy-D-galactopyranosyl residues. Neuraminidase treatment of Novikoff cells did not alter their agglutination by Con A or wheat germ agglutinin. Similar treatment produced only a 2-fold increase in their agglutination by RCAI but a 12-fold increase in their agglutination by RCAII, indicating that 2-acetamido-2-deoxy-D-galactopyranosyl residues become expressed upon neuraminidase treatment. This conclusion was confirmed by the observation that neuraminidase-treated Novikoff cells acquired agglutinability by soybean agglutinin. Binding studies using ferritin-conjugated RCAII indicated that neuraminidase treatment exposed cryptic cell surface receptors for RCAII. To ascertain the role of cell surface glycoproteins in lectin-induced agglutination of Novikoff cells, glycopeptides cleaved from the cell surface by papain were assayed for lectin receptor activity. The cell surface glycopeptides exhibited receptor activity for Con A, wheat germ agglutinin and RCAI but not for RCAII and soybean agglutinin. A cell surface macrosialoglycopeptide fraction, resolved by gel filtration and ion-exchange chromatography, possessed a major portion of the Con A and RCAI receptor activity.

Agglutination↗
PubMed1990

Serogroup determination of Neisseria meningitidis by whole-cell ELISA, dot-blotting and agglutination.

Two new methods for serogrouping of meningococci, whole-cell ELISA and dot-blotting, with monoclonal antibodies against serogroups A, B, C, Y and W135 were compared with slide-agglutination applying polyclonal sera. In addition to a panel of strains with previously determined serogroups by slide-agglutination, two strain collections of meningococci were studied: 1) 50 strains isolated from patients with systemic meningococcal disease in Norway during the winter 1987-1988; 2) 133 throat strains isolated from asymptomatic carriers over the same period. For the disease strains all three methods gave identical results, whereas some carrier strains which were non-agglutinable or polyagglutinable by slide-agglutination were serogroupable by the two other methods. All the systemic strains and about half of the carrier strains were serogroupable. We find that whole-cell ELISA and dot-blotting are specific, easy to read and more sensitive compared to slide-agglutination, but the former methods are at present limited by the availability of monoclonal antibodies against only serogroups A, B, C, Y and W135.

Agglutination Tests↗