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Effects of zinc and copper on adhesion and hemagglutination of Prevotella intermedia and Prevotella nigrescens.

This study investigated the mechanism of protein attachment to the surface of the putative periodontal pathogens Prevotella intermedia and Prevotella nigrescens in artificial gingival crevicular fluid, and ways to increase protein attachment to the bacterial cells. The effects of cations on protein attachment, bacterial adhesion, and hemagglutination were examined, and cation-binding components on both bacterial species were identified. The presence of cations, especially zinc, copper and cerium, increased attachment of human serum proteins to both bacterial species. In contrast, the presence of hydrophobic inhibitors or sugars had little effect. Protein attachment was reduced by heat treatment of the bacterial cells. Pretreatment of bacteria with human serum proteins inhibited adhesion of both species to buccal epithelial cells and hemagglutination. These effects were enhanced by the presence of zinc and copper during pretreatment. Using a chelating column, specific zinc- and copper-binding proteins were identified on the surfaces of both bacterial species.

Bacterial Adhesion↗

Hemagglutination and the closest distance of approach of normal, neuraminidase- and papain-treated erythrocytes.

By means of potential energy versus distance diagrams, derived from electrophoretic and surface tension data, the minimum distances of approach of normal (NOR) and of neuraminidase-treated (NEU) and papain-treated (PAP) human erythrocytes could be determined. The minimum distances between the actual cell membranes of two opposing red cells are: 184 A (NOR), 111 A (NEU), and 113 A (PAP), which agrees well with the fact that anti-D (Rho) antibodies of the IgG-class (which have a maximum distance of approximately 120 A between the two antibody-active sites) can hemagglutinate NEU and PAP cells, but are incapable of hemagglutinating normal D (Rho)-positive erythrocytes.

Antigen-Antibody Reactions↗

Indirect hemagglutination assay for antibodies to Escherichia coli lipopolysaccharides O157, O111 and O26 in patients with hemolytic uremic syndrome.

We examined sera from 10 patients with hemolytic uremic syndrome (HUS) and 51 controls, with and without diarrhea, for antibodies to Escherichia coli lipopolysaccharides (LPS) O157, O111 and O26 using the indirect hemagglutination (IHA) assay. A significant rise (to a titer of > or = 2560) in IHA antibody to O157 LPS was detected in eight of the 10 HUS patients, to O111 in two patients, one of whom showed concomitantly an antibody rise to O157, but to O26 in no patients. The IHA titers fell rapidly after the acute phase of the illness. Of the control sera 15 (29.4%) non-specifically agglutinated uncoated sheep red blood cells (SRBC) at a titer of > or = 80, six (3.9%) at > or = 320 and the maximum was 640. In spite of the relatively low level of non-specific agglutination the IHA appeared to be a useful screening method to identify verotoxin-producing E. coli infections at the early stage of HUS because the titers were clearly higher than non-specific agglutination and the assay is easy to perform and gives results quickly. Artificial carriers are being considered for use in place of SRBC to diminish the non-specific hemagglutination.

Antibodies, Bacterial↗

The hemagglutinating activities of Pseudomonas aeruginosa lectins PA-IL and PA-IIL exhibit opposite temperature profiles due to different receptor types.

The two Pseudomonas aeruginosa lectins PA-IL and PA-IIL, which are very similar in subunit size, composition and properties, but differ in carbohydrate specificity, were shown to exhibit opposite temperature profiles in hemagglutination tests. The galactophilic PA-IL, which interacts with the erythrocyte I antigen (together with B or P system antigens), resembles Ii system-specific 'cold hemagglutinins' (including antibodies and lectins of animals and plants) in low (4 degrees C) temperature optimum, while the hemagglutination by the fucose- and mannose-binding PA-IIL (like that of antibodies and lectins which do not bind to these antigens) increases on raising the temperature from 4 to 37 degrees C and even to 42 degrees C. The preferential production of both P. aeruginosa lectins at 28 degrees C and their much stronger interaction with enzyme (protease or sialidase)-damaged cells, as well as the lower temperature optimum (4 degrees C) of PA-IL-binding to the host cells, may be associated with the saprophytic rather than parasitic designation of this bacterium.

Adhesins, Bacterial↗

Hemagglutinating and adherence properties of Staphylococcus saprophyticus: epidemiology and virulence in experimental urinary tract infection of rats.

We studied hemagglutinating and adherence properties in Staphylococcus saprophyticus isolates originating from symptomatic urinary tract infections. 12/13 (92%) of strains adhered to Hep cells and 11/13 (85%) were able to agglutinate sheep erythrocytes. Adherence properties differed markedly between strains (P less than 0.0001). Two strains, one hemagglutinating and adherent and one negative for both properties were chosen for experimental urinary tract infections. Results indicate that presence of the hemagglutinin favours colonization of kidney tissue.

Animals↗

Immunological characterization and localization of a Porphyromonas gingivalis BApNA-hydrolyzing protease possessing hemagglutinating activity.

A monoclonal antibody (mAb-PC) was produced against a BA pNA-hydrolyzing protease possessing hemagglutinating activity (Pase-C) from Porphyromonas gingivalis. Other P. gingivalis BA pNA-hydrolyzing enzymes (Pase-B and Pase-S) did not react with this antibody. By ELISA or SDS-PAGE and Western immunoblotting analysis, mAb-PC recognized all P. gingivalis and P. endodontalis strains tested but did not recognize other members of the Porphyromonas genus nor other putative periodontopathogenic organisms. Pase-C, extracellular vesicles (ECV) and human strains of P. gingivalis showed two major immunoreactive bands (44 kDa and 40 kDa), whereas a different pattern was obtained with animal strains of P. gingivalis. Biotinylarginyl chloromethane, an irreversible inhibitor of trypsin-like proteases, did not affect the reactivity of Pase-C with mAb-PC on immunoblot. By reversed-phase electronmicroscopy following immunogold labeling, the antibody was shown to bind to the cell surface of P. gingivalis. mAb-PC inhibited the hemagglutinating activity of both P. gingivalis cells and ECV whereas a monoclonal antibody against LPS of P. gingivalis did not. These results suggest that Pase-C is located on the cell surface of P. gingivalis and may participate in erythrocyte binding.

Animals↗

Hemolytic and hemagglutinating activities of Prevotella intermedia and Prevotella nigrescens.

A total of 91 isolates of Prevotella intermedia or Prevotella nigrescens from subgingival sites were identified by PCR using primers specific for sequences of 16S rRNA. The hemolytic and hemagglutinating activities of the P. intermedia isolates exhibited significantly higher levels compared to those of the P. nigrescens isolates by quantitative analysis. The hemagglutinin gene (phg) was found in 23 of 26 P. intermedia isolates (88.5%), whereas it was found in only two of 44 isolates (4.5%) of P. nigrescens. The high hemolytic and hemagglutinating activities of P. intermedia may be involved in the pathogenicity of P. intermedia in the progression of periodontal disease.

Animals↗

Hemagglutination inhibition assay for gentamicin.

A rapid and simple hemagglutination inhibition test for measuring gentamicin concentrations in serum has been developed. Correlation coefficients for this assay with the radioimmunoassay and microbiological assay were r = 710 and r = 0.864, respectively. Measurements of gentamicin levels in serum by the three methods showed no statistically significant differences. The hemagglutination inhibition assay is fast, reliable, and relatively inexpensive, and should prove valuable for laboratory use.

Biological Assay↗

Effects of sublethal concentrations of antimicrobial agents on the hemagglutination, adhesion, and ultrastructure of pyelonephritogenic Escherichia coli strains.

The effects of trimethoprim, sulfadiazine, sulfamethoxazole, and sulfathiazole on the hemagglutination and adhesion by three Escherichia coli strains were studied. The strains were isolated from the urine of patients with acute pyelonephritis and carried P antigen-recognizing fimbriae (P fimbriae). At antimicrobial concentrations of 12.5 to 50% of the minimal inhibitory concentration, the ability of the bacteria to agglutinate human erythrocytes and to adhere to human buccal cells was markedly reduced. This reduction corresponded to a decrease in the number of P fimbriae per cell, suggesting that the antimicrobial agents decreased adhesion and hemagglutination by interfering with the formation of fimbriae. No major changes were observed in the outer membrane protein pattern of trimethoprim-treated cells, whereas freeze-fracture electron micrographs showed deorganization of both the cytoplasmic and outer membranes in bacteria opposed to sublethal concentrations of trimethoprim.

Adhesiveness↗

Hemagglutination and intestinal adherence properties of clinical and environmental isolates of non-O1 Vibrio cholerae.

Hemagglutination and intestinal adherence properties of non-O1 Vibrio cholerae were studied in vitro. No definite correlation between the cell-associated hemagglutinin titers and the intestinal adhesion indices was noted. Sugar- and glycoprotein-mediated inhibition data also indicated differences between the hemagglutination and adherence processes in respect to the receptor structures. Intestinal adherence of most V. cholerae strains could be inhibited to various extents by N-acetyl D-glucosamine. This observation provides a likely explanation for the ecological behavior of these organisms, which are known to associate themselves with chitinous (chitin:homopolymer of N-acetyl D-glucosamine) surfaces of zooplankton. The absence of any significant difference between the intestinal adherence indices of clinical and environmental isolates suggests that intestinal adhesion may be an essential but not sufficient prerequisite for colonization by and subsequent expression of pathogenicity of these microorganisms.

Animals↗

Aeromonas hydrophila isolated from food and drinking water: hemagglutination, hemolysis, and cytotoxicity for a human intestinal cell line (HT-29).

Aeromonas hydrophila isolated from food and drinking water was tested for pathogenicity by studying its hemolysis, hemagglutination, and cytotoxicity. Hemolysis, tested on erythrocytes from six different species, was more frequently seen with water isolates (64%) than with food isolates (48%). Hemagglutination was more frequently encountered with food isolates (92%) than with water isolates (73%). Cytotoxicity, evaluated on seven cell lines, was frequently observed with food isolates (92%) and with water isolates (73%). Heat treatment (56 degrees C for 10 min) of culture supernatant fluids inhibited the toxicity of some but not all toxin-producing isolates. Our results suggest that the human intestinal cell line HT-29 could be a useful complement for testing A. hydrophila exotoxins and for studying the enteropathogenicity of this species for humans.

Aeromonas hydrophila↗

Involvement of a sialic acid-binding lectin with hemagglutination and hydrophobicity of Flavobacterium psychrophilum.

Strains of Flavobacterium psychrophilum were studied for their ability to adhere and cause agglutination of erythrocytes and yeast cells. Strains of the serotype Th showed low or no hemagglutinating (HA) properties toward human, avian, bovine, and rainbow trout erythrocytes, whereas strains of serotype Fd and Fp(T) exhibited distinct HA properties. None of the strains was able to cause agglutination of yeast cells. Greater adherence specificity toward rainbow trout blood cells was seen for the HA-positive strains. Growth at 5 degrees C, compared to that at 15 degrees C, induced an increase in the hemagglutination of some strains. HA activities of F. psychrophilum were inhibited only by sialic acid (N-acetyl-neuraminic acid), heat treatment at 65 degrees C, and proteinase K treatment and not by any of seven other carbohydrates, periodate oxidation, or treatment with trypsin. The supernatant from washed bacterial cells also showed some HA properties. All strains were shown to be highly hydrophobic by the hydrophobic interaction chromatography test, although some contradictions to the results of the salt aggregation test (showing some strains as less hydrophobic) were seen. These results indicate that the aggregation of F. psychrophilum and erythrocytes depend on a lectin present on the surface of HA-positive F. psychrophilum strains and absent on HA-negative strains. This lectin reacts specifically with sialic acid. The adhesion differences observed for F. psychrophilum strains do not appear to correlate with the virulence but still provide insights into the interaction of F. psychrophilum and rainbow trout.

Animals↗

Enterotoxin B: serological assay in cultures by passive hemagglutination.

Bis-diazotized benzidine hemagglutination with Formalinized sheep erythrocytes was adapted to the rapid and specific detection of enterotoxin B in staphylococcal culture fluids. There was complete agreement between hemagglutination inhibition (HI) and gel diffusion in detecting 8 enterotoxin B-positive cultures from a total of 68 staphylococcal cultures tested. The sensitivity of HI equals or exceeds that of gel diffusion. Also, results can be obtained in several hours, even with extremely low concentrations of enterotoxin, whereas it may require 24 hr to 1 week to obtain comparable results with gel diffusion. Problems associated with the presence of potent hemagglutinins for sheep erythrocytes in several staphylococcal culture fluids are discussed.

Amines↗

Production of rubella hemagglutinating antigen in suspension cultures.

Rubella virus specific hemagglutinating antigen was prepared in the fluid phase of suspension cultures. Systems employing baby hamster kidney culture adapted inocula, nonadapted inocula, and cells derived from long-term infected suspension cultures were evaluated. Optimal specific hemagglutinating titers were obtained when kaolin-treated fetal bovine serum was used in the media and when the incoulum had previously been adapted in a suspension culture system. When cultures derived from long-term infected suspension systems were studied, the number of daily harvests in which acceptable titers were present was prolonged. However, titers were generally higher in suspension systems employing cells which had recently been infected.

Animals↗

Induction of an inhibitor of influenza virus hemagglutination by treatment of serum with periodate.

Serum is commonly treated with potassium periodate to destroy nonspecific inhibitors of influenza virus hemagglutination. We have observed, however, that such treatment of serum without pre-existing inhibitor produced high titers of inhibitor against certain strains of influenza virus. Inhibitor was induced in the serum from several different animal species but not in hamster or mouse serum. Periodate treatment of serum albumin, fraction V, from several animals, including man, creates this inhibitor. Our data indicate that the inhibitor induced in the serum of various animal species differs in its mechanism of induction and in its resistance to receptor-destroying enzyme and trypsin. Hemagglutination by B/Singapore/3/64, B/Colorado/2/65, B/Georgia/1/65, and B/Massachusetts/3/66 strains of influenza virus is inhibited by periodate-treated human serum at dilutions as high as 1:5,120. The routine use of periodate treatment of serum in diagnostic and surveillance studies of influenza virus infections is not recommended.

Animals↗

Indirect hemagglutination with Mycoplasma antigens: effects of pH on antigen sensitization of tanned fresh and formalinized sheep erythrocytes.

An investigation of the influence of different factors affecting the sensitivity of the indirect hemagglutination test has been performed with antigens of four mycoplasmas isolated from sheep or goat. Tanned erythrocytes of sheep, fresh and formalinized, were sensitized with the above antigens. It was demonstrated that, with formalinized erythrocytes, the sensitivity was increased by 50 to 100 times when the sensitization was done at a low pH level. The pH level was unimportant for sensitizing fresh erythrocytes. The greatest sensitivity of the indirect hemagglutination test was obtained with fresh rather than formalinized erythrocytes. Three different types of antigens were used, and the most suitable antigen was found to be the supernatant fluid from an ultrasonically treated centrifuged Mycoplasma suspension.

Animals↗

Comparison of indirect hemagglutination and immunodiffusion tests for detecting type II leukosis (Marek'ine.

The indirect hemagglutination and immunodiffusion tests were compared for detection of antigen and antibody to JM strain of leukosis virus infection between S- and K-line chickens. The indirect hemagglutination test was more sensitive than the immunodiffusion test for detecting the smallest amount of viral antigen and corresponding antibody in the plasma of infected chickens. The Cornell S-line had higher levels of antigen and antibody as compared with the Cornell K-line during the 20-week experimental period.

Administration, Oral↗

Reactions of purified hemagglutinating antigens of flaviviruses with 19S and 7S antibodies.

The rapidly sedimenting hemagglutinin (RHA) representing the purified virion and the slower-sedimenting hemagglutinin (SHA) of several flaviviruses were separated and used in hemagglutination inhibition tests with the 19S (immunoglobulin M) and 7S (immunoglobulin G) immunoglobulin fractions of rabbit antisera, prepared against purified viral antigens or against crude virus pools. The antibody specificity in tests with RHA was identical to the specificity in those employing SHA. 7S antibody cross-reacted broadly with all flavivirus antigens, whereas 19S antibodies were relatively specific in cross-reactions among flaviviruses (RHA or SHA). SHA was consistently inhibited by antibody to a greater extent than RHA. Anti-envelope protein, anti-RHA antibodies and anti-SHA antibodies were unable to discriminate between RHA and SHA. It was concluded that the relative amounts of RHA or SHA in crude hemagglutinin preparations have no influence on the result of hemagglutination inhibition tests with flaviviruses.

Animals↗