Agglutinating activity was widely distributed among 101 Vibrio anguillarum strains of different origin and three Vibrio ordalii strains from salmonids. The spectrum of cells which were agglutinated comprised yeast cells and human (type O), poultry, guinea pig, and trout erythrocytes, whereas ovine, bovine, and tanned bovine erythrocytes were not affected. Mannose-sensitive hemagglutination, man...

We have evaluated for their potential use in the routine clinical laboratory enzyme-linked immunosorbent assays (ELISA) for human thyroglobulin antibodies (hTg-Ab) and microsomal antibodies (M-Ab). Results are expressed in terms of an "ELISA Index," based on comparison with a laboratory standard. The specificity of both ELISA assays is shown by dose-dependent inhibition of the hTg-Ab and M-Ab a...

The hemagglutination (HA) activity of Escherichia coli was enhanced by subminimal inhibitory concentrations (sub-MICs) of ampicillin. One half of the MIC of ampicillin caused a bacterial filamentation and diminished bacterial piliation (as observed by light and electron microscopies) as well as an increase of HA activity. HA activity, however, decreased after separation of ampicillin-treated ba...

To study the hemagglutinin of Fusobacterium nucleatum, methods were sought to solubilize and purify this component. When cells of F. nucleatum were ruptured by passage through a French press, the fragments lost virtually all ability to agglutinate human erythrocytes. Extraction of the fragments with 2% Triton X-100 for 30 min at 22 degrees C restored hemagglutinating activity (HA). Hemagglutina...

When purified polyoma virus is exposed to 0.01 M dithiothreitol in the presence of 0.2 M Na(2)CO(3)-NaHCO(3) (pH 10.6) at 0-4 degrees C, the capsids are rapidly disrupted to protein subunits of capsomere size, as judged by density gradient centrifugation, sedimentation equilibrium centrifugation, and electron microscopy. Hemagglutination activity and infectivity of disrupted virus are reduced t...

Various concentrations of pig, guinea pig, chicken, and turkey erythrocytes (RBCs) were cryopreserved and compared with fresh RBCs in hemagglutination and hemagglutination inhibition tests. Hemagglutination and hemagglutination inhibition titers obtained with cryopreserved or fresh RBCs from the same donor differed by not more than one twofold dilution. RBCs cryopreserved at a concentration of ...

The incidence and height of antibody titers to colon, assayed by indirect hemagglutination with a heat stable colon extract from germ free rats, is significantly higher in sera from patients with ulcerative colitis than in those from healthy controls or from patients with amebic liver abscess or dysentery. While sera from ulcerative colitis patients and controls are indistinguishable in regard ...

In the foregoing study (1), infectivity titrations were employed to measure the concentration of influenza virus in portions of chorioallantoic membrane in culture medium containing 2,5-dimethylbenzimidazole. This highly sensitive procedure made possible an examination of the effects of this inhibitory compound (2) on the initial phases of multiplication of the virus; i.e., the first reproducti...

Porphyromonas gingivalis is a bacterium frequently isolated from chronic periodontal lesions and is involved in the development of chronic periodontitis. To colonize the gingival crevice, P. gingivalis has to adapt to environmental stresses. Microbial gene expression is regulated by transcription factors such as those in two-component systems and extracytoplasmic function (ECF) sigma factors. E...