Subspecies-specific haemagglutination patterns of fimbriated Bacillus thuringiensis spores.

Electron microscopy revealed fimbrial appendages (pili) of three types on the surface of Bacillus thuringiensis spores. Fimbriated spores induced mannose-resistant agglutination of rat, guinea pig and/or chicken red blood cells. Each haemagglutination pattern correlated with the subspecies of a given B. thuringiensis strain, rather than with its flagellar serotype. Fimbriation and haemagglutination patterns of B. thuringiensis spores are considered to be of possible taxonomic value.

[A method for assessing the microfloral status of the human intestines by the quantity of adhesion-active bacteria and by the type of adhesins]. / Sposob otsenki sostoianiia mikroflory kishechnika cheloveka po kolichestvu adgezivno-aktivnykh bakterii i tipu adgezinov.

The method for the evaluation of the state of intestinal microflora in the diagnosis of enteric diseases by the determination of the number of actively adhesive bacteria and the type of adhesins in the primary culture of human microflora has been developed. This method permits the simultaneous analysis of all colonies grown in a given Petri dish by the sign of their adhesion, which eliminates the possibility of mistakes due to the occasional choice of colonies, as it may happen in the agglutination test. The time necessary for the study of adhesive properties is reduced, as the result is evaluated as early as on day 2 after the inoculation of the seed material. It is also of importance that the method is simple in realization, needs no special equipment, preparation and staining of the material. To determine the type of adhesins, a series of identical inoculations may be obtained by replication with the use of red blood cells of different animals. The proposed method may be used for the confirmation of the etiological role of enterobacteria as evidenced by the presence of high percentage of their actively adhesive colonies.

[The role of adhesin in the polymeric structure of Vi-antigen]. / Rol' adgezina v polimernom stroenii Vi-antigena.

Samples of Vi-antigen subjected to hydrolysis of different duration have been studied. As revealed in this study, 12-hour hydrolysis causes the depolymerization of the preparation. The fragments thus obtained have been found to possess Vi-specificity. The polymeric form of Vi-antigen contains adhesin differing in specificity from Vi-determinant. This component is absent in the low-molecular fraction of Vi-antigen. Adhesin is the binding element of the molecule of Vi-antigen and ensures its polymeric structure.

[Protective properties of Vi-antigen preparations as dependent on their adhesin content]. / Protektivnye svoistva preparatov Vi-antigena v zavisimosti ot soderzhaniia v nikh adgezina.

Adhesins contained in the preparation of Vi-antigen have been found to enhance its immunogenic and protective properties. In the preparations of Vi-antigen obtained from Salmonella typhi and Citrobacter freundii the presence of two antigenic determinants has been revealed. One of them is associated with the Vi-receptor and the other determinant, with adhesin. Both determinants take part in the protection of mice from Salmonella infection.

[Use of the coagglutination reaction of yeast-like Candida maltosa fungi for detecting fimbriae in intestinal bacteria]. / Ispol'zovanie reaktsii koaggliutinatsii drozhzhepodobnykh gribov Candida maltosa dlia vyiavleniia fimbrii u kishechnykh bakterii.

The capacity of nonpathogenic yeast-like C. maltosa strains to coagglutinate Escherichia coli has been studied. C. maltosa cells have also been shown to coagglutinate E. coli possessing mannose-sensitive adhesins in a wide range of their concentrations (5-140 bacterial cells per C. maltosa cell). Strains belonging to types CFA/I and CFA/II with fimbriae, similarly to their corresponding paired genetically related strains without these adhesins, are practically incapable of agglutinating C. maltosa cells, while strains K88 and B41 react with them. The reaction occurs at a concentration of 9.5-37.0 and 38.0-55.5 bacteria respectively per C. maltosa cell and is not inhibited by 1% d-mannose. The suggestion that C. maltosa cell surface glycoproteins contain not only receptors for E. coli fimbriae, type I, but also components similar in their structure to receptors specific to the mannose-resistant adhesins of strains K88, K99 and 41, has been confirmed by hemagglutination inhibition with C. maltosa surface antigens as inhibiting agents.

Using SIB and API kits to identify and biotype enterobacteria of different origin.

A collection of 26 Enterobacteriaceae reference strains provided by Reference Centres in Moscow (USSR) and Copenhagen (Denmark) as well as a collection of 660 freshly isolated cultures of Gram-negative bacteria of different origin were investigated using SIB indicator systems manufactured at the Gorky Institute of Epidemiology and Microbiology (USSR) and API-20E, Rapid-20E and API-10S kits (API, France) with the aim of species determination. In analyzing freshly isolated cultures, API-20E, API-10S and SIB-B kits proved to be of approximately equal efficiency, whereas the Rapid-20E system enabled species identification in no more than 78% of the tested cultures. In a model biotyping of 284 E. coli cultures of different origin, SIB-B and API-20E kits in combination with the Analytical Profile Index enabled sufficiently rapid and standard identification of Enterobacteriaceae biovars.

[Vi antigen and microbial adhesion factors. The detection of adhesins in commercial Vi antigen preparations]. / Vi-antigen i faktory adgezii mikrobov. Vyiavlenie adgezinov v kommercheskikh preparatakh Vi-antigena.

Enterobacterial Vi-antigen inhibit the Escherichia coli-induced agglutination of red blood cells of guinea pigs and other animals, which indicates that Vi-antigen contains the admixture of adhesion associated with type I pili. The amount of adhesion contained in Vi-antigen can be determined from the degree to which its hemagglutination-inhibiting effect is manifested.