Immunological characteristics of the protein antigens of the family Neisseriaceae. II. The importance of an immunochemical analysis of the protein complexes for a study of taxonomy problems]

The study of antigenic interrelations in the family Neisseriaceae resulted in the isolation of 2 main immunologically separated variants of protein complexes: the first variant was characteristic of nonpathogenic and pathogenic species of the genus Neisseria as well as of 7 taxonomically undefined Neisseria species (N. lactamicus, N. cuniculi, N. ellongata, N. ovis, N. animalis, N. cinerea, N. canis) and Gemella haemolysans; the second variant was represented by the genera Branhamella and Acinetobacter. N. caviae and 3 out of 14 Neisseria strains of undefined species had no common antigens with the genera Neisseria and Branhamella. The importance of the immunotyping of protein complexes for studying the problems connected with the taxonomy of the family Neisseriaceae was considered.     

Neuraminidase activity in representatives of the genus Francisella]

In two Francisella species (F. tularensis and F. novicida) neuraminidase activity, heretofore unknown, was detected. The enzyme exhibited specificity with respect to the substrates used in the investigation, neutralizing natural mucins, but not other compounds (glycoproteins and glycoproteins). All F. tularensis strains were found to have enzymatic activity irrespective of their subspecies, but neuraminidase activity was higher in the strains belonging to the American subspecies. Experimentally obtained F. tularensis noncapsular variants possessed higher neuraminidase activity than the capsular parent strains. The conclusion on the possible role of this enzyme in F. tularensis colonization of the host body was made.     

Neuramininase activity of the representatives of the genus Yersinia]

The authors demonstrated the presence of neuraminidase in Past. pestis. Optimal conditions for its formation and detection were chosen. Extracellular form of neuraminidase was revealed. An increase of cultivation temperature led to the elevation of the neuraminidase activity in Past. pestis cells. Neuraminidase was revealed in bacteria affiliated to Past. pestis (causative agents of pseudotuberculosis and Y. enterocolitica).     

Superoxide dismutase activity in representatives of the genus Francisella]

Superoxide dismutase (SOD) activity has been registered in representatives of the genus Francisella. The electrophoretic mobility of the enzyme and a number of its isoforms in F. tularensis are linked with the subdivision of this species into several subspecies. Avirulent and noncapsular variants of F. tularensis are characterized by a higher SOD activity than the initial virulent strains. Attempts to detect catalase activity in F. tularensis have failed.     

Comparative characteristics of penicillin-binding proteins of representatives of the genus Streptomyces

Penicillin-binding proteins (PBPs) in Strepomyces strains producing clavulanic acid and beta-lactamase and in Streptomyces strains not producing these compounds were studied comparatively. In S. clavuligerus, the organism producing clavulanic acid, there were detected 3 PBPs in the membrane fraction. S. griseus, the organism producing beta-lactamase, contained 6 PBP. In S. cacaoi and S. olivaceus, organisms producing neither beta-lactams nor beta-lactamase, there were detected 5 and 4 PBP, respectively. The set of the PBP in the organism producing clavulanic acid varied during fermentation. In a variant of S. clavuligerus isolated after protoplasting of the mycelial cells and their regeneration the content of the electrophoretically most mobile PBP lowered. The PBP of S. clavuligerus did no show any high affinity to other beta-lactams such as methicillin and ampicillin tested as competing agents of 14C-benzylpenicillin.     

Antigenic characteristics and various biological properties of glycoprotein from Neisseria meningitidis of serological group A]

It was shown that the antigen determining the group specificity of meningococcus belonging to serological group A was of mixed polysaccharide-protein nature. Carbohydrate component is responsible for the interaction with the group-specific antibodies in this antigen. Glycoprotein can be isolated both from the cells and from the culture fluid where it passes during the N. meningitidis cultivation in fluid nutrient medium. The described antigen possesses no properties of endotoxin.     

Antigenic and molecular heterogeneity of the transferrin-binding protein of Neisseria meningitidis

The transferrin-binding protein in 35 Neisseria meningitidis isolates was examined using a binding assay involving 125I-transferrin. The results show that most strains have a binding protein with a Mr between 78 kDa and 83 kDa; only 4 strains had a binding protein with a Mr of about 68 kDa. The side of the protein appears unrelated to the serogroup or serotype of the organism. Using antibodies raised to whole cells of N. meningitidis grown under iron restriction we show also that considerable antigenic heterogeneity exists amongst the transferrin-binding proteins. This makes it a less than promising vaccine candidate antigen, although conserved antigenic domains are now being sought.     

Cross-reacting intraspecific antigens of Neisseria meningitidis. I. The isolation, immunochemical and serological characteristics of the cross-reacting antigens of N. meningitidis serogroup A

New data on the cross-reacting antigen of N. meningitidis, serogroup A, are presented. A complex of antigens has been isolated by treatment with tryptone X-100, ethanol precipitation and the subsequent treatment with trichloroacetic acid. The immunological analysis of the isolated preparation has shown that the proteinaceous part of the biopolymer contains 7 polypeptide fragments; of these, one fragment with a molecular weight of 31000 daltons has been found to constitute 49, 15% of all polypeptide fragments. The evaluation of the serological properties of this preparation in the precipitation test and the passive hemagglutination test has revealed that the preparation contains various cross-reactive antigenic determinants. Polyvalent erythrocyte diagnosticum obtained on the basis of this preparation permits the detection of antibodies to meningococci irrespective of their serogroup.     

Antigenic polymorphism of the LamB protein among members of the family Enterobacteriaceae.

In this study we demonstrate that most members of the family Enterobacteriaceae possess a maltose-inducible outer membrane protein homologous to the LamB protein of Escherichia coli K-12. These proteins react with polyclonal antibodies raised against the LamB protein of E. coli K-12. We compared the antigenic structure of the LamB protein in members of the family Enterobacteriaceae with six monoclonal antibodies raised against the LamB protein of E. coli K-12. Four of them reacted with epitopes located at the outer face of the membrane, and two reacted with epitopes located at the inner face of the membrane. A great degree of variability was observed for the external epitopes. Even in a single species, such as E. coli, an important polymorphism was present. In contrast, the internal epitopes were more conserved.     

Immunologic study of artificial complex antigens obtained from P. aeruginosa lipopolysaccharides]

Artificial antigens were obtained on the basis of the polysaccharide component of P. aeruginosa complexed with an indifferent protein. Immunological study indicated that the specific polysaccharide of P. aeruginosa lipopolysaccharide contained two structures, high molecular and low molecular, having qualitative and quantitative differences in their hydrocarbon composition. Artificial complex antigens possessed serological and immunogenic properties, the low molecular polysaccharide fraction complexed with protein having less pronounced serological and immunogenic activity than polysaccharide and the high molecular fraction complexed with protein. Antificial complex antigens exerted no protective effect in generalized P. aeruginosa infection in rats.     

Triploidy in hybrids of carp with other representatives of the Cyprinidae family]

As a result of remote hybridization of carp (Cyprinus carpio L.) with the representatives of certain other subfamilies of Cyprinidae a few viable F1 hybrids were obtained for the first time. These hybrids proved to be allotriploids. In the cross Cyprinus carpio L. female X Hemiculter eigenmanni (Jord. et Metz.) male the rate of survival of this year's brood was 0,5% of the fertilized eggs and 3n=128; whereas in the cross Cyprinus carpio L. male X Ctenopharyngodon idella (val.) female the rate of survival was 0,008%, while the chromosome number (3n) varied from 124 to 128. The chromosome number of non-viable E1 hybrids derived from this cross was intermediate (2n=76). The diploidization of the maternal chromosome set was spontaneous, since no stimulating agents were used to induce it. It is assumed by the authors that it is the tetraploid nature of carp that affords the possibility of the initiation of allotriploids.