[Pertussis toxin and cross-reactive antigens in dynamics of Bordetella pertussis cultivation].

Cultures of Bordetella pertussis from phases of exponential growth, retarded growth and from stationary phase were obtained during periodic dynamic cultivation. Preparations for intravenous immunization of rabbits were made from these cultures. Levels of IgG to pertussis toxin, cell walls preparations from 12 bacterial species, 4 organo-specific antigens, and 7 organospecific human antigens were measured in obtained sera. It was shown that higher levels of IgG to pertussis toxin were found in sera of rabbits immunized with cultures from exponential growth phase whereas decrease of this level in 8 times was observed in sera of rabbits immunized with cultures from retarded growth phase or end of stationary phase. After immunization with culture from exponential growth phase increase of IgG levels to cross-reactive antigens was not observed compared to levels of these antibodies in control sera obtained before immunization. After immunization with cultures from retarded growth phase or end of stationary phase increase of IgG levels to preparations of cell walls of Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, to denaturated DNA, elastin, and renal and liver microsomal fractions was detected compared to control sera. Described data can substantiate usefulness of obtaining the most specific diagnostic sera and test-systems using cultures of B. pertussis from the phase of exponential growth.

[Bordetella pertussis agglutinogens in cultivation dynamics].

Bordetella pertussis growth phases during homogenous batch dynamic cultivation in the liquid medium as well as during the static cultivation on the solid medium were established. The maximal activity of agglutination reaction with antisera to B. pertussis agglutinogens 1, 2, and 3 was detected in bacterial culture at the end of exponential phase of growth. The activity of agglutination reaction decreased when cultures in stationary and death phases were used. During transition from exponential to death phase level of antibodies to agglutinogen 2 decreased by4 - 32 times. 2 - 4-fold decrease of antibodies level was observed when antiserum to agglutinogen 3 was used. Activity of agglutination reaction with antiserum to agglutinogen 1 was high and did not depend from phase of growth. When polyvalent antiserum to B. pertussis was used 4-fold decrease of antibody titers was observed in parallel with change of growth phases. Sera from rabbits immunized with B. pertussis cultures from the middle of exponential growth phase, the end of this phase, and begin of the death phase had high (maximal) level of agglutinating antibodies (6400), which was detected on 101 day after immunization with the former culture and on 31 day after immunization with either of the two latter cultures. To the end of experiment (292 day) titers decreased to 800, 3200, and 1600 respectively. These findings confirm an advisability of use of exponential growth culture for immunization of rabbits in order to obtain highly active diagnostic antisera to B. pertussis.

[Perspectives for development of polyvalent meningococcal vaccine].

Experimental whole-culture oral polyvalent meningococcal vaccines against serogroups A, B and C consisting of three monovalent components in different proportions have been developed and evaluated. Kinetics of IgG response to meningococcal antigens (outer membrane proteins, polysaccharide, lypooligosaccharide of these serogroups) in sera of rabbits immunized orally with these preparations was measured. Sharp rise of IgG levels (on 2 - 3 orders) compared to baseline has been detected as well as persistence of high titers during the observation period (322 days).

[Level of IgG antibodies to bacteria of 12 species in the blood sera of rabbits, immunized with preparations obtained from Neisseria meningitidis, grown under the stress conditions].

The blood sera of rabbits, immunized with preparations obtained from N. meningitidis of serogroups A, B or C, cultivated under the stress conditions, were studied. These sera were found to contain IgG antibodies not only to N. meningitidis antigens, but also to the bacterial antigens of 12 species. The sera of rabbits, immunized with meningococcal preparation of serogroup A, were found to have the elevated levels of IgG antibodies, in comparison with the control, to the antigens of 3 other bacterial species; the blood sera of rabbits, immunized with meningococcal preparation of serogroup B, were found the elevated levels of IgG antibodies to the antigens of 11 other bacterial species; and the blood sera of rabbits, immunized with meningococcal preparation of serogroup C, to the antigens of 9 other bacterial species. The study of serogroup B meningococci, used as an example, revealed the influence of the growth phase of the culture on the content of cross-reacting antigens. Their greatest amount was determined at the stationary phase when the stressor effect on the culture reached its maximum and their least amount, at the exponential phase when the stressor effect on the culture was minimal. It was, therefore, found to be expedient to obtain immunodiagnostic and test systems from N. meningitidis cultures, grown to middle of the exponential phase of growth.

[Influence of the growth phase of Neisseria meningitidis on the accumulation of antigens cross-reacting with human antigens in the culture].

The content of N. meningitidis antigens with epitopes cross-reacting with human antigens was studied in the dynamics of the meningococci cultivation. The absence of these antigens in the culture in the middle of the exponential phase of growth and their presence in the culture at the end of the stationary growth phase of growth were shown. Thus the expediency of using the culture in the middle of the exponential phase of growth for obtaining meningococcal (serogroups A, B and C) vaccines was demonstrated. The trend, found to be promising for the development of immunologically safe vaccines which contained no antigens having common epitopes with human antigens, was determined.

[Humoral immune response in animals after the oral administration of group C meningococcal whole-culture preparation]. / Gumoral'nyi immunnyi otvet zhivotnykh na peroral'noe vvedenie meningokokkovogo serogruppy C tsel'nokul'turnogo preparata.

Experimental data giving grounds for the development of a new group C meningococcal whole-culture preparation for oral administration are presented. The study revealed that the use of the controlled cultivation of group C meningococci and a nutrient medium with definite chemical composition in combination with the "soft" method of the isolation of the whole-culture preparation ensured the preservation of polysaccharide, outer membrane protein and lipooligosaccharide in a native state, as well as retaining their full antigenic value, in the preparation. The oral immunization with the whole-culture preparation stimulated the multiple elevation of the level of hemagglutinating and IgG antibodies to these antigens and their prolonged preservation in the blood of immunized animals.

[Antigenic activity of oral whole-culture meningococcal serogroup B vaccine]. / Antigennaia aktivnost' peroral'nogo tsel'nokul'tural'nogo preparata meningokokkov serogruppy B.

The whole-culture vaccine preparation of Neisseria meningitidis, serogroup B, obtained by cultivation in a computer-controlled bioreactor, was studied. The preparation was shown to contain antigenically active polysaccharide, outer membrane proteins, as well as lipooligosaccharide, faintly pyrogenic and with low toxicity. After oral immunization of rabbits a multiple increase in the levels of IgG antibodies to these antigens in their blood serum was noted during the period of observation (303 days).

[Immune response to the oral administration of a new meningococcal preparation, serogroup A, under experiment]. / Immunnyi otvet na peroral'noe vvedenie novogo meningokokkovogo preparata serogruppy A v éksperimente.

In the experiment on rabbits immune response to the oral administration of a new Neisseria meningitidis whole culture preparation, serogroup A, was demonstrated. The preparation was based on the acetone fixed culture, grown by the continuous flow method under a computer-controlled constant level of oxygen. The immunological activity of the preparation was demonstrated. In the blood sera of rabbits examined by immunoenzyme assay and the passive hemagglutination test, a multiple increase in the content of hemagglutinating and IgG antibodies to polysaccharide, outer membrane proteins and lipooligosaccharide was noted, their content remaining at a high level for 303 days (the term of observation). The oral immunization with the preparation protected mice infected with N. meningitidis live culture, serogroup A.

[Antigen properties of oral intake whole-culture preparations from Neisseria meningitides of serogroups A, B and C]. / Antigennye svoistva peroral'nykh tsel'nokul'tural'nykh preparatov iz Neisseria meningitidis serogrupp A, B i C.

A new technology of deriving the whole-culture peroral meningococcal mono-vaccines of serogroups A, B and C from the acetone-inactivated cultures was experimentally substantiated. The latter cultures were obtained through computer-aided continuous-flow cultivation of Neisseria meningitides of the above serogroups in the bioreactor with a synthetic nutrient medium. The whole-culture meningococcal mono-preparation of 3 serogroups comprised a complete set of antibodies, i.e. polysaccharides (PS), external membrane proteins (EMP) and lipopolysaccharides (LPP), in their native condition. High levels of IgG to PS, EMP and LPP were detected in blood sera of rabbits, which had been perorally immunized by the above preparations; such high levels persisted for a long time (303 days--observation period). It is noteworthy, that in accumulating of IgG to all investigated antigens of meningococcus of serogroups A and C, the optimal doses of whole-culture peroral monovaccines did not exceed the culture doses used to derive the hyper-immune sera at intravenous immunization.

[Acidic stress in bacteria]. / Kislotnyi stress u bakterii.

Information on acidic stress in bacteria, studied not only on the phenomenological, but also molecular and genetic levels, are systematized. Acidic stress in bacteria, appearing as the result of the acidification of the medium, is characterized by many events on the level of gene regulation. An increased expression of some genes and a decreased expression of others result in growth deceleration, quantitative and qualitative changes in the synthesis of proteins. Some of the newly synthesized proteins ensure the survival of bacteria in a medium with higher acidity and their protection from other stresses. The applied importance of acidic stress is relevant to some aspects of biotechnology, immunobiology and medicine.

[Killer toxins of clinically important yeasts]. / Killernye toksiny klinicheski znachimykh drozhzhei.

The review deals with some theoretical and applied aspects of the capacity of yeasts for synthesizing toxins. Similarly to antibiotic formation in micellar fungi and actinomycetes and the synthesis of bactericins in prokaryotes, yeast cells also have their mechanism of protection from other microorganisms. The substances, essentially of the same nature, synthesized by yeast are known for more than 30 years as mycocins or killer toxins. They are proteins or glycoproteins, active mainly against yeast microorganisms. Mycocins are not active against bacteria and protozoa exhibiting only fungicidal or fungistatic action. The formation of mycocins may be determined by nucleus or plasmid DNA. In this review information on killer toxins produced by clinically important yeasts of the genera Candida, Cryptococcus and Rhodotorula is systematized.

[Effect of metal oxides on the growth, hemolytic and serologic properties of Klebsiella pneumoniae]. / Vliianie oksidov metallov na rost, gemoliticheskie i serologicheskie svoistva Klebsiella pneumoniae.

Silicon, dysprosium, germanium, yttrium, iron, cobalt, samarium, lutecium oxides, as well as the mixture of 8 metal oxides, at a concentration of 20 g/l were found to produce a stimulating or inhibiting effect on the growth of K. pneumoniae strains 204 and K-9. Silicon, dysprosium, germanium and yttrium oxides were shown to stimulate the growth of K. pneumoniae strain 204. Iron, cobalt, samarium and lutecium oxides, as well as the mixtures of all oxides under study, inhibited the growth of this strain. Silicon, samarium and lutecium oxides produced no effect on the growth of K. pneumoniae strain K-9; at the same time germanium and yttrium oxides stimulated the growth of these bacteria, while dysprosium, iron, cobalt oxides, as well as the mixture of all oxides, inhibited their growth. The presence of metal oxides did not change the serological activity of the cultures of both strains growing old, i.e. by 24 hours of their growth. The addition of silicon, germanium and iron oxides to the culture medium increased the hemolytic activity of K. pneumoniae strain K-9 seven to ninefold in comparison with the control grown in a synthetic nutrient medium without metal oxides. The comparison of these two strains (K-9 and 204) revealed that K. pneumoniae strain K-9 possessed greater hemolytic activity.

[Common stressor proteins in bacteria]. / Obshchie stressornye belki u bakterii.

Research data on common stressor proteins of bacteria obtained during recent 10 years are updated and analyzed. Bacteria of one and the same species were shown to give similar response to the action of different stressors; the main stressor proteins of different bacteria appeared to be homologous; bacteria have cross protection from different stressors. In addition, some common stressor proteins of bacteria were found to be homologous with human antigens that is of great importance for immunobiotechnology.

[Effect of metal ions on Escherichia coli NAT 99-50R penicillin acylase production]. / Vliianie ionov metallov na produktsiiu penitsillinatsilazy Escherichia coli NAT 99-50R.

The processes of growing E. coli NAT 99-50R in a synthetic nutrient medium containing metal salts (iron nitrate, lutecium nitrate or cerium nitrate) were carried out. As shown in experiments, the addition of metal salts at different concentrations into the medium produced different impact on the penicillinase activity of the culture. This activity increased 7- to 10-fold when the bacteria were grown in a synthetic medium with iron nitrate added at a concentration of 0.0001% or with lutecium nitrate added at a concentration of 0.01%.

[Cold shock in bacteria]. / Kholodovoi shok u bakterii.

Various species and genera of bacterial show the same responses to low temperature. Cold induces cold shock genes, by causing significant changes in the regulation of protein synthesis. The synthesis of major proteins in the microbial cell is suppressed. However, there is synthesis of a great deal of new proteins, the so-called cold shock ones. The chief protein in this family is E. coli CspA that activates the translation of other cold shock genes and negatively regulates the expression of its own gene. E. coli CspA homologies were identified in many bacteria. They can be also identified in other microorganisms, including the pathogens of infectious diseases. This can be attributable to the presence of common antigens in different bacteria. The data presented should be borne in mind in identifying bacteria and in designing immunodiagnostic agents if there is a culture cooling stage in their technology.

[Starvation of bacteria as a stress caused by substrate limitation]. / Golodanie bakterii--stress, obuslovlennyi limitom substrata.

The analysis of literature has made it possible to establish the priority of Russian research works made in the 1970-80s on the subject of starvation of bacteria caused by substrate limitation as well as research made in the 1990s concerning starvation of bacteria. This state is characterized by synthesis of additional proteins, so-called stress proteins, which not only ensure the survival of bacteria under the conditions of substrate limitation, but also protect them from a number of other stressors. In spite of the fact that genetic mechanisms regulating the synthesis of some stressor proteins have been revealed their significance for microbiological technology is not yet clear.

[Stress-inducible bacterial proteins and virulence]. / Stressor-indutsibel'nye bakterial'nye belki i virulentnost'.

Different species of pathogenic bacteria, including Salmonella, Neisseria, Listeria and Francisella have been used to demonstrate relationship between the synthesis of stressor induced proteins by cells and the phenotypic manifestation of their virulence. The impact of such external factors as high temperature, low pH, osmolarity, substrate limitation, the content of active forms of oxygen, etc. is accompanied by the synthesis of different stressor induced proteins playing a complex role. Under unfavorable environmental conditions the synthesis of these proteins ensures the survival of the infective agents. Under conditions of a macroorganism synthesis of some stressor induced proteins promotes the survival of infective agents and their resistance to the action of humoral and cell-mediated protective factors of the host. As is known, the expression of virulence genes is not constitutive. The expression of these genes greatly depends on environmental conditions and its induction is determined by extra- or intracellular location of the infective agent. Several systems of the regulation of bacterial pathogenicity factors have been described that are relatively not numerous, conservative and respond to external signals. The relevance of a number of stressor induced proteins of bacteria to virulence associated factors is discussed.

[The criterion of cell division synchronization for assessing the stressor exposure of a Salmonella typhi population]. / Kriterii sinkhronizatsii deleniia kletok dlia otsenki stressornogo vozdeistviia na populiatsiiu Salmonella typhi.

Criterion of the synchronization (CS) of cells division for S. typhi population is proposed. The criterion is based on the assumption of the normal distribution of cells with different generation time in the population after stressor (shock) action. CS is equal to the ratio of the dispersion of the generation time of cells in the population to the average generation time of the whole population and determined from the parameters of the mathematical model. The quantitative values of the parameters of the mathematical model were obtained by the minimization of error between the calculation and experimental data. CS was used for the evaluation and choice of the optimum stressor action in the synchronization of the division of S. typhi.