Mikrobiologicheskii zhurnal最新文献

The quantity and distribution of heterotrophic and enteric bacteria as indicators of the human activity influence on the marine ecosystem have been studied in water thickness of the Odessa Bay. It has been established that in the late autumn period the average quantity of heterotrophic bacteria in Bay waters is 6500 cells/ml and the number of the enteric ones--2400 cells/l. The spatial distribution of the heterotrophic bacterioplankton was mosaic and a tendency to decrease their quantity while moving away from the shore was not observed. This indicated the absence of the shore flow influence on the distribution of heterotrophic bacteria. On the contrary, the number of enteric bacteria significantly decreased with an increase of the distance from the shore, but on the greater part of the Bay they were absent at all. As to the vertical distribution of the heterotrophic bacteria quantity their maximum was in the water layer (0.5) below the surface, whereas the distribution of enteric bacteria did not correspond to this rule. Proceeding from the number of heterotrophic bacteria in the late autumn period waters of the Odessa Bay can be characterized as mesoeutrophic and according to the value of coli-index--as mesosaprobic ones.

Antibiotics, inhibitors of nucleic acids' synthesis from the group of chromomycins (olivomycin of sodium salt), anthracyclines (carminomycin and doxorubicin) and streptonigrin (bruneomycin) have been studied for their effect on DNA synthesis in vitro performed by DNA polymerases (1st and 2nd forms) of Acholeplasma laidlawii PG-8. It has been stated that olivomycin inhibits the function of both the first and second forms of DNA polymerases in proportion to an increase of the antibiotic concentration in the medium. Carminomycin in the concentration of about 1 microgram/ml almost completely inhibited the activity of both DNA polymerases. However, doxorubicin also belonging to the group of anthracyclins completely inhibited the activity of the first form of DNA polymerase in the concentration of 1 microgram/ml and practically has no effect in the concentration up to 100 micrograms/ml on the activity of the second form possessing 3'-->5'-function. Streptonigrin also proved to be suitable for differentiate the forms of DNA polymerases and to determine their functions. The first form of DNA polymerase with 5'-->3'-polymerase and exonuclease functions was not sensitive by this antibiotic in the concentration of 1000 micrograms/ml, while the activity of the second form of DNA polymerase with 3'-->5'-exonuclease functions was fully inhibited by this concentration of the antibiotic in the medium. The combination of doxorhubicin and streptonigrin in the medium can be used to determine the form of DNA polymerases and to identify their 5'-->3'- or 3'-->5'-exonuclease function and for selectivity inhibition of the function of one or another DNA polymerase in the medium.

The dynamics of accumulation of Bacillus subtilis 39 cells and spores under different conditions of aeration has been studied. It is shown possible to intensify the process of growth, biomass accumulation and sporulation of bacteria using aeration conditions. The growth of cells of the studied bacilli proceeds under conditions of providing the culture with oxygen according to its real demands for the whole period of fermentation. The mathematical models have been obtained which connect the aeration conditions with the rate of biomass accumulation and sporulation of the studied bacteria. It has been stated that with an increase of aeration the yield of microbic cells, degree of using the substrate by them as well as the specific growth rate become higher. Intensive aeration 4.4 = 5.8 g O2/l.h promotes the creation of the most optimal conditions for the growth of bacteria. While deteriorating the aeration to 3.2 g O2/l.h and over, the specific growth rate and yield of viable cells decrease. The optimal conditions of air feed and medium agitation rate decrease the duration of fermentation exerting no effect on the final yield of biomass. It is shown that yield of biomass and spores depends on the growth phase.

The method of electron microscopy has been used to study adhesion of the microbic cells of standard strains of Staphylococcus aureus, Escherichia coli and fungi of genus Candida on the organosilicon sorbent polymethylsiloxane (PMS) and medicamentous complex containing it. This complex contains furazolidone and metronidazole immobilized on silver ions-modified PMS. It is shown that the adhesion of microorganisms is accompanied by their destruction whose rate on pure PMS and medicamentous complex is different. Using experimental data the assumptions are advanced concerning the mechanism of the PMS interaction with Gram-positive and Gram-negative microorganisms as well as with fungi of genus Candida.

A method for identification of genomic polymorphism of strains belonging to different biovars Corynebacterium diphtheriae has been described. The method is based on the polymerase chain reaction (PCR) using universal inter-species oligonucleotide primer N 45. Using this method 17 strains of C. diphtheria, isolated in the western region of Ukraine during epidemic activity in 1992, were studied. The study has shown high similarity of PCR patterns of toxicogenic and non-toxicogenic strains of both mitis and gravis biovars. It is supposed that the method will be used in molecular epidemiology to identify new pathogenic isolates from different regions and countries.

While comparatively analyzing the properties of Klebsiella pneumoniae from three studied sources (patients, healthy people, environment), no reliable differences between the comparable strains have been revealed. No differences have been found in the toxin formation, hemagglutinating and antilysozymic activity, adhesivity and invasive properties as well as in the peculiarities of gas exchange, while growing on media with different nitrogen and carbon sources. The studied microorganisms differed only in antibiotic resistance: strains isolated from the environment were sensitive to antibiotics, whereas strains of human origin were resistant to them.

A new method to detect the protective value of antitetanic antibody in latex agglutination test (LAT) has been described. The new method is highly sensitive and fast, and requires no special equipment. The optimal conditions of sensibilization, latex types, test providing procedure have been selected. New LAT detects approximately 0.0015 IU antitoxin per ml. This method can be used to determine the state of immunization of population against tetanus and to detect the protective antibodies in production series of human and horse antitetanic immunoglobulins.

The nutrient medium has been developed on the basis of home components to determine toxigenicity of Corynebacterium diphtheriae using the biological method of diphtheria diagnosis. The advantage of the proposed nutrient medium is independence of delivers of commercial dry nutrient agar from Dagestan Research Institute of Nutrient Media.

The results from examination of intestinal microflora and immune status in 75 patients with nonspecific ulcerative colitis with different degree of disease seriousness are presented. The deviations in the composition of normal microflora were primarily expressed in a decrease of the number of bifidobacteria. In 64.9% of patients the disease proceeded against the background of deficit of T-cellular immunity link. The sufficiently expressed bacteriological and immunological efficiency of complex therapy including preparation from spore-forming bacteria as a normalizer of microflora is shown.