[Bacillus genus bacteria are producers of biologically active compounds with antimicrobial effect].

Biologically active compounds of spore-forming bacteria of Bacillus genus, which have antagonistic effect on opportunistic and pathogenic microorganisms, are characterized in the review. Information about known to date antibiotics and bacteriocins produced by Bacillus species is presented.

[Experimental study of antiviral activity of spore-forming bacterium Bacillus pumilus "Pashkov"].

AIM: To study antiviral activity of metabolites of spore-forming strain "Pashkov" of B. pumilus on the model of enterovirus infection in vitro. MATERIALS AND METHODS: B. pumilus strain "Pashkov" isolated from environment and identified by common methods. Cell cultures: Vero-6, Vero-ECC, and Vero-E6. Enteroviruses: type 1 poliovirus, Coxsackie B virus (1-6), ECHO-3, and ECHO-6 viruses. Unfectious activity of viruses was evaluated according to their cytopathogenic effect on Vero- E6 cell line by method of serial dilutions. Cultural fluid (CF) for the study was obtained by centrifugation and sterilizing filtration of B. pumilus strain "Pashkov" biomass produced by cultivation during 72 hours on optimized nutrient medium. Cytotoxicity of CF (chronic and acute) and maximal tolerated dose were measured by effect on viability of Vero-E6 cells, which was assessed by trypan blue exclusion test of cell viability. For measurement of antiviral activity (AV-activity), two treatment schedules--therapeutic and prophylactic--were used. RESULTS: The most sensitive cell lines were Vero-ECC and Vero-E6. Assessment of AV-activity showed that protective effect was observed for all dilutions of CF and lasted for 7 days from time of infection by used doses of virus. CF does not have acute and chronic cytotoxicity. CF studied in vitro with Vero-E6 cells infected with 4 types of enteroviruses provided protection against viruses and had prophylactic effect. Degree of effect of CF depended from type of enterovirus, dose used and CF dilution. CONCLUSION: For the first time effective antiviral activity of CF, which have low cytotoxicity for Vero-E6 cell culture in vitro and is produced by strain "Pashkov" of B. pumilus, was demonstrated. Obtained data open perspectives for development of medications against enterovirus infections.

[Effect of growth medium content on antagonistic characteristics of Bacillus pumilus].

AIM: To study the effect of growth medium content on antagonistic characteristics of "Pashkov" strain of B. pumilus. MATERIALS AND METHODS: The following strains were used in the study: B. subtitlis 3H, B. subtitlis 534, B. subtitlis 1719, B. pumilus "Pashkov". Test strains from collection of Tarasevich State Institute for Standardization and Control of Medical Biological Preparations were used for determination of antagonistic activity. Growing of B. pumilus cultures on medium (No. 9, No. 5, VK-2, Spizeisen, and L-broth) was performed by periodic cultivation during 72 h in conditions of continuous aeration at 37 degrees C. Inhibiting effect of obtained samples was assessed on growth kinetics of test strains using microbiological analyzer with plan-table photometer "BIOSCREEN/iEMS--reader MF" (LabMetod, Finland). RESULTS: Expressed antagonistic characteristics were revealed during cultivation on media No. 9 and No. 5 with maximal expression on day 3. Addition of lactose to medium No. 9 resulted in increase of bacteriostatic effect (BSE) against both individual strains and all test strains--up to 16% in average. Selection of optimal concentrations of different components allowed to develop a new growth medium which provides maximal antagonistic activity in studied strain of B. pumilus. CONCLUSION: Effect of growth medium content on antagonistic characteristics against pathogenic and opportunistic bacteria was confirmed on the example of cultivation of spore-forming strain "Pashkov" of B. pumilus. Optimization of carbohydrate, salt and other components of growth medium allowed to increase up to 100% the BSE of "Pashkov" strain of B. pumilus against both individual and all test strains. This study opens perspectives for generation of compounds with directional probiotic effect.

[Isolation and study of perspective probiotic strain of spore-forming bacteria from Bacillus genus].

AIM: To study physiologic, biochemical as well as antagonistic characteristics of isolated strain of Bacillus pumilus in comparison with known spore-forming bacteria from B. subtilis species. MATERIALS AND METHODS: Four strains of Bacillus spp. were used in the study: B. subtilis 3H, B. subtilis 534, B. subtilis 1719, B. pumilus isolated from the environment. The following strains from the collection of Tarasevich State Institute of Standardization and Control for Immunobiologicals were used for determining of antagonistic activity: Staphylococcus xylosus 25, Proteus mirabilis 24a, S. aureus "Nikiforov", S. aureus "Filippov", P. vulgaris 177, Shigella flexneri 337, Escherichia coil O111:H55, S. sonnei 170, Pseudomonas aeruginosa 9022, Candida albicans 690; clinical test-strains of yeast fungi: C. albicans (3 strains), C. haemuloni, C. tropicalis, Rhodotorula spp., Debaryomyces hansenii. RESULTS: Identification of isolated strain on combination of morphologic, tinctorial, cultural and biochemical characteristics showed that studied strain belonged to B. pumilus species. It did not have hemolytic and lecitinase activities, was resistant to several groups of antibiotics and had index of adhesion 1.76 +/- 2.5. In experiments in vivo the strain was non-toxic, non-toxigenic and avirulent. In preparations of isolated DNA, plasmids were not found. B. pumilus had high antagonistic effect against opportunistic and pathogenic bacteria as well as yeast fungi. Comparative assessment of tested strains from Bacillus genus showed that the isolated strain was not inferior than other representatives of spore-forming bacteria on spectrum and intensity of aforementioned characteristics. CONCLUSION: Low-adhesive, safe, plasmid-less strain of B. pumilus, which have intensive antagonistic properties, could be considered as a candidate for the development of new probiotic drugs for medical or veterinary use.