[Morpho-functional changes of Staphylococcus aureus biofilms under the effect of batumin].

AIM: Study the effect of batumin isolated from metabolites of Pseudomonas batumici bacteria on the formation of biofilms by staphylococci under the control of atomic force microscopy. MATERIALS AND METHODS; S. aureus 25923 (ATCC) and S. aureus 104 were used as test cultures. Batumin with the degree of purification of 80% was used in the experiments. Microscopy of the preparations was carried out on atomic force microscope SMM-2000 (Proton-MIET Closed Joint-Stock Company, Russia) in contact mode in air environment. Biofilm formation (BFF) was studied by photometric method (O'Toole G.A., 2000). Dissociation of microbial population was detected during seeding of staphylococci into agarized LB medium. RESULTS: Changes of structural component of biofilm were noted visually under the effect of the preparation--exopolymeric matrix and reduction of quantity of adherent staphylococci in the form of separate islet formations. Similar pattern was detected during determination of staphylococci biofilm formation by photometric method. Redistribution of S. aureus clonal structure with the appearance of dissociants that do not possess the ability to form biofilms and reduction of quantity of clones with high values of BFF also occurred under the effect of batumin. CONCLUSION: The data obtained reveal one of the mechanisms of antimicrobial effect of batumin based on suppression of staphylococci biofilm formation by the preparation.

[Functional characterization of Pseudomonas batumici 17/20 upon long-term storage].

Variability of properties and antibiotic activity, as well as cells survival of Pseudomonas batumici 17/20--the producer of batumin (antistaphylococcal antibiotic) after long-term storage under vaseline oil layer have been studied. The main culture-morphological and physiological biochemical properties of the mutant strain have been investigated. It has been shown that storage under vaseline oil allows to preserve high level of antibiotic activity: batumin synthesis by the producer was 150 mg/l. Therewith, the survival of cells decreases by two orders during 5 years of storage. The conditions of strain maintenance have been formulated.

[Influence of antistaphylococcus antiobiotic batumin on microorganism biofilm formation].

AIM: Study the influence of batumin on microorganism biofilm formation. MATERIALS AND METHODS: Experimental data on the antimicrobial effect of batumin on microorganisms and biofilm formation (BFF) was obtained by studying 80 strains of bacteria and fungi isolated from microbial biocenosis of the nose of staphylococcus carriers and patients during examination for intestine dysbiosis. 80% pure batumin was used in the experiments. Antimicrobial activity of batumin was studied by serial dilutions method (CLSI, 2005), BFF--by photometry method (O'Toole G., 2000). The results were statistically treated by non-parametric method by using Mann-Whitney criterion. RESULTS: Minimal inhibitory concentration (MIC) of batumin varied from 0.25 mcg/ml to 64 mcg/ml depending on the species of the studied microorganisms. The most sensitive to batumin strains were Staphylococcus aureus when compared with escherichia and klebsiella. Batumin had no antimicrobial effect on the studied Candida albicans. Inhibitory effect of batumin against BFF of staphylococci, klebsiella and fungi that have an initial level of this property above 2.5 units was established. While in strains that have the initial BFF level of 2.5 units or less, batumin stimulated biofilm formation. Such a dependence was not detected in the studied escherichia coli cultures: batumin stimulated BFF of Escherichia in 80 - 90% of cases. CONCLUSION: The data obtained uncover one of the possible mechanisms of microsymbiocenosis formation in the human associative symbiosis and open the perspectives for further studies of batumin not only as an antimicrobial preparation but also a substance possessing anti-persistence effect against pathogens.

[Sensitivity of Pseudomonas chlororaphis to antibiotics and chemical tools of plant protection].

Examination of sensitivity of 10 Pseudomonas chlororaphis strains belonging to different subspecies to 54 antibiotics has shown that all studied representatives of Pchlororaphis subsp. chlororaphis, P. chlororaphis subsp. aureofaciens and Pchlororaphis subsp. aurantiaca were sensitive to aminoglycoside antibiotics and fluoroquinolones derivatives. Only part of studied strains has shown sensitivity to some beta-lactam antibiotics, imipeneme and meropeneme. In contrast to representatives of two other subspecies both strains of P. chlororaphis subsp. chlororaphis proved to be sensitive to chlortetracycline and cefepime that allows to consider this difference as the characteristic useful for differentiation. All studied P. chlororaphis strains were resistant to chemical fungicides (Scor and Svitch) and the insect growth regulators (Match, Lufox, Engio, Actellik). Resistance of bacteria to these herbicides gives evidence that their combined use is possible.

[The Black Sea bacteria--producers of hydrolytic enzymes].

Investigation of 15 different glycoside activities of 64 strains isolated from water and invertebra of the Black Sea has shown that 64% of the studied strains displayed the capacity to synthesize enzymes with alpha-L-ramnosidase activity which varied from 0.01 to 0.20 un/ml depending on the strain. The greatest number of the enzyme producers was found in representatives of Alteromonas macleodii. Other investigated glycosidase activities: alpha-amylase, beta-N-acetyl-D-glucosaminidase, beta-D-glucuronide, alpha-N-acetyl-D-galactosaminidase, beta-N-acetyl-D-galactosaminidase, beta-D-galactosidase, alpha-D-galactosidase, beta-D-glucosidase, KM-cellulase activities though have been found, but mainly with inconsiderable indices, alpha-D-glucosidase, alpha-D-mannosidase, alpha-L-fucosidase, beta-D-xylosidase and alpha-D-xylosidase activities were found in neither of the studied strains. Strains with rather high proteolytic activity were found among marine species of bacteria. It has been established that 18 strains (28%) of 64 marine isolates were characterized by rather high level of total proteolytic activity (from 0.1 to 05 un/ml), 43.75% of them displayed inconsiderable (up to 0.1 un/ml) or only trace (up to 0.01 un/ml), 18.75% did not display any hydrolytic activity in respect of casein. Investigation of substrate specificity to a number of fibrillar and globular proteins of 9 studied strains, which displayed considerable general (caseinolytic) activity has shown that 8 of them displayed fibrinolytic activity from 0.15 to 2.175 un/ml. All 9 strains were characterized by gelatin activity. Collagenase and keratinase activity was also revealed. Neither of 9 studied strains displayed elastase activity.

[Use of Pseudomonas bacteria strains for determining water-assimilable carbon].

The ability of 12 Pseudomonas putida and Pseudomonas fluorescens strains for growth in the tap water has been studied. All of them grew well in pasteurized Kyiv tap water at 500 colony-forming units--CFU/ml inoculum reaching the maximal titre 1.7 x 10(4)-4.6 x 10(6) CFU/ml after 240 hours of incubation. The most intensive growth was observed in strain P. putida UCM B-143, capable to assimilation of 84 different sources of carbon nutrition. The linear dependence between strain 143 growth and acetate carbon concentration in the interval of 10 to 60 microg/l has been demonstrated in deionized water with addition of necessary mineral salts; its yield was 4.5 x 10(6) CFU/microg of assimilable acetate carbon (AOC). Determination of AOC of water using standard methods, standard strain P. fluorescens UCM B-385 (P17, ATCC 49642) and selected strain P. putida B-143 gave the similar values of AOC quantities in the Kyiv tap water (536 and 600 microg of AOC in 11, accordingly). Viability of strain 143 grown in the artesian water decreased more quickly than that of the standard strain which is possibly connected with origin of both cultures: strain 143 was isolated from wheat rhizosphere while strain P17--from the drinking water.

[Physiological properties and taxonomic position of soil microorganisms-destructors of hexachlorcyclohexane].

Eleven (11) microbial strains capable to decompose insecticide hexachlorcyclohexane (HCH) have been isolated from microbial association resistant to chloro-organic pesticides. On the basis of investigation of morphological, cultural, physiological, biochemical characteristics and results of sequence of gene 16S rRNA it has been established, that the best strain-destructors N 3 and N 9 belong to Pseudomonas putida species, and strain N 6 belongs to Stenotrophomonas maltophilia species.

[Characterization of batumin resistant variants of Staphylococcus aureus clinical isolates].

Population analysis of 20 batumin susceptible staphylococcal strains, isolated from clinical materials allowed to detect resistant clones only in 3 strains. The frequency of batumin resistant variants isolation was low and depended on the antibiotic concentration. Resistance to batumin in 5 clinical strains and in 1 reference strain of Staphylococcus aureus ATCC 6538 P (209P) developed under laboratory conditions and induced significant phenotypic and chemotaxonomic changes in the pathogen. The variants, resistant to batumin, had the same degree of virulence for mice as the initial susceptible strain. The batumin resistant variants of S. aureus were unstable and on the medium without batumin completely restored their initial phenotype.