Probiotic Potential, Safety Properties, and Antifungal Activities of Corynebacterium amycolatum ICIS 9 and Corynebacterium amycolatum ICIS 53 Strains.

The purpose of this study was to evaluate the probiotic characteristics and safety and to study the antifungal activity of C. amycolatum ICIS 9 and C. amycolatum ICIS 53 against Candida spp.

subsp. subsp. nov., a psychrotolerant facultative anaerobe isolated from a cold spring.

A psychrotolerant facultative anaerobe, strain SKBG, was isolated from the bottom sediments of the cold mineral spring Buxichen (Buryatia, Russia). Gram-positive non-motile cocci with a diameter of 1.75-2.

Pore-forming bacteriocins: structural-functional relationships.

Peptides and proteins are important bioorganic compounds in nature, among which a special place is occupied by antimicrobial substances. There are more than 2000 different antimicrobial peptides (AMPs) produced by a variety of living organisms. Bacteriocins produced by bacteria are the minor group, whose chemical structures are most complicated among all AMPs.

A Novel High-Molecular-Mass Bacteriocin Produced by Enterococcus faecium: Biochemical Features and Mode of Action.

Discovery of a novel bacteriocin is always an event in sciences, since cultivation of most bacterial species is a general problem in microbiology. This statement is reflected by the fact that number of bacteriocins is smaller for tenfold comparing to known antimicrobial peptides. We cultivated Enterococcus faecium on simplified medium to reduce amount of purification steps.

Purification of a Novel Bacteriocin-Like Inhibitory Substance Produced by Enterococcus faecium ICIS 8 and Characterization of Its Mode of Action.

Objective: The aim of this work was to purify and characterize a bacteriocin-like antimicrobial substance produced by an antagonistic active strain of Enterococcus faecium.

Methods And Results: A novel bacteriocin-like inhibitory substance (BLIS) produced by the E. faecium ICIS 8 strain was purified and characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and N-terminal amino acid sequencing revealed the following partial sequence: NH-APKEKCFPKYCV.

[BIOLOGICAL ACTIVITY OF ANTIMICROBIAL PEPTIDES OF ENTEROCOCCUS FAECIUM].

Aim: Isolate bacteriocins from Enterococcus faecium metabolites and characterize their effect on cells of Gram positive (Listeria monocytogenes) and Gram negative (Escherichia coli) bacteria.

Materials And Methods: Methods of solid-phase extraction, ion-exchange and reversed phase chromatography were applied for isolation of bacteriocins from cultural medium of bacteria MALDI time-of-flight mass-spectrometry was used for characterization of the obtained preparations. The mechanism of biological effect of peptides was evaluated using DNA-tropic dyes (SYTO 9 and PI) with subsequent registration of fluorescence spectra: Atomic-force microscopy (AFM) was used for characterization of morpho-functional reaction of target cells.

[Morphologic changes in listeria cells under the effect of metabolites of human intestinal microflora enterococci].

Aim: Characterization of morphologic changes in listeria cells under the effect of metabolites of human intestine microflora enterococci.

Materials And Methods: Culture of Listeria monocytogenes 88-BK cells was cultivated in the presence of enterococci waste products (experiment) or without them (control). The samples obtained were studied by atomic-force microscopy (AFM) in contact mode using scanning probe microscope SMM-2000.

[Antimicrobial compounds of enterococci].

The main studies of a group of antimicrobial compounds produced by Enterococcus genus bacteria: bacteriocins, organic acids, activated oxygen metabolites, enzymes, exopolysaccharides--are described in the review. Data on synergic interaction of these substances in killing of pathogens, formation of active substances from different components as a result of metabolic activity of enterococci are presented. Production of these compounds is a reflection of competitive habitation of bacteria under the conditions of multi-species microbiomes and ensures colonization resistance of host biotopes.

[Bacteriocinogenia of enterococci of human intestine microflora].

Aim: Characteristics of bacteriocinogenicity and bacteriocin-sensistivity of enterococci isolated from human feces.

Materials And Methods: Principle of delayed antagonism on solid nutrient mediu (120 x 120 cultures) was used for detection of bacteriocinogenicity of microorganisms. Factors of pathogenicity (production of hemolysin, gelatinase, DNase) as well as antagonism against Listeria genus bacteria were determined in highly active strains.

[Study of features of the effect of cationic antimicrobial peptide nisin on Listeria monocytogenes bacteria by using atomic-force microscopy].

Aim: Characteristic of morpho-functional reaction of Listeria monocytogenes bacterial cells to the effect of cationic peptide nisin.

Materials And Methods: Culture of L. monocytogenes 88-BK bacterial cells was grown in the presence of nisin (experiment) and without it (control).

[Corneal ulcer caused by Serratia marcescens: case report].

A case of corneal ulcer caused by Serratia marcescens is reported in a patient with history of corneal microtrauma. Biological features (pathogenicity factors, antibiotic resistance) of isolated culture were characterized. Keratitis cases caused by this agent were analyzed.

[Mechanisms of resistance of enterococci to antimicrobial proteins and peptides].

Mechanisms of resistance of bacteria genus Enterococcus to the most important factors of innate immunity of the host--antimicrobial proteins and peptides--are described in the review. Data on enterococci lysozyme resistance associated with modification of peptidoglycan and changes in the net charge of the bacterial cell surface are presented. The role of enterococci sigma-factor with extra cytoplasmic SigV function is described.

[Pathogenicity factors of enterococci of human intestinal microflora].

Aim: Characteristic of pathogenicity factors of enterococci isolated from human feces.

Materials And Methods: Production of hemolysin, gelatinase and DNase was determined in 161 enterococci cultures.

Results: Hemolytic activity detected in 14.

[Features of microbiocenosis of the large intestine in dysbiotic disorders].

Aim: To determine features of intestinal microbiocenosis in dysbiosis as well as biological characteristics of isolated microflora in residents of Orenburg city.

Materials And Methods: 70 children one year old and 60 adult 1 - 60 years old were examined for dysbiosis. Bacteriologic identification of the large intestine's content was performed using method of serial dilutions.

[Multilocus sequence-typing of Enterococcus faecium fecal isolates].

Aim: Genetic characteristics of Enterococcus faecium strains isolated from human intestine in Russia.

Materials And Methods: Seven strains of E. faecium with antimicrobial activity against Gram-positive bacteria and yeast fungi were isolated from persons aged 4 months - 44 years.

[Formation of biofilms by fecal strains of enterobacteria and yeast fungi from Candida genus].

Aim: To assess the ability of bacteria and Candida genus' yeast fungi from human fecal microflora to form biofilms.

Materials And Methods: Thirty-one strains of enterobacteria and 45 strains of yeast fungi from Candida genus isolated from feces of patients during test on intestinal dysbiosis were used. In order to study the ability of microorganisms to form biofilms, level of binding of crystal violet by the formers in sterile 96-well polystyrene plates was studied.

[Species characteristic and factors of persistence of gut bifidoflora during healthy state and dysbiosis].

Aim: To determine features of species composition and factors of persistence of bifidobacteria of human gut microflora in healthy state and during dysbiosis.

Materials And Methods: Strains of bifidobacteria isolated from feces of patients with gut dysbiosis grades I - III (24 participants) and conditionally healthy persons (14 participants) were used for the study. Isolation and identification of microorganisms were performed by conventional methods.

[Interaction of a causative agent with associative bacteria during salmonellosis].

Aim: To determine a composition of gut microflora during salmonellosis and to study the modification of persistent characteristics (antilysozyme activity, ALA) of symbiotic microorganisms in associations.

Materials And Methods: Bacteriologic study of feces was performed in 90 patients aged 18-39 years, which were divided to three groups: patients with salmonellosis in acute phase, reconvalescent patients, and conditionally healthy persons. Condition of gut microflorawas determined; microorganisms associated with Salmonella infection were isolated, and their influence on ALA of Salmonella was studied.

[Algorithm for prediction of reconvalescent salmonellosis carriage].

Of total of 181 patients with Salmonella infection were examined by clinical and laboratory methods. As many as 124 indices characterizing biological properties of Salmonellae, a large intestine microbiocenosis status, systemic and local immunity, were investigated as well. Among these indices, the most revealing signs were defined to prognosticate the reconvalescent carrier state.

[The role of anti-lactoferrin activity of bacteria in their persistence].

The role of anti-lactoferrin activity (ALfA) of bacteria in the persistence phenomenon, i.e. long survival of a causative agent in a host body, was studied in experimental staphylococcal infection.

[Microbial inhibitors of lysozyme].

Lysozyme is one of the most important factors of innate immunity, possessing anti-microbial action against a wide range of microorganisms due to cationic nature of protein and, in a lesser degree, due to muramidase activity. In the process of evolution, different mechanisms of lysozyme inhibition, defined as anti-lysozyme activity (ALA), were formed in microorganisms. The usage of the delayed antagonism principle allowed to reveal anti-lysozyme sign in microorganisms of different phylogenetic groups.

[Persistence factors of Francisella tularensis].

The study of the persistence potential of 64 F. tularensis strains isolated from different sources was carried out. The wide spread of the antilysozyme, antilactoferrin and anticomplementory activities of F.

[Influence of plasmid pR50 controlling bacterial protease activity on Salmonella experimental infection].

The comparative analysis of the infectious process and immunological parameters in (CBA x C57BL/6)F1 mice infected with S. typhimurium isogenic strains differing by the presence of plasmid pR50 determining protease activity, was carried out. A growth in the expression level of antilactoferrin, anticomplementary and anti-immunoglobulin activity in bacteria isolated from the spleen in the course of the infectious process was detected.

[Biological properties of salmonellae and local immunity in Salmonella infection].

The comparative study of the biological properties of S. enteritidis and S. typhimuruim, isolated from patients and convalescent carriers, was carried out.

[Biological properties of microorganisms as the basis for the prognosis of the severity of pyoinflammatory pleuropulmonary diseases].

In the study of 65 microbial cultures isolated from the purulent foci in acute pulmonary abscess and acute pyothorax of 48 patients, a wide spectrum of microflora was detected. Staphylococci and Pseudomonas prevailed among aerobes, bacteroids and peptostreptococci--among anaerobes. In cases of the prolonged course of the pathological process, as compared with the common one, microorganisms exhibited hemolytic activity and high antilysozyme and anticomplementary levels.