[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. RESULTS: Intrageneric antagonism was detected in 65% of bacterial cultures. Almost a quarter (23.1%) of bacteriocinogenic strains suppressed growth of more than 50 cultures of enterococci. This feature however was noted in members of 4 species, vast majority (77.8%) of the isolates with a wide specter of activity was attributed to Enterococcus faecium species. Under in vitro conditions these cultures displayed a pronounced anti-listeriosis effect, they did not have expression of pathogenicity factors. CONCLUSION: Higher prevalence of intra- and intergeneric antagonism in enterococci explains the significant importance of bacteria of this group of intestine microbiome in colonization resistance of host organism biotope.

[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 14.9 +/- 2.8% of the studied cultures was the most prevalent characteristic; 22 of 24 hemolytic strains belonged to E. faecalis species. Human erythrocyte lysis was also caused by E. faecium and E. durans cultures (1 strain each). Other pathogenicity factors were detected solely in E. faecalis species members. Enterococci proteolytic activity associated with gelatinase enzyme production manifested on various substrates--both gelatin and milk. This property was detected in 7.5 +/- 2.1% cultures. Deoxyribonuclease was detected in 1 (1.2 +/- 0.9%) E. faecalis strain. A number of E. faecalis cultures possessing hemolytic activity additionally hydrolyzed gelatin (22.7 +/- 8.9% strains) and DNA (4.5 +/- 4.4% isolates). CONCLUSION: Though pathogenicity factors occur in enterococci of intestine microflora relatively rarely, separate cultures with expression of 2 or more pathogenicity factors may be essential in the development of endogenous infections especially in immune compromised patients.