Hydrogen peroxide production activity and adhesive properties of aerococci, isolated in women

Abstract

Introduction. Antagonistic activity of probiotic microorganisms against other species of bacteria is an important mechanism of their ecology and it is widely used in practice. This activity is inherent in many heme-deficient bacteria, which include aerococci, and can be composed of several components: the production of organic acids, antibiotics, lysozyme, hydrogen peroxide and others.Ability to produce hydrogen peroxide under aerobic conditions and in a state of relative anaerobiosis was established in aerococci. They were divided into strong and weak producers, depending on the amount of peroxides.Lack of data about peroxide-productive ability of aerococci, isolated from the lower genital tract of women, as well as a proven mechanism of hydrogen peroxide excretion in the oxidation of lactic acid, led to need in studying the aerococci hydrogen peroxide production level, to create autobacterial drugs, based on aerococci symbiont strains for sanitation of birth canal.Colonization resistance of the vaginal mucous and normal microflora value depends largely on the degree of adhesion of microbial cells to the mucosal surface.Along with numerous studies of lactobacilli adhesive properties to the vaginal epithelium, there are no data on the adsorption capacity of aerococci to the vaginal epithelial cells. Material and methods. 18 aerococci resident strains and 1 museum strain were explored in total.Presence and quantity of autosymbiont aerococci content in different parts of the birth tract (cervical canal, vagina, external genitalia skin (EGS) and perineum) was studied in 44 healthy women. Isolation and identification of aerococci from the women body was conducted by the method, taking into account growth on selective indicator medium, growth and biochemical activity in environments with selenium and tellurium salts, lactate oxidase and superoxide dismutase activity. Hydrogen peroxide was determined by iodometric method. Hydrogen peroxide production in 19 strains of aerococci (museum strain - Aerococcus viridans 167 and 18 strains of autosymbiont aerococci) was investigated. The level of hydrogen peroxide production was compared with aerococci adhesive activity to cells of vaginal epithelium.Autosymbiont strains were used to evaluate the aerococci adhesion on vaginal epitheliocytes.18 aerococci resident strains and 1 museum strain were explored in total. Results and discussion. Comparison of hydrogen peroxide production levels between the museum and symbiotic Aerococcus viridans strains showed a lower level (from p <0,05 to p <0,001) in strains isolated from vaginal microbiocenosis, cervix and lower genital skin.Despite approximately the same number of multiplied cells, the amount of hydrogen peroxide produced by aerococci varied in a fairly large range. Thus, 8 Aerococcus viridans strains (167, 2V, 9V, 10V, 4S, 13S, 18S, 39 S) during reproduction in the number lg 8,9 -9,1 SUN / ml, extracted considerable amount of hydrogen peroxide in the range 0, 34-0,79 mg / ml. However, 11 autosymbiont aerococci strains, with identical number of multiplied cells produced hydrogen peroxide in much smaller amounts - within 0,07-0,24 mg / ml.The foregoing results allowed to divide aerococci cultures into two groups: strong and weak peroxide producers.Comparative evaluation of aerococci strains isolated from the birth canal activity, showed the predominance of weak producers of hydrogen peroxide (7 - 61.1% of cases) under strong (11 - 38.9%). Aerococci strains isolated from microbiocenosis of EGS skin showed the maximal activity compared with strains isolated from other parts of the birth path - 4 out of 5 cases (80.0%) compared with 3 of 13 (23.1%) cases (p <0,05 ).The aerococcal ability to adhere varied in a wide range (AA from 3.25 to 10.24). 3 strains were isolated from all aerococcal strains with low adhesion (15.8%), with average degree - 12 (63.2%) and 4 highly adhesive aerococcal strains were identified (21.0%).Analysis of the aerococci symbiont strains ability to adhere (tab. 2) showed that highly adhesive strains were observed only in the vagina, while autosymbionts isolated from the skin of the genital organs had usually low or medium level of adhesion to epithelial cells. The average index of adhesion (AA) for all strains isolated from the vagina, equaled 7,87 ± 0,12, for the cervical canal strains - 6,30 ± 0,09, for strains from the skin of EGS - 4,89 ± 0,11 (p <0,001 in all comparisons). Conclusion. 1. Aerococcus viridans autosymbionts are a component of normal flora of the female genital organs. 2. Aerococci autosymbiont cultures isolated from the birth canal, are mainly weak hydrogen peroxide producers (61.1%) and have medium adhesive (61.1%) and high adhesive (22.2%) properties on vaginal epithelium. 3. Strains isolated from vagina possessed higher adhesive ability (p <0,001). 4. Aerococcus viridans museum strain 167 was the strongest hydrogen peroxide producer (from p <0,05 to p <0,001).