Characterization of Bacteriophages Against Streptococci Causing Respiratory Infections

Author: Nino Tatrishvili
Keywords: respiratory infections, streptococcus pyogenes, streptococcus pneumonia, bacteriophage
Annotation:

Nowadays respiratory infections represent a particular serious problem in the medical practice. Irrational use of antibiotics has caused growth of resistant forms of bacterial strains and made a battle against them more complicated. Searching the ways to solve the problem has led to the actuality of forgotten treatment with bacteriophages or phage therapy many years ago. Safety and no side-effects, strong specificity, maintaining normal micro-flora-these features are priority of phage preparations. Among the causatives of respiratory infections one of the leading role belongs to Streptococcus-microorganisms. Basing on the above-mentioned a goal of our work was to isolate and study the phages against multi-resistant pathogenic bacterial strains of Streptococcus causing respiratory infections. 57Streptococcus strains were isolated and differentiated, out of which antibiotic and phage sensitivity of 38 pathogenic strains was tested. vB_GEC_Spy_S_1 and vB_GEC_Spn_S_6303 bacteriophages were isolated and characterized to 2 resistant strains. As a result of electron microscopic research it was established, that both of newly-isolated phages belong to Siphoviridae group. One-step multiplication cycle, adsorption, lysis activity and also, environmental factors like: temperature, UV, effect of chloroform on them were studied. The obtained results demonstrated a high stability of the phages to the environmental factors. As a result or their genetic study it was determined, that vB_GEC_Spy_S_1 and vB_GEC_Spn_S_6303 are different phages. Range of lysis activity was studied and it was determined ,that the given phages are active only to Streptococcus spp. Characterized vB_GEC_Spy_S_1 and vB_GEC_Spn_S_6303 phages were incorporated into the commercial therapeutic-prophylactic phage preparation , in consequence of which phage activity has increased.