PERSISTENCE OF BURKHOLDERIA CENOCEPACIA BACTERIA IN VIVO IN DEPENDENCE OF THEIR ABILITY TO FORM BIOFILMS

Aim. To select the most susceptible line of mice which allows to conduct comparative studies of infectious process caused by different strains of B.cepacia in order to explore correlation between ability to form biofilms and persistence of bacteria in organs of infected animals. Materials and methods. Strain B.cenocepacia 370, which is a clinical isolate, and its mutants with modified ability to form biofilms were used. Conditional microbiologic methods and biological models of intraperitoneal and intranasal inoculation of mice belonging to 4 lines: BALB/c, BLACK, I/St, and A/Sn derived in Central Institute of Tuberculosis were employed. Criteria of persistence was duration of isolation of different strains of bacteria from lungs and spleen of inoculated animals as well as number of CFU. Results. The most susceptible line of mice which enables to conduct comparative studies of infectious process caused by Burkholderia species was determined. It was shown that even after intraperitoneal inoculation the agent was better preserved in lungs than in spleen that corresponds to natural localization of this infection. At any time of observation the number of cells of mutant strain, which is a superproducer of biofilms, isolated from organs of inoculated mice was 2 — 10 times higher than number of isolated cells of mutant, which do not produce biofilms. Conclusion. Correlation of more prolonged persistence of B.cenocepacia in organs of inoculated animals in vivo with ability of the agent to form biofilms determined in vitro is experimentally established. The susceptible line of mice which allows to conduct comparative studies of dynamics of infectious process caused by various strains of Burkholderia species was revealed. It was shown that irrespective from method of inoculation B.cepacia are able to continuously persist in organism of susceptible animals with lungs as a predominant localization.

Burkholderia cenocepacia, persistence, biofilms