Observational study of respiratory tract microflora in CF patients over a 15-year period

Significant progress has been made in cystic fibrosis (CF) treatment using new antibiotic (AB) therapy options. However, the spectrum of bacterial pathogens and their susceptibility to AB have changed as well. Study objective: to investigate microflora prevailing in CF subjects’ respiratory tract (RT) change over 15 years. CF subjects’ sputum culture test results collected from 2000 till 2015 were analyzed. There were 9774 samples reviewed, 16703 strains identified. “MYCROB” system of microbiological monitoring was used for entry, statistical processing and analysis of data. Study results: S. aur. identification dropped from 42% (2000-03) to 32% (2012-15). P. aerug. from 24% (2000-03) to 11% (2011-15), P. aerug. muc. from 17% (2000-03) to 9% (2012-15). Incidence of chronic P. aerug. infection in CF children decreased from 57% in 1999 to 26% in 2011 and even 14% in 2014. MRSA identification growth from 6% (2000-03) to 9,5% (2008-11) and further to 12% (2012-15) is worrisome. B. cepacia comp. identification grew from 1% (2000-03) to 11% (2008-11) and 7% (2012-15). S. maltophilia identification dropped from 6% (2000-03) to 3% (2012-15). A. xylosoxidans identification grew from 3% (2000-03) to 5% (2012-15). The data presented demonstrate significant change in the distribution of the species identified. In parallel with P. aerug, and P. aerug. muc. identification frequency drop and reduction of chronic P. aerug. infection cases, there is a tendency to higher incidence of B.cepacia complex, A. xylosoxidans and MRSA identification which is quite challenging for further CF subjects care.