Multiplex quantitative PCR for Streptococci species identification and detection of genetic drug resistance markers in COPD patients

The aim of this study was to develop a new diagnostic tool for Streptococcus identification and simultaneous macrolide resistance genetic marker detection in chronic obstructive pulmonary disease (COPD) patients. Methods. The "Streptopol +" experimental diagnostic panel (Lytech Ltd) was used to test laboratory collection of Streptococcus strains and DNA samples isolated from oropharyngeal swabs of 89 patients with stable COPD with length of disease ≥ 12 months, smoking history ≥ 10 pack / years, no exacerbations during the previous 4 weeks and no antibiotic therapy during the previous 12 weeks prior to study entry. Resluts. The "Streptopol +" experimental set allowed detection of drug resistance genetic markers and Streptococcus species identification based on a multiplex real-time PCR. Streptococcus was determined reliably in 83 (83 / 89; 93.3 %) samples obtained from COPD patients; Streptococcus was not found in one sample; 5 samples were in a "gray" zone with low DNA titers. Mainly, Streptococcus was identified as S. viridans, mitis group which was revealed to be as a reservoir for macrolide resistance genetic determinants. This increases a risk of macrolide resistance and therapeutic failure of these drugs. The mef genes were detected in all samples (89 / 89; 100 %), ermB gene was less frequent (81 / 89; 91.0 %). Conclusion. The "Streptopol +" experimental diagnostic panel has shown a high specificity and sensitivity to diagnose Streptococcus infection in COPD patients. 

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