Surveillance of antibiotic resistance of Streptococcus pneumoniae in the Čzech Republic, respiratory study results, 2010-2017
Abstract
Aim. The purpose of the surveillance performed from October to December during 2010-2017 period was to monitor the state and trends of susceptibility to betalactam and macrolide antibiotics in Streptococcus pneumoniae causing respiratory tract infections in the Czech Republic.
Material and methods. The study was attended by 42-55 laboratories every year.
Non-duplicate pneumococcal isolates from relevant microbiological specimens from patients with community-acquired bacterial respiratory tract infection were sequentially included in the study. Laboratories recorded qualitative results of penicillin and erythromycin susceptibility testing, susceptibility to antibiotics was determined by disk diffusion method.
Penicillin non-susceptible and / or erythromycin resistant isolates were sent to the National Reference Laboratory for Antibiotics, where minimum inhibitory concentration of antibiotics was tested using the broth microdilution method, the serotype was determined in the National Reference Laboratory for Streptococcal Infections. In isolates reffered in 2017 (26), molecular typing was performed using multilocus sequence typing.
Results. In total, 7 491 pneumococcal strains were examined, of which 53.7 % (4 023) were from upper respiratory tract, 47.7 % (3 573) were obtained from children under 15 years of age.
Susceptibility to penicillin decreased from 2.6% in 2010 to 1.2 % in 2017, while resistance to erythromycin increased from 7.4 % to 9.7 % over the same period. Penicillin non-susceptible isolates included serotypes 19A, 19F and 15A in particular.
Macrolide resistant but penicillin susceptible isolates were predominantly represented by serotype 19A and 3. The presence of the Taiwan19F-14 clone was confirmed in penicillin non-susceptible isolates, the most frequently identified sequence type (ST) in macrolide resistant isolates was ST416 belonging to the Netherlands15B-37 clone.
Conclusions. Respiratory study of antibiotic resistance in S. pneumoniae confirmed the decreasing trend of resistance to penicillin but revealed a growing resistance to macrolide antibiotics in the Czech Republic.
The results of our study confirm that antibiotic resistance is associated primarily with non-vaccine serotypes in the vaccination era, and the clonal expansion of macrolide resistant serotype 19A was apparently supported by the growing prescription of macrolide antibiotics.