No detection of macrolide-resistant Mycoplasma pneumoniae from Swedish patients, 1996–2013

BACKGROUND Mycoplasma pneumoniae is a common cause of respiratory infections which can cause life-threatening pneumonia and serious extrapulmonary manifestations. Since the year 2000, the emergence of macrolide-resistant M. pneumoniae strains has increased with varying incidences across countries. In China more than 90% of the strains are resistant. M. pneumoniae diagnostics is mostly done with molecular methods, and in Sweden antibiotic resistance surveillance is not routinely performed. The prevalence of macrolide-resistant M. pneumoniae has not previously been studied in Sweden. MATERIAL AND METHODS A total of 563 M. pneumoniae-positive respiratory samples, collected from four counties in Sweden between 1996 and 2013, were screened for mutations associated with macrolide resistance using a duplex FRET real-time PCR method. The real-time PCR targets the 23S rRNA gene, and differentiation between wild-type and resistant strains was achieved with a melting curve analysis. RESULTS Of the 563 samples included, 548 were analyzed for mutations associated with macrolide resistance. No mutations were found. The detection rate of macrolide-resistant M. pneumoniae in this study was 0% [0.00-0.84%]. CONCLUSION No macrolide-resistant M. pneumoniae has been detected in Sweden. However, the emergence and spread of macrolide-resistant M. pneumoniae strains in many countries commands continuous epidemiological surveillance.