Aims: Although the cases of macrolide-resistant Mycoplasma pneumoniae (MRMP) have been increasing substantially among children, there are very few studies that have focused on MRMP in adults. This study aimed to investigate the prevalence and clinical features of community-acquired pneumonia (CAP) caused by MRMP from adults in Jeju Island, Korea. Methods: We retrospectively recruited adult patients with CAP in whom M. pneumoniae infections had been confirmed for a 7-year period. Macrolide resistance was determined by identifying a mutation in the 23S rRNA gene using PCR. Results: In total, 70 subjects were included. Their mean age was 46.1 years and 36 (51.4%) were women. Only two isolates (2.9%) carried macrolide resistance mutations in the 23S rRNA gene, and all the mutations were A2063G transitions. No significant differences were observed in age, comorbidities, symptoms, duration of fever, and length of hospital stay between the MRMP and macrolide-sensitive Mycoplasma pneumoniae groups. The number of involved pulmonary lobes was greater in the MRMP group (3.50 vs. 1.44, p = 0.008). Conclusion: The prevalence of CAP caused by MRMP was relatively low in adults in Jeju Island. Patients with MRMP pneumonia tended to have multilobar pneumonic infiltrates.
Keywords: drug resistance; macrolides.