Background
The factors to predict the progression of Mycoplasma pneumoniae infection remain inconclusive. Therefore, we investigated macrolide resistance prevalence, M. pneumoniae genotype, and clinical characteristics of childhood M. pneumoniae respiratory tract infections in Taiwan.
Methods
A total of 295 children hospitalized with respiratory tract infections with positive serological M. pneumoniae immunoglobulin M test results were enrolled in this 3-year prospective study. Oropharyngeal swabs were obtained for M. pneumoniae cultures and PCR tests. All M. pneumoniae specimens were further characterized by P1 typing, multilocus variable-number tandem-repeat analysis (MLVA), and macrolide resistance genotyping. The clinical characteristics and blood cytokine profiles were analyzed accordingly.
Results
Of 138 M. pneumoniae specimens, type I P1 was the predominant (136/138, 98.6%). MLVA type P (4-4-5-7-2) was the leading strain (42/138, 30.4%), followed by type J, U, A, and X. The overall macrolide-resistant rate was 38.4% (53/138); the resistance rate increased dramatically yearly: 10.6% in 2017, 47.5% in 2018, and 62.5% in 2019 (P < .001). All macrolide-resistant M. pneumoniae (MRMP) harbored the A2063G mutation and were MLVA type 4-5-7-2 (49/53, 92.5%), especially type U and X. No significant differences in clinical symptoms, duration of hospital stay, and radiographic findings were identified among patients between MRMP and macrolide-sensitive M. pneumoniae (MSMP) groups. Patients with MRMP infection had more febrile days before and during hospitalization; higher IL-13 and IL-33 levels than patients with MSMP infection (P < .005).
Conclusions
MRMP surged in Taiwan throughout the study period, but macrolide resistance was not a determinant factor of clinical severity.