All issues > Volume 53(2); 2010

Original Article

Korean J Pediatr. 2010;53(2):178-183. Published online February 15, 2010.

Detection of genetic mutations associated with macrolide resistance of Mycoplasma pneumoniae

Chi Eun CE Oh¹, Eun Hwa EH Choi¹, Hoan Jong HJ Lee¹

¹Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea

Correspondence Hoan Jong HJ Lee ,Tel: +82.31-787-7283, Fax: +82.31-717-7283, Email: eunchoi@snu.ac.kr

Abstract

Purpose
: The aim of this study was to identify mutations associated with macrolide resistance in Mycoplasma pneumoniae (MP) and to establish a cultural method to determine antimicrobial susceptibility.
Methods
: Nasopharyngeal aspirates (NPAs) were collected from 62 children diagnosed with MP pneumonia by a serologic method or polymerase chain reaction. The 23S rRNA and L4 ribosomal protein genes of MP were amplified and sequenced. To identify mutations in these 2 genes, their nucleotide sequences were compared to those of the reference strain M129. MP cultivation was carried out for 32 (28 frozen and 5 refrigerated) NPAs and M129 strain using Chanock’s glucose broth and agar plate in a 5% CO2 incubator at 37℃ and examined at 2-3 day intervals for 6 weeks.
Results
: Among the 62 specimens, 17 had M144V mutations in ribosomal protein L4. The A2064G mutation was observed in 1 specimen; its 23S rRNA gene was successfully sequenced. Culture for MP was successful from the M129 strain and 2 of the 5 NPAs that were refrigerated for no longer than 3 days. However, MP did not grow from the 28 NPAs that were kept frozen at -80℃ since 2003.
Conclusion
: We found the M144V mutation of L4 protein to be common and that of domain V of 23S rRNA gene was relatively rare among MP. Studies on the prevalence of macrolide-resistant MP and the relationship between the mutations of 23S rRNA gene and ribosomal protein L4 will aid in understanding the mechanism of macrolide resistance in MP.

Keywords :Mycoplasma pneumoniae, Macrolides, Resistance, Mutation