Molecular Characterization of Mycoplasma pneumoniae Infections in Two Rural Populations of Thailand from 2009 to 2012

Abstract

Studies on Mycoplasma pneumoniae in Thailand have focused on urban centers and have not included molecular characterization. In an attempt to provide a more comprehensive understanding of this organism, we conducted a systematic random sampling to identify 3,000 nasopharyngeal swab specimens collected from January 2009 through July 2012 during population-based surveillance for influenza-like illness in two rural provinces. M. pneumoniae was detected by real-time PCR in 175 (5.8%) specimens. Genotyping was performed using the major adhesion protein (P1) and multilocus variable-number tandem-repeat analysis (MLVA). Of the 157 specimens typed, 97 were P1 type 1 and 60 were P1 type 2. Six different MLVA profiles were identified in 149 specimens, with 4/5/7/2 (40%) and 3/5/6/2 (26%) predominating. There was no discrete seasonality to M. pneumoniae infections. Examination of the 23S rRNA sequence for known polymorphisms conferring macrolide resistance revealed that all 141 tested to possess the genotype associated with macrolide susceptibility.

Keywords: Mycoplasma pneumoniae; community-acquired pneumonia; macrolide resistance; molecular epidemiology.

FIG 1

Seasonal distribution of Mycoplasma pneumoniae-positive specimens shown by MLVA type over the study period (bar graph, left y axis) relative to the total number of specimens collected during the study period (line graphs, right y axis). NP, Nakhon Phanom (green); SK, Sa Kaeo (blue).

FIG 2

Distribution of MLVA types throughout the study period by province (top) and age (bottom).

FIG 3

Locality map detailing hospitals from Nakhon Phanom and Sa Kaeo provinces involved in population-based surveillance studies. The number of beds for each hospital is indicated by the size of the location marker in each district.