Detection of Mycoplasma pneumoniae P1 subtype variations by denaturing gradient gel electrophoresis

There were several methods to detect p1 gene variations in Mycoplasma pneumoniae. In this study polymerase chain reaction (PCR)-based denaturing gradient gel electrophoresis (DGGE) assay was performed to establish a rapid and precise detection method for identifying M. pneumoniae p1 gene variations. We detected p1 gene variations in 109 M. pneumoniae clinical isolates from Shanghai, China, which were collected from 2009 to 2011 by DGGE, and compared this method with the PCR-based restriction fragment length polymorphism assay and sequencing. By PCR-DGGE method, among the 109 M. pneumoniae isolates, 101 (92.7%) isolates were classified into type I, and 8 (7.3%) were classified into type II. Seven (6.9%) type I variations and 8 (100%) type II variations were identified. The match rate of p1 gene variation detected by DGGE reached 100% when compared to DNA sequencing and was more sensitive than restriction fragment length polymorphism. One new type II variant, designated as V2d, was found in this study. The sequence of the new variant was characterized. Our results indicated that PCR-DGGE is a rapid and reliable bio-technique for direct detection of p1 gene variations.