Strain Typing of Mycoplasma pneumoniae and its Value in Epidemiology

Genotyping of Mycoplasma pneumoniae, a pathogen responsible for community-acquired pneumonia that occurs both endemically and epidemically worldwide, is essential for understanding M. pneumoniae distribution and relatedness and for determining the epidemiology of infection caused by this pathogen. It may also explain most phenotypic variability, such as geographic distribution, host specificity, antibiotic resistance, and virulence. However, the molecular typing is hampered by the fact that M. pneumoniae is a genetically homogeneous species in which large genomic rearrangements do not frequently occur. For these reasons, it has been difficult to develop a typing method with a good discriminatory power below the species level. Many molecular methods have been used for genotyping M. pneumoniae. Some of them are based on studying the banding pattern profiles resulting from endonuclease restriction, or from PCR amplification combined with or without restriction, while some others study DNA sequence polymorphisms by sequencing. According to the method used, the target can be a single gene, multiple genes, or the whole genome. In this review, we describe these methods following the classification mentioned above. We also discuss the epidemiological value of M. pneumoniae genotyping particularly for the most commonly used techniques.