Genomic and phylogenetic analysis of Mycoplasma pneumoniae strains’ P1 adhesin Gene

Abstract

Mycoplasma pneumoniae is a common cause of respiratory diseases in children’s, responsible for approximately 40% of community-acquired pneumonia (CAP) in Indian children under five years. The pathogenicity of this agent is mediated by a terminal structure containing adhesin proteins such as the P1 and P40/90 coded respectively by the P1 and the orf6 genes. The aim of our study is to analyze and compare P1 adhesin gene sequences of M. pneumoniae isolated in children, explore their genetic variabilities and evaluate their phylogenetic relationships.

A comprehensive search of M. pneumoniae P1 adhesin gene sequences was conducted from GenBank database, the retrieved nucleotidic sequences were downloaded in FASTA format for subsequent analysis and related meta data were identified. The multiple alignement was performed using ClustalW (version 2.1) and the phylogenetic analysis was performed using Molecular Evolationary Genetics Analysis using MEGA 11 (version 3.0.1) software.

The multiple alignement of the retrieved M. pneumoniae P1 adhesin gene type 1 and type 2 sequences revealed conserved regions, in addition to various substitutions and deletions in different nucleotidic positions. The type 1 strains phylogenetic analysis highlights that only South Korean strains belong to the same cluster, and the majority of the Japaneese type 2 strains also cluster in the same clades, suggesting similar ancectry with small variations between all the divergent strains across the time and locations. However, some of the type 2 strains didn’t show close evolutionary relationship.

M.pneumoniae P1 adhesin gene genomic analysis is a significant approach to define the genetic variability and the phylogenetic analysis allows defining the evolutionary relationships between strains. Furthermore, the approach revealed that variations in the P1 adhesin gene doesn't have a deleterious effect of the encoded proteins and hence doesn’t affect the pathogenicity of M. pneumoniae isolates.