Comparison of the Virulence Factors and Analysis of Hypothetical Sequences of the Strains TIGR4, D39, G54 and R6 of Streptococcus Pneumoniae

Abstract

Whole genome sequences of the four strains of Streptococcus pneumoniae, encapsulated TIGR4, D39, G54 and nonencapsulated R6 are considered for the comparative study on genome features, whole genome pairwise alignment, gene role category, and virulence factors using relevant comparative genomics tools. The study of capsular polysaccharide synthesizing genes reveals that many cps genes are unique to TIGR4, which shows the high virulence nature of TIGR4. Further, the study on the other virulence factors such as pneumococcal surface protein A, autolysin, hyaluronate lyase, pneumolysin, neuraminidase B, and pneumococcal surface antigen A of TIGR4 are much related to those of the other three strains, and hence the virulence nature due to these factors among four strains seems to be similar. But it differs from neuraminidase A, choline binding protein A and immunoglobulin A1 protease. Also in the present study, 4 and 22 hypothetical protein sequences of TIGR4 and R6 respectively are predicted as virulence factors. Among those sequences, it is found that 8 hypothetical protein sequences with 7 different functional regions of R6 are related to other previously known virulence factors of TIGR4 and R6 of S. pneumoniae.