USE OF THE COMPLETE GENOME SEQUENCE INFORMATION OF HAEMOPHILUS-INFLUENZAE STRAIN RD TO INVESTIGATE LIPOPOLYSACCHARIDE BIOSYNTHESIS

The availability of the complete 1.83-megabase-pair sequence of the Ha emophilus influenzae strain Rd genome has facilitated significant prog ress in investigating the biology of H. influenzae lipopolysaccharide (LPS), a major virulence determinant of this human pathogen, By search ing the H. influenzae genomic database, with sequences of known LPS bi osynthetic genes from other organisms, we identified and then cloned 2 5 candidate LPS genes, Construction of mutant strains and characteriza tion of the LPS by reactivity with monoclonal antibodies, PAGE fractio nation patterns and electrospray mass spectrometry comparative analysi s have confirmed a potential role in LPS biosynthesis for the majority of these candidate genes. Virulence studies in the infant rat have al lowed us to estimate the minimal LPS structure required for intravascu lar dissemination, This study is one of the first to demonstrate the r apidity, economy and completeness with which novel biological informat ion can be accessed once the complete genome sequence of an organism i s available.