strain kw20 the only difference between noninfectious rd and infectious type b strains of h influenzae is the presence in type b of a set of eight tandemly arrayed genes that encode fimbrial proteins fimbriae are colonization factors that mediate bacterial adherence to human cells these genes have also been screened for complementary peptides the sequencing of the h influenzae chromosome is a very important landmark in biological research since this is the first complete genome sequence of a free living organism fleischmann et al 1995 the circular chromosome of this microorganism is 1 83 mb long with an overall g c content of approximately 38 the authors identified 1743 open reading frames orfs in the sequence sixty three of these orfs contain frameshifts or stop codons when compared to homologues from other species a total of 1 007 genes have been matched to the biological database 347 matched hypothetical proteins already in the database and 389 did not have any matches recently the h influenzae genome sequence has been re analyzed resulting in a new set of predicted genes among orfs without homologs tatusov et al 1996 the h influenzae sequences found in genbank have been re annotated based on this analysis the genus borrelia is one of the four genera of the.