Polymerase chain reaction-based strain characterization of noncapsulate Haemophilus influenzae.

A polymerase chain reaction-based typing methodfornoncapsulate Haemophilus influenzae wasdeveloped. Randomly amplified polymorphic DNAfingerprints weregenerated fromboiled supernatants prepared directly frombacterial colonies without theneedforDNAextraction. Thetechnique wasapplied toisolates obtained during putative outbreaks ofchest infection andvalidated bycomparison withsodiumdodecyl sulfatepolyacrylamide gelelectrophoresis analysis ofoutermembrane protein-enriched preparations andrRNAgene restriction analysis. Therewascomplete concordance between thethree techniques. Theresults showthat randomly amplified polymorphic DNA analysis provides ahighly discriminatory methodofcharacterizing strains ofnoncapsulate H.influenzae whichiseminently suitable asanepidemiological toolfortherapid investigation ofoutbreaks ofinfection. Nonserotypeable, noncapsulate Haemophilus influenzae (NCHI)cancausearangeofserious infections including chronic bronchitis, pneumonia, andbacteremia (11), especially intheelderly, andhasalsobeenresponsible for invasive disease inimmunocompromised hosts(23). The