A QUANTITATIVE CHEMILUMINESCENT RIBOSOMAL PROBE METHOD FOR MONITORINGADHERENCE OF HAEMOPHILUS-DUCREYI TO EUKARYOTIC CELLS

This study evaluated a commercially available chemiluminescent-labelle d, ribosomal RNA-directed DNA probe (CRP) as a method to quantitate at tachment of H. ducreyi to human foreskin fibroblast (HFF) cells. Evalu ation of four strains of H. ducreyi demonstrated that the CRP assay wa s unaffected by eukaryotic cells and its advantages were: (i) quantita tion was done after attachment so it did not interfere with the attach ment process, and (ii) it was a rapid, reliable method for quantitatin g bound bacteria, despite bacterial clumping. Gentamicin-killed H. duc reyi attached to both HFF cells and viable controls, suggesting that t he adhesins are components constitutively present on the surface of H. ducreyi. This method may be widely applicable, since the probe recogn izes most prokaryotic rRNA sequences.