HAEMOPHILUS-DUCREYI IS SUSCEPTIBLE TO PROTEGRIN

Protegrins, potent antimicrobial peptides found in pol cine leukocytes , have activity against the sexually transmitted pathogens Neisseria g onorrhoeae, Chlamydia trachomatis, and human immunodeficiency virus ty pe I. We tested synthetic protegrin 1 (PG-I) for activity against nine isolates of Haemophilus ducreyi, the etiologic agent of chancroid, Th e test organisms included CIP 542 (the type strain). 35000HP (a human- passaged variant of 35000), 35000HP-RSM2 tan isogenic D-glycero-D-mann o-heptosyltransferase mutant of 35000HP), and six clinical isolates. T he isolates were epidemiologically unrelated, represented three HindII I ribotypes, and had varying antimicrobial resistance patterns. In bac tericidal assays, live isolates were rapidly; killed bq synthetic PG-1 , In radial diffusion assays, all nine isolates were exquisitely sensi tive to PG-I, These data highlight the potential of protegrins for dev elopment as topical agents to prevent many sexually transmitted diseas es, including chancroid.