THE EFFECTS OF LOW CONCENTRATIONS OF ANTIBIOTICS ON EPITHELIAL DAMAGECAUSED BY NONTYPABLE HAEMOPHILUS-INFLUENZAE AND BACTERIAL MORPHOLOGY

Sterile culture filtrates from non-typable Haemophilus influenzae (NTH i) grown in medium containing no antibiotics or 0.25 MIC of amoxycilli n, ciprofloxacin or loracarbef were examined for their effect on the c iliary beat frequency (CBF) and structure of human respiratory epithel ium. CBF slowing was significantly (P < 0.05) less with 0.25 MIC of al l three antibiotics. The epithelium was significantly (P < 0.05) less disrupted with ciprofloxacin. The morphology of NTHi infecting human a denoid organ cultures after 24 h with or without 0.25 MIC of the same antibiotics was measured by scanning electron microscopy. Only ciprofl oxacin caused a significant (P < 0.05) change in morphology.