Antimicrobial interference with bacterial mechanisms of pathogenicity: effect of sub-MIC azithromycin on gonococcal piliation and attachment to human epithelial cells.

The effects of subinhibitory concentrations of azithromycin (CP-62,993) on the piliation and attachment properties of Neisseria gonorrhoeae were examined. Subinhibitory concentrations of azithromycin significantly reduced the percentage of gonococci that expressed assembled pili on their surfaces by decreasing pilin subunit synthesis and substantially decreased gonococcal adherence to human mucosal cells.