Elucidation of antibiotic effectiveness against Staphylococcus epidermidisduring intraocular lens implantation

The effect of various antimicrobial agents commonly used in irrigating solu tions on the hydrophobicity and adherence of Staphylococcus epidermidis ATC C 14990 was investigated. The longest post-antibiotic effect (PAE = 3.2 h) was obtained with gentamicin followed by ciprofloxacin (2.7 h), clindamycin (2.2 h), ceftazidime (1.8 h) and vancomycin (1.6 h). The post-antibiotic e ffect on surface hydrophobicity of cells previously treated with gentamicin , ciprofloxacin, or clindamycin for 120 min resulted in a substantial decre ase in affinities to hexadecane (31.4, 28.5 and 27%, respectively) compared with control untreated cells. Less effect was noted with cells previously treated with ceftazidime or vancomycin (20.5 and 15.8%, respectively). Simi lar but less marked results were obtained when the cells were exposed to an tibiotics for 30 or 60 min. The post-antibiotic effect on adherence of cell s to both intraocular lenses and to epithelial cells showed that adherence to lenses decreased as the time of exposure to antimicrobial agents increas ed. Adherence was greatly diminished with cells treated with gentamicin or ciprofloxacin compared with control untreated cells. Adherence was less aff ected by clindamycin, ceftazidime and vancomycin. The data supported the us e of antimicrobial agents in irrigating solution during intraocular surgery , since, reduced adherence (colonization) and might result in a lower incid ence of endophthalmitis. (C) 2001 Elsevier Science B.V. and International S ociety of Chemotherapy. All rights reserved.