Comparison of ciprofloxacin and rifampicin in experimentalLegionella pneumophila pnemnonia

Publisher Website
Google Scholar
Abstract
We evaluated intraperitoneal ciprofloxacin and rifampicin alone and as combination therapy in experimentally inducedLegionella pneumophila pneumonia in guinea pigs. Intraperitoneal treatment began 48 h after intratracheal inoculation of 3×106L.pneumophila and consisted of sterile saline (0.3ml bid), ciprofloxacin (30 mg/kg bid), rifampicin (10 mg/kg/bid), or ciprofloxacin plus rifampicin (same doses). Animals were treated for five days and survivors killed after 11 days. Quantitative lung cultures were donepost mortem. Respective mean and median days of animal survival were increased by treatment with ciprofloxacin plus rifampicin (8.4 and 9.5 days), ciprofloxacin (8.2 and 7.5 days), or rifampicin (8.3 and 7.5 days), compared with controls (5.5 and 5.0 days). Compared with control animals (log rank test) survival was improved by treatment with ciprofloxacin plus rifampicin (P≤0.047) ciprofloxacin (P≤0.047) or rifampicin (P≤0.047). Quantitative lung cultures (cfu/g) were also decreased by treatment with ciprofloxacin plus rifampicin (2.0×104), ciprofloxacin (5.4×104), or rifampicin (1.7×104) compared with controls (3.2 ×l08). No differences in survival, quantitative lung cultures, or animal weights were noted between treatment groups. This study demonstrates that ciprofloxacin is as effective as rifampicin in the treatment of experimentally induced L.pneumophila pneumonia and that the combination of ciprofloxacin plus rifampicin has no advantages over single agent therapy in this model.