Elimination of epimural microflora from guinea pig cecal epithelium by antimicrobial drugs

The effect of antimicrobial drugs on epimural bacteria of guinea pig cecum was assessed by scanning electron microscopy. Metronidazole (500 hg/ml), neomycin (50 hg/ml) or both combined were given orally in drinking water ad libitum for five consecutive days, and representative fragments of cecum were processed for analysis. In untreated animals large areas of mucosa were lined by spiral-shaped bacteria were eliminated by treatment with neomycin, only remaining fusiform bacteria at openings of crypts. metronidazole was effective for eliminating all bacterial populations; the same effect was achieved with a combination of neomycin and metronidazole, rendering the cecum free of epimural bacteria, the health of guinea pig was unaffected by these treatments. The cecal epithelium of antimicrobial-treated animals can be used for experimental studies without interference of epimural bacteria.