ANTIBACTERIAL ACTIVITY OF PERITONEAL-EXUDATE IN PATIENTS TREATED WITH2 G CEFOTIAM FOR SURGICAL ANTIMICROBIAL PROPHYLAXIS

The objective of this study was to investigate the presence of antibac terial activity in peritoneal exudate (PE) of patients treated with ce fotiam (CFT), CFT (2 g) was administered as a 'single-shot' antimicrob ial prophylaxis to 6 patients at the beginning of colorectal resection . Samples of PE were collected from each patient on days I, 2 and 3 af ter surgery. CFT was detectable in the samples of day 1 for 5 of the 6 patients. The influence of PE on antibacterial activity of the antimi crobial drug was evaluated carrying out the MICs of CFT against Escher ichia coli K-12, E. coli (ATCC 10798), Klebsiella pneumoniae (ATCC 100 3), Proteus rettgeri (Sanelli) and Staphylococcus aureus (ATCC 29213) with and without the addition of PE. The presence of PE enhanced the a ntimicrobial activity of CFT against gram-negative strains, but not ag ainst S. aureus (ATCC 29213), These results suggest the presence of su bstances in PE that possess endogenous antibacterial activity. Thus, a ntimicrobial activity in PE cannot be predicted by evaluating pathogen sensitivity in vitro only.