[In-vitro activity of enoxacin: a multicenter study]

The in vitro activity of enoxacin was tested in 14 German microbiological centers shortly after the introduction of the drug in Germany. 2748 unselected clinical isolates including 15 bacterial species were analysed using microtiter plates. The MIC90-values were as follows: Staphylococcus aureus 4 mg/l, Enterococcus faecalis 16 mg/l, Enterobacteriaceae 0.5 mg/l, Pseudomonas aeruginosa 8 mg/l. There is good correlation between these results and those of former investigations. It is known that quinolones are only moderately active against enterococci. 8.5% of S. aureus, and 1.4% of Enterobacteriaceae were found to be resistant (MIC greater than 4 mg/l). As to P. aeruginosa, the study revealed that despite a generally low rate of resistance in specific clinical settings, specific problems can arise: in one institution, the MIC90 of P. aeruginosa was 32 mg/l, with a resistance rate of 56.1% (n = 57). In the other centers the MIC90 was 2 mg/l and the resistance rate 5.0% (n = 302). In the first center, many of the isolates were from paraplegic patients or patients with cystic fibrosis pretreated with quinolones. This study will be repeated in two years' time in order to determine an eventual change in resistance.