comparative in-vitro activity of quinolones, piperacillin and nitrofurantoin against hospital urinary isolates

ABSTRACT

Ofloxacin, norfloxacin and pefloxacin, the recent quinolones were compared for their in-vitro antibacterial activity with the earlier ones as nalidixic acid, oxolinic acid and pipemidic acid against 110 recent hospital urinary isolates. The most active of the tested drugs were norfloxacin and ofloxacin [57.27% and 56.36%] followed by pefloxacin and oxolinic acid [both were 45.45%], while pipemidic acid and nalidixic acid were only 32.37% and 17.27%. The sensitivity to nitrofurantoin was 24.54% only. Pseudomonas isolates were more sensitive to the three new quinolones and piperacillin than to the earlier ones and nitrofurantoin. Norfloxacin and piperacillin gave high percentages of activity against those strains [78.90% and 68.42%]. 28 isolates showed multi-resistance to the earlier and recent quinolones. The MICs values of the resistant strains including Pseudomonas were higher [>128 mug/ml] with the earlier quinolones than the MICs of the recent ones [<32 mug/ml]