[Study of the sensitivity to pipemidic acid, pefloxacin and norfloxacin of 444 bacterial strains isolated at a general hospital].

After one year of use of pefloxacin in the intensive care unit, medicine unit and surgery unit and the following recent commercialization without prescription of norfloxacin, we studied for a period of two months (april and may 1986) the susceptibility to pipemidic acid, to pefloxacin and norfloxacin of 444 bacteria strains isolated obtained from clinical specimens. The antibiotic susceptibility is determined by disk diffusion test. We obtained the following results: susceptible methicillin Staphylococcus aureus (SMSA 63 strains): 85.7% PEFS, 11.1% PEFI, 79.4% NORS, 15.9% NORI, resistant methicillin Staphylococcus aureus (RMSA 36 strains): 33.3% PEFS, 2.9% PEFI, 41.6% NORS, 0% NORI; Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae (252 strains): 94% PIPS, 94.8% PEFS, 97.2% NORS; Enterobacter, Proteus indol (+), Providencia and Citrobacter (33 strains): 72.7% PIPS, 72.7% PEFS, 84.8% NORS; Pseudomonas aeruginosa (53 strains): 32% PEFS, 47.2% PEFI, 90.6% NORS, 5.6% NORI; Acinetobacter (7 strains): 57.2% PEFS, 42.8% PEFI, 42.8% NORS, 28.6% NORI. Norfloxacin in active in vitro against the majority of the P. aeruginosa isolated. We found an important methicillin and pefloxacin resistance among the Staphylococcus aureus isolated: 36 strains RMSA (36.4% out of Staphylococcus aureus) and 23 strains RMSA PEFR (63.8% out of RMSA). These later strains were isolated in eight different units mainly in visceral surgery unit and geriatric units but not in intensive care unit. After an epidemiologic study and the following recommendations to physicians and nurses: treatment by pefloxacin should be used only after bacteriological results and associated with an other antibiotic, the handwashing should be frequent and regular to prevent the spread of infection, four months later we isolated 26 strains of RMSA with 7 RMSA PEF (26.9%).2$