[In vitro activity of norfloxacin against gram-positive and gram-negative organisms from recent clinical isolates]

Boll Ist Sieroter Milan. 1985;64(4):289-93.
[Article in Italian]


A total of 274 recently isolated Gram-positive e Gram-negative strains have been tested. The method used for the determination of the minimal inhibitory concentration of the antibiotics was by agar dilution and the minimal bactericidal concentrations were determined by "replica plating" system. All strains demonstrated a good sensitivity, above all, to Norfloxacin which inhibited Gram-positive bacteria at the concentration of 3.12 micrograms/ml and, concerning Gram-negative, at the concentration of 0.10 microgram/ml for K.E.S. group, 0.19 microgram/ml for Escherichia coli, 6.25 micrograms/ml for Proteus sp and 1.56 microgram/ml for Pseudomonas aeruginosa. Also with the other antibiotics we obtained good results especially with Nitrofurantoin concerning Enterococcus and Ceftazidime concerning all the strains. On the basis of these results we can conclude that Norfloxacin is one of the most active antibiotics among those used against strains implicated in urinary infections.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Escherichia coli / drug effects
  • Gram-Negative Bacteria / drug effects*
  • Gram-Positive Bacteria / drug effects*
  • Humans
  • Microbial Sensitivity Tests
  • Norfloxacin / pharmacology*
  • Proteus / drug effects
  • Pseudomonas aeruginosa / drug effects
  • Staphylococcus / drug effects
  • Urinary Tract Infections / microbiology


  • Norfloxacin