Antibacterial activity of norfloxacin against 1700 relatively resistant clinical isolates

A total of 1724 clinical isolates from patients with different infections were tested in vitro to determine their susceptibility to norfloxacin. Antibacterial activity of norfloxacin was compared with other drugs that were commonly used in the hospital. Of the 919 strains of Enterobacteriaceae tested, all except four isolates of Enterobacter, two of Serratia and one of Proteus were susceptible to norfloxacin. Ninety-five percent of the 199 strains of Pseudomonas aeruginosa were also inhibited by this quinolone. Brucella melitensis (81 strains) was completely susceptible to norfloxacin. All the 250 isolates of Staphylococcus aureus and coagulase-negative staphylococci were also sensitive to norfloxacin. Pseudomonads other than P.aeruginosa, Acinetobacter/Alcaligenes and group D streptococci were less sensitive to norfloxacin, with 56%, 57% and 20% respectively being inhibited by this antimicrobial agent.