Table 4.

Selected resistance rates by organism grouping and treatment

GroupaNo. of isolates% Rb(n)Rate of resistance developmentc (%) for indicated treatment
CIPCEFMNXCAZCIP/PIPCAZ/TOB
13946.1 (18)66.7 (12/18)55.5 (5/9)0 (0/3)0 (0/7)50 (1/2)
23727 (10)6.7 (1/15)70 (7/10)50 (2/4)0 (0/3)0 (0/5)
34010 (4)17.6 (3/17)0 (0/9)20 (1/5)0 (0/5)0 (0/4)
4120 (0)0 (0/8)ND0 (0/3)0 (0/1)ND
All organisms13125 (32)27.6 (16/58)42.9 (12/28)20 (3/15)0 (0/16)9.1 (1/11)
  • a For a description of organisms in each group, see Materials and Methods.

  • b R, overall rate of resistance development.

  • c CIP, ciprofloxacin; CEFMNX, cefmenoxime; CAZ, ceftazidime; CIP/PIP, ciprofloxacin plus piperacillin; CAZ/TOB, ceftazidime plus tobramycin; ND, not done. The numbers in parentheses are numbers of resistant isolates/total numbers of isolates.