Antibiotic Concentration Sensitive (mm) Semi-sensitive (mm) Resistant (mm) Statistical test and significancy Particulars
ciprofloxacin 5 µg ≥ 21 16-20 ≤ 15 X2=83.5, p<0.001 -
Ceftriaxone 30 µg ≥ 21 14-20 ≤ 13 fisher΄s exact test=101.1, p<0.001 -
Penicillin 10 unit ≥ 29   -- ≤ 28 fisher΄s exact test=10.09, p<0.003 When testing staphylococci
  10 unit ≥ 15   -- ≤ 14 fisher΄s exact test=10.09, p<0.003 When testing enterococci
  10 unit ≥ 28 20-27 ≤ 19 fisher΄s exact test=10.09, p<0.003 When testing streptococci (not s. pneumoniae)
vancomycin 30 µg ≥ 17 15-16 ≤ 14 X2=61.07, p<0.001 When testing enterococci
  30 µg ≥ 12 10-11 ≤ 9 X2=61.07, p<0.001 When testing other positive organisms
Table 1: Zone of inhibition (mm) according to type of sensitivity.