Detection of inducible lincosamide resistance by disk induction testing with erythromycin and clindamycin disks at different distances

Organism and phenotyped (no. of isolates)No. of isolates with positive disk induction testa at a separationb (mm) of:
S. aureus (130)
    Erys Clis (16)000
    Eryr Clis (75)343433c
    Eryr Clir (39)NAeNANA
CNS (100)
    Eryr Clis (43)NDf2525
    Eryr Clir (57)NDNANA
  • a Positive test indicated by flattening of the clindamycin zone.

  • b Distance between disks from edge to edge.

  • c One S. aureus isolate showed no blunting or flattening of the clindamycin zone at a disk spacing of 26 mm. This isolate contained the ermA gene by PCR.

  • d Ery, erythomycin; Cli, clindamycin; r, resistant; s, susceptible.

  • e NA, not applicable.

  • f ND, not done.