Journal:
Article Title: Practical Disk Diffusion Method for Detection of Inducible Clindamycin Resistance in Staphylococcus aureus and Coagulase-Negative Staphylococci
doi: 10.1128/JCM.41.10.4740-4744.2003
Figure Lengend Snippet: Disk induction testing. (A) Positive disk induction test within a routine disk diffusion format (CNS; University Hospital). Erythromycin and clindamycin disks were placed in adjacent central positions in a standard disk dispenser. (B to D) Constitutive lincosamide resistance by disk induction testing. Growth extends to the edge of the clindamycin disk. (B) S. haemolyticus (ermA ermC msrA); (C) S. epidermidis (ermA), demonstrating a “double zone” of growth around the clindamycin disk; (D) S. aureus (ermA) showing a double-zone of growth and blunting of the outer clindamycin zone (discernible at 15 and 20 mm). (E and F) Positive disk induction test indicating inducible lincosamide resistance. Flattening of the clindamycin inhibition zone adjacent to the erythromycin disk is easily discernible at 15 and 20 mm (disks placed by hand), as well as at 26 mm. (E) S. hominis (ermC); (F) S. aureus (ermC). (G and H) Negative disk induction test indicating the absence of inducible lincosamide resistance. No flattening or distortion of the clindamycin zone adjacent to the erythromycin disk can be detected at a disk spacing of 15, 20, or 26 mm. (G) S. epidermidis (msrA); (H) S. aureus (msrA).
Article Snippet: For the first part of the experiment, a standard disk diffusion dispenser (Becton Dickinson) was used to dispense the two test disks.
Techniques: Diffusion-based Assay, Inhibition