Chapter 5.9 : Detection of Inducible Clindamycin Resistance in Staphylococcus spp., Streptococcus pneumoniae, and Streptococcus spp. Beta-Hemolytic Group

Abstract:

Inducible clindamycin resistance (ICR) in staphylococci and streptococci can be detected by agar disk diffusion (D-zone test) or broth microdilution methods. The CLSI recommends testing for inducible clindamycin resistance in all staphylococci, Streptococcus pneumoniae, and beta-hemolytic streptococci that are erythromycin resistant and clindamycin susceptible or intermediate prior to reporting clindamycin results. Isolates with inducible clindamycin resistance should be reported as clindamycin resistant alongside a comment stating that clindamycin resistance is presumed by the presence of inducible resistance and clindamycin may still be effective in some patients ( 1 , 2 , 3 ). Both the D-zone test and the broth microdilution method are described here. See Appendix 5.9–1 for a summary of testing conditions for staphylococci and streptococci using these methods. Also refer to procedures 5.1 and 5.2 for details of performing the disk diffusion and broth microdilution MIC methods, respectively.