Clindamycin spectrum of activity?

Clindamycin is a lincosamide with activity mainly against anaerobes and Gram-positive cocci. Key points:

- Excellent/strong coverage:
- Gram-positive cocci: Streptococcus species (including group A, B, viridans; pneumococcus variable), Staphylococcus aureus (mostly MSSA; MRSA coverage is variable and often unreliable)
- Anaerobic Gram-positive cocci: Peptostreptococcus, some Propionibacterium (Cutibacterium) spp.
- Actinomyces
- Some anaerobic Gram-negative cocci (e.g., Veillonella)

- Moderate to variable coverage:
- Some oral and other anaerobes; activity against Bacteroides fragilis group is unreliable and often poor because many strains are resistant

- Poor/not active:
- Most aerobic Gram-negative rods (Enterobacteriaceae like E. coli, Klebsiella; Haemophilus, Pseudomonas)
- Most Enterococcus
- Mycoplasma, Chlamydia, Rickettsia (not active)

- Important resistance issue:
- Inducible MLSB resistance in Staphylococcus aureus and other staph species can confer resistance to clindamycin even if in vitro testing looks susceptible. The D-test is used to detect inducible resistance.

Clinical takeaway:
- Suitable for many streptococcal and MSSA infections and for some anaerobic infections (especially oral/soft tissue), but avoid relying on it for many Gram-negative or B. fragilis–type infections. Check local susceptibility and perform D-test when MRSA or erythromycin-resistant strains are suspected. If you want, I can tailor this to a specific organism or infection type.