Granulicatella spp

• G. adiacens
• G. balaenopterae
• G. elegans

Gram Stain

• Gram positive cocci in pairs and chains-often very pleomorphic (aerobic)

Clinical Significance

These organisms are part of commensal oropharyngeal flora.

They can cause native and prosthetic valve endocarditis, bacteremia, ophthalmic infections, and iatrogenic central nervous system infections (brain abscesses/meningitis).  Note: More commonly associated with endocarditis than Abiotrophia spp and tend to cause more relapses.

They have rarely been implicated in post-partum infections, febrile neutropenia, wound infections, and chronic sinusitis.

Usual Susceptibility Pattern

Penicillin susceptibility is variable but most isolates remain susceptible to ampicillin.

Susceptibility to cephalosporins is variable (including 3rd and 4th generation).

Imipenem has better activity than meropenem. 

Tolerance to beta-lactam antibiotics has been documented.

These organisms are typically susceptible to clindamycin, vancomycin, linezolid, and rifampin (rifampin may be useful as combination therapy for central nervous system infections).