Streptococcus spp Group C & G

• S. dysgalactiae subsp dysgalactiae (C)
• S. dysgalactiae subsp equisimilis (C,G)
• S. equi subsp equi (C)
• S. equi subsp zooepidermicus (C)
• S. canis (G)

Gram Stain

• Gram positive cocci in chains (aerobic)

Clinical Significance

These organisms are part of the commensal oropharyngeal and gastrointestinal flora. They may also temporarily colonize the skin.

They are associated with skin, soft tissue, bone and joint infections, pharyngitis, endocarditis, septicemia, meningitis, pneumonia, neonatal and postpartum infections, especially in patients with diabetes, immunosuppression, malignancy (especially Group G), chronic cardiopulmonary disease, or alcoholism.

S. dysgalactiae subsp equisimilis (C) and S. canis (G) cause a variety of infections in animals.  Human infections may be associated with animal exposure (especially dogs and cats).

S. canis - associated with soft tissue infections, bacteremia, urinary tract infections, osteomyelitis, and pneumonia.  Infections are often polymicrobial.  Diabetes appears to be a predisposing condition.

Usual Susceptibility Pattern

These organisms are usually susceptible to penicillin (although tolerance has been described), cephalosporins, and vancomycin.

Tolerance to vancomycin has rarely been described in certain Group G streptococci.

There is significant resistance to macrolides and clindamycin.