Streptococcus Gallolyticus (Group D Strep)

Streptococcus gallolyticus (previously known as Strep bovis or Strep equinus complex) is a group D strep bacteria. These bacteria are gram-positive cocci that typically occur in chains or pairs and are encapsulated with a polysaccharide capsule. Strep gallolyticus is generally gamma-hemolytic, meaning it does not cause hemolysis on blood agar plates. It is capable of forming biofilms and growing in bile salt media, particularly on collagen-rich surfaces such as heart valves. Strep gallolyticus is often found in the GI tract of animals and humans, acting as an opportunistic pathogen. Clinically, it can cause bacteremia and endocarditis, as well as infections such as hepatobiliary disease, septic arthritis, osteomyelitis, UTIs, meningitis, and mastitis. There is also a strong association between Strep gallolyticus infection and colorectal neoplasia. This bacteria's sensitivity to 3rd generation cephalosporins, vancomycin, and penicillin makes these antibiotics effective treatments for Strep gallolyticus infections.