Group G Streptococcus (GGS) refers to a diverse group of bacteria commonly found on human skin, in the throat, and within the digestive tract. While often part of the normal human flora and causing mild infections, GGS can sometimes lead to more serious health complications. The potential for severe disease depends on various factors, including an individual’s overall health.
Understanding Group G Strep
Group G Streptococcus is a type of beta-hemolytic bacteria, meaning it completely breaks down red blood cells in a lab setting. These bacteria are commonly found as normal microbiota in areas like the skin, oral cavity, nasopharynx, gastrointestinal tract, and vagina. While GGS can cause infections similar to Group A Streptococcus (GAS), such as strep throat, GGS infections are often less severe in healthy individuals. Streptococcus dysgalactiae subspecies equisimilis (SDSE) is a prominent species within Group G associated with human infections.
Assessing the Danger
For many healthy individuals, Group G Strep infections typically present as mild conditions that may resolve on their own or with standard treatment. These often include localized infections such as pharyngitis, or skin and soft tissue infections like cellulitis or impetigo. However, the danger associated with GGS increases significantly in certain populations, particularly among the elderly, those with weakened immune systems, or individuals with pre-existing medical conditions like diabetes or malignancy. In these vulnerable groups, GGS can act as an opportunistic pathogen, leading to more widespread and severe infections, including systemic illness like bloodstream infections.
Serious Health Outcomes
GGS can lead to invasive disease when bacteria enter normally sterile areas of the body, potentially resulting in severe, life-threatening conditions. One serious outcome is bacteremia, the presence of GGS in the bloodstream. This can originate from various sites, often skin infections, and is more common in patients with underlying health issues like diabetes, cardiovascular disease, or malignancy. Endocarditis, an inflammation of the heart’s inner lining or valves, is another serious infection that may arise on previously healthy heart valves. GGS endocarditis often progresses rapidly and carries a high mortality rate.
Bone infections, known as osteomyelitis, can also be caused by GGS, sometimes affecting the spine. These infections have been reported in older adults and individuals with underlying conditions, and symptoms can sometimes mimic those of bone tumors. Septic arthritis, an infection within a joint, can result from GGS, frequently affecting large joints such as the knee or hip. Risk factors include advanced age, pre-existing joint disease, or conditions that suppress the immune system.
Although rare, GGS is implicated in necrotizing fasciitis, a severe, rapidly spreading “flesh-eating” infection that destroys soft tissues. This condition, similar in severity to those caused by Group A Streptococcus, requires immediate surgical intervention and antibiotic therapy. Additionally, GGS can cause puerperal sepsis, an infection following childbirth. While Group A Streptococcus has historically been a more recognized cause of postpartum infections, GGS can also lead to this serious complication, especially when mucosal barriers are disrupted. Unlike Group A Strep, GGS is rarely associated with post-streptococcal complications like rheumatic fever.
Identification and Management
Diagnosing a Group G Strep infection typically involves a combination of clinical assessment and laboratory tests. A healthcare provider may collect samples such as a throat swab, blood culture, or wound culture, depending on the suspected site of infection. These samples are then analyzed to identify the presence of GGS bacteria. Rapid antigen detection tests can also be used, though they may not always differentiate between different streptococcal groups.
Treatment for GGS infections primarily involves antibiotics. Penicillin or amoxicillin are generally considered first-line treatments due to the bacteria’s susceptibility. For individuals with penicillin allergies, alternative antibiotics like clindamycin or certain cephalosporins may be prescribed. Completing the full course of antibiotics, even if symptoms improve, is important to ensure complete eradication and prevent complications. Timely diagnosis and appropriate treatment are important for invasive infections or in high-risk individuals to reduce severe health outcomes.