Finegoldia magna is a type of bacterium categorized as an anaerobic, Gram-positive coccus. It was previously known as Peptostreptococcus magnus before being reclassified into its own genus in 1999. This bacterium is a natural part of the human microbiome, meaning it commonly lives on and within the human body without causing harm. However, under specific conditions, Finegoldia magna can become an opportunistic pathogen and lead to various infections.
Where Finegoldia is Found
Finegoldia magna commonly inhabits several parts of the human body, particularly environments with low oxygen. It is frequently found on the skin, where it is a regular component of the skin microbiota.
Beyond the skin, Finegoldia magna colonizes various mucous membranes. This includes the genitourinary tract, the gastrointestinal tract, and the oral cavity.
Finegoldia’s Impact on Health
Finegoldia magna plays a dual role in human health. As part of the normal human microbiome, particularly on skin and mucosal surfaces, it generally coexists without causing disease. Its presence can even contribute to host protection by competing with more harmful microbes for nutrients and preventing their adherence.
However, Finegoldia magna can become an opportunistic pathogen when natural barriers, like the skin or mucous membranes, are compromised, allowing the bacteria to enter deeper, normally sterile tissues. Breaches can occur due to trauma, surgery, or in individuals with weakened immune systems. It is considered one of the most virulent gram-positive anaerobic cocci.
Finegoldia magna is frequently associated with a variety of infections. These include skin and soft tissue infections, such as abscesses, cellulitis, and necrotizing fasciitis, particularly in immunocompromised patients or those with conditions like diabetes. It is also implicated in bone and joint infections, including osteomyelitis and prosthetic joint infections, where it can form biofilms that contribute to chronic infection.
The bacterium can also cause deeper-seated infections, such as bloodstream infections, infective endocarditis, necrotizing pneumonia, and mediastinitis. It often participates in polymicrobial infections, though it can also be isolated as the sole pathogen in some cases.
Addressing Finegoldia Infections
Diagnosis typically involves culturing samples from infected tissues or fluids, though this can be challenging due to its slow growth and specific anaerobic requirements. Molecular methods, such as PCR and 16S rRNA gene sequencing, have proven valuable in diagnosing these infections, especially when traditional cultures are negative or difficult.
Treatment strategies for Finegoldia infections primarily involve antibiotic therapy, often combined with surgical drainage or debridement for localized collections of pus or necrotic tissue. Metronidazole, amoxicillin-clavulanate, cefoxitin, linezolid, and chloramphenicol show good activity against Finegoldia magna. While most strains are susceptible to common anti-anaerobic antibiotics, resistance to certain agents like clindamycin has been observed in some isolates, with resistance rates for clindamycin reported around 9.5-10% and penicillin around 2.4%.
Surgical intervention, such as debridement, is often necessary for severe infections like subcutaneous abscesses or necrotizing fasciitis, especially in diabetic patients. This helps to remove infected tissue and improve antibiotic penetration. The prognosis for Finegoldia magna infections is favorable with appropriate treatment, typically involving targeted antibiotics and surgical management.