Eggerthella

Eggerthella is a genus of Gram-positive bacteria within the family Eggerthellaceae. These bacteria are anaerobic and non-motile, and they are part of the normal human microbiota, particularly in the gastrointestinal tract. Eggerthella species have been implicated in various human infections, especially in immunocompromised individuals.

Taxonomy

Eggerthella was first described in 1999 by Wade et al. The genus is named after the German bacteriologist Arnold Eggerth. It belongs to the phylum Actinomycetota, class Coriobacteriia, and order Eggerthellales.

Species

The genus Eggerthella includes several species, with the most notable being:

• Eggerthella lenta
• Eggerthella sinensis

Morphology

Eggerthella species are Gram-positive rods. They are non-spore-forming and non-motile. The cells are typically 0.5-0.8 µm in diameter and 1.0-2.5 µm in length. They often appear singly or in pairs.

Metabolism

Eggerthella species are obligate anaerobes, meaning they thrive in environments devoid of oxygen. They are chemoorganotrophic, utilizing organic compounds for energy. Eggerthella lenta, for example, is known for its ability to metabolize bile acids and steroids.

Habitat

Eggerthella species are commonly found in the human gastrointestinal tract, where they are part of the normal gut microbiota. They have also been isolated from the oral cavity and vagina.

Clinical Significance

Eggerthella species, particularly Eggerthella lenta, have been associated with various infections, including:

• Bacteremia
• Endocarditis
• Intra-abdominal infections
• Soft tissue infections

These infections are more common in immunocompromised patients or those with underlying health conditions. Eggerthella infections can be challenging to diagnose due to their slow growth and the need for anaerobic culture conditions.

Antibiotic Resistance

Eggerthella species have shown resistance to several antibiotics, including clindamycin and metronidazole. However, they are generally susceptible to penicillin and carbapenems. The choice of antibiotic treatment should be guided by antibiotic susceptibility testing.

Role in the Gut Microbiota

In the gut, Eggerthella species play a role in the metabolism of complex carbohydrates and the transformation of bile acids and steroids. They contribute to the maintenance of gut health and the balance of the microbiome.

Research and Future Directions

Research on Eggerthella is ongoing to better understand its role in health and disease. Studies are focusing on its metabolic capabilities, interactions with other gut microbes, and potential implications in metabolic disorders and inflammatory diseases.

See Also

• Gut microbiota
• Anaerobic bacteria
• Antibiotic resistance