Nocardia is a genus of bacteria that belong to the family Nocardiaceae. These bacteria are characterized by their branching, filamentous structure and are often referred to as filamentous, aerobic actinomycetes. The genus Nocardia comprises various species that are commonly found in the environment, particularly in soil, water, and decaying organic matter.
Nocardia bacteria are Gram-positive, meaning they retain the crystal violet stain during the Gram staining process. They are usually classified as acid-fast bacteria due to their ability to retain a red stain when subjected to an acid-fast staining technique. This characteristic is attributed to the presence of mycolic acids in their cell wall.
Nocardia species are considered opportunistic pathogens, meaning they typically cause infections in individuals with weakened immune systems. These infections can manifest in different forms, including cutaneous, pulmonary, and brain abscesses. Nocardiosis, the disease caused by Nocardia, often presents as a chronic or subacute infection and primarily affects the lungs, leading to symptoms such as cough, chest pain, and difficulty breathing. However, it can also involve other organs, such as the skin, brain, and kidneys.
Treatment of nocardiosis usually involves a combination of antibiotics, such as sulfonamides or trimethoprim-sulfamethoxazole, over an extended period. However, the choice of antimicrobial therapy may vary depending on the species of Nocardia involved and the site of infection.
In summary, Nocardia is a genus of filamentous, aerobic actinomycetes that can cause opportunistic infections primarily in immunocompromised individuals.
