Which Nocardia species commonly cause pulmonary disease?

The genus Nocardia has many species and an increasing number are recognized as causes of human disease. N. asteroides usually causes pulmonary and disseminated infection.

Does Nocardia cause pneumonia?

Nocardia infection develops when you breathe in (inhale) the bacteria. The infection causes pneumonia-like symptoms. The infection can spread to any part of the body. People with a weak immune system are at a high risk for nocardia infection.

What disease does Nocardia cause?

In the United States, nocardiosis most often shows up as a lung infection. In all cases, if the disease is left untreated, it can spread to other parts of the body, including the spinal cord and the brain. The brain is the most common site of disseminated infection.

What is nocardia infection?

Nocardiosis is a disease caused by bacteria found in soil and water. It can affect the lungs, brain, and skin. It is most common in people with weakened immune systems who have difficulty fighting off infections (for example, people with cancer or those taking certain medications such as steroids).

What are the hallmarks of actinomycosis and Nocardia?

The hallmark of both infections is abscess formation and chronic progression of infection without regard to anatomic barriers. Patients frequently present with fistulous tracts and draining sinuses. Likewise, treatment of these infections require long courses of parenteral and oral therapy (e.g., months to years).

Why is early diagnosis of pulmonary actinomycosis important?

Even when the clinical suspicion is high, the disease is commonly confused with other chronic suppurative lung diseases and with malignancy. An early, accurate diagnosis will prevent the considerable psychological and physical morbidity, including unwarranted surgery, associated with delayed diagnosis.

Is the Actinomyces bacteria a true pathogen?

Otherwise, Actinomyces may be part of normal oral or GI flora and not represent a true pathogen. Main differential is Nocardia [see Table Comparison with Nocardia ]. Looks similar on Gram stain, but Nocardia spp. are weakly AFB, and is usually disease of an immunocompromised host.

How many species of actinomycosis are there in the world?

Anaerobic gram-positive Actinomyces species have a beaded appearance in this clinical specimen ( left panel ), while the aerobic Nocardia species ( right panel) stain acid fast in this sputum specimen. The genus Actinomyces comprises a group of 42 species and 2 subspecies ( 3 ).