Chlamydia Species and Mycoplasma pneumoniae.

Chlamydia psittaci, Chlamydia pneumoniae, and Mycoplasma pneumoniae are a group of respiratory pathogens that have similar pulmonary and extrapulmonary manifestations. Recent studies suggest that C. pneumoniae and M. pneumoniae may play a role in the pathogenesis of asthma, but further studies are needed to delineate the importance of these organisms in this disease. The diagnosis of C. pneumoniae infection is hindered by the lack of a gold standard: Asymptomatic carriage of C. pneumoniae lowers the specificity of culture and polymerase chain reaction, and the current use of single high titers to identify infection also has specificity problems. Newer antibiotics simplify the management of infection with C. psittaci, C. pneumoniae, and M. pneumoniae and offer the potential for prophylaxis.