Genome Sequences of the Zoonotic Pathogens Chlamydia psittaci 6BC and Cal10

Chlamydia psittaci is a highly prevalent avian pathogen and the cause of a potentially lethal zoonosis, causing life-threatening pneumonia in humans. We report the genome sequences of C. psittaci 6BC, the prototype strain of the species, and C. psittaci Cal10, a widely used laboratory strain. The obligate intracellular pathogen Chlamydia psittaci causes zoonotic psittacosis or ornithosis, a severe and some-times fatal respiratory disease of humans that is acquired from infected birds. C. psittaci is found in bird populations world-wide, with sporadic epidemic outbreaks (1). Infection in birds is often asymptomatic, with transmission to humans reported regularly, particularly in individuals with a high exposure risk, such as veterinarians and other animal handlers (4). C. psittaci is a U.S. CDC category B bioterrorism agent due to the ease of respiratory dissemination and associated morbidity and mor-tality rates (5). Notably, a 1930 Maryland outbreak of psitta-cosis, linked to the 1929-1930 psittacosis pandemic, directly le