n. pl. chla·myd·i·ae (-ē-ē′) 1. Any of various gram-negative, coccoid bacteria of the genus Chlamydia, especially C. psittaci and C. trachomatis, that are pathogenic to humans and other animals, causing infections such as conjunctivitis in cattle and sheep and trachoma, urethritis, and pneumonia in humans. 2. Any of several common, often asymptomatic, sexually transmitted diseases caused by the bacterium Chlamydia trachomatis. [New Latin, genus name, from Latin chlamys, chlamyd-, mantle (in reference to the reticulate form, resembling a mantle around the host cell's nucleus, that the bacterium assumes within the host's cytoplasm); see CHLAMYS.] chla·mydi·al adj. |
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