chlamydial vs chlamydia

chlamydial is not a noun while chlamydia is a noun.

Word	Noun	Adjective	Verb	Adverb
chlamydial	No	Yes	No	No
chlamydia	Yes	No	No	No

chlamydial (noun)	chlamydia (noun)
	coccoid rickettsia infesting birds and mammals; cause infections of eyes and lungs and genitourinary tract
	a sexually transmitted infection caused by bacteria of the genus Chlamydia

chlamydial (adjective)	chlamydia (adjective)
of or pertaining to the sexually transmitted infection or to the parasite