 Whipple himself probably observed the organisms as rod-shaped structures with silver stain in his original case.No name was given to the organism until 1991 when the name "Tropheryma whippelii" was proposed after sections of the bacterial genome were sequenced.The name was changed to "Tropheryma whipplei" in 2001 (correcting the spelling of Whipple's name) when the organism was deposited in bacterial collections.