Trinity Blood

How does one turn into a vampire in trinity blood?

i dont think it says and i am wondering because i am looking for refrances from vampire anime/manga/movie/books, because i am planing to write a book

Methuselah (Vampires) are created in two ways: from being born from Methuselah parents or from a human being infected with the Bacillus bacteria that causes the vampire-like conditions.

Trinity Blood – 1 – Flight Night (SUB)