Fastidious organism

A fastidious organism is any organism that has complex or particular nutritional requirements. In other words, a fastidious organism will only grow when specific nutrients are included in its medium. The more restrictive term fastidious microorganism is used in microbiology to describe microorganisms that will grow only if special nutrients are present in their culture medium.^[1] Thus fastidiousness is often practically defined as being difficult to culture, by any method yet tried.