Explanation:
While L. pneumophila is categorized as a Gram-negative organism, it stains poorly due to its unique lipopolysaccharide content in the outer leaflet of the outer cell membrane.
Failure to diagnose Legionnaires' disease is largely due to a lack of clinical awareness. In addition, legionellae, the bacteria that cause this disease, are fastidious and not easily detected. Legionellae are gram-negative bacteria found in freshwater environments.
