Gram negative

Bacteria that are gram negative are not stained dark blue or violet by gram staining, in contrast to gram positive bacteria, which have a high amount of peptidoglycan in their cell wall. Among the gram negative bacteria are :

• Neisseria?
• Moraxella?
• Enterobacteriaceae
• Pseudomonas?
• [Helicobacter pylori]?
• Stenotrophomonas?