Gram-negative bacterial infection

• Mycoplasma are sometimes considered gram-negative, but because of its lack of a cell wall and unusual membrane composition, it is sometimes considered separately from other gram-negative bacteria.
• Gardnerella is often considered gram-negative, but it is classified in MeSH as both gram-positive and gram-negative. It has some traits of gram-positive bacteria, but has a gram-negative appearance. It has been described as a "gram-variable rod".Medical Dictionary Lookup!">