Which Of The Following Bacteria Is Gram Negative?

Which Of The Following Bacteria Is Gram Negative? Example species. The proteobacteria are a major phylum of gram-negative bacteria, including Escherichia coli (E. coli), Salmonella, Shigella, and other Enterobacteriaceae, Pseudomonas, Moraxella, Helicobacter, Stenotrophomonas, Bdellovibrio, acetic acid bacteria, Legionella etc. Which are the gram negative bacteria? Commonly isolated Gram-negative organisms include Pseudomonas, Klebsiella, Proteus, Salmonella, Providencia,