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E. coli stains green (just fyi) otherwise, perfect.
only E coli stains green, all other lactose fermenters stain purple/black (just fyi) otherwise, perfect. ;)
I think this is actually a separate concept – E. coli stains "metallic green" on eosin methylene blue agar, which is in the E. coli sketchy and first aid. However this question is referring to the methylene blue test on a fecal smear. From what I can gather, this test will be positive (indicated by presence of neutrophils) in cases of invasive diarrhea (i.e. shigella, salmonella, enterohemorrhagic E. coli). The test will be negative (no neutrophils) in cases of diarrhea caused by toxins (cholera, enterotoxigenic E. coli, giardia, viral diarrhea).
So even though E. coli can present with fecal PMNs (if it's the enterohemorrhagic type), I guess that's less likely than shigella?