Which staining method is noted to readily demonstrate Helicobacter pylori?

• A. Romanowsky-type stain
• B. Gram stain
• C. Ziehl-Neelsen stain
• D. Giemsa stain

Answer: (A)

Helicobacter pylori are best visualized in gastric tissue when a stain provides strong contrast between the bacteria and the surrounding mucosa. Romanowsky-type stains, such as Giemsa and Wright-Giemsa, stain the organisms a dark blue/purple against a lighter background, making the spiral bacteria readily identifiable in the mucous layer and on the epithelial surface. This contrast is more reliably achieved with these stains than with routine Gram staining on tissue sections, where the delicate organisms can be missed amid the tissue background. Ziehl-Neelsen targets acid-fast organisms and is not suitable for H. pylori. So, the Romanowsky-type stain is most effective for readily demonstrating this bacterium.