Bipolar staining is seen in-

Organisms with bipolar staining: Staining at poles better In between poorly stained (like safety pin appearance) Seen in: Yersinia pestis Klebsiella granulomatis Burkholderia mallei Burkhoolderia pseudomallei Vibrio parahaemolyticus Haemophilus ducreyi Yersinia pestis: Gram-negative oval coccobacilli with rounded ends surrounded by capsule. Wayson stain /Giemsa: Demonstrates bipolar appearance (safety pin appearance) with both ends densely stained and a clear central area of the bacteria. Option 1 - Gram staining of Bacillus anthracis: Gram positive chain of bacilli arranged in bamboo stick appearance. Option 3, 4 - Proteus vulgaris or mirabilis - GNB (gram negative bacteria) - Klebsiella pneumonia - Capsulated GNB