A Pseudomonas aeruginosa keratitis case. (A) Slit lamp microscopic image of severe central corneal infiltrate (blue arrow) with intensive conjunctival injection and a temporal satellite lesion (black arrow). Magnification: ×10. (B) Microbiological cultures obtained from a superficial corneal swab showed the presence of Pseudomonas aeruginosa. (C) Hematoxylin and eosin stains demonstrate that the corneal specimen contains numerous polymorphonuclear leukocytes (black arrow) and the epithelium and endothelium are absent (blue arrow). The lamellar architecture is lost and the frayed collagen is the result of widespread collagenolysis. Magnification: ×40. (D) Gram staining shows that Pseudomonas species could be found in the corneal deep stroma, which appear as short stubby rods and are Gram negative (blue arrow). Magnification: ×100.