A farm worker with a contaminated puncture wound develops trismus and risus sardonicus. Gram stain of wound material shows Gram-positive rods with round, terminal spores producing a characteristic shape. This appearance is described as:
- A Boxcar-shaped rods without spores
- B Drumstick appearance ✓
- C Tennis racket appearance
- D Bamboo stick appearance
Correct answer: B. Drumstick appearance
Explanation
Clostridium tetani forms spherical terminal spores that bulge beyond the width of the vegetative rod, giving the classic drumstick or pin-cushion appearance on Gram or stained smears. Boxcar rods describe non-sporing large Gram-positive rods such as Clostridium perfringens, which does not sporulate in tissues. Tennis racket appearance refers to Corynebacterium diphtheriae arranged at angles, and bamboo stick describes Bacillus anthracis chains.
Reference: Ananthanarayan and Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.