A 4-month-old infant is brought to the emergency department by his mother with progressive muscular weakness and failure to thrive. The mother reports that her mother-in-law recommended mixing honey with formula to improve consumption of the formula when fed through the bottle. The infant is admitted to the hospital, antitoxin is administered, and a diagnosis of infant botulism is confirmed by identification of toxin in the stool. The infant is given supportive care and is eventually discharged from the hospital after a prolonged stay.
Which of the following describes the causative organism?
The correct answer is:
E) Gram-positive rod
Infant botulism (also known as floppy baby syndrome) presents with gastrointestinal upset and proceeds to a descending flaccid paralysis due to botulinum toxin produced by the spore forming gram-positive rod Clostridium botulinum. Clostridium botulinum is ubiquitous and easily isolated from the surfaces of fruits and vegetables and exists in soil and marine sediment. Spores thrive in anaerobic environments such as canned food and release neurotoxin, which is then consumed. Spores can also be released from the soil by construction work. In infants, the spores germinate in the gastrointestinal tract, releasing neurotoxin from there and causing floppy baby syndrome. The heat-labile toxin blocks release of acetylcholine at the neuromuscular junction leading to an inability to create the required action potential. Treatment involves antitoxin and supportive care with intubation and ventilation. The adult gastrointestinal flora is resistant to Clostridium botulinum colonization, but the microbe may colonize wounds (called wound botulism) and release toxin, leading to flaccid paralysis, especially of cranial nerves.
Key Learning Point
Clostridium botulinum is a spore-forming gram-positive rod which causes infant botulism.
