An 11-day-old neonate has been brought to his pediatrician because the infant has developed a sharp cough. Physical examination also reveals a mild conjunctivitis with some pus; a chest film confirms pneumonia. No organisms are seen on Gram stain of the pus. What is the most likely causative agent?

Question

Quizplus · Accepted Answer

The presentation is most likely Chlamydia trachomatis conjunctivitis and pneumonia. This obligate intracellular organism is unable to make its own ATP. Choice B (gonococcus) should have been eliminated on Gram stain, and most would have been intracellular but not in phagosomes. Choice C is mycoplasma, which is not intracellular and rarely causes pneumonias in neonates this young. Choice D would be a rickettsia, which is both unlikely and not a good fit for the disease. Choice E (mycobacterium) also is unlikely to cause pneumonia in someone this young and is not known to cause eye infections producing pus.

An 11-Day-Old Neonate Has Been Brought to His Pediatrician Because