What is the causative agent of ophthalmia neonatrum?

Ophthalmia neonatrum is primarily caused by Neisseria gonorrhoeae, a bacterium that can be transmitted from an infected mother to her newborn during vaginal delivery. This condition is characterized by severe conjunctivitis in newborns, which can lead to serious complications if left untreated.

Neisseria gonorrhoeae is specifically known for its role in sexually transmitted infections and can cause inflammation and discharge in the eyes of the neonate, leading to the symptoms associated with ophthalmia neonatrum. The other organisms listed, such as Streptococcus, Escherichia, and Haemophilus, are not the primary causative agents of this condition. While they can cause other types of infections or conjunctivitis, they do not have the same direct association with the transmission from mother to child leading to ophthalmia neonatrum. Neisseria gonorrhoeae stands out due to its specific transmission route and the severity of the eye infections it can cause in newborns.