**Core Concept**
Acute neonatal meningitis is a serious infection of the meninges in newborns, typically caused by bacteria that are transmitted from the mother or acquired during delivery. The most common pathogens responsible for this condition are group B streptococcus (GBS), Escherichia coli (E. coli), and Listeria monocytogenes.

**Why the Correct Answer is Right**
Group B streptococcus (GBS) is the leading cause of neonatal meningitis, accounting for approximately 50% of cases. It is a gram-positive coccus that colonizes the maternal genital tract and can be transmitted to the fetus during delivery. E. coli is another common cause of neonatal meningitis, often associated with premature infants and those with underlying medical conditions. Listeria monocytogenes is a gram-positive rod that can also cause neonatal meningitis, particularly in full-term infants.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided, but typically, the distractors would include other bacteria such as Staphylococcus aureus, Streptococcus pneumoniae, or Haemophilus influenzae, which are not the primary causes of acute neonatal meningitis.
* **Option B:** This option might be a distractor like Klebsiella pneumoniae, which is not a common cause of neonatal meningitis.
* **Option C:** This option could be a distractor like Pseudomonas aeruginosa, which is not typically associated with neonatal meningitis.

**Clinical Pearl / High-Yield Fact**
In pregnant women, vaginal and rectal colonization with group B streptococcus is common, and screening and intrapartum antibiotic prophylaxis are recommended to reduce the risk of neonatal GBS disease.

**Correct Answer: B.**