A bacterium associated with bacteremia, meningitis, and pneumonia in newborns is
a. Staphylococcus aureus
b. Staphylococcus epidermidis
c. Streptococcus pyogenes
d. Streptococcus agalactiae

Verified step by step guidance

1. Step 1: Understand the clinical context of the question, which involves infections such as bacteremia, meningitis, and pneumonia specifically in newborns. These conditions are serious and often caused by particular bacterial pathogens.
2. Step 2: Review the characteristics and common diseases caused by each listed bacterium: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, and Streptococcus agalactiae.
3. Step 3: Recall that Staphylococcus aureus is often associated with skin infections and some systemic infections but is not the primary cause of neonatal meningitis or pneumonia.
4. Step 4: Recognize that Staphylococcus epidermidis is usually a skin commensal and an opportunistic pathogen, often related to infections involving medical devices, but not typically linked to neonatal meningitis or pneumonia.
5. Step 5: Identify that Streptococcus agalactiae (Group B Streptococcus) is well-known for causing bacteremia, meningitis, and pneumonia in newborns, making it the most likely correct answer.

Key Concepts

Bacteremia and Its Clinical Significance

Bacteremia refers to the presence of bacteria in the bloodstream, which can lead to systemic infections. Understanding bacteremia is crucial because it can cause severe conditions like sepsis, especially in vulnerable populations such as newborns.

Pathogens Causing Neonatal Meningitis and Pneumonia

Certain bacteria are known to cause meningitis and pneumonia in newborns. Identifying these pathogens, such as Streptococcus agalactiae (Group B Streptococcus), helps in diagnosing and treating infections early to prevent serious complications.

Characteristics of Streptococcus agalactiae

Streptococcus agalactiae, or Group B Streptococcus, is a common cause of neonatal infections including bacteremia, meningitis, and pneumonia. It colonizes the maternal genital tract and can be transmitted to newborns during delivery, making it a key target for prenatal screening.