Final answer:
The most common bacterium causing neonatal septic arthritis and osteomyelitis is Group B Streptococcus (S. agalactiae). This pathogen is also the leading cause of neonatal meningitis and can be transmitted to the infant during childbirth.
Step-by-step explanation:
Common Bacteria causing Neonatal Septic Arthritis
Septic arthritis in neonates is a serious and potentially life-threatening condition often caused by bacterial infection within a joint. The most common bacterial pathogen associated with neonatal septic arthritis and osteomyelitis is Group B Streptococcus (S. agalactiae), which is also known for causing neonatal meningitis. This bacterium can be found in the urogenital and gastrointestinal microbiota of approximately 10-30% of humans and is typically transmitted to the baby during childbirth, leading to early onset disease in the first week of life. In addition to S. agalactiae, other bacteria such as Staphylococcus aureus and gram-negative bacteria like Escherichia coli can also be responsible for infections in neonates, including septic arthritis.
Proper identification and management of septic arthritis are crucial to prevent complications such as joint destruction and growth disturbances. The condition requires prompt antibiotic therapy, which can significantly reduce morbidity and mortality associated with this infection. In cases where S. agalactiae is suspected, intrapartum antibiotic prophylaxis is an effective preventative measure to protect neonates against early onset disease.