Final answer:
The go-to antibiotic for a positive Group B Streptococcus test is Penicillin, but alternatives like erythromycin or clindamycin may be used in case of penicillin allergy.
Step-by-step explanation:
If the test or culture for Group B Streptococcus is positive, the first-line antibiotic choice is often Penicillin. This is because Group B Streptococcus, also known as Streptococcus agalactiae, is typically susceptible to penicillin and other ß-lactam antibiotics. In situations where patients are allergic to penicillin, alternatives like erythromycin, clindamycin, or vancomycin may be considered, depending on the susceptibility profile of the isolated strain. Streptococcal infections, particularly those caused by Group B Streptococcus, are of serious concern in neonates, as they can lead to severe conditions like neonatal meningitis, which requires immediate treatment with appropriate antibiotics such as penicillin or ampicillin plus gentamicin.