Final answer:
A nurse should monitor for ototoxicity as an adverse effect in a client receiving vancomycin for a beta-hemolytic streptococci infection.
Step-by-step explanation:
In a patient receiving vancomycin for a beta-hemolytic streptococci infection, a nurse should monitor for ototoxicity as a potential adverse effect. Vancomycin is known to have the potential to cause damage to the inner ear, leading to hearing loss or ringing in the ears. Therefore, regular auditory assessments should be conducted to detect any changes in hearing.