Controversies in the treatment of streptococcal pharyngitis An increasing number of cases of sore throat caused by group A beta-hemolytic streptococci occur with concomitant colonization by organisms that may "protect" the streptococci through beta-lactamase inactivation of penicillin at the site of infection. The failure of penicillin to eradicate many of these bacteria, which include Staphylococcus aureus, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and a multitude of pharyngeal anaerobes, may help to explain why penicillin is sometimes ineffective for acute and recurrent group A streptococcal infections. Therapeutic alternatives currently include cephalosporins, erythromycin, rifampin combined with penicillin, amoxicillin/clavulanate potassium and others. 