J Pediatr Infect Dis 2013; 08(02): 059-069
DOI: 10.3233/JPI-130386
Review Article
Georg Thieme Verlag KG Stuttgart – New York

Penicillin failure in the treatment of group A streptococcal pharyngo-tonsillitis: Causes and solutions

Itzhak Brook
a  Department of Pediatrics, Georgetown University School of Medicine, Washington DC, USA
› Author Affiliations

Subject Editor:
Further Information

Publication History

30 January 2013

14 March 2013

Publication Date:
28 July 2015 (online)


Despite its in vitro efficacy, the increased inability of penicillin to eradicate Group A beta-hemolytic streptococci (GABHS) from patients with acute and relapsing pharyngo-tonsillitis (PT) is of great concern. This review describes the causes of penicillin failure in eradicating GABHS PT. These include the presence of beta-lactamase producing bacteria (BLPB) that "protect" GABHS from penicillins; the absence of bacteria that interfere with the growth of GABHS; co-aggregation between GABHS and Moraxella catarrhalis; and the poor penetration of penicillin into the tonsillar tissues and the tonsillo-pharyngeal cells which allows intracellular GABHS and Staphylococcus aureus to survive. The inadequate intracellular penetration of penicillns can allow intracellular GABHS and S. aureus to persist. In the treatment of acute tonsillitis, the use of cephalosporins can overcome these interactions by eradicating aerobic BLPB (including M. catarrhalis), while preserving the potentially interfering organisms and eliminating GABHS. In treatment of recurrent and chronic PT the administration of clindamycin, or amoxicillin-clavulanic acid can eradicate both aerobic and anaerobic BLPB as well as GABHS. The superior intracellular penetration of cephalosporins and clindamycin enhances their efficacy against intracellular GABHS and S. aureus.