Affiliations: Department of Pediatrics, Georgetown University School
of Medicine, Washington DC, USA
Note: [] Correspondence: Itzhak Brook, 4431 Albemarle St. NW, Washington
DC, USA. Tel.: +1 202 744 8211; E-mail: ib6@georgetown.edu
Abstract: 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.
Keywords: Tonsillitis, group A streptococci, penicillin, cephalosporins, beta-lactamase