Lack of influence of beta-lactamase-producing flora on recovery of group A streptococci after treatment of acute pharyngitis.
Because production of beta-lactamase by normal pharyngeal flora could account for penicillin treatment failure, we studied the effect of anaerobic and aerobic beta-lactamase-producing bacteria on bacteriologic outcome in acute group A beta-hemolytic streptococcal (GABHS) pharyngitis. We compared 10-day courses of orally administered phenoxymethyl penicillin and amoxicillin-clavulanic acid, using a randomized, single-blind treatment protocol. Eligible patients were 2 to 16 years of age and had culture-proven acute GABHS pharyngitis; 89 patients (43 penicillin, 46 amoxicillin-clavulanic acid) were compliant with therapy. beta-Lactamase-producing organisms were isolated before therapy from the throats of 67% of patients treated with penicillin and 63% treated with amoxicillin-clavulanic acid. Throat cultures after completion of therapy were positive for GABHS in 7 (7.9%) of 89 patients. The initial GABHS T type persisted (treatment failure) in only 4 (4.5%) of 89 patients, including 3 (6.5%) of 46 who received amoxicillin-clavulanic acid and in 1 (2.3%) of 43 who received penicillin (not statistically significant). Bacteriologic treatment failure was unrelated to recovery of beta-lactamase-producing bacteria at the time of enrollment or after treatment. We conclude that beta-lactamase production by normal pharyngeal flora does not fully explain the failure of penicillin therapy for acute streptococcal pharyngitis. Using an antibiotic effective against beta-lactamase-producing bacteria will not eliminate the problem of bacteriologic treatment failure.
Tanz
R R
RR
Division of General Academic and Emergency Pediatrics, Children's Memorial Hospital, Chicago, IL 60614.
Shulman
S T
ST
Sroka
P A
PA
Marubio
S
S
Brook
I
I
Yogev
R
R
D000293:Adolescent; D000658:Amoxicillin / Q000008:administration & dosage / Q000627:therapeutic use*; D019980:Amoxicillin-Potassium Clavulanate Combination; D001420:Bacteria, Aerobic / Q000145:classification; D001421:Bacteria, Anaerobic / Q000145:classification; D002648:Child; D002675:Child, Preschool; D002969:Clavulanic Acids / Q000008:administration & dosage / Q000627:therapeutic use*; D004359:Drug Therapy, Combination / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D010404:Penicillin V / Q000008:administration & dosage / Q000627:therapeutic use*; D010612:Pharyngitis / Q000188:drug therapy / Q000382:microbiology*; D010614:Pharynx / Q000382:microbiology*; D012703:Serotyping; D016037:Single-Blind Method; D013290:Streptococcal Infections / Q000188:drug therapy / Q000382:microbiology*; D013297:Streptococcus pyogenes; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000494:pharmacology
D002969:Clavulanic Acids; D019980:Amoxicillin-Potassium Clavulanate Combination; D000658:Amoxicillin; D001618:beta-Lactamases; D010404:Penicillin V