In vivo activity of amoxicillin/clavulanic acid and erythromycin in experimental otitis media caused by Streptococcus pneumoniae plus Haemophilus influenzae.
A gerbil model of acute otitis media induced by Streptococcus pneumoniae plus Haemophilus influenzae was used to assess the efficacy of amoxicillin/clavulanic acid (A/C) (1.5/0.3, 2.5/0.5 and 10/2 mg/kg) and erythromycin (2.5, 10, 20 and 50 mg/kg) with or without acetaminophen. The amoxicillin/clavulanic acid MIC was 1/0.5 mg/l for both organisms and the erythromycin MICs were 0.12 and 4 mg/l for S. pneumoniae and H. influenzae, respectively. The organisms were inoculated directly into the middle ear (ME) and antibiotic treatment started 2 h post-inoculation and continued at 8h intervals for three doses. Acetaminophen was administered at 50 mg/kg. Samples for bacterial counting were obtained from the ME on day 2. Amoxicillin/clavulanic acid peri-MIC concentrations in ME were effective in eradicating both organisms. Despite the inflammation induced by S. pneumoniae, erythromycin did not eradicate H. influenzae at ME concentrations (2.4 mg/l for erythromycin 50 mg/kg) higher than those obtained in humans but lower than the MIC.
Parra
Araceli
A
Department of Medical Microbiology, Fundación Jiménez Díaz, Avenida de Reyes Católicos 2, 28040 Madrid, Spain.
Ponte
Carmen
C
Cenjor
Carlos
C
García-Olmos
Marta
M
Giménez
María J
MJ
Aguilar
Lorenzo
L
Soriano
Francisco
F
D019980:Amoxicillin-Potassium Clavulanate Combination / Q000627:therapeutic use*; D000818:Animals; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D004917:Erythromycin / Q000627:therapeutic use*; D005849:Gerbillinae; D006192:Haemophilus Infections / Q000188:drug therapy*; D006193:Haemophilus influenzae / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D010033:Otitis Media / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology; D011008:Pneumococcal Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000302:isolation & purification
D004917:Erythromycin; D019980:Amoxicillin-Potassium Clavulanate Combination