Between June 2006 and April 2007, I measured T serotypes and antibiotic susceptibilities of 367 strains of Streptococcus pyogenes isolated from children with pharyngotonsillitis in Asahikawa. Prevalent serotypes were 12 (33.8%), 1 (22.9%), and 28 (12.5%). The MIC90s of β-lactams were 0.008 μg/ml in penicillin G, cefcapene, cefditoren, cefteram, cefdinir and faropenem, and 0.015 μg/ml in amoxicillin. Of 367 isolates, macrolide-resistant (erythromycin>0.5μg/ml) strains account for 42 (11.4%).
The only oral penem antibiotic, faropenem (FRPM: Farom ®r y Syrup for pediatrics), is one of the few antibiotics that exerts potent antibacterial activity against penicillin-resistant Streptococcus pneumoniae (PRSP), and the dosage and administration schedule has been established for children. We studied the efficacy and safety of the drug in 113 pediatric patients with mild-to-moderate bacterial infectious diseases: upper respiratory tract infection (pharyngitis or tonsillitis), acute bronchitis, otitis media and urinary tract infection (UTI). The patients were administered oral FRPM at the dose of 15-30mg/kg/day three times a day for 3 to 8 days (or 5 to 14 days for group A streptococcal infection). The study drug was found to be clinically effective in 63/70 cases (90.0%) of upper respiratory tract infection, 6/7 cases of acute bronchitis, 16/17 cases (94.1%) of otitis media and 6/6 cases of UTI. FRPM was demonstrated to have very potent antibacterial activity against S. pneumoniae, with a high bacteriological eradication rate. No serious adverse drug reactions were observed. The only side effect was diarrhea in 12.5% of the patients (14/112 cases). There was little difference in the incidence of diarrhea between FRPM and other oral beta-lactam antibiotics. Compliance with FRPM was found to be very good in this study. These findings suggest that FRPM is as useful for the treatment of bacterial infectious diseases in children as oral penicillin and cephem antibiotics.
After incubation of four of ten strains of multi-drug resistant Pseudomonas aeruginosa (MDRP) with the healthy human serum for one hour, the bacteria lysed and the viable cell count decreased with the disappearance of the C3 complement. Over 99% of IgG was deleted from the serum by passing the serum through a Protein G Sepharose column. In such IgG-deleted serum, the bactericidal activity on P. aeruginosa was cancelled. The bactericidal activity recovered by adding human intravenous immunoglobulin preparation (IVIG) at the concentration of 2-4 mg/mL to the serum. Moreover, a strong bactericidal activity was shown in the case of some strains that the antibody titers of IVIG were high. It was thought that specific antibodies to some of P. aeruginosa are contained in IVIG and activated the classical pathway of complement system; as a result, the bacterial lyses had been caused. Sera from healthy persons contain antibodies to P. aeruginosa as well as complement components. Since the complement-mediated bactericidal activity disappeared by removing IgG in this study. These results suggest that the IVIG therapy in bacterial infections is expected to recover the immune function so as complement-mediated bactericidal activity as well as opsonic activity against P. aeruginosa, especially in the patient with neutropenia.