[Antibacterial activity for clinical isolates from pediatric patients of clavulanic acid/amoxicillin (1: 14) -outcomes of special drug use investigation on antibacterial activity (annual changes)].

Abstract

As a special drug use investigation, we monitored and assessed trends in antibacterial activity of clavulanic acid/amoxicillin (1:14) (hereafter, "CVA/AMPC (1:14)") and other antimicrobial agents for clinical isolates from pediatric patients with otitis media or respiratory, skin, and urinary tract infections. Against Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis isolated and identified from otorrhea, epipharynx and rhinorrhea of pediatric patients with otitis media, the MIC90s of CVA/AMPC (1:14) in five years between 2006-2010 were 1 microg/mL for S. pneumoniae and 8 microg/mL for H. influenzae and 0.25-0.5microg/mL for M catarrhalis. The changes of MIC90s of CVA/AMPC (1:14) for penicillin-resistant S. pneumoniae (PRSP) and beta-lactamase non-producing H. influenzae were two times, and no decrease in drug susceptibility was found in the period of the present investigation. In addition, the MIC changes of other antimicrobial agents for these three organisms were approximately two to four times as well. Against organisms isolated and identified from pus, sputum, pharynx, skin and urine of pediatric patients with respiratory, skin, and urinary tract infections, the MIC90s of CVA/AMPC (1:14) in four years between 2008-2011 were 1 microg/mL for S. pneumoniae, < or =0.06microg/mL for penicillin susceptible S. pneumoniae (PSSP) without any change, 0.5-1 microg/mL for penicillin intermediate resistant S. pneumoniae (PISP) with a twofold change and 1 microg/mL for PRSP with no change. The MIC90s of CVA/AMPC (1:14) were 2-8 microg/mL for S. aureus with a fourfold change, 2 microg/mL for methicillin-sensitive S. aureus without any change, 4-8 microg/mL for H. influenzae with a twofold change. Against beta-lactamase non-producing H. influenzae, MIC90s of CVA/AMPC (1:14) were 1 microg/mL for beta-lactamase negative ampicillin susceptible (BLNAS), 8 microg/mL for beta-lactamase negative ampicillin resistant (BLNAR), showing no change. Neither Streptococcus pyogenes or Klebsiella pneumoniae demonstrated any change and M. catarrhalis and Escherichia coli showed twofold changes of MIC90s of CVA/AMPC (1: 14). In the present investigation conducted to monitor annual changes in antibacterial activity intended for pediatric patients with otitis media or other infections, there was no significant change in antibacterial activity of CVA/AMPC (1: 14).