Antibiotic resistance of serogroup 19 streptococcus pneumoniae isolated from children in Beijing Children's Hospital from 2000 to 2005

Objective To investigate the antimicrobial resistance characters of serogroup 19 Streptococcus pneumoniae(S.pneumoniae) isolated from children in Beijing from 2000 to 2005.Methods The serogroup the pneumococcal isolates were determined by the Quellung reaction using simplified chessboard system.The minimum inhibitory concentrations(MIC) was determinated by E-test method for penicillin,amoxicillin/clavulanic acid,cefaclor,cefuroxime,ceftriaxone,and erythromycin.Results The rate of serogroup 19 among S.pneumoniae isolates in 2002-2003 and 2004-2005 increased significantly compared to that in 2000-2001.The susceptibility rates to penicillin,cefaclor and cefuroxime sodium decreased significantly.The values of MIC50,MIC90 and the maximum value of MIC increased for the three antibiotics.The susceptibility to amoxicillin/clavulanic acid and ceftriaxone decreased according to the MICs distribution,but they were still in the susceptibility range estimated by interpretive standard.Conclusions The increased serogroup 19 of S.pneumoniae isolates from children in Beijing are more potent resistant to β-lactam antibiotics.