title: In vitro activity of cefditoren and other comparators against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis causing community-acquired respiratory tract infections in China.
abstract: The aim of this study was to evaluate the in vitro activity of cefditoren and comparators against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis causing community-acquired respiratory tract infections (CARTIs). A total of 391 Streptococcus pneumoniae, 266 H. influenzae, and 76 M. catarrhalis were isolated from 10 centers located at 6 cities in China from January 2009 to May 2010. The microdilution method was used to determine minimum inhibitory concentrations (MICs). The pneumococci comprised 189 (48.3%) penicillin susceptible, 129 (33.0%) penicillin intermediate, and 73 (18.7%) penicillin resistant. Moxifloxacin and levofloxacin showed the highest activity (99.2% and 97.7%, respectively) against Streptococcus pneumoniae, followed by parenteral penicillin G (95.7%), cefditoren (83.1%) and amoxicillin-clavulanic acid (79.3%). Among the 266 H. influenzae isolates, 26 (9.8%) were ampicillin-resistant β-lactamase-producing strains and 24 (9.0%) were ampicillin-resistant β-lactamase-nonproducing strains (BLNAR). Most of antimicrobial agents demonstrated good activity (>97% susceptibility) against H. influenzae except ampicillin, cefuroxime, and cefaclor, which showed relatively lower activity (81.2%, 88.7%, and 88%, respectively). Cefditoren showed excellent activity with the lowest MIC(50) and MIC(90) (≤0.016/0.064 μg/mL) among all tested drugs, which is independent of β-lactamase production or ampicillin resistance. Cefditoren at a concentration of 0.5 μg/mL inhibited all BLNAR strains. Seventy of 76 isolates of M. catarrhalis produced β-lactamase. Cefditoren also showed excellent activity with MIC(90) of 0.064 μg/mL against β-lactamase-nonproducing strains and 0.5 μg/mL against β-lactamase-producing strains. In conclusion, the excellent intrinsic activity of cefditoren suggests that it may be a good choice for the treatment of CARTIs caused by Streptococcus pneumoniae, H. influenzae, and M. catarrhalis in China, while the activity should be closely monitored.
authors.affiliation: Department of Clinical Laboratory, Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Qiwen
authors.initials: Q
authors.lastname: Yang
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Xu
authors.forename: Minjun
authors.initials: M
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Hongli
authors.initials: H
authors.lastname: Sun
authors.forename: Yunjian
authors.initials: Y
authors.lastname: Hu
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Duan
authors.forename: Chao
authors.initials: C
authors.lastname: Zhuo
authors.forename: Bin
authors.initials: B
authors.lastname: Cao
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Yunsong
authors.initials: Y
authors.lastname: Yu
authors.forename: Ziyong
authors.initials: Z
authors.lastname: Sun
authors.forename: Yunzhuo
authors.initials: Y
authors.lastname: Chu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D002681:China / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests; D001936:Moraxella catarrhalis / Q000187:drug effects* / Q000302:isolation & purification; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C073460:cefditoren