title: Antimicrobial susceptibility of Gram-negative bacteria causing intra-abdominal infections in China: SMART China 2011.
abstract: BACKGROUND
  The Study for Monitoring Antimicrobial Resistance Trends program monitors the activity of antibiotics against aerobic and facultative Gram-negative bacilli (GNBs) from intra-abdominal infections (IAIs) in patients worldwide.
  
  
  METHODS
  In 2011, 1 929 aerobic and facultative GNBs from 21 hospitals in 16 cities in China were collected. All isolates were tested using a panel of 12 antimicrobial agents, and susceptibility was determined following the Clinical Laboratory Standards Institute guidelines.
  
  
  RESULTS
  Among the Gram-negative pathogens causing IAIs, Escherichia coli (47.3%) was the most commonly isolated, followed by Klebsiella pneumoniae (17.2%), Pseudomonas aeruginosa (10.1%), and Acinetobacter baumannii (8.3%). Enterobacteriaceae comprised 78.8% (1521/1929) of the total isolates. Among the antimicrobial agents tested, ertapenem and imipenem were the most active agents against Enterobacteriaceae, with susceptibility rates of 95.1% and 94.4%, followed by amikacin (93.9%) and piperacillin/tazobactam (87.7%). Susceptibility rates of ceftriaxone, cefotaxime, ceftazidime, and cefepime against Enterobacteriaceae were 38.3%, 38.3%, 61.1%, and 50.8%, respectively. The leastactive agent against Enterobacteriaceae was ampicillin/sulbactam (25.9%). The extended-spectrum β-lactamase (ESBL) rates among E. coli, K. pneumoniae, Klebsiella oxytoca, and Proteus mirabilis were 68.8%, 38.1%, 41.2%, and 57.7%, respectively.
  
  
  CONCLUSIONS
  Enterobacteriaceae were the major pathogens causing IAIs, and the most active agents against the study isolates (including those producing ESBLs) were ertapenem, imipenem, and amikacin. Including the carbapenems, most agents exhibited reduced susceptibility against ESBL-positive and multidrug-resistant isolates.
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
authors.forename: Qiwen
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Xiao
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
authors.forename: Minjun
authors.initials: M
authors.lastname: Chen
authors.affiliation: International Health Management Associates, Schaumburg, IL 60173- 3817, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Badal
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China. Email: xycpumch@139.com.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity*; D006090:Gram-Negative Bacteria / Q000145:classification / Q000235:genetics*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006801:Humans; D059413:Intraabdominal Infections / Q000382:microbiology*; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents