title: Antimicrobial susceptibility of Gram-negative organisms from intraabdominal infections and evolution of isolates with extended spectrum β-lactamases in the SMART study in Spain (2002-2010).
abstract: BACKGROUND
  The SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study records the antimicrobial susceptibility of Gram-negative bacilli obtain from intraabdominal infections with special focus in isolates with extended spectrum β-lactamases (ESBLs).
  
  
  METHODS
  The antimicrobial susceptibility of 8,869 isolates was analyzed by microdilution during the SMART study performed in Spain from 2002 to 2010. Isolates were recovered in 16 centres.
  
  
  RESULTS
  Escherichia coli was the most prevalent pathogen (60.9% from intraabdominal infections acquired in the community and 49.9% in those from nosocomial origin) followed by Klebsiella pneumoniae (8.9% vs 9.2%). Pseudomonas aeruginosa was more common in intraabdominal infections from nosocomial origin (5.6% community and 8.6% nosocomial). Frequency of ESBL-producing isolates was: E. coli, 8.7%; K. pneumoniae, 8.4%; Klebsiella oxytoca, 1.4%; and Proteus mirabilis, 1.6%. Overall, ESBL-producing isolates were more frequently isolated from elderly patients (6.8% >60 years). Ertapenem and meropenem were the most active antimicrobials (susceptibility range with EUCAST criteria, 89.0-100%) when considering all Enterobacteriaceae isolates and also against ESBL producers (95.5-100%). Susceptibility of amoxicillin/clavulanic acid and piperacillin/tazobactam was lower, particularly among ESBL-producing isolates. Nevertheless, ertapenem maintained a good activity (susceptibility >95%) in ESBL-producers that were resistant to amoxicillin/clavulanic acid, piperacillin/tazobactam or fluoroquinolones.
  
  
  CONCLUSIONS
  Antimicrobial susceptibility data from the SMART-Spain study reinforce current therapeutic guidelines of intraabdominal infections that include ertapenem as the empirical choice for treatment. This is also supported by the high frequency of ESBL-producers in our geographic area.
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal, Carretera de Colmenar Km 9.1, 28034 Madrid, Spain. rcanton.hrc@salud.madrid.org
authors.forename: Rafael
authors.initials: R
authors.lastname: Cantón
authors.forename: Elena
authors.initials: E
authors.lastname: Loza
authors.forename: Javier
authors.initials: J
authors.lastname: Aznar
authors.forename: Jorge
authors.initials: J
authors.lastname: Calvo
authors.forename: Emilia
authors.initials: E
authors.lastname: Cercenado
authors.forename: Ramón
authors.initials: R
authors.lastname: Cisterna
authors.forename: Fernando González
authors.initials: FG
authors.lastname: Romo
authors.forename: José Luis López
authors.initials: JL
authors.lastname: Hontangas
authors.forename: Carmen Rubio
authors.initials: CR
authors.lastname: Calvo
authors.forename: Ana Isabel Suárez
authors.initials: AI
authors.lastname: Barrenechea
authors.forename: Fe
authors.initials: F
authors.lastname: Tubau
authors.forename: Irene
authors.initials: I
authors.lastname: Weber
authors.forename: Patricia
authors.initials: P
authors.lastname: Yuste
authors.forename: Rafael
authors.initials: R
authors.lastname: Cavanillas
mesh_terms: D000005:Abdomen; D000328:Adult; D000367:Age Factors; D000368:Aged; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D024901:Drug Resistance, Multiple, Bacterial; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D006088:Gram-Negative Aerobic Bacteria / Q000187:drug effects; D006089:Gram-Negative Anaerobic Bacteria / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000201:enzymology*; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology*; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D013030:Spain / Q000453:epidemiology; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D001618:beta-Lactamases