title: Rapid detection of antibiotic resistance in Acinetobacter baumannii using quantitative real-time PCR.
abstract: OBJECTIVE
  The rapid detection of antibiotic resistance in clinical isolates of Acinetobacter baumannii would shorten the period during which patients receive empirical therapy and facilitate the early initiation of directed antibiotic therapy. The objective of this study was to evaluate the ability of a real-time PCR assay to detect antibiotic resistance to four clinically relevant antibiotics from different antibiotic classes in clinical isolates of A. baumannii.
  
  
  METHODS
  The growth of 48 clinical isolates of A. baumannii with a broad range of MICs of imipenem, ciprofloxacin, colistin and amikacin was evaluated using a real-time PCR assay targeting a highly conserved region of the ompA gene. Fold changes in the number of copies of genomic DNA after 6 h of growth were used to determine resistance and the results were compared with those obtained using broth microdilution.
  
  
  RESULTS
  The results obtained using the real-time PCR assay were concordant with broth microdilution for 184 of 192 determinations (95.8%). The global values for specificity (97.5%), sensitivity (92.9%), positive predictive value (95.6%) and negative predictive value (96.0%) indicated that the real-time PCR assay was able to reliably differentiate between resistant and non-resistant strains.
  
  
  CONCLUSIONS
  The use of real-time PCR to monitor bacterial growth in the presence of antibiotics is effective for rapidly identifying antibiotic resistance in A. baumannii.
authors: Unit of Infectious Diseases, Microbiology, and Preventive Medicine and Biomedical Institute of Seville, University Hospital Virgen del Rocío/CSIC/University of Sevilla, 41013 Sevilla, Spain.
authors: Reyes
authors: R
authors: Martín-Peña
authors: Juan
authors: J
authors: Domínguez-Herrera
authors: Jerónimo
authors: J
authors: Pachón
authors: Michael J
authors: MJ
authors: McConnell
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D024881:Drug Resistance, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D013997:Time Factors
keywords: empirical therapy; multidrug resistance; susceptibility testing