title: Rapid identification of nosocomial Acinetobacter baumannii isolated from a surgical intensive care unit in Egypt.
abstract: BACKGROUND
  The rapid and accurate identification of nosocomial clinical isolates is the first essential step in investigating nosocomial outbreaks. We aimed to evaluate the performance of MDR-CHROMagar Acinetobacter versus matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in rapid detection of nosocomial Acinetobacter baumannii isolated from patients admitted to the surgical intensive care unit (SICU) of Kasr Alainy- Cairo University.
  
  
  METHODS
  Over a period of 9 months from January 2014 until September 2014, 234 samples were collected. All samples were directly cultured on MDR-CHROMagar Acinetobacter media. MALDI-TOF MS was used to identify all non-lactose fermenting colonies on conventional media. Confirmation of species identification was done by detecting the blaOXA-51 like gene by PCR.
  
  
  RESULTS
  Statistical evaluation of MDR-CHROMagar Acinetobacter against blaOXA-51 like PCR as the reference method for identification of A baumannii showed a sensitivity of 100% (95% confidence interval [CI]: 93.36% to 100%), specificity 98.8% (95% confidence interval [CI]: 96.04% to 99.68%), positive predictive value 96.4% (95%CI: 86.61% to 99.37%), negative predictive value 100% (95% CI: 97.36% to 100%). The statistical evaluation of MALDI-TOF against blaOXA-51 PCR was 100% concordance.
  
  
  CONCLUSIONS
  MALDI-TOF MS was more specific than CHROMagar in identifying Acinetobacter spp and allowed further identification of non-A Baumannii species such as A hemolyticus and A nosocomialis, which are less common Acinetobacter spp involved in hospital-acquired infections.
authors.affiliation: Dr. Doaa Ghaith, Clinical and Chemical Pathology Department,, Faculty of Medicine, Cairo University,, 1 Al-Saray St. Al-Manial, Cairo 11559,, Egypt, T: (+202) 23654480, F: (+202) 23641687, doaa.ghaith@kasralainy.edu.eg.
authors.forename: Doaa Mohammad
authors.initials: DM
authors.lastname: Ghaith
authors.forename: Reem Mostafa
authors.initials: RM
authors.lastname: Hassan
authors.forename: Ahmed Mohamed
authors.initials: AM
authors.lastname: Hasanin
mesh_terms: D000151:Acinetobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000302:isolation & purification*; D001431:Bacteriological Techniques / Q000379:methods*; D003428:Cross Infection / Q000175:diagnosis* / Q000382:microbiology; D004534:Egypt; D006801:Humans; D007362:Intensive Care Units; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization