title: Usefulness of phenotypic and genotypic methods for metallo-beta-lactamases detection in carbapenem-resistant Acinetobacter baumannii strains.
abstract: BACKGROUND
  Acinetobacter baumannii is an opportunistic microorganism with an increasing role in nosocomial outbreaks. For the last 2 decades, a growing number of carbapenem-resistant A. baumannii strains have been identified, including the metallo-beta-lactamases (MBLs) producers. The study aimed to investigate the genetic relatedness of, and MBLs production among, a collection of A. baumannii isolates from Poland.
  
  
  METHODS
  This study involved 78 clinical isolates of carbapenem-resistant A. baumannii. Strain typing of the isolates was performed using PCR-RAPD. The presence of MBLs was phenotypically determined using different double disc synergy tests (DDST), the imipenem/EDTA combination disk test (CDT) and Etest MBL. blaIMP and blaVIM genes were detected using a duplex PCR assay.
  
  
  RESULTS
  The isolates were divided into 18 PCR-RAPD patterns. Among 18 examined isolates, 94.4% were MBL-positive by the phenotypic method relying on comparing the bacteria growth inhibition zones diameters between imipenem/EDTA and imipenem discs, 88.9% using Etest MBL, 66.7% using the double disc synergy test with ceftazidime, imipenem, meropenem and EDTA, and 88.9% using a corresponding method with 2-MPA. The existence of blaIMP was identified in 8 (10.3%) strains.
  
  
  CONCLUSIONS
  MBLs production was an important mechanism of carbapenem resistance among A. baumannii isolates in Poland. Laboratories should routinely screen for MBLs among A. baumannii isolates.
authors: Department of Microbiology, Ludwik Rydygier Collegium Medicum, Bydgoszcz Nicolaus Copernicus University, Torun, Poland.
authors: Aleksandra
authors: A
authors: Szejbach
authors: Agnieszka
authors: A
authors: Mikucka
authors: Tomasz
authors: T
authors: Bogiel
authors: Eugenia
authors: E
authors: Gospodarek
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D015780:Carbapenems / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000235:genetics; D060005:Genotyping Techniques / Q000379:methods*; D006801:Humans; D008670:Metals / Q000378:metabolism*; D010641:Phenotype; D011044:Poland; D019105:Random Amplified Polymorphic DNA Technique; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D015780:Carbapenems; D008670:Metals; D001618:beta-Lactamases