title: Does antibiotic resistance impair plasma susceptibility of multi-drug resistant clinical isolates of enterococci in vitro?
abstract: BACKGROUND
  Cold atmospheric plasma could constitute an alternative against multi-drug resistant pathogens. Susceptibility of enterococci to cold atmospheric plasma was investigated in vitro.
  
  
  METHODS
  39 clinical isolates of enterococci were grouped dependent on the most important resistance patterns and treated on agar using dielectric barrier discharge plasma. These included enterococci with combined vancomycin- and high-level gentamicin resistance, high-level resistance to gentamicin (HLGR) only, vancomycin resistance alone (VRE), and enterococci susceptible to both. Susceptibility to cold atmospheric plasma was evaluated based on the zones of inhibition and examined in terms of the enterococcal group and the "degree" of drug resistance.
  
  
  RESULTS
  Cold atmospheric plasma treatment killed all groups. Comparison of VRE and HLGR strains with non-VRE and non-HLGR isolates concerning zones of inhibition revealed that enterococci with special resistance patterns (VRE and HLGR) showed significantly smaller zones of inhibition than the sensitive ones. The mean of all isolates, irrespective of belonging to groups, showed smaller zones of inhibition with increasing "degree" of drug resistance.
  
  
  CONCLUSIONS
  Cold atmospheric plasma treatment killed all isolates of enterococci, but its efficacy depended on the "degree" of drug resistance and on membership in special resistance groups with particular clinical-outbreak importance. However, a possible role of the different genetic lineages, which might be prone to acquiring more or less resistance phenotypes, may also play a role in this context.
authors: Department of Surgery, Ernst Moritz Arndt University, Sauerbruchstrasse, 17475 Greifswald, Germany.
authors: Matthias
authors: M
authors: Napp
authors: Department of Dermatology, Ernst Moritz Arndt University, Sauerbruchstrasse, 17475 Greifswald, Germany.
authors: Sebastian
authors: S
authors: von Podewils
authors: National Reference Center for Staphylococci and Enterococci, Robert-Koch-Institute, Wernigerode branch, Burgstraße 37, 38855 Wernigerode, Germany.
authors: Ingo
authors: I
authors: Klare
authors: Department of Dermatology, Ernst Moritz Arndt University, Sauerbruchstrasse, 17475 Greifswald, Germany.
authors: Hermann
authors: H
authors: Haase
authors: Department of Orthopaedics, Ernst Moritz Arndt University, Sauerbruchstrasse, 17475 Greifswald, Germany.
authors: Richard
authors: R
authors: Kasch
authors: Department of Surgery, Ernst Moritz Arndt University, Sauerbruchstrasse, 17475 Greifswald, Germany ; Unfallkrankenhaus Berlin (ukb), Warener Straße 7, 12683 Berlin, Germany.
authors: Denis
authors: D
authors: Gümbel
authors: Department of Surgery, Ernst Moritz Arndt University, Sauerbruchstrasse, 17475 Greifswald, Germany ; Unfallkrankenhaus Berlin (ukb), Warener Straße 7, 12683 Berlin, Germany.
authors: Axel
authors: A
authors: Ekkernkamp
authors: Department of Dermatology, Ernst Moritz Arndt University, Sauerbruchstrasse, 17475 Greifswald, Germany.
authors: Michael
authors: M
authors: Jünger
authors: Department of Dermatology, Ernst Moritz Arndt University, Sauerbruchstrasse, 17475 Greifswald, Germany.
authors: Georg
authors: G
authors: Daeschlein
keywords: Antimicrobial efficacy; Cold atmospheric plasma (CAP); Dielectric barrier discharge plasma (DBD); Gentamicin-resistant enterococci; Plasma medicine; Plasma susceptibility; Vancomycin-resistant enterococci