title: Experimental approach for bacteriophage susceptibility testing of planktonic and sessile bacterial populations - Study protocol.
abstract: BACKGROUND
  Antimicrobial resistance is a growing threat for all clinical branches. This phenomenon poses important challenges in controlling infectious diseases. However, multidrug resistance is not the only issue, as bacteria that are otherwise susceptible to common antibiotics express other patterns for evading antibiotherapy, for example they can aggregate within a self-produced matrix to form biofilm.
  
  
  METHODS
  We intend to perform a prospective laboratory study of the germs isolated from different samples collected from patients admitted with infectious pathology in reference hospitals in Romania. We will perform antibiotic resistance testing as well as phage testing, both on solid and liquid growth medium, for Staphylococcus spp., Enterococcus spp., and Pseudomonas spp. We intend to collect data for 150 patients with different infections with these identified pathogens. Phage susceptibility testing will be performed using 5 types of strain-specific bacteriophage mixtures: PYO, INTESTI, STAPHYLOCOCCAL (Eliava BioPreparations, Tbilisi, Georgia), PHAGYO, PHAGESTI (JSC "Biochimpharm", Tbilisi, Georgia). For phage-susceptible strains, we will evaluate biofilm formation in the presence of phages, as well as phage effect on already formed biofilm.
  
  
  RESULTS
  Through this study, we intend to provide the first set of results on bacteriophage-susceptibility of bacteria isolated from patients with hard to treat infections, from reference hospitals in Romania. By evaluating a large number of bacterial strains we aim to predict and project biofilm kinetics, while adding binary phage dilutions at key timepoints during biofilm formation.
  
  
  BACKGROUND
  POSDRU/159/1.5/S/141531; Carol Davila University of Medicine and Pharmacy, Young Researchers Grant no. 28341/2013.
authors.affiliation: MD, PhD Student, Carol Davila University of Medicine and Pharmacy; National Institute for Infectious Diseases "Prof. Dr. Matei Balş", Bucharest, Romania.
authors.forename: Alina Cristina
authors.initials: AC
authors.lastname: Neguţ
authors.affiliation: MD, Assistant Lecturer, Department of Infectious Diseases, Carol Davila University of Medicine and Pharmacy, National Institute for Infectious Diseases "Prof. Dr. Matei Balş", Bucharest, Romania.
authors.forename: Oana
authors.initials: O
authors.lastname: Săndulescu
authors.affiliation: PhD Student, Microbiology Department, Faculty of Biology, University of Bucharest; Research Institute of the University of Bucharest, Romania.
authors.forename: Marcela
authors.initials: M
authors.lastname: Popa
authors.affiliation: MD, PhD, Lecturer, Department of Infectious Diseases, Carol Davila University of Medicine and Pharmacy, National Institute for Infectious Diseases "Prof. Dr. Matei Balş", Bucharest, Romania.
authors.forename: Anca
authors.initials: A
authors.lastname: Streinu-Cercel
authors.affiliation: PhD, Lead Scientist, "Eliava Biopreparation"; Phage Therapy Center, Tbilisi, Republic of Georgia.
authors.forename: Zemphira
authors.initials: Z
authors.lastname: Alavidze
authors.affiliation: MD, PhD Student, Department of Infectious Diseases, Carol Davila University of Medicine and Pharmacy; National Institute for Infectious Diseases "Prof. Dr. Matei Balş"
authors.forename: Ioana
authors.initials: I
authors.lastname: Berciu
authors.affiliation: PhD, Microbiology Department, Faculty of Biology, University of Bucharest; Ştefan S. Nicolau Institute of Virology, Romanian Academy, Bucharest, Romania.
authors.forename: Coralia
authors.initials: C
authors.lastname: Bleotu
authors.affiliation: MD, PhD, Professor, Department of Microbiology II, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.
authors.forename: Mircea Ioan
authors.initials: MI
authors.lastname: Popa
authors.affiliation: PhD, Professor, Microbiology Department, Faculty of Biology, University of Bucharest; Research Institute of the University of Bucharest, Romania.
authors.forename: Mariana Carmen
authors.initials: MC
authors.lastname: Chifiriuc
authors.affiliation: MD, PhD, Professor, Department of Infectious Diseases, Carol Davila University of Medicine and Pharmacy; National Institute for Infectious Diseases "Prof. Dr. Matei Balş", Bucharest, Romania.
authors.forename: Adrian
authors.initials: A
authors.lastname: Streinu-Cercel
keywords: Bacteriophages; biofilm; lysis; planktonic bacteria; spectrophotometry