title: Effect of bacteriophage infection in combination with tobramycin on the emergence of resistance in Escherichia coli and Pseudomonas aeruginosa biofilms.
abstract: Bacteriophage infection and antibiotics used individually to reduce biofilm mass often result in the emergence of significant levels of phage and antibiotic resistant cells. In contrast, combination therapy in Escherichia coli biofilms employing T4 phage and tobramycin resulted in greater than 99% and 39% reduction in antibiotic and phage resistant cells, respectively. In P. aeruginosa biofilms, combination therapy resulted in a 60% and 99% reduction in antibiotic and PB-1 phage resistant cells, respectively. Although the combined treatment resulted in greater reduction of E. coli CFUs compared to the use of antibiotic alone, infection of P. aeruginosa biofilms with PB-1 in the presence of tobramycin was only as effective in the reduction of CFUs as the use of antibiotic alone. The study demonstrated phage infection in combination with tobramycin can significantly reduce the emergence of antibiotic and phage resistant cells in both E. coli and P. aeruginosa biofilms, however, a reduction in biomass was dependent on the phage-host system.
authors.affiliation: Clinical Laboratory Science Program, Texas State University, 601 University Drive, San Marcos, TX 78666, USA. lcoulter87@gmail.com.
authors.forename: Lindsey B
authors.initials: LB
authors.lastname: Coulter
authors.affiliation: Department of Biology, Texas State University, San Marcos, 601 University Drive, TX 78666, USA. McLean@txstate.edu.
authors.forename: Robert J C
authors.initials: RJ
authors.lastname: McLean
authors.affiliation: Clinical Laboratory Science Program, Texas State University, 601 University Drive, San Marcos, TX 78666, USA. rrohde@txstate.edu.
authors.forename: Rodney E
authors.initials: RE
authors.lastname: Rohde
authors.affiliation: Department of Biology, Texas State University, San Marcos, 601 University Drive, TX 78666, USA. garyaron@txstate.edu.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Aron
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017122:Bacteriophage T4 / Q000502:physiology; D001435:Bacteriophages / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000821:virology*; D054884:Host-Pathogen Interactions; D017105:Pseudomonas Phages / Q000502:physiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000821:virology*; D014031:Tobramycin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D014031:Tobramycin