title: Simple method for measuring the antibiotic concentration required to kill adherent bacteria.
abstract: A simple method was developed for measuring the antibiotic susceptibility of bacteria adherent to plastic surfaces. Staphylococcus aureus cells adhered to the bottom of a 96-well plastic tissue culture plate were incubated in serially diluted antibiotic solutions. After a 24-hour-incubation the solutions were removed, and fresh medium without antibiotics was added to each well. The viability of the cells was judged by their growth after a further 24-hour-incubation. The antibiotic concentration required to kill adherent bacteria was far higher than that required for planktonic cells, although we used bactericidal drugs; beta-lactam, quinolone, and aminoglycoside antibiotics. The tolerance demonstrated by adherent cells is likely to play a role in the difficulties encountered in the chemotherapy of biofilm infections.
authors.affiliation: Department of Microbiology, Hiroshima University School of Dentistry, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Miyake
authors.forename: S
authors.initials: S
authors.lastname: Fujiwara
authors.forename: T
authors.initials: T
authors.lastname: Usui
authors.forename: H
authors.initials: H
authors.lastname: Suginaka
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000494:pharmacology*; D001422:Bacterial Adhesion; D008826:Microbial Sensitivity Tests / Q000379:methods*; D010969:Plastics; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D010969:Plastics