title: Improved detection of biofilm-formative bacteria by vortexing and sonication: a pilot study.
abstract: Bacteria such as staphylococci commonly encountered in orthopaedic infections form biofilms and adhere to bone implants and cements. Various methods to disrupt the biofilm and enhance bacterial detection have been reported. We will describe the effectiveness of vortexing and sonication to improve the detection of biofilm-formative bacteria from polymethylmethacrylate by conventional quantitative bacterial culture and real-time quantitative PCR. We used a single biofilm-formative Staphylococcus aureus strain and 20 polymethylmethacrylate coupons as an in vitro biofilm model; four coupons were used for each of two control groups or three experimental sonication times (1, 5, and 30 minutes). Vortexing the cement without sonication increased the yield of adherent bacteria to a considerable extent. The combination of vortexing and sonication further enhanced the yield regardless of the duration of sonication. Quantitative conventional cultures correlated with quantitative PCR assay. The combination of vortexing and sonication to disrupt the bacterial biofilm followed by quantitative PCR and/or culture seems to be a sensitive method for detecting bacteria adherent to bone cement.
authors.affiliation: Institute of Pathology and Laboratory Medicine, The Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Hideo
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Margret
authors.initials: M
authors.lastname: Oethinger
authors.forename: Marion J
authors.initials: MJ
authors.lastname: Tuohy
authors.forename: Gary W
authors.initials: GW
authors.lastname: Procop
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Bauer
mesh_terms: D001422:Bacterial Adhesion; D015373:Bacterial Typing Techniques; D018441:Biofilms; D001843:Bone Cements / Q000032:analysis*; D015169:Colony Count, Microbial; D010865:Pilot Projects; D016133:Polymerase Chain Reaction; D019904:Polymethyl Methacrylate / Q000032:analysis*; D021521:Ribotyping; D013010:Sonication; D013211:Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D013997:Time Factors
chemical_list: D001843:Bone Cements; D019904:Polymethyl Methacrylate