title: Antimicrobial Effect of a Single Dose of Amoxicillin on the Oral Microbiota.
abstract: OBJECTIVE
  Amoxicillin is commonly used in oral surgery for antimicrobial prophylaxis against surgical-site infection and bacteremia because of its effect on oral streptococci. The aim of this study was to determine whether amoxicillin reaches the break-point concentrations in saliva and has any effect on the salivary microbiota, colonizing bacteria on mucosal membranes and on the gingival crevice after a single dose of amoxicillin.
  
  
  METHODS
  Twenty subjects received 2 g of amoxicillin, per os. The facultative and strictly anaerobic microflora, as well as the streptococcal microflora specifically, were followed from baseline and after 1, 4, and 24 hours. Samples were taken for microbial analysis from saliva, the dorsum of the tongue, and the gingival crevice, and were inoculated and cultured. Plasma samples and saliva samples were analyzed for amoxicillin concentrations (free and protein bound) using liquid chromatography and mass-spectrometry.
  
  
  RESULTS
  Amoxicillin was detected in concentrations over the break-point (>2 μg/mL) of amoxicillin in plasma after 1 and 4 hours but not after 24 hours. The dose had a significant effect on the streptococci in the gingival crevice.
  
  
  CONCLUSIONS
  A single dose given as prophylaxis to prevent a surgical-site infection results in a significant reducing effect on the oral streptococcal microflora in the gingival crevice and may have an impact on bacteria spreading into tissues and the bacteremia of streptococci.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Södra Älvsborg Hospital, Borås, Sweden.|Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Larsson Wexell
authors.affiliation: Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Ryberg
authors.affiliation: Wivi-Anne Sjöberg-Andersson, Clinic of Oral Medicine and Special Care Dentistry, Östra Sjukhuset, Gothenburg, Sweden.
authors.forename: Wivi-Anne
authors.initials: WA
authors.lastname: Sjöberg Andersson
authors.affiliation: Department of Oral Microbiology and Immunology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Susanne
authors.initials: S
authors.lastname: Blomqvist
authors.affiliation: Laboratory of Medical Biochemistry and Clinical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Belgium.|Department of Anesthesiology, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: Pieter
authors.initials: P
authors.lastname: Colin
authors.affiliation: Laboratory of Medical Biochemistry and Clinical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Van Bocxlaer
authors.affiliation: Department of Oral Microbiology and Immunology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Dahlén
mesh_terms: D000658:Amoxicillin / Q000008:administration & dosage* / Q000097:blood; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000097:blood; D005881:Gingiva / Q000382:microbiology; D006801:Humans; D064307:Microbiota / Q000187:drug effects*; D012463:Saliva / Q000382:microbiology*; D014059:Tongue / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D000658:Amoxicillin
keywords: LC-MS/MS; amoxicillin; oral microbiology; oral surgery; plasma; saliva