title: Oral endotoxin in healthy adults.
abstract: This article presents a study that measured oral endotoxin levels in healthy persons with the Limulus amoebocyte lysate microassay. Only young nonsmoking adults with a healthy dentition measured with the plaque index and a good level of oral hygiene based on a twice-daily (morning and evening) tooth-brushing regimen were admitted to this open study. Each person was required to provide two oral washings of 10 ml sterile saline solution 1 week apart. Only those volunteers without oral carriage of aerobic gram-negative bacilli were enrolled in the baseline study. A total of 15 healthy adults with a median age of 29 years (range, 25 to 43 years) were included in the trial. The mean plaque score of the group was 1.2 +/- 0.1. They all maintained a twice-daily tooth-brushing regimen unaltered throughout the sampling period. A total of 30 mouth rinses were studied. None of the samples yielded potential pathogens including aerobic gram-negative bacilli, Staphylococcus aureus and yeasts; a culturing technique based on preenrichment in nutrient medium was used. Data showed mean oral endotoxin levels of 20 ng per ml of mouth rinse; the aerobic E. coli endotoxin was used as the classical standard. This is equivalent to 1 mg of anaerobic endotoxin per ml of undiluted saliva after correcting for the 10 to 10(2) dilution factor of the mouth rinse itself and for the 10(3) times less sensitivity of anaerobic endotoxin in the Limulus amoebocyte lysate-assay. The discussion includes the physiologic and clinical benefit of the low endotoxicity of anaerobic gram-negative flora apart from the technical aspects of both culture and endotoxin assays used in the study.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital, Groningen, The Netherlands.
authors.forename: T S
authors.initials: TS
authors.lastname: Leenstra
authors.forename: J J
authors.initials: JJ
authors.lastname: van Saene
authors.forename: H K
authors.initials: HK
authors.lastname: van Saene
authors.forename: M V
authors.initials: MV
authors.lastname: Martin
mesh_terms: D000328:Adult; D002353:Carrier State; D015169:Colony Count, Microbial; D004731:Endotoxins / Q000032:analysis*; D005260:Female; D006089:Gram-Negative Anaerobic Bacteria / Q000302:isolation & purification*; D006801:Humans; D008033:Limulus Test; D008297:Male; D009055:Mouth / Q000382:microbiology*; D009960:Oropharynx / Q000382:microbiology*; D012016:Reference Values; D012463:Saliva / Q000382:microbiology; D012680:Sensitivity and Specificity
chemical_list: D004731:Endotoxins