title: Resistance of the normal human microflora to mercury and antimicrobials after exposure to mercury from dental amalgam fillings.
abstract: The concentrations of mercury in saliva and feces and the resistance pattern of the gastrointestinal microflora were investigated for 20 subjects. Ten patients, with a mean number of 19 amalgam surfaces, had all amalgam fillings removed during one dental session. Ten subjects without amalgam fillings served as a control group. Saliva and fecal samples were collected before amalgam removal and 2, 7, 14, and 60 days afterward. Mercury levels in saliva and feces correlated significantly with the number of amalgam surfaces. No differences in the resistance pattern of the oral microflora were detected between the two groups. In the amalgam group there was an increase in the relative number of intestinal microorganisms resistant to mercury, ampicillin, cefoxitin, erythromycin, and clindamycin on days 7-14. This was not statistically significant in light of the normal variations of the control group. A significant correlation between the prevalence of mercury resistance and multiple antimicrobial resistance in intestinal bacterial strains was observed.
authors.affiliation: Department of Microbiology, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Edlund
authors.forename: L
authors.initials: L
authors.lastname: Björkman
authors.forename: J
authors.initials: J
authors.lastname: Ekstrand
authors.forename: G
authors.initials: G
authors.lastname: Sandborgh-Englund
authors.forename: C E
authors.initials: CE
authors.lastname: Nord
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001439:Bacteroides / Q000187:drug effects; D003723:Dental Amalgam / Q000009:adverse effects*; D004352:Drug Resistance, Microbial; D016983:Enterococcus / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D007422:Intestines / Q000382:microbiology; D008297:Male; D008628:Mercury / Q000009:adverse effects* / Q000032:analysis*; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology*; D012463:Saliva / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D003723:Dental Amalgam; D008628:Mercury