| Mercury and antibioticresistant bacteria.Summers AO, Wireman J, Vimy MJ, Lorscheider FL, Marshall B, Levy SB, Bennet S & Billard LMercury released from dental "silver" fillings provokes an increase in mercury- and antibioticresistant bacteria in oral and intestinal floras of primates. Antimicrobial Agents and Chemotherapy 37(4):825-834 (1993)
ABSTRACT:
"In a survey of 640 human subjects, a subgroup of 356 persons without recent exposure to antibiotics demonstrated that those with a high prevalence of Hg resistance in their intestinal floras were significantly more likely to also have resistance to two or more antibiotics... Resistances to mercury and to several antibiotics were examined in the oral and intestinal floras of six adult monkeys prior to the installation of amalgam fillings, during the time they were in place, and after replacement of the amalgam fillings with glass ionomer fillings (in four of the monkeys). The monkeys were fed an antibiotic-free diet, and fecal mercury concentrations were monitored. There was a statistically significant increase in the incidence of mercury-resistant bacteria during the 5 weeks following installation of the amalgam fillings and during the 5 weeks following installation of the amalgam fillings and during the 5 weeks immediatly following their replacement with glass ionomer fillings. These peaks in incidence of mercury resistant bacteria correlated with peaks of Hg elimination (as high as 1mM in the feces) immediatly following amalgam placement and immediately after replacement of the amalgam fillings. Representative mercury resistant isolates of three selected bacterial families (oral streptococci, members of the family Enterobacteriaceae, and enterococci) were also resistant to one or more antibiotics, including ampicillin... While such mercury- and antibiotic-resistant isolates among the staphylococci, the enterococci, and members of the family Enterobacteriaceae have been described, this is the first report of mercury resistance in the oral streptococci. Many of the enterobacterial strains were able to transfer mercury and antibiotic resistances together to laboratory bacterial recients, suggesting that the loci for these resistances are genetically linked. Our findings indicate that mercury released from amalgam fillings can cause an enrichment of mercury resistance plasmids in the normal bacterial floras of primates. Many of these plasmids also carry antibiotic resistance, implicating the exposure to mercury from dental amalgams in an increased incidence of multiple antibiotic resistance plasmids in the normal floras of nonmedicated subjects" |
