Metal-ion susceptibility of oral bacterial species

Abstract

Summary: Aims: This study aimed to evaluate the effect of lead (Pb) on growth of bacterial species related to dental diseases in vitro. Methods and Results: The effects of lead acetate on representative species of the oral flora were examined at 0·1-10mmoll-1 and compared with the effect of silver nitrate and ferrous sulfate. The minimal inhibitory concentration of lead acetate was between 0·15 and 5mmoll-1 for the bacterial strains tested. The minimal bactericidal concentration of lead acetate for most oral species was detected in the range of 5-10mmol l-1. Silver nitrate at a concentration of 1·25mmoll-1 was sufficient to exhibit antibacterial activity against almost all bacteria tested. Ferrous sulfate had the lowest effect. Conclusions: The study indicated a general antimicrobial effect of lead on oral bacterial species in the range of 0·15-10mmoll-1. The toxicity of silver nitrate was the highest, whereas that of ferrous sulfate was the lowest. Gram-positive species had a tendency to be less susceptible for metals than Gram-negatives. Significance and Impact of the Study: The study shows that it is possible that microbiological changes may occur in the dental plaque in children because of toxic exposure of environmental lead. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.