Anti-biofilm and antibacterial activities of zinc oxide nanoparticles against the oral opportunistic pathogens Rothia dentocariosa and Rothia mucilaginosa.
Species of the genus Rothia that inhabit the oral cavity have recently been implicated
in a number of diseases. To minimize their role in oral infections, it is imperative
to reduce and/or control the growth and biofilm formation activity of Rothia
spp. In this study, two bacterial isolates, Ora-7 and Ora-16, were obtained from the
oral cavity of a healthy male subject and identified as Rothia dentocariosa and
Rothia mucilaginosa, respectively, using a polyphasic taxonomic approach. Antimicrobial
and anti-biofilm formation activities of zinc oxide nanoparticles (ZnO-NPs),
of average size 35 nm, were assessed in in vitro assays using Crystal Violet and live
and dead staining techniques. The ZnO-NPs exhibited an IC50 value of 53 and
76 µg ml-1 against R. dentocariosa and R. mucilaginosa, respectively. Biofilmformation
assays, performed on the surfaces of polystyrene plates, artificial teeth,
and dental prostheses, revealed the efficacy of ZnO-NPs as a potential antibacterial
agent for controlling the growth of Rothia isolates in both planktonic form and
biofilm.
