Biocidal activity of metalloacid-coated surfaces against multidrug-resistant microorganisms.

BACKGROUND

The antimicrobial effects of a coating of molybdenum trioxide (MoO3) has been recently described. The metalloacid material produces oxonium ions (H3O+), which creates an acidic pH that is an effective, non specific antimicrobial. We determined the in vitro antimicrobial activity of molybdenum trioxide metalloacid-coated surfaces.

METHODS

Metalloacid-coated and non-coated (control) surfaces were contaminated by exposing them for 15 minutes to microbial suspensions containing 105 cfu/mL. Eleven microorganisms responsible for nosocomial infections were tested: two Staphylococcus aureus strains (the hetero-vancomycin intermediate MRSA Mu50 strain and a ST80-PVL-producing MRSA strain); a vancomycin-resistant vanA Enterococcus faecium strain; three extended-spectrum beta-lactamase-producing Enterobacteriaceae strains; a MBL-producing Pseudomonas aeruginosa strain; a multidrug-resistant Acinetobacter baumannii strain; a toxin-producing Clostridium difficile strain; and two fungi (Candida albicans and Aspergillus fumigatus). The assay tested the ability of the coated surfaces to kill microorganisms.

RESULTS

Against all non-sporulating microorganisms tested, metalloacid-coated surfaces exhibited significant antimicrobial activity relative to that of the control surfaces within two to six hours after contact with the microorganisms (p < 0.001). Microorganism survival on the coated surfaces was greatly impaired, whereas microorganism survival on control surfaces remained substantial.

CONCLUSIONS

We suggest that, facing the continuing shedding of microorganisms in the vicinity of colonized or infected patients, the continuous biocidal effect of hydroxonium oxides against multidrug-resistant microorganisms may help limit environmental contamination between consecutive cleaning procedures.