Susceptibility of 169 USA300 methicillin-resistant Staphylococcus aureus isolates to two copper-based biocides, CuAL42 and CuWB50

• Published in: Journal of antimicrobial chemotherapy Vol. 65; no. 5; pp. 939 - 941
• Main Authors: Luna, Vicki Ann, Hall, Tony J., King, Debbie S., Cannons, Andrew C.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.05.2010; Oxford Publishing Limited (England)
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimicrobial agents; Bacterial diseases; Bacterial Typing Techniques; Benzalkonium Compounds - pharmacology; Biological and medical sciences; Copper; Copper - pharmacology; disinfectants; DNA Fingerprinting; Drug resistance; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Genotype; Human bacterial diseases; Humans; Infectious diseases; Medical sciences; Methicillin-Resistant Staphylococcus aureus - classification; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Microbial Sensitivity Tests; Microbial Viability - drug effects; minimum inhibition concentrations; MRSA; Organisms; Pharmacology. Drug treatments; Staphylococcal Infections - microbiology; Staphylococcal infections, streptococcal infections, pneumococcal infections; Staphylococcus aureus; Staphylococcus infections; Time Factors; time–kill studies; United States; United States; United States > US; minimum inhibition concentrations; time-kill studies; Concentration; Heavy metal; Infection; Sensitivity; disinfectants; MRSA; Bacteriosis; Bacteria; Micrococcales; Isolate; Micrococcaceae; Inhibitor; Inhibition; Copper; Disinfecting agent; Staphylococcal infection; Biocide; Staphylococcus aureus
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkq092

Objectives To test the activity of two copper-based biocides, CuAL42 and CuWB50, and benzalkonium chloride against 169 isolates of methicillin-resistant Staphylococcus aureus (MRSA) pulsotype USA300, a virulent, multiply resistant, widespread clone in the USA. Methods Tests including MIC, MBC and time–kill studies were performed multiple times. Results The MIC range, MIC50 and MIC90 (0.59–18.75, 4.69 and 4.69 ppm, respectively) and the MBC range, MBC50 and MBC90 (1.17–18.75, 4.69 and 9.38 ppm, respectively) for CuAL42 were identical with those obtained with CuWB50, except that the MBC range for CuWB50 was wider (0.59–37.5 ppm). In time–kill studies, a 6 log10 reduction of cfu was achieved within 1 h (150 ppm) and 0.5 h (300 ppm) for CuAL42, and 1.5 h (150 ppm) and 0.75 h (300 ppm) for CuWB50. Conclusions Both copper-based biocides can effectively kill USA300 MRSA and may facilitate the eradication of the organism from healthcare settings.