Antibacterial Effect of Zinc Oxide in Vitro

Abstract

Antibacterial activity, zinc concentrations and pH were measured in Müller-Hinton broth containing different amounts of zinc oxide and inoculated with Staphylococcus aureus (10⁶ colony forming units/ml). The minimum inhibitory concentrations (MIC) of zinc oxide to different clinical isolates were determined using the Müller-Hinton agar dilution tests. Gram-positive bacteria were most susceptible. Gram-negative aerobic bacteria and streptococci were usually not inhibited even at the highest concentrations used (1024 μg/ml), but staphylococci—particularly some isolates of Staphylococcus epidermidis—were sensitive enough to allow determination of their MIC.

Key Words:

• zinc oxide
• zinc
• antibacterial effect