Evaluation of 222 nm Ultraviolet C Bactericidal Efficacy on Bacterial Isolates from Broiler Farms

Abstract

Ultraviolet (UV) radiation is categorized by wavelengths 100∼400 nm, with 254 nm UVC having strong germicidal effects achieved by damaging the DNA and RNA of pathogenic microorganisms. On the other hand, the use of 254 nm UVC is restricted in environments where human exposure is possible because of its potential harm to human cells. Recently, 222 nm UVC has been suggested as a safer alternative because it does not penetrate the skin surface, posing less risk to humans while demonstrating antibacterial effects similar to those of 254 nm UVC. This study evaluated the bactericidal effects of 222 nm UVC on Gram-positive bacteria, Mammaliicoccus lentus and Staphylococcus simulans, and Gram-negative bacteria, Pseudomonas putida, Proteus mirabilis, and Escherichia coli, isolated from broiler farm litter and feces. Bacterial suspensions were exposed to 222 nm UVC for 0, 10, 30, 60, and 120 seconds. The results revealed a significant reduction (P<0.001) in viability across all bacteria, with complete inactivation achieved in all species except for M. lentus after 60 seconds. These findings suggest that 222 nm UVC could be an effective disinfection method for pathogenic bacteria in specialized settings such as broiler farms, with potential applications in other livestock environments, pending confirmation of its safety for long-term exposure.

Keywords

• 222 nm uvc
• bactericidal effect
• broiler farm
• disinfection method