Abstract
UV disinfection is noted to have some problems, one of which is photoreactivation. Photoreactivation allows inactivated microorganisms to regain viability following UV disinfection. The objective of this study is to determine the susceptibility of enterohemorrhagic Escherichia coli (EHEC) O26, vancomycin resistant Enterococcus (VRE), and Pseudomonas aeruginosa to UV radiation and photoreactivation. The conclusions obtained in this study can be summarized as follows. EHEC O26 exhibited apparent inactivation under sunlight after photoreactivation following UV inactivation. VRE exhibited apparent photoreactivation. The dose of UV light required for 90% inactivation of VRE with and without photoreactivation was 10.9 and 24.2 mW sec/cm2, respectively. P. aeruginosa exhibited apparent photoreactivation under fluorescent lamp and weak regrowth under dark conditions following UV inactivation. The dose of UV light required for 90% inactivation of P. aeruginosa with and without photoreactivation was 4.1 and 5.2 mW sec/cm2, respectively.
