title: Evaluation of propidium monoazide-quantitative PCR to detect viable Mycobacterium fortuitum after chlorine, ozone, and ultraviolet disinfection.
abstract: We evaluated whether propidium monoazide (PMA) combined with real-time quantitative PCR (qPCR) is suitable for detecting viable Mycobacterium fortuitum after chlorine, ozone, and ultraviolet (UV) disinfection. PMA-qPCR was effective in determining the viability of M. fortuitum compared with qPCR based on the membrane integrity. However, with a mild chlorine concentration, PMA-qPCR as an alternative method was not applicable due to a large gap between loss of culturability and membrane integrity damage. In ozonation, PMA-qPCR was able to differentiate between viable and injured mycobacteria, and the results were similar to those obtained by the culture method. Interestingly, PMA-qPCR was successful in monitoring the viability after UV disinfection due to the long UV exposure needed to effectively inactivate M. fortuitum. The findings of the present study suggested that the characteristics of disinfectants and the M. fortuitum resistance to disinfectants play critical roles in determining the suitability of PMA-qPCR for evaluating the efficacy of disinfection methods.
authors.affiliation: Waterworks Research Institute, Seoul Metropolitan Government, 716-10 Cheonhodaero, Gwangjin-gu, Seoul, Republic of Korea. Electronic address: leuns21@seoul.go.kr.
authors.forename: Eun-Sook
authors.initials: ES
authors.lastname: Lee
authors.affiliation: Waterworks Research Institute, Seoul Metropolitan Government, 716-10 Cheonhodaero, Gwangjin-gu, Seoul, Republic of Korea.
authors.forename: Man-Ho
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Waterworks Research Institute, Seoul Metropolitan Government, 716-10 Cheonhodaero, Gwangjin-gu, Seoul, Republic of Korea.
authors.forename: Bog-Soon
authors.initials: BS
authors.lastname: Kim
mesh_terms: D001386:Azides / Q000494:pharmacology; D001431:Bacteriological Techniques / Q000379:methods*; D002713:Chlorine / Q000494:pharmacology; D004202:Disinfectants / Q000494:pharmacology; D004203:Disinfection / Q000592:standards*; D005516:Food Microbiology / Q000379:methods*; D050296:Microbial Viability / Q000187:drug effects; D019907:Mycobacterium fortuitum / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D010126:Ozone / Q000494:pharmacology; D011419:Propidium / Q000031:analogs & derivatives / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction / Q000592:standards*
chemical_list: D001386:Azides; D004202:Disinfectants; C533957:propidium monoazide; D011419:Propidium; D002713:Chlorine; D010126:Ozone
keywords: Chlorine; Mycobacterium fortuitum; Ozone; Propidium monoazide; Real-time quantitative PCR; Ultraviolet