title: Inactivation of Clostridium difficile spores by microwave irradiation.
abstract: Spores are a potent agent for Clostridium difficile transmission. Therefore, factors inhibiting spores have been of continued interest. In the present study, we investigated the influence of microwave irradiation in addition to conductive heating for C. difficile spore inactivation in aqueous suspension. The spores of 15 C. difficile isolates from different host origins were exposed to conductive heating and microwave irradiation. The complete inhibition of spore viability at 10(7) CFU/ml was encountered following microwave treatment at 800 W for 60 s, but was not observed in the conductive-heated spores at the same time-temperature exposure. The distinct patterns of ultrastructural alterations following microwave and conductive heat treatment were observed and the degree of damages by microwave was in the exposure time-dependent manner. Microwave would therefore be a simple and time-efficient tool to inactivate C. difficile spores, thus reducing the risk of C. difficile transmission.
authors.affiliation: Graduate Program in Molecular Medicine, Faculty of Science, Mahidol University, Bangkok, 10400 Thailand.
authors.forename: Suvash Chandra
authors.initials: SC
authors.lastname: Ojha
authors.affiliation: Department of Biology, Faculty of Science, Mahidol University, Bangkok, 10400 Thailand; Center for Emerging and Neglected Infectious Diseases, Mahidol University, Nakhon Pathom, 73170, Thailand.
authors.forename: Surang
authors.initials: S
authors.lastname: Chankhamhaengdecha
authors.affiliation: Department of Biology, Faculty of Science, Mahidol University, Bangkok, 10400 Thailand.
authors.forename: Sombat
authors.initials: S
authors.lastname: Singhakaew
authors.affiliation: Department of Biology, Faculty of Science, Mahidol University, Bangkok, 10400 Thailand.
authors.forename: Puey
authors.initials: P
authors.lastname: Ounjai
authors.affiliation: Center for Emerging and Neglected Infectious Diseases, Mahidol University, Nakhon Pathom, 73170, Thailand; Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, 10400 Thailand. Electronic address: tavan.jan@mahidol.ac.th.
authors.forename: Tavan
authors.initials: T
authors.lastname: Janvilisri
mesh_terms: D016360:Clostridioides difficile / Q000502:physiology* / Q000528:radiation effects*; D050296:Microbial Viability / Q000528:radiation effects*; D008872:Microwaves; D013171:Spores, Bacterial / Q000528:radiation effects* / Q000648:ultrastructure; D013696:Temperature; D013997:Time Factors
keywords: Clostridium difficile; Microwave; Spore; Ultrastructure