Assessment of bacterial endospore viability with fluorescent dyes

Authors: Laflamme, ChristianLavigne, S.; Ho, Jim; Duchaine, Caroline
Abstract: Aim: To validate three fluorescence viability assays designed primarily for vegetative cells on pure Bacillus endospores. Methods and Results: Purified fresh and gamma-irradiated Bacillus endospores (Bacillus cereus, B. coagulans and two strains of B. subtilis) were used. The viability assays were: 5-cyano-2,3-diotolyl tetrazolium chloride (CTC) to test respiratory activity and early germination, DiBAC4(3) and Live/Dead BacLight to measure membrane energization and permeabilization, respectively. Gamma irradiation treatment completely eliminated spore culturability and was used as negative control. The untreated spores showed respiratory activity after 1 h of incubation and this was characteristic of almost 100% of spores after 24 h. The membrane potential assessment gave no answer about spore viability. A lower proportion of untreated spores had permeabilized membrane compared with gamma-irradiated spores using Live/Dead BacLight (P < 0·02). Conclusion: It is possible to use CTC and Live/Dead BacLight to rapidly test endospore viability and evaluate the proportion of spores in a preparation that could not be recovered with plate count. Significance and Impact of the Study: This study shows that fluorescence tests could be applied to assess viability in potentially pathogenic Bacillus spore preparations within 1 h.
Document Type: Article de recherche
Issue Date: 23 February 2004
Open Access Date: Restricted access
Document version: VoR
This document was published in: Journal of Applied Microbiology, Vol. 96 (4), 684–692 (2004)
Blackwell Science
Alternative version: 10.1111/j.1365-2672.2004.02184.x
Collection:Articles publiés dans des revues avec comité de lecture

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