ISHS Acta Horticulturae 896: XII International Workshop on Fire Blight
RECOVERY OF ERWINIA AMYLOVORA VIABLE BUT NON-CULTURABLE CELLS IN PEAR PLANTLETS |
| Authors: | R.D. Santander, J.F. Català-Senent, E.G. Biosca, E. Marco-Noales |
| Keywords: | fire blight, oligotrophy, nutrient deprivation, chlorine, VBNC, recovery |
| DOI: | 10.17660/ActaHortic.2011.896.39 |
| Abstract:
Survival studies on Erwinia amylovora have demonstrated that it enters into the viable but non-culturable (VBNC) state when exposed to different types of stress. In this state, bacteria remain viable but unable to grow on solid general media, and are undetectable by conventional culture methods. We have evaluated the recovery of E. amylovora VBNC cells by passage through pear plantlets. Comparison with other common recovery methods included incubation in KB broth and inoculation of immature fruits. VBNC cells were obtained by exposure of bacterial cells to different types of stress (oligotrophy, nutrient deprivation and chlorine), and recovery assays were performed at 26°C. In most cases, the recovery of VBNC cells was more effective in plantlets than in liquid KB or with immature fruits. In fact, when cells were exposed to chlorine for more than 30 min, only passage through the host plant recovered E. amylovora culturable cells from symptomatic plantlets few days after inoculation. These results suggest a better recovery with plantlets than in liquid KB or detached fruits. Our results support the hypothesis of the VBNC state as a part of the E. amylovora life cycle. This physiological state should be taken in consideration in epidemiological studies about the fire blight, with the aim to optimize management and disease control. | |
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