In planta recovery of Erwinia amylovora viable but nonculturable cells

Trees ◽  
2011 ◽  
Vol 26 (1) ◽  
pp. 75-82 ◽  
Author(s):  
R. D. Santander ◽  
J. F. Català-Senent ◽  
E. Marco-Noales ◽  
E. G. Biosca
Keyword(s):  
Erwinia Amylovora ◽  
In Planta ◽  
Viable But Nonculturable ◽  
Nonculturable Cells

scholarly journals Survival Strategy of Erwinia amylovora against Copper: Induction of the Viable-but-Nonculturable State

2006 ◽  
Vol 72 (5) ◽  
pp. 3482-3488 ◽  
Author(s):  
M�nica Ordax ◽  
Ester Marco-Noales ◽  
Mar�a M. L�pez ◽  
Elena G. Biosca
Keyword(s):  
Pathogenic Bacteria ◽  
Erwinia Amylovora ◽  
Control Plant ◽  
Viable Cell ◽  
Epifluorescence Microscopy ◽  
Survival Strategy ◽  
Vbnc State ◽  
Tetrazolium Chloride ◽  
Viable But Nonculturable ◽  
Cell Counts

ABSTRACT Copper compounds, widely used to control plant-pathogenic bacteria, have traditionally been employed against fire blight, caused by Erwinia amylovora. However, recent studies have shown that some phytopathogenic bacteria enter into the viable-but-nonculturable (VBNC) state in the presence of copper. To determine whether copper kills E. amylovora or induces the VBNC state, a mineral medium without copper or supplemented with 0.005, 0.01, or 0.05 mM Cu2+ was inoculated with 107 CFU/ml of this bacterium and monitored over 9 months. Total and viable cell counts were determined by epifluorescence microscopy using the LIVE/DEAD kit and by flow cytometry with 5-cyano-2,3-ditolyl tetrazolium chloride and SYTO 13. Culturable cells were counted on King's B nonselective solid medium. Changes in the bacterial morphology in the presence of copper were observed by scanning electron microscopy. E. amylovora entered into the VBNC state at all three copper concentrations assayed, much faster when the copper concentration increased. The addition of different agents which complex copper allowed the resuscitation (restoration of culturability) of copper-induced VBNC cells. Finally, copper-induced VBNC cells were virulent only for the first 5 days, while resuscitated cells always regained their pathogenicity on immature fruits over 9 months. These results have shown, for the first time, the induction of the VBNC state in E. amylovora as a survival strategy against copper.

SIGNIFICANCE OF VIABLE BUT NONCULTURABLE BACTERIA FOR SAFETY OF FOOD PRODUCTS

2019 ◽  
Vol 1 (2) ◽  
pp. 183-189
Author(s):  
A. M. Abdullaeva ◽  
◽  
L. P. Blinkova ◽  
Yu. D. Pakhomov ◽  
◽  
...  
Keyword(s):  
Food Products ◽  
Active State ◽  
Insufficient Data ◽  
Main Hypothesis ◽  
Viable But Nonculturable ◽  
Nonculturable Cells

In this review data on hazardous influence of nonculturable cells of pathogens on humans and animals, of contamination of foodstuffs is presented and also attention is stressed on properties of such cells and their effect through foodstuffs on humans and animals. Main hypothesis of formation and resuscitation of viable but nonculturable cells are elucidated. Factors that influence shifting bacteria to nonculturability and their conversion into active state are discussed. The conclusion is drawn about biohazard of viable nonculturable cells and insufficient data about their physiology and mechanisms of transition into this state and resuscitation back.

COMPARATIVE PROTEOME ANALYSIS FROM ERWINIA AMYLOVORA GROWN IN VITRO AND IN PLANTA

2008 ◽  
pp. 179-181
Author(s):  
M. Thoelen ◽  
J.P. Noben ◽  
J. Robben ◽  
R. Valcke ◽  
T. Deckers
Keyword(s):  
Erwinia Amylovora ◽  
Proteome Analysis ◽  
In Planta

scholarly journals Respective Roles of Culturable and Viable-but-Nonculturable Cells in the Heterogeneity of Salmonella enterica Serovar Typhimurium Invasiveness

2009 ◽  
Vol 75 (16) ◽  
pp. 5179-5185 ◽  
Author(s):  
Julien Passerat ◽  
Patrice Got ◽  
Sam Dukan ◽  
Patrick Monfort
Keyword(s):  
Stationary Phase ◽  
Salmonella Enterica ◽  
Gradient Centrifugation ◽  
Health Concern ◽  
Viable But Nonculturable ◽  
Serovar Typhimurium ◽  
Nonculturable Cells ◽  
Sources Of Infection ◽  
Culturable Cell ◽  
Vbnc Cell

ABSTRACT The existence of Salmonella enterica serovar Typhimurium viable-but-nonculturable (VBNC) cells is a public health concern since they could constitute unrecognized sources of infection if they retain their pathogenicity. To date, many studies have addressed the ability of S. Typhimurium VBNC cells to remain infectious, but their conclusions are conflicting. An assumption could explain these conflicting results. It has been proposed that infectivity could be retained only temporarily after entry into the VBNC state and that most VBNC cells generated under intense stress could exceed the stage where they are still infectious. Using a Radioselectan density gradient centrifugation technique makes it possible to increase the VBNC-cell/culturable-cell ratio without increasing the exposure to stress and, consequently, to work with a larger proportion of newly VBNC cells. Here, we observed that (i) in the stationary phase, the S. Typhimurium population comprised three distinct subpopulations at 10, 24, or 48 h of culture; (ii) the VBNC cells were detected at 24 and 48 h; (iii) measurement of invasion gene (hilA, invF, and orgA) expression demonstrated that cells are highly heterogeneous within a culturable population; and (iv) invasion assays of HeLa cells showed that culturable cells from the different subpopulations do not display the same invasiveness. The results also suggest that newly formed VBNC cells are either weakly able or not able to successfully initiate epithelial cell invasion. Finally, we propose that at entry into the stationary phase, invasiveness may be one way for populations of S. Typhimurium to escape stochastic alteration leading to cell death.

scholarly journals A Single Effector Protein, AvrRpt2EA, from Erwinia amylovora Can Cause Fire Blight Disease Symptoms and Induces a Salicylic Acid–Dependent Defense Response

2018 ◽  
Vol 31 (11) ◽  
pp. 1179-1191 ◽  
Author(s):  
Susan Schröpfer ◽  
Christoph Böttcher ◽  
Thomas Wöhner ◽  
Klaus Richter ◽  
John Norelli ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Fire Blight ◽  
Systemic Acquired Resistance ◽  
Erwinia Amylovora ◽  
Acquired Resistance ◽  
Inducible Promoter ◽  
Marker Genes ◽  
Effector Protein ◽  
In Planta ◽  
Natural Fire

The AvrRpt2EA effector protein of Erwinia amylovora is important for pathogen recognition in the fire blight–resistant crabapple Malus × robusta 5; however, little is known about its role in susceptible apples. To study its function in planta, we expressed a plant-optimized version of AvrRpt2EA driven by a heat shock–inducible promoter in transgenic plants of the fire blight–susceptible cultivar Pinova. After induced expression of AvrRpt2EA, transgenic lines showed shoot necrosis and browning of older leaves, with symptoms similar to natural fire blight infections. Transgenic expression of this effector protein resulted in an increase in the expression of the salicylic acid (SA)-responsive PR-1 gene but, also, in the levels of SA and its derivatives, with diverse kinetics in leaves of different ages. In contrast, no increase of expression levels of VSP2 paralogs, used as marker genes for the activation of the jasmonic acid (JA)-dependent defense pathway, could be detected, which is in agreement with metabolic profiling of JA and its derivatives. Our work demonstrates that AvrRpt2EA acts as a virulence factor and induces the formation of SA and SA-dependent systemic acquired resistance.

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