The Viable but Nonculturable State and Starvation Are Different Stress Responses of
            <i>Enterococcus faecalis</i>
            , as Determined by Proteome Analysis

Heim, Sabina; Lleò, Maria del Mar; Bonato, Barbara; Guzmán, Carlos A.; Canepari, Pietro

doi:10.1128/jb.184.23.6739-6745.2002

Cited by 174 publications

(155 citation statements)

References 35 publications

Supporting

Mentioning

143

Contrasting

Unclassified

Order By: Relevance

“…However, it is becoming clear that many pathogens can enter a viable but non-cultivable state (VBNC) when exposed to various chemical or environmental factors. E. faecalis was shown to enter the VBNC state in response to low nutrient concentration, osmotic or oxidative stress and low temperature [24,25].…”

Section: Discussionmentioning

confidence: 99%

Repeated exposures to blue light-activated eosin Y enhance inactivation of E. faecalis biofilms, in vitro

Marinic

Manoil

Filieri

et al. 2015

Photodiagnosis and Photodynamic Therapy

View full text Add to dashboard Cite

Background: In dentistry, antibacterial photodynamic therapy (a-PDT) has shown promising results for inactivating bacterial biofilms causing carious, endodontic and periodontal diseases. In the current study, we assessed the ability of eosin Y exposed to 3 irradiation protocols at inactivating Enterococcus faecalis biofilms, in vitro. Methods: E. faecalis biofilms formed on hydroxyapatite disks were incubated with eosin Y (10-80 M), then activated with blue light using different irradiation protocols. Biofilms exposed to continuous exposure were incubated for 40 min before being light-activated for 960 s. For the intermittent exposure, biofilms were exposed 4 times to the light/photosensitizer combination (960 s total) without renewing the photosensitizer. For repeated a-PDT, the same light dose was delivered in a series of 4 irradiation periods separated by dark periods; fresh photosensitizer was added between each light irradiation. After treatment, bacteria were immediately labeled with LIVE/DEAD BacLight Bacterial Viability kit and viability was assessed by flow cytometry (FCM). Results were statistically analyzed using one-way ANOVA and Tukey multiple comparison intervals (˛= 0.05). * Corresponding author. Results:The viability of E. faecalis biofilms exposed to 10 M eosin Y, was significantly reduced compared to controls (light only-eosin Y only). After a second exposure to blue light-activated eosin Y, viability significantly decreased from 58% to 12% whereas 6.5% of the bacterial biofilm remained live after a third exposure (p < 0.05). Only 3.5% of the bacterial population survived after the fourth exposure. Conclusions:The results of this study indicate that blue light-activated eosin Y can photoinactivate E. faecalis biofilms grown on hydroxyapatite disks. Also, repeated exposures to blue light-activated eosin Y were shown to significantly improve efficacy. Further studies seem warranted to optimize the antibacterial activity of blue light-activated eosin Y on major oral pathogens.

show abstract

Section: Discussionmentioning

confidence: 99%

Repeated exposures to blue light-activated eosin Y enhance inactivation of E. faecalis biofilms, in vitro

Marinic

Manoil

Filieri

et al. 2015

Photodiagnosis and Photodynamic Therapy

View full text Add to dashboard Cite

show abstract

“…Despite evidence on the revival of growth in these dormant cells, a number of basic and logical questions have been raised as to whether this nonculturability is a dormancy state of cell adaptation to stress or a stage preceding cell death, partly owing to the unpersuasive revitalization potential. Studies also showed the molecular and functional dissimilarity of stressed (Chan et al 1998), VBNC cells (Heim et al 2002) from the NC state induced by "starvation", which was demonstrated using isolated NC cells (Desnues et al 2003), leading to the suggestion that NC cells might have been formed as a result of stochastic deterioration. Nonetheless, while co-crystallization of DNA with the stress induced proteins was proposed as a generic defense strategy to environmental stress in Escherichia coli (Wolf et al 1999), a resuscitation-promoting factor(s) (Rpf) was also identified in long-term stationary phase cultures of Micrococcus luteus (Mukamolova et al 1998).…”

Section: Introductionmentioning

confidence: 99%

A dormancy state in nonspore-forming bacteria

Sachidanandham

Gin

2009

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

While cultivation is a convenient way of proliferating and understanding bacteria, studies have shown the formation of nonculturable cells in nonspore-forming bacteria in response to environmental stress and thus in turn have generated immense interest. Whether these cells are in a state of dormancy or in a stage preceding cell death has been considered of paramount importance for the past couple of decades. In this study, osmotic-stress-induced dormant bacterial cells were separated by cell sorting and revived by osmotic down-shift in the absence of nutrients, source(s) that potentially could supply nutrients, and/or the external addition of resuscitation factor(s). Reversal of dormancy followed a definite pattern akin to population asynchrony of dormant cells, and the phenomenon was observed across three species, namely, Enterobacter sp. strain mcp11b, Klebsiella pneumonia strain mcp11d and Escherichia coli. In addition, our study precisely forecasted the presence of multiple subpopulations in dormant cells, which is explained by an emerging theory of survival mechanisms in stressful environments. These observations reveal that the state of dormancy induced by environmental stress in these nonspore-forming bacteria is "reversible" and also implies that it is an orderly and spontaneous adaptation to circumvent adverse conditions.

show abstract

“…Several starvation-survival responses have been described, with starved bacterial populations maintaining their numbers over time in a non-growing but culturable state at different levels depending on the species (Morita, 1997). This starvation-induced state for survival proved to be distinctly different from that of active growth (Heim et al, 2002). Under prolonged oligotrophy, reduction in cell size and change to a round cell shape are also considered as bacterial strategies to survive in the environment (Novitsky & Morita, 1976;Rollins & Colwell, 1986;Ruiz et al, 2001), as well as the induction of a viable but non-culturable (VBNC) state (Oliver, 2005;Roszak & Colwell, 1987) that constitutes a distinct physiological state from that of the starvation response (Heim et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

“…This starvation-induced state for survival proved to be distinctly different from that of active growth (Heim et al, 2002). Under prolonged oligotrophy, reduction in cell size and change to a round cell shape are also considered as bacterial strategies to survive in the environment (Novitsky & Morita, 1976;Rollins & Colwell, 1986;Ruiz et al, 2001), as well as the induction of a viable but non-culturable (VBNC) state (Oliver, 2005;Roszak & Colwell, 1987) that constitutes a distinct physiological state from that of the starvation response (Heim et al, 2002). R. solanacearum becomes VBNC by exposure to copper (Grey & Steck, 2001) and after incubation at low temperature in soil and water (Caruso et al, 2005;van Elsas et al, 2000van Elsas et al, , 2001van Overbeek et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Survival strategies and pathogenicity of Ralstonia solanacearum phylotype II subjected to prolonged starvation in environmental water microcosms

2008

View full text Add to dashboard Cite

Survival strategies exhibited over 4 years by Ralstonia solanacearum phylotype (ph) II biovar (bv) 2 in environmental water microcosms were examined. The bacterium is a devastating phytopathogen whose ph II bv 2 causes bacterial wilt in solanaceous crops and ornamental plants. Outbreaks of the disease may originate from dissemination of the pathogen in watercourses, where it has to cope with prolonged nutrient limitation. To ascertain the effect of long-term starvation on survival and pathogenicity of R. solanacearum in natural water microcosms, survival experiments were conducted. Microcosms were prepared from different sterile river water samples, inoculated separately with two European strains of ph II at 10 6 c.f.u. ml "1 and maintained at 24 6C for 4 years. In all assayed waters, starved R. solanacearum remained in a non-growing but culturable state during the first year, maintaining approximately the initial numbers. Thereafter, part of the population of R. solanacearum progressively lost the ability to form colonies, and non-culturable but metabolically active cells appeared. During the whole period, the bacterium remained pathogenic on host plants and underwent a transition from typical bacilli to small cocci which tended to aggregate. Some starved R. solanacearum cells filamented and formed buds. Starvation response, viable but non-culturable state, morphological changes and aggregation have not previously been reported for this pathogen as survival mechanisms induced in oligotrophic conditions. The potential existence of long-starved pathogenic cells in environmental waters may raise new concerns about the epidemiology of bacterial wilt disease.

show abstract

The Viable but Nonculturable State and Starvation Are Different Stress Responses of Enterococcus faecalis , as Determined by Proteome Analysis

Cited by 174 publications

References 35 publications

Repeated exposures to blue light-activated eosin Y enhance inactivation of E. faecalis biofilms, in vitro

Repeated exposures to blue light-activated eosin Y enhance inactivation of E. faecalis biofilms, in vitro

A dormancy state in nonspore-forming bacteria

Survival strategies and pathogenicity of Ralstonia solanacearum phylotype II subjected to prolonged starvation in environmental water microcosms

Contact Info

Product

Resources

About