Onderzoek persister cells

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Sproetje
Berichten: 3171
Lid geworden op: Di 28 Okt 2014, 20:33

Re: Onderzoek persister cells

Berichtdoor Sproetje » Ma 19 Sep 2016, 19:36

Lola Lyme schreef:
Breaking News! – What everyone was waiting for – Possible Lyme Disease Cure on Horizon

Gepubliceerd op 13 nov. 2014
All the lies are starting to come out folks, breaking news has just surfaced that Ying Zhang, MD, PhD developed a test that can identify persister cells in Chronic Lyme Disease. Borrelia burgdorferi persister cells neither die nor grow in the presence of an antibiotic. Rather, they exist in a dormant state that allows them to survive antibiotic treatment, only to awaken later and start a new wave of infection. This new test will be able to quantify how many Borrelia burgdorferi are alive and how many are dead after each drug was added to the bacteria. The method stains the living bacteria green and the dead or dying bacteria red in a way that filters out the noise that can corrupt existing tests. So now, it's only a matter of time till the CDC changes their protocol and week can seek immediate antibitiotic treatment.

Breaking News!!! - Possible Lyme Disease Cure on Horizon


Meer hierover:

http://www.gordonmedical.com/unravellin ... e-disease/


.........
Study leader Ying Zhang, MD, PhD, a professor in the Bloomberg School’s Department of Molecular Microbiology and Immunology, and his colleagues tweaked a test typically used for simply counting DNA in samples in the lab. Using the test, they were able to quantify how many Borrelia burgdorferi are alive and how many are dead after each drug was added to the bacteria. The method stains the living bacteria green and the dead or dying bacteria red in a way that filters out the noise that can corrupt existing tests.

“It’s superior to the current gold standard for testing Borrelia viability,” Zhang says. “This could become be the new gold standard.”

The most exciting part of the development of the test, Zhang says, is that his team has already used it to identify a series of antibiotics approved to treat other infections that show promise in the lab against the lingering Borrelia burgdorferi bacteria, known as persisters. In a study published in July in the journal Emerging Microbes and Infections, Zhang and colleagues used the new test – called the SYBR Green I/PI assay – to identify several antibiotics that showed promise against the persistent bacteria that appear immune to the current Lyme antibiotics. That paper has been the most popular on the journal’s website, and patients, doctors and researchers have been contacting Zhang interested in testing out the most promising of the newly identified drugs.

The new test enables researchers to analyze thousands of drugs at a time because its use can directly measure the viability of the bacteria after drug treatment and doesn’t require each bacteria sample to be washed, as the currently used LIVE/DEAD BacLight assay does. In skipping that step, the new test is not only more accurate but also more efficient, is less expensive and takes less time, Zhang says.


Hier is de studie:

http://journals.plos.org/plosone/articl ... ne.0111809

Sproetje
Berichten: 3171
Lid geworden op: Di 28 Okt 2014, 20:33

Re: Onderzoek persister cells

Berichtdoor Sproetje » Do 03 Nov 2016, 19:23

Lola Lyme schreef:
EFFECTIVENESS OF STEVIA REBAUDIANA WHOLE LEAF EXTRACT AGAINST THE VARIOUS MORPHOLOGICAL FORMS OF BORRELIA BURGDORFERI IN VITRO
P. A. S. Theophilus, M. J. Victoria, K. M. Socarras, K. R. Filush, K. Gupta, D. F. Luecke, E. Sapi*
Department of Biology and Environmental Science, University of New Haven, West Haven, CT, USA
Received: September 7, 2015; Accepted: October 26, 2015 | European Journal of Microbiology and Immunology (2015) | DOI: 10.1556/1886.2015.00031

Lyme disease is a tick-borne multisystemic disease caused by Borrelia burgdorferi. Administering antibiotics is the primary treatment for this disease; however, relapse often occurs when antibiotic treatment is discontinued. The reason for relapse remains unknown, but recent studies suggested the possibilities of the presence of antibiotic resistant Borrelia persister cells and biofilms.

In this study, we evaluated the effectiveness of whole leaf Stevia extract against B. burgdorferi spirochetes, persisters, and biofilm forms in vitro. The susceptibility of the different forms was evaluated by various quantitative techniques in addition to different microscopy methods. The effectiveness of Stevia was compared to doxycycline, cefoperazone, daptomycin, and their combinations. Our results demonstrated that Stevia had significant effect in eliminating B. burgdorferi spirochetes and persisters. Subculture experiments with Stevia and antibiotics treated cells were established for 7 and 14 days yielding, no and 10% viable cells, respectively compared to the above-mentioned antibiotics and antibiotic combination. When Stevia and the three antibiotics were tested against attached biofilms, Stevia significantly reduced B. burgdorferi forms. Results from this study suggest that a natural product such as Stevia leaf extract could be considered as an effective agent against B. burgdorferi.

Lees meer Bron: Akademiai


Ik zie dat Eva Sapi een co auteur is van bovenstaande onderzoek.

Eva Sapi vindt dat ALLES onderzocht moet worden, zo heeft ze o.a. ook stevia in combinatie met doxy onderzocht
(het is dacht ik een niet gepubliceerd onderzoek)
Het gaat over biofilms

Norvect 2014

https://www.youtube.com/watch?v=StKyCfuRdns
(vanaf 36:15)

Om het geheel goed te begrijpen, kun je beter het hele filmpje luisteren.
En vergeet niet dat doxy (samen met stevia) goed effectief is tegen biofilms, maar stel je hebt nog andere spirocheten in je bloed, buiten je biofilms om, die zouden door de doxy meteen in een round body vorm schieten, waardoor je dan uiteindelijk weer meer spirocheten krijgt dan daarvoor.

Eus
Berichten: 992
Lid geworden op: Di 28 Okt 2014, 23:27

Re: Onderzoek persister cells

Berichtdoor Eus » Vr 04 Nov 2016, 17:59

En vergeet niet dat doxy (samen met stevia) goed effectief is tegen biofilms


Dat is alleen onderzocht in het laboratorium (in vitro) en nog niet uitgetest op dieren of mensen (in vivo).

Sproetje
Berichten: 3171
Lid geworden op: Di 28 Okt 2014, 20:33

Re: Onderzoek persister cells

Berichtdoor Sproetje » Ma 07 Nov 2016, 18:58

Ja, het is in vitro, maar een mens moet toch ergens beginnen?
Het is denk ik een pilot studie.
Eigenlijk had ik de tekst die je aanhaalt tussen aanhalingstekens moeten zetten, want het is een quote uit de lezing van Eva Sapi.

Maar ik denk ook dat het eerst moet worden uitgezocht op iig dieren.
En 1 zo'n studie zegt ook nog niet veel.
De studie die ze heeft gedaan met stevia dat het ook persisters uitschakelt in vitro, is ook nog niet op dieren getest.
En ook maar 1 studie te vinden hierover.
Laatst gewijzigd door Sproetje op Di 31 Jan 2017, 19:03, 1 keer totaal gewijzigd.

Sproetje
Berichten: 3171
Lid geworden op: Di 28 Okt 2014, 20:33

Re: Onderzoek persister cells

Berichtdoor Sproetje » Ma 30 Jan 2017, 16:18

Biofilm is wel iets anders dan persister cells, ik vond een onderzoek van Kim Lewis:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC90417/
Kim Lewis
2001


NATURE OF PERSISTERS

In 1944, Joseph W. Bigger of Trinity College (Dublin, Ireland), working in the command laboratory at York, United Kingdom, published a paper in The Lancet that reported on two important discoveries (7). According to Bigger, penicillin is a cidal rather than a bacteriostatic antibiotic, contrary to the prevailing opinion at the time; and treatment of a population of staphylococci with penicillin failed to sterilize the culture, leaving a small portion of cells that he aptly named “persisters”. Bigger estimated the incidence of persisters to be about 10−6. In that pioneering but largely forgotten study, Bigger considered two main hypotheses: (i) persisters have a higher heritable resistance to growth inhibition by penicillin, and (ii) persisters are variants that have the same susceptibility to growth inhibition by penicillin as the bulk of the cells but are insensitive to killing by penicillin. Bigger showed that upon regrowth, persisters that survived treatment with penicillin produce populations indistinguishable from the original strain; they are similarly sensitive to growth inhibition and produce new persisters.

The nature of persistence is unknown, and not much has been done over the past half a century to study these very interesting cells that apparently play a crucial role in population survival. Lack of appreciation of the clinical significance of persisters is in part responsible for the paucity of knowledge. Difficulties in studying a very small part of a population that has transient peculiarities have also contributed to the current state of ignorance. Perhaps the realization that persisters are essentially responsible for the resistance of biofilms to killing will stimulate studies into the nature of persistence. At present, considerably more is known about what persisters are not rather than what they are. Persisters are not mutants. It can also be concluded that persisters do not represent a special stage in the cell cycle, which is the current popular explanation (8, 19). At a rate of 10−6, however, this distinct stage of the cell cycle should occupy 1.8 ms (30 min/106), which would call for an unrealistic synchronization of processes throughout the cell on a time scale comparable to that of a single turnover of an enzymatic reaction. Persisters are most likely not cells in a special dormant state of no growth, which has also been suggested (29) (see below).

Obtaining empirical data on persisters should be relatively straightforward. It will be important to learn such basic facts as species-specific variations in persister prevalence rates, the dependence of the rate of persisters on growth conditions, the number of divisions required for the loss of persistence, whether or not persistence can be lost without undergoing division, how long persisters survive in the presence of antibiotics, and whether persisters are made of one type of cells or, rather, whether there are subpopulations of different kinds of persisters, each more resistant to killing by a particular type or subset of factors. It would be especially important to learn how the growth rate affects the resistance of persisters. For example, it is possible that these two factors act in synergy and that the resistance of persisters to killing is aided by conditions of slow growth.


Laatst gewijzigd door Sproetje op Ma 30 Jan 2017, 19:33, 1 keer totaal gewijzigd.

Sproetje
Berichten: 3171
Lid geworden op: Di 28 Okt 2014, 20:33

Re: Onderzoek persister cells

Berichtdoor Sproetje » Di 31 Jan 2017, 18:43


Sproetje
Berichten: 3171
Lid geworden op: Di 28 Okt 2014, 20:33

Re: Onderzoek persister cells

Berichtdoor Sproetje » Zo 05 Mar 2017, 16:45

Review

Subject Category: Antimicrobials and drug resistance

Citation: Emerging Microbes & Infections (2014) 3, e3; doi:10.1038/emi.2014.3
Published online 8 January 2014

Persisters, persistent infections and the Yin–Yang model
Open access

Ying Zhang1,2


http://www.nature.com/emi/journal/v3/n1 ... 0143a.html

ABSTRACT

Persisters are a small fraction of quiescent bacterial cells that survive lethal antibiotics or stresses but can regrow under appropriate conditions. Persisters underlie persistent and latent infections and post-treatment relapse, posing significant challenges for the treatment of many bacterial infections. The current definition of persisters has drawbacks, and a Yin–Yang model is proposed to describe the heterogeneous nature of persisters that have to be defined in highly specific conditions. Despite their discovery more than 70 years ago, the mechanisms of persisters are poorly understood. Recent studies have identified a number of genes and pathways that shed light on the mechanisms of persister formation or survival. These include toxin–antitoxin modules, stringent response, DNA repair or protection, phosphate metabolism, alternative energy production, efflux, anti-oxidative defense and macromolecule degradation. More sensitive single-cell techniques are required for a better understanding of persister mechanisms. Studies of bacterial persisters have parallels in other microbes (fungi, parasites, viruses) and cancer stem cells in terms of mechanisms and treatment approaches. New drugs and vaccines targeting persisters are critical for improved treatment of persistent infections and perhaps cancers. Novel treatment strategies for persisters and persistent infections are discussed.
[.....]

MECHANISMS OF PERSISTER FORMATION AND SURVIVAL

Mechanisms of persister formation are not well understood as persisters are elusive, small in number, heterogeneous, and transient and can change with environment, which poses significant challenges to their study. Epigenetic factors can promote bacterial persister formation through bistable gene expression,59 mediated through stochastic or induced expression of persister related genes,60 or through changes in DNA modifications or signaling protein modifications. Thus, permutations at the levels of expression of multiple persister genes (Table 3), regulatory RNA, modifications of DNA and post-translational modifications of proteins could produce enormous diversity and heterogeneity of persisters as expressed in the Yin–Yang model (Figure 1). Although senescence or aging has been proposed as a persister mechanism,61 aging itself can hardly be a mechanism of persisters as aging must in turn be acting through certain cellular processes, which could involve persister mechanisms. Although various persister genes have been identified (Table 3), what and how cells sense to form persisters remain unclear.
[......]

Henriëtte
Berichten: 1707
Lid geworden op: Di 19 Mei 2015, 10:05

Re: Onderzoek persister cells

Berichtdoor Henriëtte » Vr 04 Aug 2017, 13:56


Sproetje
Berichten: 3171
Lid geworden op: Di 28 Okt 2014, 20:33

Re: Onderzoek persister cells

Berichtdoor Sproetje » Vr 04 Aug 2017, 16:54

Henriëtte schreef:https://www.youtube.com/watch?v=Oc1sRfOh5zI

Henriëtte


In Finland is ook een test ontwikkeld die Borrelia zou kunnen opsporen in de persistente vorm: de "Tick Plex":

viewtopic.php?f=38&t=1603

Henriëtte
Berichten: 1707
Lid geworden op: Di 19 Mei 2015, 10:05

Re: Onderzoek persister cells

Berichtdoor Henriëtte » Vr 04 Aug 2017, 18:35

Hoi Sproetje,

Op de site van Armin Labs staat de Tick Plex ook vermeldt.

Ik ben net pas op de hoogte van het fenomeen percister cells en het verklaart dus ook waarom ik na infusen en orale a.b. een hele tijd flink opgeknapt was en het nu alweer een poos mis is.
Zag ook dat jij er in het verleden al heel wat over gepost heb en ga dat allemaal eens goed doorlezen.
Bedankt dat je die info toen gepost hebt, ben ik heel blij mee.

Henriëtte


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