Borrelia burgdorferi pleomorfe vormen

[Sproetje]

Morphological and biochemical features of Borrelia burgdorferi pleomorphic forms

Door: Leena Meriläinen, Anni Herranen, Armin Schwarzbach, Leona Gilbert.
Microbiology. Maart 2015

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4339653/

B. burgdorferi sensu lato is pleomorphic, being able to change its morphology as a response to environmental conditions. The existence of pleomorphism among many bacterial species in vitro has been known for over a century (Mattman, 2001; Winkler, 1899). At the beginning of the 19th century, researchers proposed that spirochaete species had multiple morphologies (Berndtson, 2013). Today it is well known that many Gram-negative and Gram-positive bacteria can spontaneously or by stimulation change their morphology both in vitro and in vivo (Domingue & Woody, 1997).

Pleomorphism is commonly induced in vitro using compounds that either lyse the cell wall (lytic enzymes), or interfere with the cell wall synthesis, such as antibiotics (Briers et al., 2012). This treatment usually leads to a complete or partial loss of peptidoglycan cell wall and the resulting cells have been called cell wall deficient (CWD), L-forms or spheroplasts (Glover et al., 2009; Ranjit & Young, 2013).
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Although RBs of B. burgdorferi have been observed from limited in vivo clinical samples (Aberer et al., 1996; Hulínská et al., 1994; Mattman, 2001; Miklossy et al., 2008), the role of pleomorphism in pathogenesis of Lyme disease and other diseases has been hugely debatable and recently criticized (Lantos et al., 2014; Onwuamaegbu et al., 2005; Schnell et al., 2014). However, there is more and more plausible evidence that pleomorphism in general may help the bacteria to evade the immune system or decrease antibiotic susceptibility, as well as change its pathogenic mechanisms (Domingue & Woody, 1997; Justice et al., 2008). This study provides a systematic in-depth compilation of B. burgdorferi pleomorphic variant characterization. The analysis of induction in different conditions, morphology, cell envelope architecture and metabolic activity as well as biochemical features of pleomorphic forms provides new insight into the morphological variants of B. burgdorferi. In order to fully understand the complex life cycle of B. burgdorferi and mechanisms of how pleomorphism is associated with diseases, it is crucial to understand what will induce different forms and what the basic features are that they convey.
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Ook nog iets over blebs of blebbing:

It is known that different disturbances, such as antibiotics, ageing and complement factors (Barbour & Hayes, 1986), can cause bleb development in B. burgdorferi, and this supports our findings that the formation of blebs increases under environmental stress. Blebs contain tightly packed DNA and it is suggested that they may be involved in transfer of genetic material and have certain protectoral functions (Garon et al., 1989). Their role in the initiation of autoimmune disease processes is also proposed (Whitmire & Garon, 1993). Nevertheless, the function of these blebs is still relatively unknown.

[Sproetje]

Ik vroeg me af of er onderzoeken zijn over de L vormen ( de celwand loze vormen) van borrelia, kon er niet veel over vinden.

Nog een quote uit dezelfde bovenstaande link:

Here we confirmed for the first time that RBs actually have an intact cell envelope with a peptidoglycan layer (Figs 5 and ​and7),7), indicating that they do not fulfil clearly the definitions of spheroplasts, CWD or encysted forms although there are some modifications in the cell envelope and cell wall architecture. Furthermore, the intact cell envelope of RBs (Fig. 5), similar to the spirochaete, provides evidence for the previous suggestion (Alban et al., 2000) that RBs are not degrading cells. To avoid confusing terminology, we suggest that B. burgdorferi spherical shapes are termed ‘round bodies’ to describe these forms better

Dat betekent dat de "round bodies" wel een soort van celwand nog hebben, maar er zijn toch ook nog celwand loze vormen van borrelia?
Ik kan er niet veel over vinden

Dat vraag ik me af, omdat de celwand loze vorm denk ik bijna niet te bestrijden valt.

Wel kon ik een onderzoek vinden over celwand loze vormen bij E-coli:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4510147/

Oxidative Stress Response Genes Are Required to Support L-Form Growth

Reduction of ROS Promotes L-Form Growth in E. coli

We have previously reported that L-forms of the Gram-negative bacterium E. coli do not require an ispA-like mutation for proliferation on L-form plates (containing sucrose as osmoprotectant and fosfomycin, an inhibitor of the PG precursor pathway) [3]. Nevertheless, since the growth of E. coli L-forms is apparently much slower than that of B. subtilis, we wondered whether this was again due to oxidative damage. If so, then treatment of cells with a ROS scavenger such as reduced GSH might improve the growth of E. coli L-forms. E. coli walled cells were streaked on L-form selective plates with and without GSH (Figure 4B, i). In the absence of GSH, discrete L-form colonies were barely visible after 3 days of incubation, though a lawn of visible colonies emerged after about 5 days (Figures S2A and S2B). In contrast, in the presence of GSH, significant L-form growth was seen within 3 days (Figure 4B, i; Figure 4C, i), supporting the idea that a reduction of cellular ROS levels promotes E. coli L-form growth. If the cellular ROS levels are increased through the metabolism of molecular oxygen in the ETC pathway in E. coli cell-wall-deficent cells, then anaerobic culture should also promote the growth of L-forms. Strikingly, under anaerobic conditions, significant E. coli L-form growth was seen within 3 days even in the absence of GSH (Figure 4B, ii; Figure 4C, ii). We also examined the effects of an ispA mutation on B. subtilis L-form growth under anaerobic condition and found that ispA muation was no longer required for L-form growth when oxygen was depleted (Figures S2C and S2D).

[Sproetje]

Persisting atypical and cystic forms of Borrelia burgdorferi and local inflammation in Lyme neuroborreliosis

Door: Judith Miklossy,corresponding author1 Sandor Kasas,2 Anne D Zurn,3 Sherman McCall,4 Sheng Yu,1 and Patrick L McGeer1
2008
Uit: Journal of Neuroinflammation.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2564911/

Method

Atypical forms of Borrelia burgdorferi spirochetes were induced exposing cultures of Borrelia burgdorferi (strains B31 and ADB1) to such unfavorable conditions as osmotic and heat shock, and exposure to the binding agents Thioflavin S and Congo red. We also analyzed whether these forms may be induced in vitro, following infection of primary chicken and rat neurons, as well as rat and human astrocytes. We further analyzed whether atypical forms similar to those induced in vitro may also occur in vivo, in brains of three patients with Lyme neuroborreliosis. We used immunohistochemical methods to detect evidence of neuroinflammation in the form of reactive microglia and astrocytes.

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Atypical forms included knob, ring-shaped and loop formations, uni- or multi-spirochetal cysts, bleb formation, granular disintegration and colony-like masses enclosing numerous cystic forms. Following 1 week exposure, free minute granules and re-growing of slender motile L forms of young spirochetes along injured spirochetal cells were observed.

Zo te lezen bestaan ze wel, die L vormen, maar of die nu celwand loos zijn?
Van de biofilms en de round body vormen weten we het wel zo ongeveer, maar over die L vormen lees je niet zoveel over.

Wat precies is de L-vorm:
https://nl.wikipedia.org/wiki/L-vormen