Nejvíce citovaný článek - PubMed ID 19325879
Cell death is a natural part of the development of multicellular organisms and is central to their physiological and pathological states. However, the existence of regulated cell death in unicellular microorganisms, including eukaryotic and prokaryotic microbes, has been a topic of debate. One reason for the continued debate is the lack of obvious benefit from cell death in the context of a single cell. However, unicellularity is relative, as most of these microbes dwell in communities of varying complexities, often with complicated spatial organization. In these spatially organized microbial communities, such as yeast and bacterial colonies and biofilms growing on solid surfaces, cells differentiate into specialized types, and the whole community often behaves like a simple multicellular organism. As these communities develop and age, cell death appears to offer benefits to the community as a whole. This review explores the potential roles of cell death in spatially organized communities of yeasts and draws analogies to similar communities of bacteria. The natural dying processes in microbial cell communities are only partially understood and may result from suicidal death genes, (self-)sabotage (without death effectors), or from non-autonomous mechanisms driven by interactions with other differentiated cells. We focus on processes occurring during the stratification of yeast colonies, the formation of the extracellular matrix in biofilms, and discuss potential roles of cell death in shaping the organization, differentiation, and overall physiology of these microbial structures.
The increasing risk of antibiotic failure in the treatment of Pseudomonas aeruginosa infections is largely related to the production of a wide range of virulence factors. The use of non-thermal plasma (NTP) is a promising alternative to antimicrobial treatment. Nevertheless, there is still a lack of knowledge about the effects of NTP on the virulence factors production. We evaluated the ability of four NTP-affected P. aeruginosa strains to re-form biofilm and produce Las-B elastase, proteases, lipases, haemolysins, gelatinase or pyocyanin. Highly strains-dependent inhibitory activity of NTP against extracellular virulence factors production was observed. Las-B elastase activity was reduced up to 82% after 15-min NTP treatment, protease activity and pyocyanin production by biofilm cells was completely inhibited after 60 min, in contrast to lipases and gelatinase production, which remained unchanged. However, for all strains tested, a notable reduction in biofilm re-development ability was depicted using spinning disc confocal microscopy. In addition, NTP exposure of mature biofilms caused disruption of biofilm cells and their dispersion into the environment, as shown by transmission electron microscopy. This appears to be a key step that could help overcome the high resistance of P. aeruginosa and its eventual elimination, for example in combination with antibiotics still highly effective against planktonic cells.
- Klíčová slova
- antivirulence factors, biofilm disruption, cold atmospheric plasma (CAP), combined therapy, haemolytic activity,
- MeSH
- antibakteriální látky farmakologie MeSH
- biofilmy MeSH
- endopeptidasy farmakologie MeSH
- faktory virulence MeSH
- hemolyziny farmakologie MeSH
- lidé MeSH
- pankreatická elastasa MeSH
- plankton MeSH
- plazmové plyny * farmakologie MeSH
- proteasy MeSH
- pseudomonádové infekce * MeSH
- Pseudomonas aeruginosa MeSH
- pyokyanin MeSH
- quorum sensing MeSH
- želatinasy farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antibakteriální látky MeSH
- endopeptidasy MeSH
- faktory virulence MeSH
- hemolyziny MeSH
- pankreatická elastasa MeSH
- plazmové plyny * MeSH
- proteasy MeSH
- pyokyanin MeSH
- želatinasy MeSH
Pseudomonas aeruginosa, a Gram-negative, rod-shaped bacterium causes widespread diseases in humans. This bacterium is frequently related to nosocomial infections such as pneumonia, urinary tract infections (UTIs) and bacteriaemia especially in immunocompromised patients. The current review focuses on the recent perspectives on biofilms formation by these bacteria. Biofilms are communities of microorganisms in which cells stick to each other and often adhere to a surface. These adherent cells are usually embedded within a self-produced matrix of extracellular polymeric substance (EPS). Pel, psl and alg operons present in P. aeruginosa are responsible for the biosynthesis of extracellular polysaccharide which plays an important role in cell surface interactions during biofilm formation. Recent studies suggested that cAMP signalling pathway, quorum-sensing pathway, Gac/Rsm pathway and c-di-GMP signalling pathway are the main mechanism that leads to the biofilm formation. Understanding the bacterial virulence depends on a number of cell-associated and extracellular factors and is very essential for the development of potential drug targets. Thus, the review focuses on the major genes involved in the biofilm formation, the state of art update on the biofilm treatment and the dispersal approaches such as targeting adhesion and maturation, targeting virulence factors and other strategies such as small molecule-based inhibitors, phytochemicals, bacteriophage therapy, photodynamic therapy, antimicrobial peptides and natural therapies and vaccines to curtail the biofilm formation by P. aeruginosa.
- Klíčová slova
- Alginate, Biofilm dispersal, Biofilms, EPS, Gac/Rsm pathway, Pel, Pseudomonas aeruginosa, Psl, Quorum-sensing pathway, Treatment advancement, c-di-GMP signalling pathway,
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence MeSH
- bakteriální polysacharidy chemie MeSH
- biofilmy účinky léků MeSH
- biologické modely MeSH
- lidé MeSH
- Pseudomonas aeruginosa účinky léků genetika růst a vývoj fyziologie MeSH
- quorum sensing MeSH
- regulace genové exprese u bakterií MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- antibakteriální látky MeSH
- bakteriální polysacharidy MeSH
