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.
- MeSH
- Anti-Bacterial Agents pharmacology MeSH
- Biofilms MeSH
- Endopeptidases pharmacology MeSH
- Virulence Factors MeSH
- Hemolysin Proteins pharmacology MeSH
- Humans MeSH
- Pancreatic Elastase MeSH
- Plankton MeSH
- Plasma Gases * pharmacology MeSH
- Peptide Hydrolases MeSH
- Pseudomonas Infections * MeSH
- Pseudomonas aeruginosa MeSH
- Pyocyanine MeSH
- Quorum Sensing MeSH
- Gelatinases pharmacology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Marine sponges, a well-documented prolific source of natural products, harbor highly diverse microbial communities. Their extracts were previously shown to contain quorum sensing (QS) signal molecules of the N-acyl homoserine lactone (AHL) type, known to orchestrate bacterial gene regulation. Some bacteria and eukaryotic organisms are known to produce molecules that can interfere with QS signaling, thus affecting microbial genetic regulation and function. In the present study, we established the production of both QS signal molecules as well as QS inhibitory (QSI) molecules in the sponge species Sarcotragus spinosulus. A total of eighteen saturated acyl chain AHLs were identified along with six unsaturated acyl chain AHLs. Bioassay-guided purification led to the isolation of two brominated metabolites with QSI activity. The structures of these compounds were elucidated by comparative spectral analysis of 1HNMR and HR-MS data and were identified as 3-bromo-4-methoxyphenethylamine (1) and 5,6-dibromo-N,N-dimethyltryptamine (2). The QSI activity of compounds 1 and 2 was evaluated using reporter gene assays for long- and short-chain AHL signals (Escherichia coli pSB1075 and E. coli pSB401, respectively). QSI activity was further confirmed by measuring dose-dependent inhibition of proteolytic activity and pyocyanin production in Pseudomonas aeruginosa PAO1. The obtained results show the coexistence of QS and QSI in S. spinosulus, a complex signal network that may mediate the orchestrated function of the microbiome within the sponge holobiont.
- MeSH
- Escherichia coli drug effects physiology MeSH
- Virulence Factors MeSH
- Phylogeny MeSH
- Luminescent Measurements MeSH
- Porifera genetics metabolism microbiology MeSH
- Peptide Hydrolases chemistry pharmacology MeSH
- Pyocyanine chemistry pharmacology MeSH
- Quorum Sensing drug effects MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
The stilbenoids, a group of naturally occurring phenolic compounds, are found in a variety of plants, including some berries that are used as food or for medicinal purposes. They are known to be beneficial for human health as anti-inflammatory, chemopreventive, and antioxidative agents. We have investigated a group of 19 stilbenoid substances in vitro using a cellular model of THP-1 macrophage-like cells and pyocyanin-induced oxidative stress to evaluate their antioxidant or pro-oxidant properties. Then we have determined any effects that they might have on the expression of the enzymes catalase, glutathione peroxidase, and heme oxygenase-1, and their effects on the activation of Nrf2. The experimental results showed that these stilbenoids could affect the formation of reactive oxygen species in a cellular model, producing either an antioxidative or pro-oxidative effect, depending on the structure pinostilbene (2) worked as a pro-oxidant and also decreased expression of catalase in the cell culture. Piceatannol (4) had shown reactive oxygen species (ROS) scavenging activity, whereas isorhapontigenin (18) had a mild direct antioxidant effect and activated Nrf2-antioxidant response element (ARE) system and elevated expression of Nrf2 and catalase. Their effects shown on cells in vitro warrant their further study in vivo.
- MeSH
- Antioxidant Response Elements drug effects MeSH
- Antioxidants chemistry pharmacology MeSH
- Hep G2 Cells MeSH
- NF-E2-Related Factor 2 genetics MeSH
- Humans MeSH
- Lipid Peroxidation drug effects MeSH
- Pyocyanine chemistry MeSH
- Stilbenes chemistry pharmacology MeSH
- Thiobarbiturates chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Corylus avellana L. (Betulaceae) leaves, consumed as infusion, are used in traditional medicine, for the treatment of hemorrhoids, varicose veins, phlebitis, and edema due to their astringent, vasoprotective, and antiedema properties. In previous works we reported from the leaves of Corylus avellana cv. "Tonda di Giffoni" diarylheptanoid derivatives, a class of plant secondary metabolites with a wide variety of bioactivities. With the aim to give an interesting and economically feasible opportunity to C. avellana leaves as source of functional ingredients for pharmaceutical and cosmetic formulations, "green" extracts were prepared by employing "eco-friendly" extraction protocols as maceration, infusion and SLDE-Naviglio extraction. Metabolite profiles of the extracts were obtained by 1H NMR experiments and data were processed by multivariate statistical analysis to highlight differences in the extracts and to evidence the extracts with the highest concentrations of bioactive metabolites. Based on the NMR data, a total of 31 compounds were identified. The metabolite variation among the extracts was evaluated using Principle Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA). Furthermore, the total phenolic content of the extracts was measured by Folin-Ciocalteu colorimetric assay and the antioxidant activity of extracts was assayed by the spectrophotometric tests DPPH• and ABTS and by an in vitro test based on the evaluation of cellular reactive oxygen species production stimulated by pyocyanin.
- MeSH
- Phenols analysis pharmacology MeSH
- Humans MeSH
- Corylus chemistry metabolism MeSH
- Plant Leaves chemistry MeSH
- Metabolomics methods MeSH
- Nuclear Magnetic Resonance, Biomolecular methods MeSH
- Proton Magnetic Resonance Spectroscopy methods MeSH
- Pyocyanine pharmacology MeSH
- Reactive Oxygen Species metabolism MeSH
- Plant Extracts analysis chemistry pharmacology MeSH
- Free Radical Scavengers analysis pharmacology MeSH
- Green Chemistry Technology methods MeSH
- THP-1 Cells MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
P. aeruginosa využívá hustou síť quorum sensing receptorů a regulátorů patřících do čtyř QS systémů (las, rhl, pqs a iqs), které řídí produkci faktorů virulence. Systémy jsou hierarchicky uspořádány, přičemž las QS systém stojí na vrcholu kaskády. Nicméně, vzhledem k nedávnému zjištění, že funkce centrálního las QS systému může být v podmínkách, které jsou typické pro infekci, převzata QS systémem iqs, je zřejmé, že použití klasických QS inhibitorů cílících na las QS systém může být neúčinné. Měli bychom také mít na paměti, že systémy QS vyžadují další výzkum, aby bylo zcela jasné, jak jsou propojeny a jakým způsobem společně řídí produkci faktorů virulence. Cílem článku bylo nastínit propojení QS systémů a popsat nejznámější faktory virulence (elastasa, alkalická proteasa, exotoxin A, rhamnolipid, pyocyanin a lektin) – jejich přínosy pro bakterii P. aeruginosa a jejich účinky na buňky hostitele během infekce. V budoucnu nám všechny tyto informace společně pomohou zajistit vývoj specificky účinných anti‑‑OS terapeutik.
P. aeruginosa, use a dense network of quorum sensing receptors and regulators, belong to the four quorum sensing systems (las, rhl, pqs and iqs), which control the virulence factors production. These systems are organized in a hierarchy with las system at the top of the cascade. However, due to recent discovery that functions of central las QS system could be overtaken by iqs QS system in conditions that closely mimics host infection, it becomes clear that the application of classical QS inhibitors targeting las QS system may be ineffective. We should also keep in mind, that there is a lot of unknown about the QS systems requiring further investigations to understand how P. aeruginosa QS networks are connected and how it controls the production of virulence factors together. The aim of the article was to outline the interconnection of QS systems and to describe the most well‑‑known P. aeruginosa virulence factors (elastase, alkaline protease, exotoxin A, rhamnolipid, pyocyanin and lectin) – their benefits to P. aeruginosa and their effects to host during the infection. In the future, all this information together will help us ensure development of potent anti‑‑OS therapeutics with specific mode of action.
Zkvalitňování lékařské péče s sebou nese vyšší počet invazivních výkonů a také vyšší počet náročnými operacemi oslabených pacientů náchylných k nozokomiálním infekcím. Pseudomonas aeruginosa je jedním z nejčastěji izolovaných nozokomiálních druhů, přičemž léčba pseudomonádových infekcí je často problematická, zdlouhavá a infekce jsou často recidivující. S procesem patogeneze pseudomonádových infekcí je spojena řada faktorů virulence. V rámci překládané studie bylo vyšetřeno 93 katétrových izolátů Pseudomonas aeruginosa na tvorbu biofilmu, pohyblivost a sekreci vybraných extracelulárních látek. Vysoké procento kmenů byla schopno produkovat hemolyziny, LasB elastázu a pyoverdiny (> 70 %). Submerzní biofilm tvořilo 80 % kmenů, aerovaný biofilm byl přítomen u 90 % izolátů, přičemž byla prokázána pozitivní korelace mezi tvorbou submerzního a aerovaného biofilmu (p = 0,00583; γ = 0,551). Všechny kmeny byly pohyblivé swarming motilitou, 95 % kmenů vykazovalo swimming motilitu a 75 % twitching motilitu. Ze sledovaných faktorů virulence byla mezi kmeny nízká pouze sekrece pyocyaninu a pyochelinu (< 25 %). Pozitivní korelace byla prokázána u produkce některých extracelulárních látek (mezi produkcí pyochelinu a pyocyaninu, pyocyaninu a LasB elastázy, LasB elastázy a hemolyzinů), mezi produkcí submerzního a aerovaného biofilmu a také mezi produkcí aerovaného biofilmu a pigmentů (pyoverdinu i pyocyaninu). Naopak negativní korelaci vykazovaly vztahy mezi produkcí submerzního i aerovaného biofilmu a LasB elastázy a submerzního biofilmu a pigmentů (pyoverdinu i pyocyaninu). Všechny korelace jsou významné na hladině p = 0,05 a vykazují korelaci γ > 0,50.
Healthcare quality improvement brings about an increasing number of invasive diagnostic and therapeutic procedures and thus also an increasing number of high-risk patients prone to hospital infections. Pseudomonas aeruginosa is one of the most commonly isolated nosocomial species and the treatment of the infection is often long and problematic, with frequent recurrences. The pathogenesis of Pseudomonas infection is associated with a range of virulence factors. In the present study, 93 catheter isolates of Pseudomonas aeruginosa were screened for the biofilm formation, motility and secretion of selected extracellular products. A high rate of the strains tested were producers of hemolysins, LasB elastase, and pyoverdines (> 70%). The biofilm formation was detected in 80% of isolates and formation of aerated biofilm was present in 90% of isolates with a positive correlation found between the two types of biofilm formation (p = 0.00583; γ = 0.551). All strains showed swarming motility, 95% of strains showed swimming motility, and 75% of strains showed twitching motility. Among the virulence factors studied, only pyocyanin and pyochelin were produced by a lower proportion of isolates (< 25%). A positive correlation was seen between the production of some extracellular molecules (pyochelin and pyocyanin, pyocyanin and LasB elastase, and LasB elastase and haemolysins), between biofilm formation and formation of aerated biofilm, and between formation of aerated biofilm and pigments (pyoverdine and pyocyanin) production. On the other hand, a negative correlation was found between biofilm production and LasB elastase production and between the production of biofilm under immersion and pigments (pyoverdine and pyocyanin) production. All correlations are significant at the level p = 0.05, with the correlation coefficient γ > 0.50.
- Keywords
- biofilm, motilita, LasB elastáza,
- MeSH
- Bacterial Proteins isolation & purification MeSH
- Biofilms classification growth & development drug effects MeSH
- Pigments, Biological isolation & purification MeSH
- Virulence Factors MeSH
- Financing, Organized MeSH
- Bacterial Physiological Phenomena genetics immunology drug effects MeSH
- Hemolysin Proteins isolation & purification MeSH
- Cross Infection diagnosis etiology classification MeSH
- Coculture Techniques methods utilization MeSH
- Humans MeSH
- Pseudomonas aeruginosa isolation & purification pathogenicity MeSH
- Pyocyanine isolation & purification MeSH
- Statistics as Topic MeSH
- Catheters, Indwelling adverse effects MeSH
- Check Tag
- Humans MeSH
