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Pathogenicity and Virulence
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Salmonella, E. coli, and Klebsiella produce enterochelin, an iron-chelating agent that can obtain iron from transferrin. This compound is only produced when iron concentrations are very low. It has been demonstrated that the virulence of an enterochelin-defective mutant of S. typhi can be increased 600-fold by addition of enterochelin to a suspension of the organism prior to injection into test animals. Pyoverdin, the siderophore of P. aeruginosa, has also been shown to enhance the growth of this bacterium in vivo.
Quorum Sensing and Essential Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Isabel Charlotte Soede, Gerhard Buchbauer
Sepahi et al. (2015) investigated the EOs of Ferula and Dorema, both belonging to the Apiaceae family on their QSI potential. Both of the oils were active, Ferula oil even fully inhibited violacein production in CV026, although the exact diameters of the inhibitory halos weren't published. Regarding QS in P. aeruginosa, the team showed reduced production of different QS-controlled virulence factors (elastase, pyoverdine, pyocyanin), as well as inhibition of biofilm formation in PAO1 (Sepahi et al., 2015). EO: Extraction by hydro-distillation. The EO of Ferula foetida L. inhibited elastase, pyoverdine, pyocyanin, and biofilm formation, whereas Dorema aucheri Boiss EO did not inhibit pyocyanin and biofilm formation. However both EOs inhibited the QS-regulated violacein production in CV026.Sensor Strains: CV026, PAO1.Performed assays: Disc diffusion assay: CV026Virulence Factor Production: PAO1
Chromonychia
Published in Archana Singal, Shekhar Neema, Piyush Kumar, Nail Disorders, 2019
Michela Starace, Aurora Alessandrini, Bianca Maria Piraccini
The differential diagnosis includes chemical exposure to solutions containing pyocyanin or pyoverdine.5 After clipping away of the detached nail plate, a pale green-yellow pigmentation is evident on the bottom of the nail plate and on the nail bed: the clinical history and examination may also suggest the presence of paronychia and onycholysis.
Subtle relationships between Pseudomonas aeruginosa and fungi in patients with cystic fibrosis
Published in Acta Clinica Belgica, 2022
Kaicheng Yan, Hong Yin, Jin Wang, Yun Cai
Accordingly, PA produces low-molecular-weight molecules known as siderophores, specifically chelate iron [16]. Pyoverdine and pyochelin are the two predominant siderophores produced by PA, and pyoverdine exhibits the highest affinity for iron [17]. There are three classes of pyoverdine, which are capable of chelating iron. Among the PA strains isolated from CF patients, type II pyoverdine is the most common one [18]. Sass et al. and Anand et al. have suggested that pyoverdine is the principal PA inhibitor to AF [19], because PA mutants which lose or are lack of pyoverdine production are found to have impaired anti-fungal activities. Pyoverdine is also necessary for the formation of PA biofilm. PA cells in the biofilm can produce more pyoverdine. The competition between PA and AF seems to depend on the relative content of iron carriers, the speed at which they are produced, and their relative affinity for iron. A study has compared the antifungal activity of 10 PA isolates from the lungs of CF patients. Strains producing a small amount of pyoverdine show lower antifungal activity than those with higher pyoverdine content [20]. Kousser et al. have found that PA inhibits the germination of Rhizopus microsporus, a common cause of mucormycosis. Moreover, the growth and germination of Rhizopus microsporus can be inhibited by pyoverdine alone [21].
Synergistic effect of silver nanoparticles and polymyxin B against biofilm produced by Pseudomonas aeruginosa isolates of pus samples in vitro
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Muhammad Salman, Rizwana Rizwana, Hayat Khan, Iqbal Munir, Muhammad Hamayun, Aquib Iqbal, Abdul Rehman, Khalid Amin, Ghayour Ahmed, Majid Khan, Ajmal Khan, Faiz Ul Amin
Pseudomonas aeruginosa (P. aeruginosa) is an aerobic gram-negative, non-spore forming, rod-shaped bacterium, oxidase positive due to its synthesis of indophenol oxidase enzyme. It also produces pyoverdin and pyocyanin pigments which are water soluble. The habitat of P. aeruginosa is soil and water but can be also found on fresh vegetables and fruits. In the laboratory, it produces sweetgrape-like odor. Instead of fermentation, these get energy by oxidizing sugars. Pseudomonas aeruginosa is a nosocomial and community-acquired infectious agent. It can be found in hospital and intensive care units and can persist in some antiseptic solutions used for disinfecting surgical instruments and contact lenses [1]. It infects patients with weak immune system and leads to serious diseases, e.g. urinary tract infections, bacteremia, pneumonia and ulcerative [2]. It is an opportunistic pathogen in cystic fibrosis. It accelerates the decline in lung function and ultimately leads to increased mortality and morbidity rate [3]. The multidrug-resistant (MDR) P. aeruginosa in hospitalized patients leads to increased mortality [4]. It causes nosocomial urinary tract infection (UTI) associated with an indwelling catheter, instrumentation of the urinary system. Community-acquired UTI’s are infrequently caused by P. aeruginosa [5]. It is considered as the leading cause of ventilator-associated pneumonia [6] complications include acute respiratory distress syndrome (ARDS) and septic shock [7].
A benzimidazole-based ruthenium(IV) complex inhibits Pseudomonas aeruginosa biofilm formation by interacting with siderophores and the cell envelope, and inducing oxidative stress
Published in Biofouling, 2019
Grzegorz Czerwonka, Dawid Gmiter, Anna Guzy, Patrycja Rogala, Agnieszka Jabłońska-Wawrzycka, Andrzej Borkowski, Tomasz Cłapa, Dorota Narożna, Paweł Kowalczyk, Marcin Syczewski, Marcin Drabik, Magdalena Dańczuk, Wiesław Kaca
Pyoverdine determination was performed in TSB medium. Measurement of pyoverdine fluorescence was performed at the excitation wavelength λ = 398 nm and the emission wavelength λ = 455 nm as described previously (Imperi et al. 2009). Experiments were carried out in triplicate in 96-well black flat-bottomed microtiter plates (Greiner Monroe, NC, USA) for 24 h in cell-free culture medium using an Infinite M200PRO (Tecan, Männedorf, Switzerland). The assay was performed with ligand (2-hydroxymethylbenzimadazole), the ruthenium(IV) complex and streptomycin as a positive control, and TSB medium with inoculated bacteria as a negative control. The siderophore secretion assay was conducted as three independent repeats. The results obtained were not disturbed by the emission band characteristic of the ruthenium(IV) complex (see Supplemental material Table S1).