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Grzegorz Fila, Anna Kawiak, Mariusz Grinholc
Pseudomonas aeruginosa is among the most common pathogens responsible for both acute and chronic infections of high incidence and severity. Additionally, P. aeruginosa resistance to conventional antimicrobials has increased rapidly over the past decade. Therefore, it is crucial to explore new therapeutic options, particularly options that specifically target the pathogenic mechanisms of this microbe. The ability of a pathogenic bacterium to cause disease is dependent upon the production of agents termed 'virulence factors', and approaches to mitigate these agents have gained increasing attention as new antibacterial strategies...
October 20, 2016: Virulence
Yushu Yin, Georgia Papavasiliou, Olga Y Zaborina, John C Alverdy, Fouad Teymour
The human gastrointestinal tract is the primary site of colonization of multidrug resistant pathogens and the major source of life-threatening complications in critically ill and immunocompromised patients. Eradication measures using antibiotics carry further risk of antibiotic resistance. Furthermore, antibiotic treatment can adversely shift the intestinal microbiome toward domination by resistant pathogens. Therefore, approaches directed to prevent replacement of health promoting microbiota with resistant pathogens should be developed...
October 19, 2016: Annals of Biomedical Engineering
Xia Zhao, Canhuang Chen, Xingyu Jiang, Wei Shen, Guangtao Huang, Shuai Le, Shuguang Lu, Lingyun Zou, Qingshan Ni, Ming Li, Yan Zhao, Jing Wang, Xiancai Rao, Fuquan Hu, Yinling Tan
The impact of phage infection on the host cell is severe. In order to take over the cellular machinery, some phage proteins were produced to shut off the host biosynthesis early in the phage infection. The discovery and identification of these phage-derived inhibitors have a significant prospect of application in antibacterial treatment. This work presented a phage protein, gp70.1, with non-specific inhibitory effects on Pseudomonas aeruginosa and Escherichia coli. Gp70.1 was encoded by early gene - orf 70...
2016: Frontiers in Microbiology
Ksenija S Mileski, Ana D Ćirić, Snežana S Trifunović, Mihailo S Ristić, Marina D Soković, Vlado S Matevski, Vele V Tešević, Milka B Jadranin, Petar D Marin, Ana M Džamić
GC-FID and GC-MS were used to determine the chemical composition of the essential oil of the aerial parts of Heracleum orphanidis Boiss. Also, the HPLC-DAD/ESI-ToF-MS profile of the methanol extracts of aerial parts and roots was determined. The main components of the essential oil were n-octanol, octyl hexanoate and n-octyl acetate, while coumarins were the most prevalent compounds in methanol extracts. An evaluation of antioxidant activity showed that the methanol and aqueous extracts of the aerial parts had the highest potential...
September 14, 2016: Food & Function
Maira P de Carvalho, Giuseppe Gulotta, Matheus W do Amaral, Heinrich Lünsdorf, Florenz Sasse, Wolf-Rainer Abraham
Pathogens embedded in biofilms are involved in many infections and are very difficult to treat with antibiotics because of higher resistance compared to planktonic cells. Therefore, new approaches for their control are urgently needed. One way to search for biofilm dispersing compounds is to look at defense strategies of organisms exposed to wet environments, which makes them prone to biofilm infections. It is reasonable to assume that mushrooms have developed mechanisms to control biofilms on their sporocarps (fruiting bodies)...
October 3, 2016: Environmental Microbiology
Nessma A El-Zawawy, Sameh S Ali
OBJECTIVE: The aim of this study was to evaluate the efficiency of pyocyanin pigment as a novel compound active against tyrosinase with its depigmentation efficiency for combating Trichophyton rubrum which could be a major causative agent of tinea corporis. METHODS: Fifty swabs of fungal tinea corporis infections were collected and identified. Five MDRPA isolates were tested for their levels of pyocyanin production. The purified extracted pyocyanin was characterized by UV spectrum and FT-IR analysis...
September 23, 2016: Microbial Pathogenesis
Xiaohui Xu, Hua Yu, Di Zhang, Junzhi Xiong, Jing Qiu, Rong Xin, Xiaomei He, Halei Sheng, Wenqiang Cai, Lu Jiang, Kebin Zhang, Xiaomei Hu
During infection, bacteria might generate adaptive responses to facilitate their survival and colonization in the host environment. The alarmone guanosine 5'-triphosphate-3'-diphosphate (ppGpp), the levels of which are regulated by the RelA and SpoT enzymes, plays a critical role in mediating bacterial adaptive responses and virulence. However, the mechanism by which ppGpp regulates virulence-associated traits in Pseudomonas aeruginosa is poorly understood. To investigate the regulatory role of ppGpp, the ppGpp-deficient strain ΔRS (relA and spoT gene double mutant) and the complemented strain ΔRS(++) (complemented with relA and spoT genes) were constructed...
November 2016: Microbiological Research
Qiao Guo, Qiaolian Wu, Dangdang Bai, Yang Liu, Lin Chen, Sheng Jin, Yuting Wu, Kangmin Duan
Dimethyl Sulfoxide (DMSO) is commonly used as a solvent to dissolve water-insoluble drugs or other test samples in both in vivo and in vitro experiments. It was observed during our experiment that DMSO at non-inhibitory concentrations could significantly inhibit pyocyanin production in human pathogen Pseudomonas aeruginosa. Pyocyanin is an important pathogenic factor whose production is controlled by cell-density dependent quorum-sensing (QS) system. Investigation of the effect of DMSO on QS shows that DMSO has significant QS antagonistic activities, and micromolar range concentrations of DMSO attenuated a battery of QS-controlled virulence factors, including rhamnolipids, elastase, LasA protease and biofilm formation...
September 19, 2016: Antimicrobial Agents and Chemotherapy
Subramaniyan S, Divyasree S, Sandhia G S
BACKGROUND: Quorum sensing or the bacterial information flow in an orchestrated manner is an essential feature of many pathogenic bacteria. Quorum quenching molecules (QQ) can inhibit the growth of such bacteria. OBJECTIVE: The purpose of this study is to evaluate the potential of plant extracts as quorum quenchers and monitor the recent patents. METHODS: Many available reports and patents are on synthetic ligand molecules or even compounds isolated from cyanobacteria (Honaucin A) and other microorganisms inhibiting quorum sensing molecules...
September 8, 2016: Recent Patents on Biotechnology
Valeri V Mossine, James K Waters, Deborah L Chance, Thomas P Mawhinney
Persistent infections of biofilm forming bacteria, such as Pseudomonas aeruginosa, are common among human populations, due to the bacterial resistance to antibiotics and other adaptation strategies, including release of cytotoxic virulent factors such as pigment pyocyanin (PCN). Urinary tract infections harbor P. aeruginosa strains characterized by the highest PCN-producing capacity, yet no information is available on PCN cytotoxicity mechanism in kidney. We report here that renal tubular epithelial cell (RTEC) line NRK-52E responds to PCN treatments with paraptosis-like activity features...
September 9, 2016: Toxicological Sciences: An Official Journal of the Society of Toxicology
Bernardas Morkunas, Balint Gal, Warren R J D Galloway, James T Hodgkinson, Brett M Ibbeson, Yaw Sing Tan, Martin Welch, David R Spring
Pyocyanin is a small molecule produced by Pseudomonas aeruginosa that plays a crucial role in the pathogenesis of infections by this notorious opportunistic pathogen. The inhibition of pyocyanin production has been identified as an attractive antivirulence strategy for the treatment of P. aeruginosa infections. Herein, we report the discovery of an inhibitor of pyocyanin production in cultures of wild-type P. aeruginosa which is based around a 4-alkylquinolin-2(1H)-one scaffold. To the best of our knowledge, this is the first reported example of pyocyanin inhibition by a compound based around this molecular framework...
2016: Beilstein Journal of Organic Chemistry
Boris Pejin, Ana Ciric, Jasmina Dimitric Markovic, Jasmina Glamoclija, Milos Nikolic, Marina Sokovic
Anti-biofilm activity of three anthocyanidins (pelargonidin, cyanidin and delphinidin) was evaluated for the first time at in vitro conditions. All the compounds reduced the formation of Pseudomonas aeruginosa PAO1 biofilm at low sub-MIC (0.125 MIC) with delphinidin (c 56.25 μg/mL) being the most active (43%). In comparison, ampicillin (c 93.75 μg/mL) and streptomycin (c 21.25 μg/mL) (used as positive controls) were considerably less effective at the same sub-MIC (8 and 12%, respectively). Furthermore, at 0...
August 19, 2016: Natural Product Research
Susan Hall, Catherine McDermott, Shailendra Anoopkumar-Dukie, Amelia J McFarland, Amanda Forbes, Anthony V Perkins, Andrew K Davey, Russ Chess-Williams, Milton J Kiefel, Devinder Arora, Gary D Grant
Pyocyanin has recently emerged as an important virulence factor produced by Pseudomonas aeruginosa. The redox-active tricyclic zwitterion has been shown to have a number of potential effects on various organ systems in vitro, including the respiratory, cardiovascular, urological, and central nervous systems. It has been shown that a large number of the effects to these systems are via the formation of reactive oxygen species. The limitations of studies are, to date, focused on the localized effect of the release of pyocyanin (PCN)...
2016: Toxins
Fatima AlZahra'a Alatraktchi, Helle Krogh Johansen, Søren Molin, Winnie Edith Svendsen
AIM: Pseudomonas aeruginosa is a pathogen that is prevalent in serious infections in compromised patients worldwide. A unique virulence factor of this bacterium is the redox-active molecule pyocyanin, which is a potential biomarker for the identification of P. aeruginosa infections. Here we report a direct, selective and rapid detection technique of pyocyanin. MATERIALS & METHODS: Pyocyanin was detected by amperometry at a relatively high potential where the pyocyanin signal was unaffected by background contributions...
August 2016: Nanomedicine
Alyah Buzid, Fengjun Shang, F Jerry Reen, Eoin Ó Muimhneacháin, Sarah L Clarke, Lin Zhou, John H T Luong, Fergal O'Gara, Gerard P McGlacken, Jeremy D Glennon
Electroanalysis was performed using a boron-doped diamond (BDD) electrode for the simultaneous detection of 2-heptyl-3-hydroxy-4-quinolone (PQS), 2-heptyl-4-hydroxyquinoline (HHQ) and pyocyanin (PYO). PQS and its precursor HHQ are two important signal molecules produced by Pseudomonas aeruginosa, while PYO is a redox active toxin involved in virulence and pathogenesis. This Gram-negative and opportunistic human pathogen is associated with a hospital-acquired infection particularly in patients with compromised immunity and is the primary cause of morbidity and mortality in cystic fibrosis (CF) patients...
2016: Scientific Reports
Sneha Polisetti, Nameera F Baig, Nydia Morales-Soto, Joshua D Shrout, Paul W Bohn
Surface enhanced Raman spectroscopy (SERS) imaging was used in conjunction with principal component analysis (PCA) for the in situ spatiotemporal mapping of the virulence factor pyocyanin in communities of the pathogenic bacterium Pseudomonas aeruginosa. The combination of SERS imaging and PCA analysis provides a robust method for the characterization of heterogeneous biological systems while circumventing issues associated with interference from sample autofluorescence and low reproducibility of SERS signals...
June 28, 2016: Applied Spectroscopy
Hisham A Abbas
Resistance of Pseudomonas aeruginosa to antibiotics is a major problem. Targeting virulence factors is an alternative option to avoid the emergence of resistance to antibiotics. The effect of sub-inhibitory concentration of diclofenac sodium on the production of virulence factors of P. aeruginosa was investigated. The virulence factors included protease, haemolysin, pyocyanin and pyoverdin, in addition to pathogenic behaviors such as swimming and twitching motilities and biofilm formation. Diclofenac sodium showed significant inhibition of virulence factors as compared to the control...
July 2015: Roumanian Archives of Microbiology and Immunology
Nina Jagmann, Vera Bleicher, Tobias Busche, Jörn Kalinowski, Bodo Philipp
The opportunistic pathogen Pseudomonas aeruginosa controls the production of virulence factors by quorum sensing (QS). Besides cell density, QS in P. aeruginosa is co-regulated by metabolic influences, especially nutrient limitation. Previously, a co-culture model system was established consisting of P. aeruginosa and the chitinolytic bacterium Aeromonas hydrophila, in which parasitic growth of P. aeruginosa is strictly dependent on the QS-controlled production of pyocyanin in response to nutrient limitation (Jagmann et al...
October 2016: Environmental Microbiology
Manuel R Gonzalez, Betty Fleuchot, Leonardo Lauciello, Paris Jafari, Lee Ann Applegate, Wassim Raffoul, Yok-Ai Que, Karl Perron
Burn wound sepsis is currently the main cause of morbidity and mortality after burn trauma. Infections by notorious pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus, and Acinetobacter baumannii impair patient recovery and can even lead to fatality. In this study, we investigated the effect of burn wound exudates (BWEs) on the virulence of those pathogens. BWEs were collected within 7 days after burn trauma from 5 burn patients. We first monitored their effect on pathogen growth. In contrast to A...
March 2016: MSphere
Katarzyna Danis-Wlodarczyk, Dieter Vandenheuvel, Ho Bin Jang, Yves Briers, Tomasz Olszak, Michal Arabski, Slawomir Wasik, Marcin Drabik, Gerard Higgins, Jean Tyrrell, Brian J Harvey, Jean-Paul Noben, Rob Lavigne, Zuzanna Drulis-Kawa
Bacteriophage therapy is currently resurging as a potential complement/alternative to antibiotic treatment. However, preclinical evaluation lacks streamlined approaches. We here focus on preclinical approaches which have been implemented to assess bacteriophage efficacy against Pseudomonas biofilms and infections. Laser interferometry and profilometry were applied to measure biofilm matrix permeability and surface geometry changes, respectively. These biophysical approaches were combined with an advanced Airway Surface Liquid infection model, which mimics in vitro the normal and CF lung environments, and an in vivo Galleria larvae model...
2016: Scientific Reports
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