Pyocyanin Pigment Research Articles

Cucurbit[7]uril: Synthesis and quenching the quorum sensing in bacteria

Quorum sensing (QS) is a bacterial behavior system controlled by the cell density. In many gram-negative bacteria, several kinds of N-acyl homoserine lactones (AHLs) have been identified as signal compounds involved in this mechanism and triggered via autoinducers. In response to AHLs, Pseudomonas aeruginosa (K2153(PAGU1741), K2376 (PAGUg1834) and Chromobacterium violaceum(CV026,VIR07) produce the characteristic green pigment pyocyanin and purple pigment violacein, respectively. It is known that pyocyanin is controlled rhl system in Pseudomonas aeruginosa. In the present, we developed a simple method to synthesize and purify CB[7] in good yield and a short time compared to reported methods as novel host to bind and hydrolyze the N-acyl homoserine lactones (AHLs), which consider the common signal molecules in the quorum sensing systems of gram-negative and gram-positive bacteria. The quorum quenching abilities studied by cell culture experiments with gram negative bacteria.

Characterization, application and statistical optimization approach for enhanced production of pyocyanin pigment by Pseudomonas aeruginosa DN9

The aim of this work was to study the pyocyanin pigment from Pseudomonas aeruginosa DN9. The work involves optimization of process parameters for enhanced production of pyocyanin pigment under submerged fermentation condition. During optimization process, maximum pyocyanin production (92.12 µg/ml) was obtained with carbon source mannitole, nitrogen source peptone, inorganic salt NaCl and metal ion FeSO4. Plackett Burman design and Response Surface Methodology (RSM) showed peptone, NaCl and KH2PO4 are significant variable in the production of pyocyanin pigment. The FTIR and GC–MS study was done to evaluate structural properties of pyocyanin pigment. The purified pigment was further analyzed as colouring agent and for inhibitory action against pathogenic microorganisms. Thus, present study showed Pseudomonas aeruginosa DN9 as promising culture for pigment production with potential biotechnological application.

Study of quorum-sensing LasR and RhlR genes and their dependent virulence factors in Pseudomonas aeruginosa isolates from infected burn wounds

BackgroundPseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen responsible for burn-wound infection. High incidence, infection severity and increasing resistance characterize P. aeruginosa -induced burn infection.PurposeTo estimate quorum-sensing (QS)-dependent virulence factors of P. aeruginosa isolates from burn wounds and correlate it to the presence of QS genes.MethodsA cross-sectional descriptive study included 50 P . aeruginosa isolates from burn patients in Mansoura University Plastic and Burn Hospital, Egypt. Antibiotic sensitivity tests were done. All isolates were tested for their ability to produce biofilm using a micro-titration assay method. Protease, pyocyanin and rhamnolipid virulence factors were determined using skimmed milk agar, King’s A medium and CTAB agar test, respectively. The identity of QS lasR and rhlR genes was confirmed using PCR.Results In total, 86 % of isolates had proteolytic activity. Production of pyocyanin pigment was manifested in 66 % of isolates. Altogether, 76 % of isolates were rhamnolipid producers. Biofilm formation was detected in 96 % of isolates. QS lasR and rhlR genes were harboured by nearly all isolates except three isolates were negative for both lasR and rhlR genes and two isolates were positive for lasR gene and negative for rhlR gene. Forty-nine isolates were considered as extremely QS-proficient strains as they produced QS-dependent virulence factors. In contrast, one isolate was a QS deficient strain.ConclusionsQS affects P. aeruginosa virulence-factor production and biofilm in burn wounds. Isolates containing lasR and rhlR seem to be a crucial regulator of virulence factors and biofilm formation in P. aeruginosa whereas the lasR gene positively regulates biofilm formation, proteolytic activity, pyocyanin production and rhamnolipid biosurfactant synthesis. The QS regulatory RhlR gene affects protease and rhamnolipid production positively.

The Effect of Silver Nanoparticles on Pyocyanin Production of Pseudomonas aeruginosa Isolated From Clinical Specimens.

Background:Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen causing a wide range of human infections. The organism is resistant to a wide range of antibiotics. The purpose of this study was to investigate the effect of AgNPs on pyocyanin pigment production of P. aeruginosa bacteria isolated from clinical specimens.Methods:In this study, 15 clinical isolates of P. aeruginosa were collected from different specimens of hospitalized patients. P. aeruginosa was detected by biochemical and molecular (detection of pbo1 gene by colony PCR method) methods and the MIC and MBC of AgNPs were determined by agar dilution method. Inhibition of P. aeruginosa pyocyanin production at AgNPs concentrations of 0, 0.3, 0.5, 1 and 1.5 mg/ml of was studied with OD of 520 nm.Results:The mean MIC and MBC of AgNPs were 1.229 and 1.687 mg/ml, respectively. Pyocyanin production was investigated for all isolates at different concentrations of nanoparticles, and their comparison showed that with increasing nanoparticle concentration, pyocyanin production significantly decreased (p<0.05).Conclusion:According to the results of this study, AgNPs had an inhibitory effect on P. aeruginosa and its pigment production and with increasing nanoparticles concentration, pigment production decreased; therefore, it seems that the nanoparticles can be used to treat and prevent diseases caused by P. aeruginosa.

Optimization of nutritional and environmental conditions for pyocyanin production by urine isolates of Pseudomonas aeruginosa.

Pseudomonas aeruginosa (P. aeruginosa) is a highly pathogenic bacteria involved in numerous diseases among which, are urinary tract infections (UTIs). The pyocyanin secreted as a virulence factor by this bacterium has many beneficial applications but its high cost remains an obstacle for its widespread use. In this study, a total of fifty urine isolates were identified as P. aeruginosa. All strains produced pyocyanin pigment with a range of 1.3–31 µg/ml. The highest producer clinical strain P21 and the standard strain PA14 were used in optimization of pyocyanin production. Among tested media, king’s A fluid medium resulted in the highest yield of pyocyanin pigment followed by nutrient broth. Growth at 37 °C was superior in pyocyanin production than growth at 30 °C. Both shaking and longer incubation periods (3–4 days) improved pyocyanin production. The pyocyanin yield was indifferent upon growth of P21 at both pH 7 and pH 8. In conclusion, the optimum conditions for pyocyanin production are to use King’s A fluid medium of pH 7 and incubate the inoculated medium at 37 °C with shaking at 200 rpm for a period of three to four days.

Membrane-Interactive Compounds From Pistacia lentiscus L. Thwart Pseudomonas aeruginosa Virulence.

Pseudomonas aeruginosa is capable to deploy a collection of virulence factors that are not only essential for host infection and persistence, but also to escape from the host immune system and to become more resistant to drug therapies. Thus, developing anti-virulence agents that may directly counteract with specific virulence factors or disturb higher regulatory pathways controlling the production of virulence armories are urgently needed. In this regard, this study reports that Pistacia lentiscus L. fruit cyclohexane extract (PLFE1) thwarts P. aeruginosa virulence by targeting mainly the pyocyanin pigment production by interfering with 4-hydroxy-2-alkylquinolines molecules production. Importantly, the anti-virulence activity of PLFE1 appears to be associated with membrane homeostasis alteration through the modulation of SigX, an extracytoplasmic function sigma factor involved in cell wall stress response. A thorough chemical analysis of PLFE1 allowed us to identify the ginkgolic acid (C17:1) and hydroginkgolic acid (C15:0) as the main bioactive membrane-interactive compounds responsible for the observed increased membrane stiffness and anti-virulence activity against P. aeruginosa. This study delivers a promising perspective for the potential future use of PLFE1 or ginkgolic acid molecules as an adjuvant therapy to fight against P. aeruginosa infections.

Effects of human β-defensin 3 fused with carbohydrate-binding domain on the function of type III secretion system in Pseudomonas aeruginosa PA14.

Antimicrobial peptides are considered to be one of the candidate antimicrobial agents for antibiotic-resistant bacterial infection in the future. The effects of antimicrobial peptide hBD3-CBD on Pseudomonas aeruginosa PA14 and PA14 ΔexsA were analyzed by the bactericidal effects, hemolysis assays, pyocyanin pigment productions, and virulence factor expressions (exoU, exoS, hcnA, and lasB). Pyocyanin production and virulence factor expressions are important features of the type III secretion system in Pseudomonas aeruginosa. HBD3-CBD killed PA14 and PA14 ΔexsA with similar efficiency; it lowered the hemolysis levels of PA14 and PA14 ΔexsA and reduced the pyocyanin production, biofilm formation, and exoU, exoS, and lasB expressions in PA14. Compared with PA14, PA14 ΔexsA showed a lower hemolysis effect, pyocyanin production, exoU, and lasB expressions. The effects of hBD3-CBD on the PA14 toxin secretion were similar to the changes in the type III secretion system mutant isolate PA14 ΔexsA. Our results demonstrated that the type III secretion system was involved in the biological functions on PA 14 from hBD3-CBD.

An overview on biosynthesis and applications of extracellular pyocyanin pigment and its role in Pseudomonas aeruginosa pathogenesis

An overview on biosynthesis and applications of extracellular pyocyanin pigment and its role in Pseudomonas aeruginosa pathogenesis

Biocidal Activity of Metal Nanoparticles Synthesized by Fusarium solani against Multidrug-Resistant Bacteria and Mycotoxigenic Fungi.

Antibiotic resistance by pathogenic bacteria and fungi is one of the most serious global public health problems in the 21st century, directly affecting human health and lifestyle. Pseudomonas aeruginosa and Staphylococcus aureus with strong resistance to the common antibiotics have been isolated from Intensive Care Unit patients at Zagazig Hospital. Thus, in this study we assessed the biocidal activity of nanoparticles of silver, copper and zinc synthesized by Fusarium solani KJ 623702 against these multidrug resistant-bacteria. The synthesized Metal Nano-particles (MNPs) were characterized by UV-Vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and Zeta potential. The Fourier transform infrared spectroscopy (FTIR) result showed the presence of different functional groups such as carboxyl, amino and thiol, ester and peptide bonds in addition to glycosidic bonds that might stabilize the dispersity of MNPs from aggregation. The antimicrobial potential of MNPs by F. solani against the multidrug-resistant (MDR) P. aeruginosa and S. aureus in addition to the mycotoxigenic Aspergillus awamori, A. fumigatus and F. oxysporum was investigated, based on the visual growth by diameter of inhibition zone. Among the synthesized MNPs, the spherical AgNPs (13.70 nm) displayed significant effect against P. aeruginosa (Zone of Inhibition 22.4 mm and Minimum Inhibitory Concentration 21.33 µg/ml), while ZINC oxide Nano-Particles were the most effective against F. oxysporum (ZOI, 18.5 mm and MIC 24.7 µg/ml). Transmission Electron Microscope micrographs of AgNP-treated P. aeruginosa showed cracks and pits in the cell wall, with internalization of NPs. Production of pyocyanin pigment was significantly inhibited by AgNPs in a concentration-dependent manner, and at 5-20 µg of AgNPs/ml, the pigment production was reduced by about 15-100%, respectively.

Quorum sensing in Pseudomonas aeruginosa mediated by RhlR is regulated by a small RNA PhrD

Pseudomonas aeruginosa is a highly invasive human pathogen in spite of the absence of classical host specific virulence factors. Virulence factors regulated by quorum sensing (QS) in P. aeruginosa cause acute infections to shift to chronic diseases. Several small regulatory RNAs (sRNAs) mediate fine-tuning of bacterial responses to environmental signals and regulate quorum sensing. In this study, we show that the quorum sensing regulator RhlR is positively influenced upon over expression of the Hfq dependent small RNA PhrD in Pseudomonas. RhlR transcripts starting from two of the four different promoters have same sequence predicted to base pair with PhrD. Over expression of PhrD increased RhlR transcript levels and production of the biosurfactant rhamnolipid and the redox active pyocyanin pigment. A rhlR::lacZ translational fusion from one of the four promoters showed 2.5-fold higher expression and, a 9-fold increase in overall rhlR transcription was seen in the wild type when compared to the isogenic phrD disruption mutant. Expression, in an E. coli host background, of a rhlR::lacZ fusion in comparison to a construct that harboured a scrambled interaction region resulted in a 10-fold increase under phrD over expression. The interaction of RhlR-5′UTR with PhrD in E. coli indicated that this regulation could function without the involvement of any Pseudomonas specific proteins. Overall, this study demonstrates that PhrD has a positive effect on RhlR and its associated physiology in P. aeruginosa.

Bioprospecting studies of pigmenting Pseudomonas aeruginosa SU-1, Microvirga aerilata SU14 and Bacillus megaterium SU15 isolated from garden soil

Abstract Microbes that live in soil face more adverse environments, to adapt to the conditions they produce certain biomolecules or enzymes, where these metabolites or enzymes have industrial or biomedical applications. Some microorganisms produce carotenoid pigments for protecting themselves from photo-oxidative damage, whereas the pyocyanin pigment produced by Pseudomonas aeruginosa increases its pathogenicity. These pigments have much more applications too. In this present study, three pigment producing organisms like were isolated from soil. Pigment production by these organisms was optimized and the produced pigments were analyzed for their bioactivity. The pigment from Bacillus megaterium SU 15 was found to be with antibacterial and antioxidant property. All the isolated organisms were also checked for their ability to produce enzymes. Microvirga aerilata SU 14 and Bacillus megaterium SU 15 were found to produce amylase, thus optimization and characterization of amylase was done.

Genetic identification of Opr I and Opr L Genes in Pseudomonas aeruginosa isolated from different local sources.

P.aeruginosa bacteria are opportunistic pathogens capable of infection almost every tissue in the body as a result of possessing a large variety of virulence factors which significantly contribute to the pathogenicity of the host events. In the current study was to collect 119 samples from different clinical and environmental sources. to investigate the spread of bacteria P.aeruginosa and to study the virulence factors by a sample of 90 of those patients in several Hospitals in the city of Baghdad, including 33 samples of burns infections, 22 samples of wound infections, 17 samples of Otitis media infections, and 11 samples for urinary tract infections as well as 7 isolates belonging to patients with cystic fibrosis, The environmental samples included 10 samples of soil, 10 samples of water, and 9 samples of theaters. Diagnosed develop isolated after planted on different growth media through phenotypic traits and microscopic examinations and confirmed diagnosis using API 20E kit, as well as molecular diagnostics definitive diagnosis of isolates that give a positive result as bacteria P.aeruginosa during the previous tests were depending on the gene diagnosis 16SrDNA with a special bacterial sequence of P.aeruginosa. Diagnostic results showed that 61 isolated a 51% belonging for the type of P.aeruginosa of the total clinical and environmental samples that were divided on 15 isolates 24.6% of cases of burns infections, 13 isolates 21.4% of cases of wound infections, 10 isolates 16.3% of cases of Otitis media infections, 5 isolates 8.3% of cystic fibrosis, 4 isolates 6.5% of cases of urinary tract infections, 6 isolates 9.8% of soil, 4 isolates 6.5% of water, and 4 isolates 6.5% of the galleries operations. The results of the phenotypic detections of some virulence factors showed that 95% of the isolates were producing hemolysin enzyme type β –hemolysis, while it was 93.44% of the isolates producing protease enzyme and to varying degrees, and the percentage of isolates producing pyocyanin pigment was 73.13%. The prevalence of some virulence factors of P.aeruginosa was investigated in both clinical and environmental isolates by molecular genetic methods, included these genes each of the genes encoded of fatty proteins Opr I, Opr L. The results showed the existence of genes ( Opr I ) increased by 100%, while the gene Opr L ratio was 96.72% within the genetic structure of the isolates studied.

Isolate the bacteria Pseudomonas aeruginosa from different clinical samples and study the effect of pyocyanin pigments of some pathogenic bacterial

Three hundred clinical sample were collected from patients admitted and comers to (Azadi Teaching, Kirkuk General, kidsGeneral) hospitals, 140 sample from females with percentage (46.6%) and 160 sample frommale (53.3%), and through it found that 24 samples with percentage (17.14%) represented positive for bacterial growth in females and 26 samples with(16.25%) represented positive bacterial growth of male cases. The ability of Pseudo. aeruginosa to produce pyocyanin on various media were show that 43 clinical isolates of Pseudo.aeruginosa (86%) produced pyocyanin on two media (Nutrient agar, Muller hinton agar) and 15 (30%) produced the pigment on Macconky agar and 24 isolates (48%) on blood agar. While the effect of pyocyanin pigment on the growth of different pathogenic bacterial isolates the results showed that a gram positive bacteria such as Staphylococcus aureus was more sensitive to the pyocyanin pigment than gram negative bacteria (E.coli, klebsiella pneumonia) when grown on Nutrient agar or Muller hinton agar.

Lipopolysaccharide of Marinobacter litoralis inhibits swarming motility and biofilm formation in Pseudomonas aeruginosa PA01

The lipopolysaccharide (LPS) was isolated from a marine bacterium identified as Marinobacter litoralis BK09 using 16S rRNA gene sequence similarity analysis. The GCMS analysis showed that the LPS contained 3-hydroxy-dodecanoic acid (C12:0 3OH) (49%), dodecanoic acid (C12:0) (24%) and decanoic acid (C10:0) (19%) as major fatty acids, and the polysaccharide constituents were fucose (53.79%), xylose (28.04%) and mannose (18.15%). The LPS almost completely inhibited swarming motility in Pseudomonas aeruginosa PA01. It also reduced biofilm formation by 50% with no adverse effect on cell growth. The production of virulence factor such as pyocyanin pigment was reduced (∼40%) by the LPS. The LPS did not show any limulus amoebocyte lysate (LAL) gelation activity. The repression of swarming motility, pyocyanin production and biofilm formation by the LPS suggests its potential application against P. aeruginosa infection. This is the first report on characterization and application of LPS from M. litoralis.

Biosynthesis of pyocyanin pigment by Pseudomonas aeruginosa

Sixty-three isolates belonging to the genus Pseudomonas were isolated from different environmental sources including; soil, water and clinical specimens. Twenty out of them were identified as Pseudomonas aeruginosa and individually screened for pyocyanin production. P. aeruginosa R1; isolated from rice-cultivated soil and P. aeruginosa U3 selected from clinical specimen (Urinary tract infection) were the highest pyocyanin producers; pyocyanin production reached 9.3 and 5.9 μg/ml, respectively on synthetic glucose supplemented nutrient medium (GSNB). The identification of both selected strains (P. aeruginosa R1 and P. aeruginosa U3) was confirmed by 16S rRNA, the similarity with other strains available in database was 97% (with P. aeruginosa FPVC 14) and 94% (with P. aeruginosa 13.A), respectively. P. aeruginosa R1 and P. aeruginosa U3 are accessed at gene bank with accession numbers KM924432 and KM603511, in the same order. Pyocyanin was extracted by standard methods, purified by column chromatography and characterized by UV-Vis absorption, mass spectrometry and nuclear magnetic resonance. The antimicrobial activity of purified pyocyanin against multi-drug resistant microbes was investigated; the efficiency of pyocyanin was more obvious in Gram +ve bacteria than Gram−ve bacteria and yeast. To reduce the cost of pyocyanin production, a new conventional medium based on cotton seed meal supplemented with peptone was designed. The pyocyanin production of both selected strains P. aeruginosa R1 and P. aeruginosa U3 using the new medium is increased by 30.1% and 17.2%, respectively in comparison with synthetic GSNB medium, while the cost of production process is reduced by 56.7%.

Quorum Sensing: A Non-conventional Target for Antibiotic Discovery

Quorum sensing (QS) is known to regulate different functions viz. pathogenesis, biofilm formation, and host colonization, along with other functions by regulating bacterial virulence determinants. Therefore, QS is deemed to be an interesting target to modulate pathogenesis. Also, there have been global reports of continuous emergence of antibiotic-resistant microbes; hence, an alternative treatment that compliments antibiotic activity is highly desirable. One such approach is to look for QS inhibitors, which can quench the virulence phenotypes exerted by pathogenic bacteria and compliment antibiotic treatment. In the present study, Pseudomonas aeruginosa strain was used as the model organism which produces three pigments viz. pyocyanin, pyoverdin and pyorubin. Pyocyanin synthesis is reported to be QS dependent and is one of the virulence factors of P. aeruginosa. Hence, we envisage inhibition of pyocyanin pigment would indicate QS inhibition (QSI). Auto-inducers like N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL/3-oxo-C12-HSL) and N-butyryl-L- homoserine lactone (BHL/C4-HSL) were used to enhance the pyocyanin pigment production by the model strain at different doses and time points. BHL, at 25 microM was found to be a better inducer of pyocyanin. Tannic acid (TA) was tested to suppress this pigment synthesis and it was found to be effective when assessed at different time points. About 5.12 mg/mL TA was found to be the optimum concentration at which pyocyanin was inhibited by 77.3%. Thus, we confirm that TA can be used as a QSI, either in its purest form or in the crude form found in various plant species, and could be considered for development to compliment antibiotic therapy.

Pyocyanin pigment assisting biosurfactant-mediated hydrocarbon emulsification

A plethora of Pseudomonas strains was checked for their biosurfactant and pigment-producing abilities in Bushnell-Haas (BH) medium and proteose peptone glucose ammonium salts (PPGAS) medium. Five strains from different origins produced only biosurfactant in BH medium but both biosurfactant and pyocyanin pigment in PPGAS medium. Biosurfactant and pyocyanin exhibited a peculiar correlation as the culture supernatants containing both components emulsified hydrocarbons more than the biosurfactant alone. Enhancement in emulsification also occurred by mixing pyocyanin from PPGAS medium and biosurfactant from BH medium. Prior reports indicated that pigments protect producer strains from certain environmental stresses. The interesting finding of this study of pyocyanin pigment enhancing biosurfactant-mediated hydrocarbon emulsification was independent of the source of biosurfactant isolation. The synergistic action of pigment and biosurfactant found may be a general phenomenon for other Pseudomonas strains producing both biosurfactant and pigment, thus helping them to survive in arid conditions. The pigment-aided emulsification may help in lowering the requirement of biosurfactive agents for remediation purposes, which will also be helpful economically as the biosurfactants have very low yields. The enhancement in emulsification by the coupling of pigment with biosurfactant can have a significant impact in the paint industry and sectors dealing in environmental remediation.

Antipathogenic potential of Rhizophora spp. against the quorum sensing mediated virulence factors production in drug resistant Pseudomonas aeruginosa

Quorum sensing (QS) is a process of cell–cell communication mechanism occurs between the bacterial cells through the secretary signal molecules. This QS mechanism has been shown to control over the expression of various genes responsible for the production of virulence factors in several bacterial pathogens. Hence, the present study was intended to evaluate the antipathogenic potential of mangrove trees of the genus Rhizophora against the QS dependent virulence factors production in Pseudomonas aeruginosa PAO1, clinical isolates CI-I (GU447237) and CI-II (GU447238). The methanol extract of Rhizophora apiculata and R. mucronata (1mg/ml) showed significant inhibition against QS dependent virulence factors production such as LasA protease, LasB elastase, total protease, pyocyanin pigment production and biofilm formation in P. aeruginosa PAO1, CI-I and CI-II. This study for the first time, reports the quorum sensing inhibitory (QSI) potential of Rhizophora spp. against P. aeruginosa infections.

Effect of Traditional Chinese Herbal Medicine with Antiquorum Sensing Activity onPseudomonas aeruginosa

Traditional Chinese herbal medicines (TCHMs) were tested for their ability of antiquorum sensing. Water extracts of Rhubarb, Fructus gardeniae, and Andrographis paniculata show antiquorumsensing activity when using Chromobacterium violaceum CV12472 as reporter; the sub-MIC concentrations of these TCHMs were tested against AHL-dependent phenotypic expressions of PAO1. Results showed significant reduction in pyocyanin pigment, protease, elastase production, and biofilm formation in PAO1 without inhibiting the bacterial growth, revealing that the QSI by the extracts is not related to static or killing effects on the bacteria. The results indicate a potential modulation of bacterial cell-cell communication, P. aeruginosa biofilm, and virulence factors by traditional Chinese herbal medicine. This study introduces not only a new mode of action for traditional Chinese herbal medicines, but also a potential new therapeutic direction for the treatment of bacterial infections, which have QSI activity and might be important in reducing virulence and pathogenicity of pathogenic bacteria.

Production of pyocyanin pigment from Pseudomonas aeruginosa strains and investigation of the antimicrobial effect of pyocyanin on other microorganisms

Production of pyocyanin pigment from Pseudomonas aeruginosa strains and investigation of the antimicrobial effect of pyocyanin on other microorganisms