Displaying publications 41 - 60 of 235 in total

Abstract:
Sort:
  1. Fulltext Association of some Campylobacter jejuni with Pseudomonas aeruginosa biofilms increases attachment under conditions mimicking those in the environment
    Teh AHT, Lee SM, Dykes GA
    PLoS One, 2019;14(4):e0215275.
    PMID: 30970009 DOI: 10.1371/journal.pone.0215275
    Campylobacter jejuni is a microaerophilic bacterial species which is a major food-borne pathogen worldwide. Attachment and biofilm formation have been suggested to contribute to the survival of this fastidious bacteria in the environment. In this study the attachment of three C. jejuni strains (C. jejuni strains 2868 and 2871 isolated from poultry and ATCC 33291) to different abiotic surfaces (stainless steel, glass and polystyrene) alone or with Pseudomonas aeruginosa biofilms on them, in air at 25°C and under static or flow conditions, were investigated using a modified Robbins Device. Bacteria were enumerated and scanning electron microscopy was carried out. The results indicated that both C. jejuni strains isolated from poultry attached better to Pseudomonas aeruginosa biofilms on abiotic surfaces than to the surfaces alone under the different conditions tested. This suggests that biofilms of other bacterial species may passively protect C. jejuni against shear forces and potentially oxygen stress which then contribute to their persistence in environments which are detrimental to them. By contrast the C. jejuni ATCC 33291 strain did not attach differentially to P. aeruginosa biofilms, suggesting that different C. jejuni strains may have alternative strategies for persistence in the environment. This study supports the hypothesis that C. jejuni do not form biofilms per se under conditions they encounter in the environment but simply attach to surfaces or biofilms of other species.
    Matched MeSH terms: Pseudomonas aeruginosa/physiology*; Pseudomonas aeruginosa/ultrastructure
  2. Betacyanin-inhibited biofilm formation of co-culture of Staphylococcus aureus and Pseudomonas aeruginosa on different polymer surfaces
    Yong YY, Ong MWK, Dykes G, Choo WS
    FEMS Microbiol Lett, 2021 01 26;368(1).
    PMID: 33338235 DOI: 10.1093/femsle/fnaa214
    Staphylococcus aureus and Pseudomonas aeruginosa are bacteria that cause biofilm-associated infections. The aim of this study was to determine the activity of combined betacyanin fractions from Amaranthus dubius (red spinach) and Hylocereus polyrhizus (red pitahaya) against biofilms formed by co-culture of S. aureus and P. aeruginosa on different polymer surfaces. Various formulations containing different concentrations of the betacyanin fractions were investigated for biofilm-inhibiting activity on polystyrene surfaces using crystal violet assay and scanning electron microscopy. A combination of each betacyanin fraction (0.625 mg mL-1) reduced biofilm formation of five S. aureus strains and four P. aeruginosa strains from optical density values of 1.24-3.84 and 1.25-3.52 to 0.81-2.63 and 0.80-1.71, respectively. These combined fractions also significantly inhibited dual-species biofilms by 2.30 and reduced 1.0-1.3 log CFU cm-2 bacterial attachment on polymer surfaces such as polyvinyl chloride, polyethylene, polypropylene and silicone rubber. This study demonstrated an increase in biofilm-inhibiting activity against biofilms formed by two species using combined fractions than that by using single fractions. Betacyanins found in different plants could collectively be used to potentially decrease the risk of biofilm-associated infections caused by these bacteria on hydrophobic polymers.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/physiology
  3. Carbapenem-resistant Pseudomonas aeruginosa in malaysia producing IMP-7 beta-lactamase
    Ho SE, Subramaniam G, Palasubramaniam S, Navaratnam P
    Antimicrob Agents Chemother, 2002 Oct;46(10):3286-7.
    PMID: 12234862
    We have isolated and identified a carbapenem-resistant Pseudomonas aeruginosa strain from Malaysia that produces an IMP-7 metallo-beta-lactamase. This isolate showed high-level resistance to meropenem and imipenem, the MICs of which were 256 and 128 micro g/ml, respectively. Isoelectric focusing analyses revealed pI values of >9.0, 8.2, and 7.8, which indicated the possible presence of IMP and OXA. DNA sequencing confirmed the identity of the IMP-7 determinant.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/enzymology*
  4. The patterns and transmissibility of antibiotic resistance among clinical strains of Pseudomonas aeruginosa
    Palillo ES, Salleh MA
    Microbiol. Immunol., 1992;36(11):1195-200.
    PMID: 1491621
    Four hundred and ninety-eight predominantly pyocin-type 10 clinical strains of Pseudomonas aeruginosa were analyzed for resistance to carbenicillin, cefoperazone, cefotaxime, ceftazidime, gentamicin, amikacin and netilmicin. Based on NCCLS-recommended MIC breakpoints, 245 strains were found to be resistant, of which 41.6% were resistant to carbenicillin, 38% to gentamicin, 37.8% to netilmicin, 26.3% to cefoperazone, 17.9% to cefotaxime, 0.6% to amikacin and none to ceftazidime. Quadruple resistance to carbenicillin, cefoperazone, gentamicin and netilmicin was the most frequent pattern observed. Resistance to older antibiotics (kanamycin, streptomycin and tetracycline) and to mercuric chloride were also common. Conjugation experiments suggested that self-transmissible and non-transmissible plasmids occurred in at least 66 strains.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/genetics
  5. Plant-derived Compounds as Potential Source of Novel Anti-Biofilm Agents Against Pseudomonas aeruginosa
    Chung PY
    Curr Drug Targets, 2017;18(4):414-420.
    PMID: 27758704 DOI: 10.2174/1389450117666161019102025
    Pseudomonas aeruginosa is the most common Gram-negative bacterium associated with nosocomial and life-threatening chronic infections in cystic fibrosis patients. This pathogen is wellknown for its ability to attach to surfaces of indwelling medical devices to form biofilms, which consist of a regular array of extracellular polymers. Tenaciously bound to the surface of devices and inherently resilient to antibiotic treatment, P. aeruginosa poses a serious threat in clinical medicine and contributes to the persistence of chronic infections. Studies on microbial biofilms in the past decade involved mainly the understanding of environment signals, genetic elements and molecular mechanisms in biofilm formation, tolerance and dispersal. The knowledge obtained from the studies of these mechanisms is crucial in the establishment of strategies to eradicate or to prevent biofilm formation. Currently, biofilm infections are usually treated with combinations of antibiotics and surgical removal, in addition to frequent replacement of the infected device. More recently, specific natural sources have been identified as antibiofilm agents against this pathogen. This review will highlight the recent progress made by plant-derived compounds against P. aeruginosa biofilm infections in both in vitro or in vivo models.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/physiology
  6. Antibiofilm activity and mode of action of DMSO alone and its combination with afatinib against Gram-negative pathogens
    Yahya MFZR, Alias Z, Karsani SA
    Folia Microbiol (Praha), 2018 Jan;63(1):23-30.
    PMID: 28540585 DOI: 10.1007/s12223-017-0532-9
    Biofilms are complex microbial communities that tend to attach to either biotic or abiotic surface. Enclosed in a self-produced extracellular polymeric substance (EPS) matrix, the biofilms often cause persistent infections. The objective of this study was to investigate the antibiofilm activity of dimethyl sulfoxide (DMSO) and afatinib against Gram-negative pathogens. Test microorganisms used in this study were Escherichia coli ATCC 1299, Pseudomonas aeruginosa ATCC 10145, and Salmonella typhimurium ATCC 14028. Biofilms were developed in 96-well microplate at 37°C for 24 h. Following removal of non-adherent cells, analysis of biofilm viability, biofilm biomass, and extracellular polymeric substances (EPS) matrix were performed using resazurin assay, crystal violet assay, and attenuated total reflectance fourier transform infrared (ATR-FTIR) spectroscopy, respectively. Bradford protein assay was conducted to determine the total amount of EPS proteins. The results demonstrated that both 32% DMSO alone and its combination with 3.2 μg/mL afatinib were effective in killing biofilm cells and reducing biofilm biomass. IR spectral variations of EPS matrix of biofilms in the range between 1700 and 900 cm-1 were also observed. Reduction in EPS proteins verified the chemical modifications of EPS matrix. In conclusion, 32% DMSO alone and its combination with 3.2 μg/mL afatinib showed remarkable antibiofilm activities against Gram-negative pathogens. It was suggested that the biofilm inhibition was mediated by the chemical modification of EPS matrix.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/physiology
  7. Fulltext Prodigiosin inhibits bacterial growth and virulence factors as a potential physiological response to interspecies competition
    Yip CH, Mahalingam S, Wan KL, Nathan S
    PLoS One, 2021;16(6):e0253445.
    PMID: 34161391 DOI: 10.1371/journal.pone.0253445
    Prodigiosin, a red linear tripyrrole pigment, has long been recognised for its antimicrobial property. However, the physiological contribution of prodigiosin to the survival of its producing hosts still remains undefined. Hence, the aim of this study was to investigate the biological role of prodigiosin from Serratia marcescens, particularly in microbial competition through its antimicrobial activity, towards the growth and secreted virulence factors of four clinical pathogenic bacteria (methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, Salmonella enterica serovar Typhimurium and Pseudomonas aeruginosa) as well as Staphylococcus aureus and Escherichia coli. Prodigiosin was first extracted from S. marcescens and its purity confirmed by absorption spectrum, high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrophotometry (LC-MS/MS). The extracted prodigiosin was antagonistic towards all the tested bacteria. A disc-diffusion assay showed that prodigiosin is more selective towards Gram-positive bacteria and inhibited the growth of MRSA, S. aureus and E. faecalis and Gram-negative E. coli. A minimum inhibitory concentration of 10 μg/μL of prodigiosin was required to inhibit the growth of S. aureus, E. coli and E. faecalis whereas > 10 μg/μL was required to inhibit MRSA growth. We further assessed the effect of prodigiosin towards bacterial virulence factors such as haemolysin and production of protease as well as on biofilm formation. Prodigiosin did not inhibit haemolysis activity of clinically associated bacteria but was able to reduce protease activity for MRSA, E. coli and E. faecalis as well as decrease E. faecalis, Salmonella Typhimurium and E. coli biofilm formation. Results of this study show that in addition to its role in inhibiting bacterial growth, prodigiosin also inhibits the bacterial virulence factor protease production and biofilm formation, two strategies employed by bacteria in response to microbial competition. As clinical pathogens were more resistant to prodigiosin, we propose that prodigiosin is physiologically important for S. marcescens to compete against other bacteria in its natural soil and surface water environments.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/growth & development
  8. Fulltext Phenotypic detection of metallo-β-lactamase in imipenem-resistant Pseudomonas aeruginosa
    Khosravi Y, Loke MF, Chua EG, Tay ST, Vadivelu J
    ScientificWorldJournal, 2012;2012:654939.
    PMID: 22792048 DOI: 10.1100/2012/654939
    Carbapenems are the primary choice of treatment for severe Pseudomonas aeruginosa infection. However, the emergence of carbapenem resistance due to the production of metallo-β-lactamases (MBLs) is of global concern. In this study, 90 imipenem- (IPM- or IP-) resistant P. aeruginosa (IRPA) isolates, including 32 previously tested positive and genotyped for MBL genes by PCR, were subjected to double-disk synergy test (DDST), combined disk test (CDT), and imipenem/imipenem-inhibitor (IP/IPI) E-test to evaluate their MBLs detection capability. All three methods were shown to have a sensitivity of 100%. However, DDST was the most specific of the three (96.6%), followed by IP/IPI E-test interpreted based on the single criteria of IP/IPI ≥8 as positive (62.1%), and CDT was the least specific (43.1%). Based on the data from this evaluation, we propose that only IRPA with IP MIC >16 μg/mL and IP/IPI ≥8 by IP/IPI E-test should be taken as positive for MBL activity. With the new dual interpretation criteria, the MBL IP/IPI E-test was shown to achieve 100% sensitivity as well as specificity for the IRPA in this study. Therefore, the IP/IPI E-test is a viable alternative phenotypic assay to detect MBL production in IRPA in our population in circumstances where PCR detection is not a feasible option.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/enzymology*
  9. Antibacterial activity and morphological changes of Pseudomonas aeruginosa cells after exposure to Vernonia cinerea extract
    Latha LY, Darah I, Kassim MJ, Sasidharan S
    Ultrastruct Pathol, 2010 Aug;34(4):219-25.
    PMID: 20594042 DOI: 10.3109/01913121003651513
    The antibacterial activity of Vernonia cinerea (L.) extract was investigated using the broth dilution method. The extract showed a favorable antimicrobial activity against Pseudomonas aeruginosa with a minimum inhibition concentration (MIC) value of 3.13 mg/mL. V. cinerea extract at (1/2), 1, or 2 times the MIC significantly inhibited bacterial growth with a noticeable drop in optical density (OD) of the bacterial culture, thus confirming the antibacterial activity of the extract on P. aeruginosa. Imaging using scanning (SEM) and transmission (TEM) electron microscopy was done to determine the major alterations in the microstructure of the extract-treated P. aeruginosa. The main abnormalities noted via SEM and TEM studies were the alteration in morphology of the bacterial cells. The main reason for this destruction was the severe alterations of the cell wall with the formation of holes, invaginations, and morphological disorganization caused by the extract. The authors conclude that the extract may be used as a candidate for the development of antimicrobial agents.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/ultrastructure
  10. Physical factors affecting the production of organic solvent-tolerant protease by Pseudomonas aeruginosa strain K
    Rahman RN, Geok LP, Basri M, Salleh AB
    Bioresour Technol, 2005 Mar;96(4):429-36.
    PMID: 15491823
    The physical factors affecting the production of an organic solvent-tolerant protease from Pseudomonas aeruginosa strain K was investigated. Growth and protease production were detected from 37 to 45 degrees C with 37 degrees C being the optimum temperature for P. aeruginosa. Maximum enzyme activity was achieved at static conditions with 4.0% (v/v) inoculum. Shifting the culture from stationary to shaking condition decreased the protease production (6.0-10.0% v/v). Extracellular organic solvent-tolerant protease was detected over a broad pH range from 6.0 to 9.0. However, the highest yield of protease was observed at pH 7.0. Neutral media increased the protease production compared to acidic or alkaline media.
    Matched MeSH terms: Pseudomonas aeruginosa/classification*; Pseudomonas aeruginosa/enzymology*
  11. Fulltext Antibacterial activity of selected Malaysian honey
    Zainol MI, Mohd Yusoff K, Mohd Yusof MY
    BMC Complement Altern Med, 2013;13:129.
    PMID: 23758747 DOI: 10.1186/1472-6882-13-129
    Antibacterial activity of honey is mainly dependent on a combination of its peroxide activity and non-peroxide components. This study aims to investigate antibacterial activity of five varieties of Malaysian honey (three monofloral; acacia, gelam and pineapple, and two polyfloral; kelulut and tualang) against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/growth & development
  12. Fulltext The influence of agitation on oil substrate dispersion and oxygen transfer in Pseudomonas aeruginosa USM-AR2 fermentation producing rhamnolipid in a stirred tank bioreactor
    Nur Asshifa MN, Zambry NS, Salwa MS, Yahya ARM
    3 Biotech, 2017 Jul;7(3):189.
    PMID: 28664380 DOI: 10.1007/s13205-017-0828-0
    Water-immiscible substrate, diesel, was supplied as the main substrate in the fermentation of Pseudomonas aeruginosa USM-AR2 producing rhamnolipid biosurfactant, in a stirred tank bioreactor. In addition to the typical gas-aqueous system, this system includes gas-hydrocarbon-aqueous phases and the presence of surfactant (rhamnolipid) in the fermentation broth. The effect of diesel dispersion on volumetric oxygen transfer coefficient, k L a, and thus oxygen transfer, was evaluated at different agitations of 400, 500 and 600 rpm. The oxygen transfer in this oil-water-surfactant system was shown to be affected by different oil dispersion at those agitation rates. The highest diesel dispersion was obtained at 500 rpm or impeller tip speed of 1.31 m/s, compared to 400 and 600 rpm, which led to the highest k L a, growth and rhamnolipid production by P. aeruginosa USM-AR2. This showed the highest substrate mixing and homogenization at this agitation speed that led to the efficient substrate utilization by the cells. The oxygen uptake rate of P. aeruginosa USM-AR2 was 5.55 mmol/L/h, which showed that even the lowest k L a (48.21 h-1) and hence OTR (57.71 mmol/L/h) obtained at 400 rpm was sufficient to fulfill the oxygen demand of the cells. The effect of rhamnolipid concentration on k L a showed that k L a increased as rhamnolipid concentration increased to 0.6 g/L before reaching a plateau. This trend was similar for all agitation rates of 400, 500 and 600 rpm, which might be due to the increase in the resistance to oxygen transfer (k L decrease) and the increase in the specific interfacial area (a).
    Matched MeSH terms: Pseudomonas aeruginosa
  13. Fulltext In-silico Taxonomic Classification of 373 Genomes Reveals Species Misidentification and New Genospecies within the Genus Pseudomonas
    Tran PN, Savka MA, Gan HM
    Front Microbiol, 2017;8:1296.
    PMID: 28747902 DOI: 10.3389/fmicb.2017.01296
    The genus Pseudomonas has one of the largest diversity of species within the Bacteria kingdom. To date, its taxonomy is still being revised and updated. Due to the non-standardized procedure and ambiguous thresholds at species level, largely based on 16S rRNA gene or conventional biochemical assay, species identification of publicly available Pseudomonas genomes remains questionable. In this study, we performed a large-scale analysis of all Pseudomonas genomes with species designation (excluding the well-defined P. aeruginosa) and re-evaluated their taxonomic assignment via in silico genome-genome hybridization and/or genetic comparison with valid type species. Three-hundred and seventy-three pseudomonad genomes were analyzed and subsequently clustered into 145 distinct genospecies. We detected 207 erroneous labels and corrected 43 to the proper species based on Average Nucleotide Identity Multilocus Sequence Typing (MLST) sequence similarity to the type strain. Surprisingly, more than half of the genomes initially designated as Pseudomonas syringae and Pseudomonas fluorescens should be classified either to a previously described species or to a new genospecies. Notably, high pairwise average nucleotide identity (>95%) indicating species-level similarity was observed between P. synxantha-P. libanensis, P. psychrotolerans-P. oryzihabitans, and P. kilonensis- P. brassicacearum, that were previously differentiated based on conventional biochemical tests and/or genome-genome hybridization techniques.
    Matched MeSH terms: Pseudomonas aeruginosa
  14. Biofilm inhibiting activity of betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms
    Yong YY, Dykes G, Lee SM, Choo WS
    J Appl Microbiol, 2019 Jan;126(1):68-78.
    PMID: 30153380 DOI: 10.1111/jam.14091
    AIMS: To investigate the biofilm inhibitory activity of betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms.

    METHODS AND RESULTS: The pulp of red pitahaya and the leaves of red spinach were extracted using methanol followed by subfractionation to obtain betacyanin fraction. The anti-biofilm activity was examined using broth microdilution assay on polystyrene surfaces and expressed as minimum biofilm inhibitory concentration (MBIC). The betacyanin fraction from red spinach showed better anti-biofilm activity (MBIC: 0·313-1·25 mg ml-1 ) against five Staph. aureus strains while the betacyanin fraction from red pitahaya showed better anti-biofilm activity (MBIC: 0·313-0·625 mg ml-1 ) against four P. aeruginosa strains. Both betacyanin fraction significantly reduced hydrophobicity of Staph. aureus and P. aeruginosa strains. Numbers of Staph. aureus and P. aeruginosa attached to polystyrene were also reduced without affecting their cell viability.

    CONCLUSION: Betacyanins can act as anti-biofilm agents against the initial step of biofilm formation, particularly on a hydrophobic surface like polystyrene.

    SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first to investigate the use of betacyanin as a biofilm inhibitory agent. Betacyanin could potentially be used to reduce the risk of biofilm-associated infections.

    Matched MeSH terms: Pseudomonas aeruginosa/drug effects*; Pseudomonas aeruginosa/genetics; Pseudomonas aeruginosa/physiology
  15. Fulltext The epidermal mucus extract of clarias batrachus inhibits gram negative bacteria growth
    Ahmad Zorin Sahalan, Engku Sharmila, Nazahiyah Sulaiman
    Jurnal Sains Kesihatan Malaysia, 2018;16(101):83-87.
    MyJurnal
    Recently, epidermal mucus of fish has been identified as a rich biological source of various bioactive substances, particularly antibacterial peptides. This study was conducted to identify the potential of epidermal mucosa of Clarias batrachus as a source of antibacterial material. Mucosal samples were collected from C. batrachus epidermis and extracted using an aqueous extraction method. Antibacterial activity of the crude epidermal mucus extract was determined by using spectrophotometric method. As a result there was antibacterial activity by the mucus extract against Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853). The results of this study supports the role of mucus as a part of body immune system with antibacterial peptide as a component of innate body immune system. Hence, these findings can be used as one of the first steps towards the development of new class antibiotics.
    Matched MeSH terms: Pseudomonas aeruginosa
  16. Synthesis, characterization and antibacterial activity of mono-, di- and tri-tosylate of glycerol
    Yusrabbil Amiyati Yusof, Azhar Ariffin
    Sains Malaysiana, 2016;45:621-625.
    Glycerol is a valuable co-product from oleochemical industry such as from fatty acid and biodiesel production. By having three hydroxyl groups in its molecule, glycerol can undergo chemical modifications that lead to many possible applications. This paper reports the tosylation process of glycerol with para-toluenesulfonyl chloride (p-TsCl). Reaction of glycerol with p-TsCl in the presence of a base produced mono-, di- and tri-tosylate of glycerol even though the reaction was carried out at the mole ratio of 1.2:1.0 of glycerol to p-TsCl. The compounds were successfully isolated and characterized. Mono-, di- and tri-tosylate of glycerol exhibited inhibitory activity against Staphylococcus aureus (gram positive bacteria) and Pseudomonas aeruginosa (gram negative bacteria).
    Matched MeSH terms: Pseudomonas aeruginosa
  17. Fulltext Research on the treatment of Pseudomonas aeruginosa pneumonia in children by macrolide antibiotics
    Huang XQ, Deng L, Lu G, He CH, Wu PQ, Xie ZW, et al.
    Open Med (Wars), 2015;10(1):479-482.
    PMID: 28352740 DOI: 10.1515/med-2015-0082
    To observe a therapeutic effect of macrolide antibiotics in children with Pseudomonas aeruginosa pneumonia. Fifty-four cases of children with Pseudomonas aeruginosa pneumonia were randomly divided into an observation group (n=30) and a control group (n=24). The observation group was treated with macrolide antibiotics and cefoperazone/sulbactam. The control group was treated with cefoperazone/sulbactam during a course of 10-14 days. The total effective rate was 93.3% in the observation group, and 58.3% in the control group, and results in the observation group were superior to the control group notably (P>0.05). There were no significant differences in bacterial clearance rate, adverse reaction rate between two groups (P>0.05). The combined application of cefoperazone/sulbactam with macrolide antibiotics to treat Pseudomonas aeruginosa pneumonia in children would be a more effective clinical method.
    Matched MeSH terms: Pseudomonas aeruginosa
  18. Fulltext Effect of nutritional factors on the growth and production of biosurfactant by Pseudomonas aeruginosa strain 181
    Al-Araji, L., Rahman, R.N.Z.A., Basri, M., Salleh, A.B.
    ASM Science Journal, 2008;2(1):45-56.
    MyJurnal
    The growth and production of biosurfactant by P. seudomonas aeruginosa (181) was dependant on nutritional factors. Among the eleven carbon sources tested, glucose supported the maximum growth (0.25 g/L) with the highest biosurfactant yield and this was followed by glycerol. Glucose reduced the surface tension to 35.3 dyne/cm and gave an E24 reading of 62.7%. Butanol gave the lowest growth and had no biosurfactant production. For the nitrogen sources tested, casamino acid supported a growth of 0.21 g/L which reduced the surface tension to 41.1 dyne/cm and gave an E24 reading of 56%. Soytone was assimilated similarly, with good growth and high biosurfactant production. Corn steep liquor gave the lowest growth and did not show any biosurfactant activity.
    Matched MeSH terms: Pseudomonas aeruginosa
  19. In situ functionalizing calcium phosphate biomaterials with curcumin for the prevention of bacterial biofilm infections
    Lee WH, Rohanizadeh R, Loo CY
    Colloids Surf B Biointerfaces, 2021 Oct;206:111938.
    PMID: 34198233 DOI: 10.1016/j.colsurfb.2021.111938
    This study developed a novel bioactive bone substitute (hydroxyapatite, HA) with improved anti-biofilm activity by functionalizing with curcumin (anti-biofilm compound) which provide sufficient flux of curcumin concentration for 14 days. The released curcumin acts to inhibit biofilm formation and control the number of viable planktonic cells simultaneously. To prepare curcumin-functionalized HA, different concentrations of curcumin (up to 3% w/v) were added simultaneously during the precipitation process of HA. The highest loading (50 mg/g HA) of curcumin onto HA was achieved with 2% w/v of curcumin. Physicochemical characterizations of curcumin-functionalized HA composites revealed that curcumin was successfully incorporated onto HA. Curcumin was sustainably released over 14 days, while higher curcumin release was observed in acidic condition (pH 4.4) compared to physiological (pH 7.4). The cytotoxicity assays revealed that no significant difference on bone cells growth on curcumin-functionalized HA and non-functionalized HA. Curcumin-functionalized HA was effective to inhibit bacterial cell attachment and subsequent biofilm maturation stages. The anti-biofilm effect was stronger against Staphylococcus aureus compared to Pseudomonas aeruginosa. The curcumin-functionalized HA composite significantly delayed the maturation of S. aureus compared to non-functionalized HA in which microcolonies of cells only begin to appear at 96 h. Up to 3.0 log reduction in colony forming unit (CFU)/mL of planktonic cells was noted at 24 h of incubation for both microorganisms. Thus, in this study we have suggested that curcumin loaded HA could be an alternative antimicrobial agent to control the risk of infections in post-surgical implants.
    Matched MeSH terms: Pseudomonas aeruginosa
  20. Fulltext Application strategies by selective medium treated with entomopathogenic bacteria Serratia marcescens and Pseudomonas aeruginosa as potential biocontrol against Coptotermes curvignathus
    Chin KL, H'ng PS, Lee CL, Wong WZ, Go WZ, Khoo PS, et al.
    R Soc Open Sci, 2021 Apr 14;8(4):201311.
    PMID: 33996113 DOI: 10.1098/rsos.201311
    The success of microbial termiticides in controlling termites depends on the ability of microbes to grow in different media and the functionality of the microbes as a resistant barrier or toxic bait. This study was conducted to understand the mortality rate and behaviour changes of the subterranean termite Coptotermes curvignathus Holmgren introduced with different concentrations of Serratia marcescens strain LGMS 1 and Pseudomonas aeruginosa strain LGMS 3 using wood and soil as bacterial transfer medium. In general, higher concentration of bacteria in soil caused a reduction in tunnelling activity and wood consumption and an increase in mortality. However, application on wood revealed a different outcome. Wood treated with S. marcescens of 106 CFU ml-1 concentration proved to be more efficient as bait than higher concentration applications as it caused a high mortality rate while still highly palatable for termites. Wood or soil treated with S. marcescens concentration higher than 109 CFU ml-1 creates a high toxicity and repellent barrier for termites. Pseudomonas aeruginosa of 109 CFU ml-1 concentrations applied on wood served as a slow-acting toxic bait. However, the ability for S. marcescens and P. aeruginosa to survive on wood is low, which made the bait unable to retain a useful level of toxicity for a long period of time and frequent reapplication is needed.
    Matched MeSH terms: Pseudomonas aeruginosa
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links