MyMedR

Displaying publications 261 - 280 of 366 in total

Abstract:

Sort:

Fulltext Phenazine from Pseudomonas aeruginosa UPMP3 induced the host resistance in oil palm (Elaeis guineensis Jacq.)-Ganoderma boninense pathosystem

Parvin W, Govender N, Othman R, Jaafar H, Rahman M, Wong MY

Sci Rep, 2020 Sep 24;10(1):15621.
PMID: 32973199 DOI: 10.1038/s41598-020-72156-7

Pseudomonas aeruginosa developed its biocontrol agent property through the production of antifungal derivatives, with the phenazine among them. In this study, the applications of crude phenazine synthesized by Pseudomonas aeruginosa UPMP3 and hexaconazole were comparatively evaluated for their effectiveness to suppress basal stem rot infection in artificially G. boninense-challenged oil palm seedlings. A glasshouse experiment under the randomized completely block design was set with the following treatments: non-inoculated seedlings, G. boninense inoculated seedlings, G. boninense inoculated seedlings with 1 mg/ml phenazine application, G. boninense inoculated seedlings with 2 mg/ml phenazine application and G. boninense inoculated seedlings with 0.048 mg/ml hexaconazole application. Seedlings were screened for disease parameters and plant vigour traits (plant height, plant fresh weight, root fresh, and dry weight, stem diameter, and total chlorophyll) at 1-to-4 month post-inoculation (mpi). The application of 2 mg/ml phenazine significantly reduced disease severity (DS) at 44% in comparison to fungicide application (DS = 67%). Plant vigour improved from 1 to 4 mpi and the rate of disease reduction in seedlings with phenazine application (2 mg/ml) was twofold greater than hexaconazole. At 4, 6 and 8 wpi, an up-regulation of chitinase and β-1,3 glucanase genes in seedlings treated with phenazine suggests the involvement of induced resistance in G. boninense-oil palm pathosystem.

Matched MeSH terms: Pseudomonas aeruginosa/chemistry*
Fulltext In vitro activity of ceftazidime-avibactam and comparators against Gram-negative bacterial isolates collected in the Asia-Pacific region as part of the INFORM program (2015-2017)

Ko WC, Stone GG

Ann Clin Microbiol Antimicrob, 2020 Apr 01;19(1):14.
PMID: 32238155 DOI: 10.1186/s12941-020-00355-1

BACKGROUND: Antimicrobial resistance among nosocomial Gram-negative pathogens is a cause for concern in the Asia-Pacific region. The aims of this study were to measure the rates of resistance among clinical isolates collected in Asia-Pacific countries, and to determine the in vitro antimicrobial activities of ceftazidime-avibactam and comparators against these isolates.
METHODS: CLSI broth microdilution methodology was used to determine antimicrobial activity and EUCAST breakpoints version 9.0 were used to determine rates of susceptibility and resistance. Isolates were also screened for the genes encoding extended-spectrum β-lactamases (ESBLs) or carbapenemases (including metallo-β-lactamases [MBLs]).
RESULTS: Between 2015 and 2017, this study collected a total of 7051 Enterobacterales isolates and 2032 Pseudomonas aeruginosa isolates from hospitalized patients in Australia, Japan, South Korea, Malaysia, the Philippines, Taiwan, and Thailand. In the Asia-Pacific region, Enterobacterales isolates that were ESBL-positive, carbapenemase-negative (17.9%) were more frequently identified than isolates that were carbapenemase-positive, MBL-negative (0.7%) or carbapenemase-positive, MBL-positive (1.7%). Multidrug-resistant (MDR) isolates of P. aeruginosa were more commonly identified (23.4%) than isolates that were ESBL-positive, carbapenemase-negative (0.4%), or carbapenemase-positive, MBL-negative (0.3%), or carbapenemase-positive, MBL-positive (3.7%). More than 90% of all Enterobacterales isolates, including the ESBL-positive, carbapenemase-negative subset and the carbapenemase-positive, MBL-negative subset, were susceptible to amikacin and ceftazidime-avibactam. Among the carbapenemase-positive, MBL-positive subset of Enterobacterales, susceptibility to the majority of agents was reduced, with the exception of colistin (93.4%). Tigecycline was active against all resistant subsets of the Enterobacterales (MIC90, 1-4 mg/L) and among Escherichia coli isolates, > 90% from each resistant subset were susceptible to tigecycline. More than 99% of all P. aeruginosa isolates, including MDR isolates and the carbapenemase-positive, MBL-positive subset, were susceptible to colistin.
CONCLUSIONS: In this study, amikacin, ceftazidime-avibactam, colistin and tigecycline appear to be potential treatment options for infections caused by Gram-negative pathogens in the Asia-Pacific region.

Matched MeSH terms: Pseudomonas aeruginosa/drug effects*
Biodegradation of a medium-chain-length polyhydroxyalkanoate in tropical river water

Ho YH, Gan SN, Tan IK

Appl Biochem Biotechnol, 2002 10 25;102-103(1-6):337-47.
PMID: 12396135

The medium-chain-length polyhydroxyalkanoate (PHA(MCL)) produced by Pseudomonas putida PGA1 using saponified palm kernel oil as the carbon source could degrade readily in water taken from Kayu Ara River in Selangor, Malaysia. A weight loss of 71.3% of the PHA film occurred in 86 d. The pH of the river water medium fell from 7.5 (at d 0) to 4.7 (at d 86), and there was a net release of CO2. In sterilized river water, the PHA film also lost weight and the pH of the water fell, but to lesser extents. The C8 monomer of the PHA was completely removed after 6 d of immersion in the river water, while the proportions of the other monomers (C10, C12, and C14) were reversed from that of the undegraded PHA. By contrast, the monomer composition of the PHA immersed in sterilized river water did not change significantly from that of the undegraded PHA. Scanning electron microscopy showed physical signs of degradation on the PHA film immersed in the river water, but the film immersed in sterilized river water was relatively unblemished. The results thus indicate that the PHA(MCL) was degraded in tropical river water by biologic as well as nonbiologic means. A significant finding is that shorter-chain monomers were selectively removed throughout the entire PHA molecule, and this suggests enzymatic action.

Matched MeSH terms: Pseudomonas putida/metabolism
Toluene promotes lid 2 interfacial activation of cold active solvent tolerant lipase from Pseudomonas fluorescens strain AMS8

Yaacob N, Mohamad Ali MS, Salleh AB, Rahman RNZRA, Leow ATC

J Mol Graph Model, 2016 07;68:224-235.
PMID: 27474867 DOI: 10.1016/j.jmgm.2016.07.003

The utilization of cold active lipases in organic solvents proves an excellent approach for chiral synthesis and modification of fats and oil due to the inherent flexibility of lipases under low water conditions. In order to verify whether this lipase can function as a valuable synthetic catalyst, the mechanism concerning activation of the lid and interacting solvent residues in the presence of organic solvent must be well understood. A new alkaline cold-adapted lipase, AMS8, from Pseudomonas fluorescens was studied for its structural adaptation and flexibility prior to its exposure to non-polar, polar aprotic and protic solvents. Solvents such as ethanol, toluene, DMSO and 2-propanol showed to have good interactions with active sites. Asparagine (Asn) and tyrosine (Tyr) were key residues attracted to solvents because they could form hydrogen bonds. Unlike in other solvents, Phe-18, Tyr-236 and Tyr-318 were predicted to have aromatic-aromatic side-chain interactions with toluene. Non-polar solvent also was found to possess highest energy binding compared to polar solvents. Due to this circumstance, the interaction of toluene and AMS8 lipase was primarily based on hydrophobicity and molecular recognition. The molecular dynamic simulation showed that lid 2 (residues 148-167) was very flexible in toluene and Ca(2+). As a result, lid 2 moves away from the catalytic areas, leaving an opening for better substrate accessibility which promotes protein activation. Only a single lid (lid 2) showed the movement following interactions with toluene, although AMS8 lipase displayed double lids. The secondary conformation of AMS8 lipase that was affected by toluene observed a reduction of helical strands and increased coil structure. Overall, this work shows that cold active lipase, AMS8 exhibits distinguish interfacial activation and stability in the presence of polar and non-polar solvents.

Matched MeSH terms: Pseudomonas fluorescens/enzymology*
Successful surgical management of a case of pulmonary and pericardial melioidosis

Majid AA

Aust N Z J Surg, 1990 Feb;60(2):139-41.
PMID: 2327916

A 35 year old diabetic presented with features of septicaemia and developed cardiac tamponade. He was found to have pulmonary, acute septicaemic and pericardial melioidosis. Some initial improvement was achieved with medical therapy but only with surgical intervention was a successful outcome achieved.

Matched MeSH terms: Pseudomonas/isolation & purification
Fulltext Sputum bacteriology and in-vitro antibiotic susceptibility in hospitalized patients with community acquired pneumonia in a state tertiary-referral hospital – a retrospective study

Chin, Yow-Wen, Loh, Li-Cher, Wong, Thim-Fatt, Abdul Razak Muttalif

International e-Journal of Science, Medicine & Education, 2007;1(2):74-79.
MyJurnal

Introduction: To review the sputum bacteriology and its in-vitro antibiotic susceptibility in patients hospitalized with community-acquired pneumonia (CAP) in a state tertiary-referral Hospital (Penang hospital, Malaysia) in order to determine the most appropriate empiric antibiotics.
Methods: From September 2006 to May 2007, 68 immunocompetent adult patients [mean age: 52 years (range 16-89); 69% male] admitted to respiratory wards for CAP with positive sputum isolates within 48 hours of admission were retrospectively identified and reviewed.
Results: 62 isolates were Gram(-) bacilli (91%) & 6 were Gram(+) cocci (9%). The two commonest pathogens isolated were Pseudomonas aeruginosa (n=20) and Klebsiella pneumoniae (n=19) together constituted 57% of all positive isolates. Among the Pseudomonas isolates, 84.2% were fully sensitive to cefoperazone and cefoperazon/sulbactam; 95% to ceftazidime, cefepime, piperacillin/tazobactam, ciprofloxacin and amikacin, and 100% to gentamycin, netilmycin, imipenem and meropenem. Among the Klebsiella isolates, 5.3% were fully sensitive to ampicillin; 84.2% to amoxicillin, ampicllin/sulbactam, cefuroxime and ceftriazone; 89.5% to piperacillin/ tazobactam; 93.3% to cefoperazon/sulbactam and 100% sensitive to ceftazidime, cefepime, ciprofloxacin, all aminoglycosides and carbopenems.
Conclusion: In view of the high prevalence of respiratory Pseudomonas aeruginosa, ampicillin/ sulbactam, currently the most prescribed antibiotic to treat CAP in our respiratory wards, may not be the most appropriate empiric choice. Higher generation cephalosporins with or without beta-lactamase inhibitors, ciprofloxacin or carbapenem may be the more appropriate choices. The lack of information on patients’ premorbidities such as recent hospitalization and prior antibiotic exposure, limits the interpretation of our findings and may have biased our results towards higher rates of Gram negative organisms.

Matched MeSH terms: Pseudomonas; Pseudomonas aeruginosa
Production and characterization of rhamnolipid using palm oil agricultural refinery waste

Radzuan MN, Banat IM, Winterburn J

Bioresour Technol, 2017 Feb;225:99-105.
PMID: 27888734 DOI: 10.1016/j.biortech.2016.11.052

In this research we assess the feasibility of using palm oil agricultural refinery waste as a carbon source for the production of rhamnolipid biosurfactant through fermentation. The production and characterization of rhamnolipid produced by Pseudomonas aeruginosa PAO1 grown on palm fatty acid distillate (PFAD) under batch fermentation were investigated. Results show that P. aeruginosa PAO1 can grow and produce 0.43gL(-1) of rhamnolipid using PFAD as the sole carbon source. Identification of the biosurfactant product using mass spectrometry confirmed the presence of monorhamnolipid and dirhamnolipid. The rhamnolipid produced from PFAD were able to reduce surface tension to 29mNm(-1) with a critical micelle concentration (CMC) 420mgL(-1) and emulsify kerosene and sunflower oil, with an emulsion index up to 30%. Results demonstrate that PFAD could be used as a low-cost substrate for rhamnolipid production, utilizing and transforming it into a value added biosurfactant product.

Matched MeSH terms: Pseudomonas aeruginosa/metabolism*
Modulation of cell surface hydrophobicity and attachment of bacteria to abiotic surfaces and shrimp by Malaysian herb extracts

Hui YW, Dykes GA

J Food Prot, 2012 Aug;75(8):1507-11.
PMID: 22856578 DOI: 10.4315/0362-028X.JFP-12-062

The use of simple crude water extracts of common herbs to reduce bacterial attachment may be a cost-effective way to control bacterial foodborne pathogens, particularly in developing countries. The ability of water extracts of three common Malaysian herbs (Andrographis paniculata, Eurycoma longifolia, and Garcinia atroviridis) to modulate hydrophobicity and attachment to surfaces of five food-related bacterial strains (Bacillus cereus ATCC 14576, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 10145, Salmonella Enteritidis ATCC 13076, Staphylococcus aureus ATCC 25923) were determined. The bacterial attachment to hydrocarbon assay was used to determine bacterial hydrophobicity. Staining and direct microscopic counts were used to determine attachment of bacteria to glass and stainless steel. Plating on selective media was used to determine attachment of bacteria to shrimp. All extracts were capable of either significantly ( P < 0.05) increasing or decreasing bacterial surface hydrophobicity, depending on the herb extract and bacteria combination. Bacterial attachment to all surfaces was either significantly (P < 0.05) increased or decreased, depending on the herb extract and bacteria combination. Overall, hydrophobicity did not show a significant correlation (P > 0.05) to bacterial attachment. For specific combinations of bacteria, surface material, and plant extract, significant correlations (R > 0.80) between hydrophobicity and attachment were observed. The highest of these was observed for S. aureus attachment to stainless steel and glass after treatment with the E. longifolia extract (R = 0.99, P < 0.01). The crude water herb extracts in this study were shown to have the potential to modulate specific bacterial and surface interactions and may, with further work, be useful for the simple and practical control of foodborne pathogens.

Matched MeSH terms: Pseudomonas aeruginosa/physiology
Fulltext Biosynthesis and characterization of polyhydroxyalkanoates copolymers produced by Pseudomonas putida Bet001 isolated from palm oil mill effluent

Gumel AM, Annuar MS, Heidelberg T

PLoS One, 2012;7(9):e45214.
PMID: 23028854 DOI: 10.1371/journal.pone.0045214

The biosynthesis and characterization of medium chain length poly-3-hydroxyalkanoates (mcl-PHA) produced by Pseudomonas putida Bet001 isolated from palm oil mill effluent was studied. The biosynthesis of mcl-PHA in this newly isolated microorganism follows a growth-associated trend. Mcl-PHA accumulation ranging from 49.7 to 68.9% on cell dry weight (CDW) basis were observed when fatty acids ranging from octanoic acid (C(8:0)) to oleic acid (C(18:1)) were used as sole carbon and energy source. Molecular weight of the polymer was found to be ranging from 55.7 to 77.7 kDa. Depending on the type of fatty acid used, the (1)H NMR and GCMSMS analyses of the chiral polymer showed a composition of even and odd carbon atom chain with monomer length of C4 to C14 with C8 and C10 as the principal monomers. No unsaturated monomer was detected. Thermo-chemical analyses showed the accumulated PHA to be semi-crystalline polymer with good thermal stability, having a thermal degradation temperature (T(d)) of 264.6 to 318.8 (± 0.2) (o)C, melting temperature (T(m)) of 43. (± 0.2) (o)C, glass transition temperature (T(g)) of -1.0 (± 0.2) (o)C and apparent melting enthalpy of fusion (ΔH(f)) of 100.9 (± 0.1) J g(-1).

Matched MeSH terms: Pseudomonas putida/metabolism*
Use of intestinal Pseudomonas aeruginosa in fish to detect the environmental pollutant benzo[a]pyrene

Karami A, Christianus A, Ishak Z, Shamsuddin ZH, Masoumian M, Courtenay SC

J Hazard Mater, 2012 May 15;215-216:108-14.
PMID: 22417397 DOI: 10.1016/j.jhazmat.2012.02.038

This study examined the potential of Pseudomonas aeruginosa abundance in the intestines of fish as an indicator of exposure to benzo[a]pyrene (BaP). P. aeruginosa populations were enumerated in juvenile African catfish (Clarias gariepinus) injected intramuscularly three days previous with 0, 10, 30, 40, 50 or 70mg/kg of BaP. Hepatic EROD and GST activities and biliary fluorescent aromatic compounds (FACs) 1-OH BaP, 3-OH BaP, 7,8-D BaP and BaP were quantified to investigate agreements between the new indicator and established fish biomarkers. The shape of bacterial population (logarithm of colony-forming unit) dose-response curve generally matched those of biliary FACs concentrations. Conversely, the EROD and GST dose-response curves were generally the mirror images of the bacterial population curve. Changes in intestinal P. aeruginosa population appear to be an indirect effect of BaP exposure because exposure to 0-100μg/ml BaP had no effect on P. aeruginosa populations grown on agar plates containing BaP. Using intestinal P. aeruginosa population of fish as a universal indicator of BaP pollution in aquatic environments is discussed.Conversely, the EROD and GST dose-response curves were generally the mirror images of the bacterial population curve.

Matched MeSH terms: Pseudomonas aeruginosa/isolation & purification*
A new sesquiterpenoid from the rhizomes of Homalomena sagittifolia

Wong KC, Hamid A, Eldeen IM, Asmawi MZ, Baharuddin S, Abdillahi HS, et al.

Nat Prod Res, 2012;26(9):850-8.
PMID: 21999629 DOI: 10.1080/14786419.2010.551770

A new sesquiterpenoid, 1α,4β,7β-eudesmanetriol (1), was isolated together with the known compounds 1β,4β,7β-eudesmanetriol (2) and oplopanone (3) from the rhizomes of Homalomena sagittifolia. The structures of these compounds were determined by extensive spectral analyses. The compounds 1 and 2 inhibited growth of Pseudomonas stutzeri with a MIC value of 117 µM when evaluated for antibacterial activity using the minimum concentration assay. Both these compounds showed remarkable activities against acetylcholinesterase enzyme with IC(50) values ranging between 25 and 26 µM. The isolation of these sesquiterpenoids and their biological activities observed in this study support the reported traditional uses of H. sagittifolia for the treatment of microbial related diseases and central nervous system disorders.

Matched MeSH terms: Pseudomonas stutzeri/drug effects
Antimicrobial and in vitro wound healing properties of novel clay based bionanocomposite films

Mishra RK, Ramasamy K, Lim SM, Ismail MF, Majeed AB

J Mater Sci Mater Med, 2014 Aug;25(8):1925-39.
PMID: 24831081 DOI: 10.1007/s10856-014-5228-y

The present study investigates the development of methyl cellulose (MC)-sodium alginate (SA)-montmorillonite (MMT) clay based bionanocomposite films with interesting wound healing properties. The differential scanning calorimetry analysis of the composite films revealed presence of single glass transition temperature (Tg) confirming the miscible nature of the ternary blended films. The increase in MMT ratio in the composite films reduced the mobility of biopolymer chains (MC/SA) which increased the Tg of the film. Thermogravimetric analysis showed that dispersion of clay (MMT) at nano level significantly delayed the weight loss that correlated with higher thermal stability of the composite films. It was observed that the developed films were able to exhibit antimicrobial activity against four typical pathogenic bacteria found in the presence of wound. The developed films were able to significantly inhibit (10 mg/ml) the growth of Enterococcus faecium and Pseudomonas aeruginosa. In vitro scratch assay indicated potential wound closure activities of MC-2-4 bionanocomposite films at their respective highest subtoxic doses. In conclusion, these ternary bionanocomposite films were found to be promising systems for wound healing applications.

Matched MeSH terms: Pseudomonas aeruginosa/drug effects
Fever/clinical signs and association with neutropenia in solid cancer patients--bacterial infection as the main cause

Rasool Hassan BA, Yusoff ZB, Othman SB

Asian Pac J Cancer Prev, 2010;11(5):1273-7.
PMID: 21198276

INTRODUCTION: Neutropenia remains one of the serious side effects of chemotherapeutics drugs making cancer patients face serious risk of infections. Fever and clinical signs are considered as important indicators. The objectives of this study were to assess fever and clinical signs with neutropenia onset and/ or severity in solid cancer cases, using culture tests to determine the type of bacteria predominating, whether gram positive or gram negative.
METHODS: This observational retrospective study was conducted on files of all solid cancer patients who admitted to a general hospital between 1 January 2003 and 31 December 2006. All data were categorical and analyzed for association with neutropenia.
RESULTS: 117 neutropenic patients were studied, 83 (70.9%) of them suffering from fever ranging between 38.5-39 °C, with hypotension (53; 27.3%) and headache 51 (26.3%) as the most common clinical signs. Only 34 (29.1%) neutropenic patients underwent culture testing and only 14 (41.2%) showed positive growth, gram negative types predominating (9; 64.2%), mainly Escherichia coli (5; 35.7%), with gram positive only in 5 (35.7%). Significant associations were found for fever and clinical signs with neutropenia severity (P<0.05), but not neutropenia onset (P>0.05). Logistic regression results showed strong significant association between presence of fever (P=0.02, OR=1.3) (95% confidence interval (CI)) hypotension and headache (P=0.001, OR=1.148) (95% CI) with neutropenia severity.
CONCLUSION: Fever and clinical signs specifically headache and hypotension are symptoms associated with severe neutropenia in solid cancer patients. Both may primarily result from bacterial infection, particularly gram negative forms.

Matched MeSH terms: Pseudomonas aeruginosa/isolation & purification
Comparison of four antibiotics with indigenous marine Bacillus spp. in controlling pathogenic bacteria from shrimp and Artemia

Banerjee S, Devaraja TN, Shariff M, Yusoff FM

J Fish Dis, 2007 Jul;30(7):383-9.
PMID: 17584435

Use of antibiotics for the control of bacterial diseases in shrimp culture has caused several adverse impacts to the industry. This has resulted in the search for alternative environment friendly approaches to overcome bacterial infections. This study was conducted to investigate the use of beneficial bacteria as an alternative to antibiotics. Ten pathogenic bacterial species isolated from shrimp, Penaeus monodon, and Artemia cysts were tested for susceptibility to indigenous marine Bacillus subtilis AB65, Bacillus pumilus AB58, Bacillus licheniformis AB69 and compared with oxytetracycline, chloramphenicol, gentamicin and bacitracin, which are common antibiotics used in Asian aquaculture. The Bacillus spp. were isolated from the local marine environment for bioremediation use in shrimp hatcheries and were proven to reduce total ammonium nitrogen. The pathogenic bacterial isolates were 90% susceptible to B. subtilis AB65, 70% susceptible to B. pumilus AB58 and B. licheniformis AB69 and 100% susceptible to oxytetracycline, chloramphenicol and gentamicin but only 40% to bacitracin. Two representative isolates of the vibrio group, Vibrio alginolyticus VaM11 and Vibrio parahaemolyticus VpM1, when tested for competitive exclusion by a common broth method using the marine Bacillus spp., showed decreased viable counts from 10(8) to 10(2) cfu mL(-1). The results suggest that the action of the marine bacteria appears to be significant in protecting the host shrimp against pathogenic bacteria. In addition to the alternative use of antibiotics, the selected marine bacteria had additional bioremediation properties of reducing ammonia.

Matched MeSH terms: Pseudomonas/drug effects
Unrecognised infection in a cystic fibrosis patient

Asiah K, Hanifah YA, Norzila MZ, Hasniah L, Rusanida A

J Paediatr Child Health, 2006 Apr;42(4):217-8.
PMID: 16630326

We report a 17-year-old Malay boy with cystic fibrosis who over a 14-month period experienced worsening respiratory symptoms and deteriorating lung function. Burkholderia pseudomallei was eventually isolated from his sputum. He improved clinically following treatment for meliodosis and his lung function returned to normal.

Matched MeSH terms: Pseudomonas/isolation & purification
Exhaustive study of the novel hyper alkalophil, thermostable, and chelator resistant metalloprotease

Samie N, Haerian B, Muniandy S, Green D, Ashouri M

Appl Biochem Biotechnol, 2015 Apr;175(7):3397-417.
PMID: 25820296 DOI: 10.1007/s12010-015-1513-6

Our newly discovered metalloprotease, designated as ALP NS12 was selected using gelatin agar plates with incubation at 100 °C. Subcloning of the fragments in to pUC118 to make E. coli HB101 (pPEMP01NS) with following two-step chromatography using diethylaminoethyl sepharose (DEAE-sepharose) and Sephadex G-100 columns to purify 97-kDa expressed enzyme was performed. Although activity of immobilized ALP NS12 on glass surface was established at temperatures between 70 and 120 °C and pH ranges 4.0-13.0, the optimum temperature and pH were achieved at 100 °C and 11.0, respectively. Enhancement of enzyme activity was obtained in the presence of 5 mM MnCl2 (91 %), CaCl2 (357 %), FeCl2 (175 %), MgCl2 (94 %), ZnCl2 (412 %), NiCl (86 %), NaCl (239 %), and Na-sulfate (81 %) while inhibition was observed with EDTA (5 mM), PMSF (3 mM), urea (8 M), and SDS (1 %) at 65, 37, 33, and 42 %, respectively. Consequently, the enzyme was well analyzed using crystallography and protein modeling. ALP NS12 can be applied in industrial processes at extreme temperatures and under highly basic conditions, chelators, and detergents.

Matched MeSH terms: Pseudomonas aeruginosa/enzymology*
Anti-infective potential of caffeic acid and epicatechin 3-gallate isolated from methanol extract of Euphorbia hirta (L.) against Pseudomonas aeruginosa

Perumal S, Mahmud R, Ramanathan S

Nat Prod Res, 2015;29(18):1766-9.
PMID: 25571920 DOI: 10.1080/14786419.2014.999242

Euphorbia hirta (L.) plant is traditionally used in Malaysia for the treatment of gastrointestinal, bronchial and respiratory ailments caused by nosocomial infectious agents. Bioactivity-guided fractionation of the methanol extract of the aerial parts of E. hirta and analysis using high-performance liquid chromatography have led to the isolation of two antibacterial compounds. These compounds were identified as caffeic acid (CA) and (-)-epicatechin 3-gallate (ECG) based on spectroscopic analyses and comparison with previously published data. Using broth microdilution method, both ECG and CA had demonstrated significant minimum inhibitory concentration of 15.6 and 31.3 μg/mL respectively, against Pseudomonas aeruginosa. Time-kill assessment of ECG and CA displayed bactericidal effect on P. aeruginosa cells.

Matched MeSH terms: Pseudomonas aeruginosa/drug effects*
Fulltext Anti-quorum sensing activity of the traditional Chinese herb, Phyllanthus amarus

Priya K, Yin WF, Chan KG

Sensors (Basel), 2013;13(11):14558-69.
PMID: 24169540 DOI: 10.3390/s131114558

The discovery of quorum sensing in Proteobacteria and its function in regulating virulence determinants makes it an attractive alternative towards attenuation of bacterial pathogens. In this study, crude extracts of Phyllanthus amarus Schumach. & Thonn, a traditional Chinese herb, were screened for their anti-quorum sensing properties through a series of bioassays. Only the methanolic extract of P. amarus exhibited anti-quorum sensing activity, whereby it interrupted the ability of Chromobacterium violaceum CVO26 to response towards exogenously supplied N-hexanoylhomoserine lactone and the extract reduced bioluminescence in E. coli [pSB401] and E. coli [pSB1075]. In addition to this, methanolic extract of P. amarus significantly inhibited selected quorum sensing-regulated virulence determinants of Pseudomonas aeruginosa PA01. Increasing concentrations of the methanolic extracts of P. amarus reduced swarming motility, pyocyanin production and P. aeruginosa PA01 lecA::lux expression. Our data suggest that P. amarus could be useful for attenuating pathogens and hence, more local traditional herbs should be screened for its anti-quorum sensing properties as their active compounds may serve as promising anti-pathogenic drugs.

Matched MeSH terms: Pseudomonas aeruginosa/drug effects
Cold plasma inactivation of chronic wound bacteria

Mohd Nasir N, Lee BK, Yap SS, Thong KL, Yap SL

Arch Biochem Biophys, 2016 09 01;605:76-85.
PMID: 27046340 DOI: 10.1016/j.abb.2016.03.033

Cold plasma is partly ionized non-thermal plasma generated at atmospheric pressure. It has been recognized as an alternative approach in medicine for sterilization of wounds, promotion of wound healing, topical treatment of skin diseases with microbial involvement and treatment of cancer. Cold plasma used in wound therapy inhibits microbes in chronic wound due to its antiseptic effects, while promoting healing by stimulation of cell proliferation and migration of wound relating skin cells. In this study, two types of plasma systems are employed to generate cold plasma: a parallel plate dielectric barrier discharge and a capillary-guided corona discharge. Parameters such as applied voltage, discharge frequency, treatment time and the flow of the carrier gas influence the cold plasma chemistry and therefore change the composition and concentration of plasma species that react with the target sample. Chronic wound that fails to heal often infected by multidrug resistant organisms makes them recalcitrant to healing. Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (Pseudomonas aeruginosa) are two common bacteria in infected and clinically non-infected wounds. The efficacies of the cold plasma generated by the two designs on the inactivation of three different isolates of MRSA and four isolates of P. aeruginosa are reported here.

Matched MeSH terms: Pseudomonas aeruginosa*
A PROspective study on the Usage patterns of Doripenem in the Asia-Pacific region (PROUD study)

Mustafa M, Chan WM, Lee C, Harijanto E, Loo CM, Van Kinh N, et al.

Int J Antimicrob Agents, 2014 Apr;43(4):353-60.
PMID: 24636429 DOI: 10.1016/j.ijantimicag.2014.01.017

Doripenem is approved in the Asia-Pacific (APAC) region for treating nosocomial pneumonia (NP) including ventilator-associated pneumonia (VAP), complicated intra-abdominal infections (cIAIs) and complicated urinary tract infections (cUTIs). Clinical usage of doripenem (500mg intravenously, infused over 1h or 4h every 8h for 5-14 days) in APAC was evaluated in a prospective, open-label, non-comparative, multicentre study of inpatients (≥18 years) with NP, VAP, cIAI or cUTI. A total of 216 [intention-to-treat (ITT)] patients received doripenem: 53 NP (24.5%); 77 VAP (35.6%); 67 cIAI (31.0%); and 19 cUTI (8.8%). Doripenem MIC90 values for Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae were 32, 32, 0.094 and 0.64μg/mL, respectively. Doripenem was used most commonly as monotherapy (86.6%) and as second-line therapy (62.0%). The clinical cure rate in clinically evaluable patients was 86.7% at the end of therapy (EOT) and 87.1% at test of cure (TOC) (7-14 days after EOT). In the ITT population, overall clinical cure rates were 66.2% at EOT and 56.5% at TOC. The median duration of hospital stay, intensive care unit (ICU) stay and mechanical ventilation was 20, 12 and 10 days, respectively. Of 146 discharged patients, 7 were re-admitted within 28 days of EOT; 1 VAP patient was re-admitted to the ICU. The all-cause mortality rate was 22.7% (49/216). The most common treatment-related adverse events were diarrhoea (1.4%) and vomiting (1.4%). Doripenem is a viable option for treating APAC patients with NP, VAP, cIAI or cUTI. [ClinicalTrials.gov: NCT 00986102].

Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/pathogenicity; Pseudomonas Infections/drug therapy

Filters

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

External Links