MyMedR

Displaying all 6 publications

Abstract:

Sort:

Fulltext Mechanical characteristics of antibacterial epoxy resin adhesive wood biocomposites against skin disease

Chen ZX, Zhang ZF, Aqma WS

Saudi J Biol Sci, 2016 Jan;23(1):S126-36.
PMID: 26858557 DOI: 10.1016/j.sjbs.2015.09.026

Moldy wood can cause some skin disease. However epoxy resin adhesive (EP) can inhibit mold growth. Therefore, antibacterial EP/wood biocomposites were reinforced and analyzed by the nonlinear finite element. Results show that glass fiber cloth and aluminum foil have the obvious reinforced effect under flat pressure, but this was not the case under side pressure. And when the assemble pattern was presented in 5A way, the strengthening effect was better. The nonlinear finite element showed that the aluminum foil and glass fiber cloth have the obvious reinforced effect. The mutual influence and effect of span, thickness and length on the ultimate bearing capacity of specimen were studied. And the simulation results agreed with the test. It provided a theoretical basis on the preparation of antibacterial EP/wood biocomposites against skin disease.
Fulltext Optimisation and production of alpha amylase from thermophilic Bacillus spp. and its application in food waste biodegradation

Msarah MJ, Ibrahim I, Hamid AA, Aqma WS

Heliyon, 2020 Jun;6(6):e04183.
PMID: 32566789 DOI: 10.1016/j.heliyon.2020.e04183

This study employed Bacillus spp. with α-amylase production isolated from Malaysian hot spring for domestic kitchen food waste treatment contained grains, vegetables, chicken and tuna that mimic the food waste discharge from domestic kitchens in Malaysian household. Results showed that Bacillus licheniformis HULUB1 and Bacillus subtilis SUNGB2 possess excellent amylolytic properties. Highest α-amylase activity was obtained when both isolates were cultivated at pH 6.0 and 65 °C with concentrations of 18.15 U/mL for HULUB1 and 22.14 U/mL for SUNGB2. Stability of α-amylase with significant levels of enzyme activity were recorded at 55-85 °C and pH 5.0-9.0. The extracted mixed α-amylase of HULUB1 and SUNGB2 showed greatest reduction were achieved at day 12 with 45% ± 0.03 solid content at 65 °C. While the mixed culture of HULUB1 and SUNGB2 displayed an enhanced effect on the food waste contents reduction with 43% ± 0.02 solid content at 45 °C after day 12. The findings showed that the combination of the two Bacillus spp. isolates possessed degradation of food wastes at faster rate than α-amylase. It was also pointed out that the standard food waste (SFW) and the treatment process assimilated for this study was suitable for the growth of Bacillus spp.
Antimicrobial, antiadhesive, and antibiofilm actions of rhamnolipids on ESKAPE pathogens

Firdose A, Chong NHH, Ramli R, Aqma WS

Lett Appl Microbiol, 2023 Feb 16;76(2).
PMID: 36702549 DOI: 10.1093/lambio/ovad013

The aim of this study was to test the antimicrobial, antiadhesive, and antibiofilm activities of a rhamnolipid extracted from Pseudomonas aeruginosa UKMP14T previously isolated from oil-contaminated soil in Malaysia against ESKAPE (i.e. multidrug resistant) pathogens. Zones of inhibition in an agar well diffusion assay were observed at 50 µg mL-1 concentrations of rhamnolipid for all the ESKAPE bacteria. The MIC and MBC values ranged between 7.81-62.5 µg mL-1 and 31.25-1000 µg mL-1, respectively. Percent killing was recorded to be >90% except for Klebsiella pneumoniae (86.84%). Furthermore, antiadhesion studies showed that there was 76% hindrance in attachment of Enterococcus faecium and 91% in Acinetobacter baumannii at 4 × MIC. The highest inhibition in adhesion was found at 4 × MIC, which was 46% for Ac. baumannii and 62% for Enterococcus faecium. Finally, the antibiofilm capability of the rhamnolipid was determined, which ranged between 25%-76% in Ac. baumannii and 35%-88% in Enterococcus faecium. To the best of our knowledge, this is the first study to include research on antimicrobial, antiadhesive and antibiofilm activities of rhamnolipid from the local isolate Ps. aeruginosa UKMP14T against ESKAPE bacteria. Obtained results suggest that this rhamnolipid can be exploited commercially for the production of novel antibiotics.
Fulltext Transcriptomic Response in Pseudomonas aeruginosa towards Treatment with a Kaempferol Isolated from Melastoma malabathricum Linn Leaves

Alwash MS, Aqma WS, Ahmad WY, Ibrahim N

Int J Microbiol, 2020;2020:6915483.
PMID: 32089696 DOI: 10.1155/2020/6915483

Pseudomonas aeruginosa is one of the main causes of nosocomial infections and is frequently associated with opportunistic infections among hospitalized patients. Kaempferol-3-O-(2',6'-di-O-trans-p-coumaroyl)-β-D glucopyranoside (KF) is an antipseudomonal compound isolated from the leaves of the native medicinal plant Melastoma malabathricum. Herein, an RNA-seq transcriptomic approach was employed to study the effect of KF treatment on P. aeruginosa and to elucidate the molecular mechanisms underlying the response to KF at two time points (6 h and 24 h incubation). Quantitative real-time PCR (qRT-PCR) was performed for four genes (uvrD, sodM, fumC1, and rpsL) to assess the reliability of the RNA-seq results. The RNA-seq transcriptomic analysis revealed that KF increases the expression of genes involved in the electron transport chain (NADH-I), resulting in the induction of ATP synthesis. Furthermore, KF also increased the expression of genes associated with ATP-binding cassette transporters, flagella, type III secretion system proteins, and DNA replication and repair, which may further influence nutrient uptake, motility, and growth. The results also revealed that KF decreased the expression of a broad range of virulence factors associated with LPS biosynthesis, iron homeostasis, cytotoxic pigment pyocyanin production, and motility and adhesion that are representative of an acute P. aeruginosa infection profile. In addition, P. aeruginosa pathways for amino acid synthesis and membrane lipid composition were modified to adapt to KF treatment. Overall, the present research provides a detailed view of P. aeruginosa adaptation and behaviour in response to KF and highlights the possible therapeutic approach of using plants to combat P. aeruginosa infections.
Effects of Malaysian thermal spring water as adjunct therapy for mild to moderate acne vulgaris - a prospective, randomised, controlled, split face study

Faisal UA, Jamil A, Jaafar H, Aqma WS, Arumugam M

Med J Malaysia, 2024 Mar;79(2):157-164.
PMID: 38553920

INTRODUCTION: Acne is a common skin disease with a high psychosocial burden, affecting mostly adolescents and youth worldwide. Management of acne is often challenged by cutaneous side effects that leads to therapeutic intolerance, poor compliance and impaired efficacy.
MATERIALS AND METHODS: This was a single-centre, evaluatorblinded, split-face, randomised study investigating the effects of thermal spring water (TSW) in improving efficacy and tolerability of standard acne therapy. Total of 31 participants with mild-to-moderate acne were recruited and subjected to TSW spray to one side of the face 4 times daily for 6 weeks in addition to standard therapy. The other side received standard therapy only.
RESULTS: Six (19.4%) males and 25 (80.6%) female with mean age 25.1±6.13 participated, 15 (48.4%) had mild acne while 16 (51.6%) had moderate acne. Seven (22.6%) were on oral antibiotics, 25 (80.6%) used adapalene, 6 (19.4%) tretinoin and 21 (67.7%) benzoyl peroxide. Skin hydration improved and better on spring water treated side with mean difference12.41±30.31, p = 0.04 at the forehead, 39.52±65.14, p < 0.01 at the cheek and 42.172±71.71, p < 0.01 at the jaw at week 6. Participants also report significant reduction in dryness at the treated side at week 6, mean difference 0.93±0.10, p < 0.001. TEWL, sebum and pH were comparable on both sides with no significant differences. Tolerability towards standard therapy improved as early week 2 with reduction of stinging following application of topical therapy (mean difference 0.62±1.43, p = 0.03), increase in skin feeling good (-1.79±1.70, p < 0.001) and skin suppleness (0.62±1.43, p < 0.001). These improvements were significantly maintained till week 6. Cardiff acne disability index significantly improved at week 6 (p<0.001) despite no significant changes in Comprehensive Acne Severity Scale score before and after treatment.
CONCLUSION: TSW may have a role as an adjunct to standard acne therapy by improving hydration, acne disability index and tolerability towards standard topical treatment.
Antibacterial mechanism of Pseudomonas aeruginosa UKMP14T rhamnolipids against multidrug resistant Acinetobacter baumannii

Firdose A, Maeda T, Sukri MAM, Yasin NHM, Sabturani N, Aqma WS

Microb Pathog, 2024 Aug;193:106743.
PMID: 38879138 DOI: 10.1016/j.micpath.2024.106743

Rhamnolipids, a major category of glycolipid biosurfactant, have recently gained enormous attention in medical field because of their relevance as effective antibacterial agents against a wide variety of pathogenic bacteria. Our previous studies have shown that rhamnolipids from an environmental isolate of Pseudomonas aeruginosa UKMP14T possess antibacterial, anti-adhesive and anti-biofilm activity against multidrug-resistant ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter sp.) pathogens. However, the mechanism of their antibacterial action remains unclear. Thus, this study aimed to elucidate the mechanism of the antibacterial action of P. aeruginosa UKMP14T rhamnolipids by studying the changes in cells of one of the ESKAPE pathogens, Acinetobacter baumannii, which is the most difficult strain to kill. Results revealed that rhamnolipid treatment rendered A. baumannii cells more hydrophobic as evaluated through contact angle measurements. It also induced the release of cellular proteins measuring 510 μg/mL at a rhamnolipid concentration of 1000 μg/mL. In addition, rhamnolipids were found to be bactericidal in their action as they could permeate the inner membranes, leading to a leak-out of nucleotides. More than 50 % of the cells were found to be killed upon 1000 μg/mL rhamnolipid treatment as observed through fluorescence microscopy. Other cellular changes such as irregular shape and size, membrane perturbations, clumping, shrinkage and physical damage were clearly visible in SEM, FESEM and laser micrographs. Furthermore, rhamnolipid treatment inhibited the levels of acyl-homoserine lactones (AHLs) in A. baumannii, which are vital for their biofilm formation and virulence. The obtained results indicate that P. aeruginosa UKMP14T rhamnolipids target outer and inner bacterial membranes through permeation, including physical damage to the cells, leading to cell leakage. Furthermore, AHL inhibition appears to be the mechanism behind their anti-biofilm action. All these observations can be correlated to rhamnolipids' antibacterial effect against A. baumannii.