Displaying publications 1 - 20 of 357 in total

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  1. A Al-Kafaween M, Mohd Hilmi AB, A Nagi Al-Jamal H, A Elsahoryi N, Jaffar N, Khairi Zahri M
    Iran J Biotechnol, 2020 Oct;18(4):e2542.
    PMID: 34056021 DOI: 10.30498/IJB.2020.2542
    Background: Honey has been known as a traditional medicine for centuries with its antibacterial properties. It is considered one of the most enduring substances used in wound management.

    Objectives: This study aimed to: (i) evaluate the effects of Malaysian Trigona honey on bacterial structure and (ii) assess the anti-virulence potential of this honey by examining their impacts on the expression of selected genes (involved in stress survival and biofilm formation) in a test organism.

    Materials and Methods: Trigona honey's impacts on the bacterial structure (cell morphology) and the expression profiles of select Pseudomonas Aeruginosa and Streptococcus Pyogenes genes were examined using scanning electron microscopy (SEM) and real-time PCR (RT-qPCR) analysis, respectively.

    Results: SEM showed that the decreased cell density deformed, disrupted, and damaged cells for both bacteria. RT-qPCR showed that the expression of fleN, fleQ, and fleR genes of P.aeruginosa were decreased, 4.26-fold, 3.80-fold and 2.66- fold respectively. In addition, scpA, ftsY, and emm13 of S.pyogenes were decreased, 2.87-fold, 3.24-fold, and 4.65-fold respectively.

    Conclusion: Our results indicate that Trigona honey may be an effective inhibitor and virulence modulator of P. aeruginosa and S. pyogenes via multiple molecular targets. This deduction needs to be investigated in vivo.

    Matched MeSH terms: Pseudomonas aeruginosa
  2. Abbas SZ, Yong YC, Ali Khan M, Siddiqui MR, Hakami AAH, Alshareef SA, et al.
    Polymers (Basel), 2020 Jul 13;12(7).
    PMID: 32668712 DOI: 10.3390/polym12071545
    Four strains of bioflocculant-producing bacteria were isolated from a palm oil mill effluent (POME). The four bacterial strains were identified as Pseudomonas alcaliphila (B1), Pseudomonas oleovorans (B2), Pseudomonas chengduensis (B3), and Bacillus nitratireducens (B4) by molecular identification. Among the four bacterial strains, Bacillus nitratireducens (B4) achieved the highest flocculating activity (49.15%) towards kaolin clay suspension after eight hours of cultivation time and was selected for further studies. The optimum conditions for Eriochrome Black T (EBT) flocculation regarding initial pH, type of cation, and B4 dosage were determined to be pH 2, Ca2⁺ cations, and a dosage of 250 mL/L of nutrient broth containing B4. Under these conditions, above 90% of EBT dye removal was attained. Fourier transform infrared spectroscopic (FT-IR) analysis of the bioflocculant revealed the presence of hydroxyl, alkyl, carboxyl, and amino groups. This bioflocculant was demonstrated to possess a good flocculating activity, being a promissory, low-cost, harmless, and environmentally friendly alternative for the treatment of effluents contaminated with dyes.
    Matched MeSH terms: Pseudomonas; Pseudomonas oleovorans
  3. Abdallah EM, Modwi A, Al-Mijalli SH, Mohammed AE, Idriss H, Omar AS, et al.
    Molecules, 2022 Nov 28;27(23).
    PMID: 36500402 DOI: 10.3390/molecules27238309
    In this work, ZnO, CrZnO, RuZnO, and BaZnO nanomaterials were synthesized and characterized in order to study their antibacterial activity. The agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays were used to determine the antibacterial activity of the fabricated nanomaterials against Staphylococcus aureus ATCC 29213, Escherichia coli ATCC35218, Klebsiella pneumoniae ATCC 7000603, and Pseudomonas aeruginosa ATCC 278533. The well-diffusion test revealed significant antibacterial activity against all investigated bacteria when compared to vancomycin at a concentration of 1 mg/mL. The most susceptible bacteria to BaZnO, RuZnO, and CrZnO were Staphylococcus aureus (15.5 ± 0.5 mm), Pseudomonas aeruginosa (19.2 ± 0.5 mm), and Pseudomonas aeruginosa (19.7 ± 0.5), respectively. The MIC values indicated that they were in the range of 0.02 to 0.2 mg/mL. The MBC values showed that the tested bacteria's growth could be inhibited at concentrations ranging from 0.2 to 2.0 mg/mL. According to the MBC/MIC ratio, BaZnO, RuZnO, and CrZnO exhibit bacteriostatic effects and may target bacterial protein synthesis based on the results of the tolerance test. This study shows the efficacy of the above-mentioned nanoparticles on bacterial growth. Further biotechnological and toxicological studies on the nanoparticles fabricated here are recommended to benefit from these findings.
    Matched MeSH terms: Pseudomonas aeruginosa
  4. Abdul-Aziz MH, Abd Rahman AN, Mat-Nor MB, Sulaiman H, Wallis SC, Lipman J, et al.
    Antimicrob Agents Chemother, 2016 01;60(1):206-14.
    PMID: 26482304 DOI: 10.1128/AAC.01543-15
    Doripenem has been recently introduced in Malaysia and is used for severe infections in the intensive care unit. However, limited data currently exist to guide optimal dosing in this scenario. We aimed to describe the population pharmacokinetics of doripenem in Malaysian critically ill patients with sepsis and use Monte Carlo dosing simulations to develop clinically relevant dosing guidelines for these patients. In this pharmacokinetic study, 12 critically ill adult patients with sepsis receiving 500 mg of doripenem every 8 h as a 1-hour infusion were enrolled. Serial blood samples were collected on 2 different days, and population pharmacokinetic analysis was performed using a nonlinear mixed-effects modeling approach. A two-compartment linear model with between-subject and between-occasion variability on clearance was adequate in describing the data. The typical volume of distribution and clearance of doripenem in this cohort were 0.47 liters/kg and 0.14 liters/kg/h, respectively. Doripenem clearance was significantly influenced by patients' creatinine clearance (CL(CR)), such that a 30-ml/min increase in the estimated CL(CR) would increase doripenem CL by 52%. Monte Carlo dosing simulations suggested that, for pathogens with a MIC of 8 mg/liter, a dose of 1,000 mg every 8 h as a 4-h infusion is optimal for patients with a CL(CR) of 30 to 100 ml/min, while a dose of 2,000 mg every 8 h as a 4-h infusion is best for patients manifesting a CL(CR) of >100 ml/min. Findings from this study suggest that, for doripenem usage in Malaysian critically ill patients, an alternative dosing approach may be meritorious, particularly when multidrug resistance pathogens are involved.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/growth & development; Pseudomonas aeruginosa/pathogenicity
  5. Abjani F, Khan NA, Jung SY, Siddiqui R
    Exp Parasitol, 2017 Dec;183:187-193.
    PMID: 28919333 DOI: 10.1016/j.exppara.2017.09.007
    The aim of this study was (i) to assess the antimicrobial effects of contact lens disinfecting solutions marketed in Malaysia against common bacterial eye pathogens and as well as eye parasite, Acanthamoeba castellanii, and (ii) to determine whether targeting cyst wall would improve the efficacy of contact lens disinfectants. Using ISO 14729 Stand-Alone Test for disinfecting solutions, bactericidal and amoebicidal assays of six different contact lens solutions including Oxysept®, AO SEPT PLUS, OPTI-FREE® pure moist®, Renu® fresh™, FreshKon® CLEAR and COMPLETE RevitaLens™ were performed using Manufacturers Minimum recommended disinfection time (MRDT). The efficacy of contact lens solutions was determined against keratitis-causing microbes, namely: Pseudomonas aeruginosa, Methicillin-resistant Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, and Acanthamoeba castellanii. In addition, using chlorhexidine as an antiamoebic compound and cellulase enzyme to disrupt cyst wall structure, we determined whether combination of both agents can enhance efficacy of marketed contact lens disinfectants against A. castellanii trophozoites and cysts, in vitro. The results revealed that all contact lens disinfectants tested showed potent bactericidal effects exhibiting 100% kill against all bacterial species tested. In contrast, none of the contact lens disinfectants had potent effects against Acanthamoeba cysts viability. When tested against trophozoites, two disinfectants, Oxysept Multipurpose and AO-sept Multipurpose showed partial amoebicidal effects. Using chlorhexidine as an antiamoebic compound and cellulase enzyme to disrupt cyst wall structure, the findings revealed that combination of both agents in contact lens disinfectants abolished viability of A. castellanii cysts and trophozoites. Given the inefficacy of contact lens disinfectants tested in this study, these findings present a significant concern to public health. These findings revealed that targeting cyst wall by using cyst wall degrading molecules in contact lens disinfecting solutions will enhance their efficacy against this devastating eye infection.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects
  6. Adam Zafdri Md Zali, Rashidah Iberahim
    MyJurnal
    Pseudomonas aeruginosa and Staphylococcus aureus are types of bacteria known to cause bacterial keratitis. Pseudomonas aeruginosa causes bacterial keratitis by adhering to the surface of the contact lenses, when the P. aeruginosa are in contact with the eye, resulting in infectious keratitis. As for Staphylococcus aureus, when there is a predisposing factor such as wearing expired or extended use of contact lenses (contact lenses that can be used continually for up to one week even while sleeping) weaken the individual defences and leads to the development of bacterial keratitis. Both bacteria are capable to infect eye cornea and lead to bacterial keratitis through contact lenses wearer. The findings of this study provide information on the importance of routine practices in handling contact lenses to help reduce the incidence of bacterial keratitis caused by wear contact lenses in an individual. The side effect of wearing contact lenses such as redness of the eye and keratitis due to the infection by pathogenic bacteria which comes from the behavior and low hygiene level management of individual had led the study to create awareness to contact lenses wearer. In this study, 25 soft and hard contact lenses with purposed for colored or toric contact lenses were obtained among UiTM Negeri Sembilan students. The users required to answer the questionnaire form regarding the type, behavior, and routine practices of their contact lenses. Pathogenic bacteria were isolated using the cotton swab technique and cultured on nutrient broth. The streak technique was used to cultured bacteria from broth to nutrient agar, blood agar, and MacConkey agar. Later, the identification of bacteria was carried out using biochemical tests and microscopic observation. From the laboratory results, 84% of the tested contact lenses contained pathogenic bacteria on their surface. These findings concluded that the presences of pathogenic microorganisms on the contact lenses used closely related to the behavior in handling and hygenic practices level by the contact lenses users.
    Matched MeSH terms: Pseudomonas aeruginosa
  7. Agamuthu P, Faizura PN
    Waste Manag Res, 2005 Apr;23(2):95-100.
    PMID: 15864950
    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.
    Matched MeSH terms: Pseudomonas aeruginosa/metabolism*
  8. Agustian J, Kamaruddin AH, Aboul-Enein HY
    Chirality, 2017 Jul;29(7):376-385.
    PMID: 28439969 DOI: 10.1002/chir.22702
    As the (R)-enantiomer of racemic atenolol has no β-blocking activity and no lack of side effects, switching from the racemate to the (S)-atenolol is more favorable. Transesterification of racemic atenolol using free enzymes investigated as a resource to resolve the racemate via this method is limited. Screenings of enzyme, medium, and acetyl donor were conducted first to give Pseudomonas fluorescens lipase, tetrahydrofuran, and vinyl acetate. A statistical design of the experiment was then developed using Central Composite Design on some operational factors, which resulted in the conversions of 11.70-61.91% and substrate enantiomeric excess (ee) of 7.31-100%. The quadratic models are acceptable with R2 of 95.13% (conversion) and 89.63% (ee). The predicted values match the observed values reasonably well. Temperature, agitation speed, and substrate molar ratio factor have low effects on conversion and ee, but enzyme loading affects the responses highly. The interaction of temperature-agitation speed and temperature-substrate molar ratio show significant effects on conversion, while temperature-agitation speed, temperature-substrate molar ratio, and agitation speed-substrate molar ratio affect ee highly. Optimum conditions for the use of Pseudomonas fluorescens lipase, tetrahydrofuran, and vinyl acetate were found at 45°C, 175 rpm, 2000 U, and 1:3.6 substrate molar ratio.
    Matched MeSH terms: Pseudomonas fluorescens/enzymology*
  9. Ahmad SA, Shukor MY, Shamaan NA, Mac Cormack WP, Syed MA
    Biomed Res Int, 2013;2013:871941.
    PMID: 24381945 DOI: 10.1155/2013/871941
    A molybdenum-reducing bacterium from Antarctica has been isolated. The bacterium converts sodium molybdate or Mo⁶⁺ to molybdenum blue (Mo-blue). Electron donors such as glucose, sucrose, fructose, and lactose supported molybdate reduction. Ammonium sulphate was the best nitrogen source for molybdate reduction. Optimal conditions for molybdate reduction were between 30 and 50 mM molybdate, between 15 and 20°C, and initial pH between 6.5 and 7.5. The Mo-blue produced had a unique absorption spectrum with a peak maximum at 865 nm and a shoulder at 710 nm. Respiratory inhibitors such as antimycin A, sodium azide, potassium cyanide, and rotenone failed to inhibit the reducing activity. The Mo-reducing enzyme was partially purified using ion exchange and gel filtration chromatography. The partially purified enzyme showed optimal pH and temperature for activity at 6.0 and 20°C, respectively. Metal ions such as cadmium, chromium, copper, silver, lead, and mercury caused more than 95% inhibition of the molybdenum-reducing activity at 0.1 mM. The isolate was tentatively identified as Pseudomonas sp. strain DRY1 based on partial 16s rDNA molecular phylogenetic assessment and the Biolog microbial identification system. The characteristics of this strain would make it very useful in bioremediation works in the polar and temperate countries.
    Matched MeSH terms: Pseudomonas/genetics; Pseudomonas/isolation & purification*; Pseudomonas/metabolism*
  10. Ahmad Zorin Sahalan, Nazahiyah Sulaiman, Nihayah Mohammed, Kaswandi Md. Ambia, Hing, Hian Lian
    MyJurnal
    Two species of plants, Andrographis paniculata and Euphorbia hirta were screened for antibacterial activities against three Gram positives and Gram negatives. The leaves from both plants were extracted by methanol extraction. The antibacterial activity was detected with spread plate well diffusion method. The extracts of both plants demonstrated inhibitory activity against both Gram negative and positives bacteria. Staphylococcus aureus, Bacillus subtilis, Streptococcus epidemidis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. The minimum inhibitory concentration (MIC determination using micro dilution method showed that the A/tic of A. paniculata for the tested bacteria were 1.56 mg/ml (Staph. aureus), 3.13 mg/ml (Bacillus subtilis), 3.13 mg/ml (Strept. epidemidis), 1.56 mg/ml (Escherichia cob), 12.50 mg/ml (Klebsiella pneumoniae) and 3.13 mg/ml (Pseudomonas aeruginosa) respectively. The MIC value for E. hirta was 6.25 mg/ml (Staph. aureus) and 3.13 mg/ml (Bacillus subtilis), 3.13 mg/ml (Strept. Epidemidis), 3.13 mg/ml (Pseudomonas aeruginosa),12.5 mg/ml (Escherichia coli), and 6.25 mg/ml (Klebsiella pneumoniae). Both plants represent a potential for pharmaceutical and agricultural applications and are worthy of further study.
    Matched MeSH terms: Pseudomonas aeruginosa
  11. Ahmad Zorin Sahalan, Baharudin Omar, Aima Yusirah Mohamed, Jeffery, John
    MyJurnal
    Natural peptides in insect vectors played an important role in the control of
    pathogens. Musca domestica Linnaeus and Chrysomya megacephala Fabricius were
    two species of local fly chosen to detect presence of antimicrobial peptide substance.
    The screening of the antimicrobial activity was carried using a spectrophotometric
    method. Results were obtained much quicker and less laborious. The results showed
    larva hemolymph of M. domestica lysed Bacillus subtilis and two Gram negatives,
    Escherichia coli and Pseudomona. aeruginosa. The pupae hemolymph only lysed E.
    coli. Whereas, the hemolymph of C. megacephala larva showed bactericidal effect
    against both of the Gram positives tested, i.e. B. subtilis and Staph. aureus. and no
    effect was against the Gram negatives. The pupa showed lytic activity against Staph.
    aureus and P. aeruginosa. As a conclusion, the larva and pupa hemolymph of M.
    domestica and C. megacephala demonstrated antibacterial activity. However, larva
    hemolymph of M. domestica and C. megacephala has broader antibacterial activity
    against both Gram positive and negative bacteria.
    Matched MeSH terms: Pseudomonas aeruginosa
  12. 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
  13. Ahmad, Mani Malam, Abd. Aziz Mohd Azoddein, Jami, Mohammed Saed
    MyJurnal
    : Studies on bacterial growth pattern from the conventional approach are defective due
    to their failure to explain the interactions or simply the complementary effects of the factors
    influencing the bacterial growth. In this study, the individual and collaborative effects of
    Pseudomonas putida growth variables were evaluated using a 2-level fractional factorial design of
    experiment (FFDOE). The growth of the organism was found to respond remarkably to different
    concentrations of nutrient media (carbon source) and the other independent variables. Factorial
    models were developed from the experimental design to study the individual and interactive effects
    of the studied parameters on the response. The studied parameters and their levels were as follows:
    nutrient concentration (4-16 g/L), acclimatization time (24-72 hrs), agitation (140-200 rpm), and
    temperature (30-40oC). These parameters were statistically validated using analysis of variance
    (ANOVA) and the results revealed that the model terms were statistically significant with an Fvalue of 415.17 at P temperature > nutrient concentration versus temperature >
    agitation > nutrient concentration versus agitation. Based on the R
    2
    and the adjusted R
    2
    values of
    >95%, the estimated variables showed a high degree of relationship between the observed and the
    predicted values; thus, the predictive ability of the models was suggested. It could, therefore, be
    concluded that nutrient concentration, temperature, and agitation can greatly influence the growth
    of P. putida within a specific range.
    Matched MeSH terms: Pseudomonas putida
  14. Ainon Hamzah, Tavakoli A, Amir Rabu
    Sains Malaysiana, 2011;40:1231-1235.
    Toluene (C7H8) a hydrocarbon in crude oil, is a common contaminant in soil and groundwater. In this study, the ability to degrade toluene was investigated from twelve bacteria isolates which were isolated from soil contaminated with oil. Out of 12 bacterial isolates tested, most of Pseudomonas sp. showed the capability to grow in 1 mM of toluene compared with other isolates on the third day of incubation. Based on enzyme assays towards toluene monooxygenase, Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were shown to have the highest ability to degrade toluene. The toluene monoxygenase activity was analysed by using two calorimetric methods, Horseradish peroxidase (HRP) and indole-indigo. Both of the methods measured the production of catechol by the enzymatic reaction of toluene monooxygenase. In the HRP assay, the highest enzyme activity was 0.274 U/mL, exhibited by Pseudomonas aeruginosa UKMP-14T. However, for indole-indigo assay, Bacillus cereus UKMP-6G produced the highest enzyme activity of 0.291 U/ml. Results from both experiments showed that Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were able to degrade toluene.
    Matched MeSH terms: Pseudomonas; Pseudomonas aeruginosa
  15. Ainon Hamzah, Siti Nursyazana Md Salleh, Sukiman Sarmani
    Sains Malaysiana, 2014;43:1327-1332.
    Bioremediation of crude oil using biostimulation and/or bioaugmentation was done by simulation study in the green house under uncontrolled environment temperature. In this study, the soil with indigenous microbes was spiked with Tapis crude oil at 200 g/kg. The microbial density of the amended soils was augmented by addition of fresh inoculum of microbial consortium which consist of Pseudomonas aeruginosa UKMP-14T, Acinetobacter baumannii UKMP-12T and seed culture two strains of fungi, Trichoderma virens UKMP-1M and Trichoderma virens UKMP-2M at ratio 1:1:1:1 (v/w). The amendment soil was added with 20% (v/w) of standardize consortium inoculum, 20% (w/w) of dried empty fruit bunch (EFB) and the effect of EFB was compared with 0.7% commercial fertilizer (v/w) which contain NPK (8:8:1). Soil with indigenous microbes was used as a control. Results showed total petroleum hydrocarbon (TPH) degradation for treatment added with NPK fertilizer was 70.36%, addition with EFB bulking agent 68.86% and addition of both NPK and EFB was 100% at day 30 of incubation. The control plot, 62% of TPH degradation was achieved after 30 days incubation.
    Matched MeSH terms: Pseudomonas aeruginosa
  16. Ainon Hamzah, Amir Rabu, Raja Farzarul Hanim Raja Azmy, Noor Ainni Yussoff
    Sains Malaysiana, 2010;39:161-168.
    Four species of bacteria, Acinetobacter lwoffii, Aeromonas hydrophila, Pseudomonas aeruginosa and Pseudomonas putida, were isolated from soil contaminated with hydrocarbons and selected for the determination of growth requirements and the ability to degrade petroleum hydrocarbon. The bacteria were grown in mineral salt medium (MSM) supplemented with two types of crude oil, either Sumandak or South Angsi at 1% (v/v) concentration. The optimum pH for growth of A. hydrophila and P. aeruginosa was 6.5 when grown with Sumandak and South Angsi oil. For A. lwoffii and P. putida the optimum pH for growth with Sumandak and South Angsi oil was 6.5 or 7.0, respectively. The growth of P. aeruginosa was the highest in MSM when supplemented with 1% South Angsi oil and 0.5% tryptone at pH 6.5 while, in Sumandak oil the growth was the highest when yeast extract was added. Gas chromatography analysis showed that the South Angsi crude oil components of C12 to C25 were more extensively degraded by A. lwoffii after 24 h of incubation compared to the other bacteria over the same period.
    Matched MeSH terms: Pseudomonas aeruginosa; Pseudomonas putida
  17. Akbar N, Khan NA, Sagathevan K, Iqbal M, Tawab A, Siddiqui R
    Sci Rep, 2019 11 18;9(1):17012.
    PMID: 31740685 DOI: 10.1038/s41598-019-52738-w
    Antimicrobial resistance is a major threat to human health, hence there is an urgent need to discover antibacterial molecule(s). Previously, we hypothesized that microbial gut flora of animals are a potential source of antibacterial molecules. Among various animals, Cuora amboinensis (turtle) represents an important reptile species living in diverse ecological environments and feed on organic waste and terrestrial organisms and have been used in folk medicine. The purpose of this study was to mine turtle's gut bacteria for potential antibacterial molecule(s). Several bacteria were isolated from the turtle gut and their conditioned media were prepared. Conditioned media showed potent antibacterial activity against several Gram-positive (Bacillus cereus, Streptococcus pyogenes and methicillin-resistant Staphylococcus aureus) and Gram-negative (neuropathogenic Escherichia coli K1, Serratia marcescens, Pseudomonas aeruginosa, Salmonella enterica and Klebsiella pneumoniae) pathogenic bacteria. Conditioned media-mediated bactericidal activity was heat-resistant when treated at 95°C for 10 min. By measuring Lactate dehydrogenase release, the results showed that conditioned media had no effect on human cell viability. Tandem Mass Spectrometric analysis revealed the presence of various secondary metabolites, i.e., a series of known as well as novel N-acyl-homoserine lactones, several homologues of 4-hydroxy-2-alkylquinolines, and rhamnolipids, which are the signature metabolites of Pseudomonas species. These findings are significant and provide the basis for rational development of therapeutic interventions against bacterial infections.
    Matched MeSH terms: Pseudomonas aeruginosa/drug effects; Pseudomonas aeruginosa/physiology
  18. Akbar N, Siddiqui R, Sagathevan K, Iqbal M, Khan NA
    Antibiotics (Basel), 2019 Sep 24;8(4).
    PMID: 31554316 DOI: 10.3390/antibiotics8040164
    For the past few decades, there has been limited progress in the development of novel antibacterials. Previously, we postulated that the gut microbiota of animals residing in polluted environments are a forthcoming supply of antibacterials. Among various species, the water monitor lizard is an interesting species that feeds on organic waste and the carcass of wild animals. Gut microbiota of the water monitor lizard were sequestered, identified and cultivated in RPMI-1640 to produce conditioned medium (CM). Next, the antimicrobial properties of CM were evaluated versus a selection of Gram-negative (Escherichia coli K1, Serratia marcescens,Pseudomonas aeruginosa, Salmonella enterica and Klebsiella pneumoniae) and Gram-positive bacteria (Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus, and Bacillus cereus). CM were partially characterized by heat inactivation at 95°C for 10 min and tested against P. aeruginosa and S. pyogenes. CM were also tested against immortalized human keratinocytes (HaCaT) cells lines. The results demonstrated that gut microbiota isolated from water monitor lizard produced molecules with remarkable bactericidal activities. To determine the identity of the active molecules, CM were subjected to Liquid Chromatography-Mass Spectrometry. Several molecules were identified belonging to the classes of flavonoids, terpenoids, alkaloids, polyhydroxy alkaloids, polyacetylenes, bisphenols, amides, oxylipin and pyrazine derivatives with known broad-spectrum antimicrobial, anti-tumour, anti-oxidant, anti-inflammatory, and analgesic attributes. Furthermore, the detailed analysis of these molecules could lead us to develop effective therapeutic antibacterials.
    Matched MeSH terms: Pseudomonas aeruginosa
  19. Akbar N, Siddiqui R, Iqbal M, Sagathevan K, Kim KS, Habib F, et al.
    ACS Omega, 2021 May 11;6(18):12261-12273.
    PMID: 34056379 DOI: 10.1021/acsomega.1c01137
    Among several animals, Rattus rattus (rat) lives in polluted environments and feeds on organic waste/small invertebrates, suggesting the presence of inherent mechanisms to thwart infections. In this study, we isolated gut bacteria of rats for their antibacterial activities. Using antibacterial assays, the findings showed that the conditioned media from selected bacteria exhibited bactericidal activities against Gram-negative (Escherichia coli K1, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, and Salmonella enterica) and Gram-positive (Bacillus cereus, methicillin-resistant Staphylococcus aureus, and Streptococcus pyogenes) pathogenic bacteria. The conditioned media retained their antibacterial properties upon heat treatment at boiling temperature for 10 min. Using MTT assays, the conditioned media showed minimal cytotoxic effects against human keratinocyte cells. Active conditioned media were subjected to tandem mass spectrometry, and the results showed that conditioned media from Bacillus subtilis produced a large repertoire of surfactin and iturin A (lipopeptides) molecules. To our knowledge, this is the first report of isolation of lipopeptides from bacteria isolated from the rat gut. In short, these findings are important and provide a platform to develop effective antibacterial drugs.
    Matched MeSH terms: Pseudomonas aeruginosa
  20. Akinsanya MA, Goh JK, Lim SP, Ting AS
    FEMS Microbiol Lett, 2015 Dec;362(23):fnv184.
    PMID: 26454221 DOI: 10.1093/femsle/fnv184
    Twenty-nine culturable bacterial endophytes were isolated from surface-sterilized tissues (root, stem and leaf) of Aloe vera and molecularly characterized to 13 genera: Pseudomonas, Bacillus, Enterobacter, Pantoea, Chryseobacterium, Sphingobacterium, Aeromonas, Providencia, Cedecea, Klebsiella, Cronobacter, Macrococcus and Shigella. The dominant genera include Bacillus (20.7%), Pseudomonas (20.7%) and Enterobacter (13.8%). The crude and ethyl acetate fractions of the metabolites of six isolates, species of Pseudomonas, Bacillus, Chryseobacterium and Shigella, have broad spectral antimicrobial activities against pathogenic Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Salmonella Typhimurium, Proteus vulgaris, Klebsiella pneumoniae, Escherichia coli, Streptococcus pyogenes and Candida albicans, with inhibition zones ranging from 6.0 ± 0.57 to 16.6 ± 0.57 mm. In addition, 80% of the bacterial endophytes produced 1,1-diphenyl-2-picrylhydrazyl (DPPH) with scavenging properties of over 75% when their crude metabolites were compared with ascorbic acid (92%). In conclusion, this study revealed for the first time the endophytic bacteria communities from A. vera (Pseudomonas hibiscicola, Macrococcus caseolyticus, Enterobacter ludwigii, Bacillus anthracis) that produce bioactive compounds with high DPPH scavenging properties (75-88%) and (Bacillus tequilensis, Pseudomonas entomophila, Chryseobacterium indologenes, Bacillus aerophilus) that produce bioactive compounds with antimicrobial activities against bacterial pathogens. Hence, we suggest further investigation and characterization of their bioactive compounds.
    Matched MeSH terms: Pseudomonas; Pseudomonas aeruginosa
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