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Malabaricone C from Myristica cinnamomea exhibits anti-quorum sensing activity

Chong YM, Yin WF, Ho CY, Mustafa MR, Hadi AH, Awang K, et al.

J Nat Prod, 2011 Oct 28;74(10):2261-4.
PMID: 21910441 DOI: 10.1021/np100872k

A methanol-soluble extract of the bark of Myristica cinnamomea was found to exhibit anti-quorum sensing activity, and subsequent bioassay-guided isolation led to the identification of the active compound malabaricone C (1). Compound 1 inhibited violacein production by Chromobacterium violaceum CV026 when grown in the presence of a cognate signaling molecule, N-3-oxohexanoyl-homoserine lactone. Furthermore, 1 inhibited the quorum sensing-regulated pyocyanin production and biofilm formation in Pseudomonas aeruginosa PAO1. These results suggest that the anti-quorum sensing activity of 1 and related molecules should be investigated further.

Matched MeSH terms: Pseudomonas aeruginosa/drug effects
Fulltext Simultaneous detection of methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa by multiplex PCR

Thong KL, Lai MY, Teh C SJ, Chua KH

Trop Biomed, 2011 Apr;28(1):21-31.
PMID: 21602765 MyJurnal

A PCR-based assay that can simultaneously detect and differentiate five different types of nosocomial bacterial pathogens was developed. Six pairs of selected primers targeting femA (132 bp) and mecA (310 bp) of methicillin-resistant Staphylococcus aureus, gltA (722 bp) of Acinetobacter baumannii, phoA (903 bp) of Escherichia coli, mdh (364 bp) of Klebsiella pneumoniae and oprL (504 bp) of Pseudomonas aeruginosa were used in this study. The conditions were optimized for the multiplex PCR to ensure specific amplification of the selected targets. Sensitivity and specificity tests were also carried out using a blind test approach on 50 bacterial cultures and resulted in 100% for both positive and negative predictive values.

Matched MeSH terms: Pseudomonas aeruginosa/isolation & purification
Pulmonary actinomycosis and skin sinuses

Lee JK

J Paediatr Child Health, 2007 Dec;43(12):854-5.
PMID: 18036023

A 12-year old girl presented with an unusual problem of recurrent discharging multiple skin sinuses on her right anterior and posterior chest wall for a year. There was ipsilateral lower lobe pneumonia and imaging showed multiple abscesses in her lower back muscles bilaterally. A purulent fluid was aspirated from her back muscles and the histology examination showed sulphur granules with gram positive branched filaments. She responded well to the treatment for actinomycosis with penicillin and doxycycline.

Matched MeSH terms: Pseudomonas aeruginosa/isolation & purification
In vitro evaluation of the growth enhancing or cytotoxic effect of Sticophus species (Gamat) on established human fibroblast cell lines and antimicrobial activity

Philip R, Dinsuhaimi S, Rosdan S, Samsudin AR, Shamsuria O, Mohd Zaki S, et al.

Med J Malaysia, 2004 May;59 Suppl B:95-6.
PMID: 15468835
Matched MeSH terms: Pseudomonas aeruginosa/drug effects
The potential use of a layer-by-layer strategy to develop LDPE antimicrobial films coated with silver nanoparticles for packaging applications

Azlin-Hasim S, Cruz-Romero MC, Cummins E, Kerry JP, Morris MA

J Colloid Interface Sci, 2016 Jan 01;461:239-248.
PMID: 26402783 DOI: 10.1016/j.jcis.2015.09.021

Commercial low-density polyethylene (LDPE) films were UV/ozone treated and coated using a layer-by-layer (LbL) technique by alternating the deposition of polyethyleneimine (PEI) and poly(acrylic acid) (PAA) polymer solutions and antimicrobial silver (Ag). The effects of the initial pH of the PEI/PAA polymer solutions alternating layers (pH 10.5/4 or 9/6.5) on the antimicrobial activity of the developed LbL coatings combined with Ag against Gram-negative and Gram-positive bacteria were investigated. The results from fourier transform infrared spectroscopy and toluidine blue O assay showed that LDPE LbL coated using PEI/PAA polymer solutions with initial pH of 10.5/4 significantly increased the presence of carboxylic acid groups and after Ag attachment the coating had higher antimicrobial activity against both Gram-negative and Gram-positive bacteria compared to the LDPE LbL coated using PEI/PAA polymer solutions with initial pH of 9/6.5. The LDPE LbL coated films using non-modified pH PEI/PAA polymer solutions decreased the water contact-angle indicating an increased hydrophilicity of the film, also increased the tensile strength and roughness of LDPE LbL coated films compared to uncoated LbL samples. The LDPE LbL coated films attached with Ag(+) were UV/ozone treated for 20 min to oxidise Ag(+) to Ag(0). The presence of Ag(0) (Ag nanoparticles (NPs)) on the LDPE LbL coated films was confirmed by XRD, UV-vis spectrophotometer and colour changes. The overall results demonstrated that the LbL technique has the potential to be used as a coating method containing antimicrobial Ag NPs and that the manufactured films could potentially be applied as antimicrobial packaging.

Matched MeSH terms: Pseudomonas fluorescens/drug effects
Antibacterial effect of the red sea soft coral Sarcophyton trocheliophorum

Gomaa MN, Soliman K, Ayesh A, Abd El-Wahed A, Hamza Z, Mansour HM, et al.

Nat Prod Res, 2016;30(6):729-34.
PMID: 26186031 DOI: 10.1080/14786419.2015.1040991

The marine soft corals Sarcophyton trocheliophorum crude extracts possessed antimicrobial activity towards pathogenic bacterial strains, i.e. Bacillus cereus, Salmonella typhi, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Bioassay-guided fractionation indicated that the antimicrobial effect was due to the presence of terpenoid bioactive derivatives. Further biological assays of the n-hexane fractions were carried out using turbidity assay, inhibition zone assay and minimum inhibitory concentration for investigating the growth-inhibition effect towards the Gram-positive and Gram-negative bacteria. The fractions were screened and the structure of the isolated compound was justified by interpretation of the spectroscopic data, mainly mass spectrometry (GC-MS). The structure was assigned as (5S)-3-[(3E,5S)-5-hydroxy-3-hepten-6-yn-1-yl]-5-methyl-2(5H)-furanone and was effective at concentrations as low as 0.20 mg/mL. The above findings, in the course of our ongoing research on marine products, may implicate that the profound anti-microbial activity of the S. trocheliophorum soft corals, inhabiting the red sea reefs, is attributed to the presence of growth-inhibiting secondary metabolites mainly terpenoids.

Matched MeSH terms: Pseudomonas aeruginosa/drug effects
Acceleration of cutaneous wound healing by Lucilia sericata maggots in diabetic Wistar rats

Borkataki S, Katoch R, Goswami P, Bhat A, Chakraborty D

Trop Biomed, 2021 Mar 01;38(1):86-93.
PMID: 33797529 DOI: 10.47665/tb.38.1.015

The study was aimed to evaluate the effectiveness of maggot therapy in healing of cutaneous infected wound in streptozotocin (STZ) induced diabetic Wistar rat. For live maggots, the sterilized eggs of Lucilia sericata were obtained from colonies established in laboratory. Diabetes model was established in 48 male Wister rat by intra-peritoneal injection of STZ at the dose of 60 mg/kg body-weight. Cutaneous wounds exposed with mixed colonies of bacteria like Staphylococcus aureus, E. coli and Pseudomonas aeruginosa were prepared in all rat. The animals equally divided in 4 groups with 12 rats each being presented as treatment group of control, antibiotic, maggot and maggot with antibiotic in combination. All treatments were done once and hold for 24 hours. Wound kinetics and bacterial bio burden were measured at weekly interval to till complete healing. Significant reduction in wound area with maximum contraction was found (>95%) in maggot treated group when compared to antibiotic treated (79%) and control (72%). In maggot as well as maggot and antibiotic in combination group showed early elimination of bacterial bio-burden 7.88±0.03log CFU/ml to 1.12±0.65log CFU/ml and 7.86±0.04) log CFU/ml to 1.54±0.52log CFU/ml respectively in three weeks of time. Early healing indication was also experienced on histomorphological examination of wounded tissue of maggot treated groups by early and better epithelialization, collagenation and neovascularization with complete healing of wound in three weeks in comparison to antibiotic and control respectively. However, the present study did not show any difference in healing of wound with use of maggot alone or in antibiotic combination. Live maggot of Lucilia sericata effectively lower bacterial bioburden and and accelerate healing of infected cutaneous wound in diabetic conditions.

Matched MeSH terms: Pseudomonas Infections/therapy
Distribution, genetic diversity and antimicrobial resistance of clinically important bacteria from the environment of a tertiary hospital in Malaysia

Phoon HYP, Hussin H, Hussain BM, Lim SY, Woon JJ, Er YX, et al.

J Glob Antimicrob Resist, 2018 09;14:132-140.
PMID: 29540306 DOI: 10.1016/j.jgar.2018.02.022

OBJECTIVES: Hospital environments are potential reservoirs of bacteria associated with nosocomial infections. In this study, the distribution of cultivable environmental bacteria of clinical importance from a Malaysian tertiary hospital was determined and their resistotypes and genotypes were investigated.
METHODS: Swab and fluid samples (n=358) from healthcare workers' hands, frequently touched surfaces, medical equipment, patients' immediate surroundings, ward sinks and toilets, and solutions or fluids of 12 selected wards were collected. Biochemical tests, PCR and 16S rRNA sequencing were used for identification following isolation from CHROMagar™ Orientation medium. Clinically important bacteria such as Enterococcus spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter spp., Pseudomonas aeruginosa and Enterobacter spp. were further characterised by disc diffusion method and rep-PCR.
RESULTS: The 24 Gram-negative and 19 Gram-positive bacteria species identified were widely distributed in the hospital environment. Staphylococci were predominant, followed by Bacillus spp. and P. aeruginosa. Frequently touched surfaces, medical equipment, and ward sinks and toilets were the top three sources of bacterial species. Nine S. aureus, four Acinetobacter spp., one K. pneumoniae and one Enterobacter spp. were multidrug-resistant (MDR). The ESKAPE organisms were genetically diverse and widely dispersed across the hospital wards. A MDR MRSA clone was detected in a surgical ward isolation room.
CONCLUSION: The large variety of cultivable, clinically important bacteria, especially the genetically related MDR S. aureus, K. pneumoniae, Acinetobacter spp. and Enterobacter spp., from various sampling sites indicated that the surfaces and fomites in the hospital were potential exogenous sources of nosocomial infection in the hospital.

Matched MeSH terms: Pseudomonas aeruginosa
Fulltext Synergistic effects of Persicaria odorata (daun kesom) leaf extracts with standard antibiotics on pathogenic bacteria

Ridzuan, P.M., Hairul Aini Hamzah, Anis Shah, Norazian Mohd Hassan, Baharudin Roesnita

International Medical Journal Malaysia, 2017;16(2):27-32.
MyJurnal

Antibacterial activity of different types of P. odorata leaf extracts was evaluated in combination with
standard antibiotics. Persicaria. odorata leaves were extracted with n-hexane (n-hex), dichloromethane
(DCM) and methanol (MeOH). Each extract was applied on vancomycin (30µg), erythromycin (15µg) and
gentamicin (10µg) discs, respectively. Disk diffusion method was used to evaluate the synergistic activity of
each combination on Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes,
Streptococcus pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, and Escherichia coli. Minimum
inhibitory concentration (MIC) and gas chromatography mass spectrometry (GCMS) analysis was performed on
the active extract. Synergistic effects seen were mainly from the n-hex+antibiotics combinations, mainly on
the Gram-positive bacteria (7 additive, 5 antagonistic), with MIC range from 50 µg/ml to 100 µg/ml, as well
as Gram-negative bacteria (2 additive, 2 indifferent, 5 antagonistic). In particular, synergism showed by the
combination of n-hex+van were all additive against the susceptible bacteria. DCM extract combination
showed synergistic effects on three Gram-positive species (S. aureus, S. epidermidis, S. pyogenes).
Meanwhile, MeOH+antibiotics combination showed significant additive synergistic effects (p

Matched MeSH terms: Pseudomonas aeruginosa
Fulltext Stem bark of Canarium Odontophyllum Miq. (dabai) as potential source of antimicrobial agent

Noor Fazdilah Mustari, Zafira Ayushah Zainul Alamin, Noraziah Mohammad Zin, Dayang Fredalina Basri

Jurnal Sains Kesihatan Malaysia, 2017;15(1):1-6.
MyJurnal

The objective of this study was to evaluate the antimicrobial potential of methanol, acetone and distilled water stem
bark extracts from Canarium odontophyllum against Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 6633,
Escherichia coli ATCC 25932, Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii strain sensitive, Candida
albicans ATCC 64677, Candida glabrata ATCC 90028, Aspergillus niger and Fusarium solani M2781. The extracts from
C. odontophyllum stem bark from 3.125 mg/ml to 25 mg/ml were screened against the tested microorganisms using disc
diffusion method. The Minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the
extracts against susceptible organisms were determined using microbroth dilution method and streak-plate technique,
respectively. From the antibacterial screening assay, the growth of S. aureus, B. cereus and A. baumannii were inhibited
by methanol extract whereas the acetone extract was capable of inhibiting all the tested microorganisms except E.coli,
F. solani and A. niger. The lowest MIC value for methanol extract was against A. baumannii (0.195 mg/ml) whereas
its MBC value was twice its MIC value (0.391 mg/ml), indicating that methanol extract was bacteriostatic against A.
baumannii. While for acetone extract, S. aureus showed bactericidal effect with equal MIC and MBC values at 0.195 mg/
ml. In conclusion, stem bark of C. odontophyllum has the potential to be the source of antibacterial agent and can be
exploited as an alternative phytoantimicrobial.

Matched MeSH terms: Pseudomonas aeruginosa
Spray coating application for the development of nanocoated antimicrobial low-density polyethylene films to increase the shelf life of chicken breast fillets

Azlin-Hasim S, Cruz-Romero MC, Morris MA, Cummins E, Kerry JP

Food Sci Technol Int, 2018 Dec;24(8):688-698.
PMID: 30044138 DOI: 10.1177/1082013218789224

Antimicrobial coated films were produced by an innovative method that allowed surface modification of commercial low-density polyethylene films so that well-defined antimicrobial surfaces could be prepared. A Pluronic™ surfactant and a polystyrene-polyethylene oxide block copolymer were employed to develop modified materials. The Pluronic™ surfactant provided a more readily functionalised film surface, while block copolymer provided a reactive interface which was important in providing a route to silver nanoparticles that were well adhered to the surface. Antimicrobial films containing silver were manufactured using a spray coater and the amount of silver used for coating purposes varied by the concentration of the silver precursor (silver nitrate) or the number of silver coatings applied. Potential antimicrobial activity of manufactured silver-coated low-density polyethylene films was tested against Pseudomonas fluorescens, Staphylococcus aureus and microflora isolated from raw chicken. The microbiological and physicochemical quality of chicken breast fillets wrapped with silver-coated low-density polyethylene films followed by vacuum skin packaging was also assessed during storage. Antimicrobial activity of developed silver-coated low-density polyethylene films was dependent ( p

Matched MeSH terms: Pseudomonas fluorescens
Fulltext Isolation and characterization of a heavy metal-reducing Pseudomonas sp. strain Dr.Y Kertih with the ability to assimilate phenol and diesel

Veeraswamy Kesavan, Abdulrasheed Mansur, Mohd Syahmi Ramzi Salihan, Rahman, M.F., Suhaili, Zarizal, Shukor, M.Y.

Bioremediation Science and Technology Research, 2018;6(1):14-22.
MyJurnal

The indiscriminate released of heavy metals and xenobiotics into soils and aquatic bodies
severely alter soil organisms and the ecosystem. The isolation of xenobiotics degrading
microorganisms is cost-effective and naturally pleasant approach. Lately, the toxicological effect
of molybdenum to the spermatogenesis of several organisms has been record. This present study
is aimed at the isolation and characterization of a bacterium capable of converting molybdenum
to the colloidal molybdenum blue. Bacteria characterization was performed in a microplate
format using resting cells. Thus, the reduction process can be employed as a device for
molybdenum bioremediation. The results of the study revealed an optimum reduction at pH
between 6.0 and 6.3 and temperatures of between 25 and 40 oC. Similarly, it was also observed
that a phosphate concentration not greater than 5.0 mM and a sodium molybdate concentration
at 20 mM was required for reduction. Glucose was observed as the best carbon source to support
reduction. Following the scanning of molybdenum blue, it revealed an absorption spectrum
indicating the characteristics of molybdenum blue as a reduced phosphomolybdate. Molybdenum
reduction is inhibited by heavy metals like silver, lead, arsenic and mercury. Furthermore, the
ability of the bacterium (Pseudomonas sp. strain Dr.Y Kertih) to utilize several organic
xenobiotics such as phenol, acrylamide, nicotinamide, acetamide, iodoacetamide, propionamide,
acetamide, sodium dodecyl sulfate (SDS) and diesel as electron donor sources for aiding
reduction or as carbon sources for growth was also examined. Finding showed that none was
capable of aiding molybdenum reduction, however the bacterium was capable of growing on both
diesel and phenol as carbon sources. GC analysis was used to confirmed diesel degradation.

Matched MeSH terms: Pseudomonas
Fulltext Antibacterial activity of biosynthesized gold nanoparticles using biomolecules from Lignosus rhinocerotis and chitosan

Katas H, Lim CS, Nor Azlan AYH, Buang F, Mh Busra MF

Saudi Pharm J, 2019 Feb;27(2):283-292.
PMID: 30766441 DOI: 10.1016/j.jsps.2018.11.010

A simple, cost-effective, and environmentally friendly method is needed for synthesizing metal nanoparticles, including gold nanoparticles (AuNPs). In this study, AuNPs were synthesized with Lignosus rhinocerotis sclerotial extract (LRE) and chitosan (CS) as reducing and stabilizing agents, respectively. Different LRE concentrations from cold and hot water extraction (CWE and HWE, respectively) were used to reduce chloroauric acid (HAuCl4) to form AuNPs. Positively charged chitosan stabilized AuNPs (CS-AuNPs) mediated by LRE exhibited a surface plasmon resonance (SPR) band at 533 nm. The CS-AuNPs synthesized using CWE had a smaller particle size (49.5 ± 6.7-82.4 ± 28.0 nm) compared to that of the HWE samples (80.3 ± 23.4-125.3 ± 41.5 nm), depending on LRE concentration. FTIR results suggested protein and polysaccharides in LRE were the sources of reducing power, reducing gold ions to AuNPs. CS-AuNPs were mostly spherical with higher LRE concentrations, whereas some triangular, pentagonal, irregular, and rod shaped AuNPs were observed at lower LRE concentrations. CS-AuNPs mediated by LRE displayed effective antibacterial activity against gram-negative (Pseudomonas aeruginosa and Escherichia coli) and gram-positive bacteria (Staphylococcus aureus and Bacillus sp.). Thus, the biosynthesized AuNPs using LRE and chitosan provide opportunities for developing stable and eco-friendly nanoparticles with effective antibacterial properties.

Matched MeSH terms: Pseudomonas aeruginosa
PHA synthase (PhaC): interpreting the functions of bioplastic-producing enzyme from a structural perspective

Chek MF, Hiroe A, Hakoshima T, Sudesh K, Taguchi S

Appl Microbiol Biotechnol, 2019 Feb;103(3):1131-1141.
PMID: 30511262 DOI: 10.1007/s00253-018-9538-8

Polyhydroxyalkanoates (PHAs) are biopolymers synthesized by a wide range of bacteria, which serve as a promising candidate in replacing some conventional petrochemical-based plastics. PHA synthase (PhaC) is the key enzyme in the polymerization of PHA, and the crystal structures were successfully determined using the catalytic domain of PhaC from Cupriavidus necator (PhaCCn-CAT) and Chromobacterium sp. USM2 (PhaCCs-CAT). Here, we review the beneficial mutations discovered in PhaCs from a structural perspective. The structural comparison of the residues involved in beneficial mutation reveals that the residues are near to the catalytic triad, but not inside the catalytic pocket. For instance, Ala510 of PhaCCn is near catalytic His508 and may be involved in the open-close regulation, which presumably play an important role in substrate specificity and activity. In the class II PhaC1 from Pseudomonas sp. 61-3 (PhaC1Ps), Ser325 stabilizes the catalytic cysteine through hydrogen bonding. Another residue, Gln508 of PhaC1Ps is located in a conserved hydrophobic pocket which is next to the catalytic Asp and His. A class I, II-conserved Phe420 of PhaCCn is one of the residues involved in dimerization and its mutation to serine greatly reduced the lag phase. The current structural analysis shows that the Phe362 and Phe518 of PhaC from Aeromonas caviae (PhaCAc) are assisting the dimer formation and maintaining the integrity of the core beta-sheet, respectively. The structure-function relationship of PhaCs discussed in this review will serve as valuable reference for future protein engineering works to enhance the performance of PhaCs and to produce novel biopolymers.

Matched MeSH terms: Pseudomonas
Fulltext The significant association between polymicrobial diabetic foot infection and its severity and outcomes

Hitam SAS, Hassan SA, Maning N

Malays J Med Sci, 2019 Jan;26(1):107-114.
PMID: 30914898 MyJurnal DOI: 10.21315/mjms2019.26.1.10

Background: Foot infection is a major complication of diabetes mellitus (DM) and its agents are usually polymicrobial. This study aims to describe the agent and determine the association between polymicrobial infections and the severity of diabetic foot infections (DFI) and their outcomes.

Methods: This retrospective cohort study was conducted during one year and it involved 104 patients. Their records were reviewed and assessed. The causative agents and its sensitivity pattern were noted. The results were presented as descriptive statistic and analysed.

Results: A total of 133 microorganisms were isolated with 1.28 microorganisms per lesion. The microorganism isolated were 62% (n = 83) GN (Gram-negative) and 38% (n = 50) GP (Gram-positive). GN microorganisms include Pseudomonas spp (28%), Proteus spp (11%), Klebsiella spp (8%) and E. coli (4%). Staphylococcus aureus (54%) was predominant among GP, followed by Group B Streptococci (26%) and Enterococcus spp (6%). Thirty patients (28.8%) had polymicrobial infections. The association between the quantity of microorganisms and severity of DFI was significant. Among severe DFI cases, 77.8% with polymicrobial microorganisms underwent amputation compared to 33.3% with monomicrobial infection.

Conclusion: GN microorganisms were predominantly isolated from DFIs and remained sensitive to widely used agents. Polymicrobial infections were associated with DFI severity.

Matched MeSH terms: Pseudomonas
Culture-independent-based analyses identified site-specific microbial in two oil-wells from Malaysia

Cheng-Yee Fish-Low, Chee HY, Ainon Hamzah

Sains Malaysiana, 2015;44:1625-1633.

Microbial communities of two oil reservoirs from Malaysia, denoted as Platform Bo and Platform Pe were studied using
culture-independent approach. Environmental DNA was extracted and the universal amplified ribosomal region (UARR)
was target amplified for both prokaryotes and eukaryotes. The amplified products were purified and cloned into pTZ57R/T
vector to construct the 16S/18S rDNA library. Restriction endocucleases HhaI and MspI were used to screen the library.
From that, 125 and 253 recombinant plasmid representative clones from Platform Bo and Platform Pe, respectively, were
sent for DNA sequencing. Twenty-six operational taxonomic units (OTUs) consist of 20 genera detected at Platform Bo
and 17 OTUs consist of 13 genera detected at Platform Pe. Marinobacter and Acinetobacter species co-occurred in both
platforms whereas the rest are site-specific. Gammaproteobacteria accounted for 86.0% of the microbial community in
Platform Bo, where OTUs affiliated to Marinobacter, Pseudomonas and Marinobacterium that were the most abundant. The
major OTUs in the Platform Pe were with affinities to Achromobacter, followed by Stenotrophomonas and Serratia. The
only archaeal isolates were detected in Platform Pe, which affiliated to Thermocladium. The singletons and doubletons
accounted for about 50.0% of the OTU abundance in both platforms, which considerably significant despite their rare
occurrence.

Matched MeSH terms: Pseudomonas
Fulltext Gut Bacteria of Water Monitor Lizard (Varanus salvator) Are a Potential Source of Antibacterial Compound(s)

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
Fulltext Microbiology of diabetic foot infections in three district hospital in Malaysia and comparison with South East Asian Countries

Kow RY, Low CL, Ruben JK, Zaharul Azri WMZ, Mor Japar Khan ESK

Med J Malaysia, 2019 Oct;74(5):394-399.
PMID: 31649215

INTRODUCTION: Diabetic foot infection, a complication that is associated with lower-limb amputation, incurs a huge economic burden to the hospital and health care system of Malaysia. The bacteriological profile of pathogens in diabetic foot infections in Malaysia has been sparsely studied. We investigated the microbiology of diabetic foot infections in patients admitted to the district hospitals on the east coast of Malaysia.

METHODS: A retrospective analysis was conducted in three district hospitals (Hospital Kuala Lipis, Hospital Bentong and Hospital Raub) in Malaysia from 1st of January 2016 to 31st December 2016. The clinical specimens were cultured using Clinical and Laboratory Standards Institute (CLSI) guidelines. Antibiotic sensitivity testing to different antibiotics was carried out using the disc diffusion method.

RESULT: A total of 188 pathogens were isolated from 173 patients, with an average of 1.09 pathogens per lesion. Majority of the pathogens isolated were gram negative pathogens (73.4%). The most commonly isolated pathogens were Staphylococcus aureus (17.5%). This was followed by Klebsiella spp. (17%), Pseudomonas spp. (15.4%) and Proteus spp. (13.8%). Gram positive pathogens were sensitive to most of the antibiotics tested except penicillin and fusidic acid. Gram negative pathogens were sensitive to all antibiotics tested except ampicillin and amoxicillin/clavulanic acid. Amikacin provide coverage for all gram negative pathogens in DFI.

CONCLUSION: For the management of patient with infection in diabetic foot, the choice of antibiotic therapy depends on the sensitivity of the pathogens, the severity of the infection, the patient's allergies history, toxicity and excretion of the antibiotics.

Matched MeSH terms: Pseudomonas
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.

Matched MeSH terms: Pseudomonas aeruginosa
In vitro antimicrobial activity of narasin and monensin in combination with adjuvants against pathogens associated with canine otitis externa

Chan WY, Hickey EE, Khazandi M, Page SW, Trott DJ, Hill PB

Vet Dermatol, 2020 Apr;31(2):138-145.
PMID: 31710159 DOI: 10.1111/vde.12803

BACKGROUND: The emergence of antimicrobial resistance represents a serious human and animal health risk. Good antimicrobial stewardship is essential to prolong the lifespan of existing antibiotics, and new strategies are required to combat infections in man and animals.
HYPOTHESIS/OBJECTIVES: To determine the in vitro interaction of ionophores (narasin or monensin) with antimicrobial adjuvants (N-acetylcysteine (NAC), Tris-EDTA or disodium EDTA) against bacterial strains representing pathogens associated with canine otitis externa (OE).
ANIMAL/ISOLATES: American Type Culture Collection (ATCC) strains Staphylococcus aureus 29213, Pseudomonas aeruginosa 27853 and P. aeruginosa biofilm producer PAO1, and a clinical isolate of Proteus mirabilis from a case of canine OE were tested.
METHODS AND MATERIALS: A 2D microdilution checkerboard method was used, allowing calculation of fractional inhibitory concentration index (FICI), dose reduction index (DRI) and plotting of isobolograms.
RESULTS: The combination of narasin with either Tris-EDTA or disodium EDTA produced additive effects (FICI = 0.75) against P. aeruginosa ATCC 27853 and P. aeruginosa biofilm producer ATCC PAO1. An additive effect (FICI = 0.53-0.75) was found against S. aureus ATCC 29213 when narasin or monensin were combined with NAC. The highest DRI (32-fold) was found with monensin/NAC where the MIC of monensin was reduced from 4 to 0.125 μg/mL.
CONCLUSIONS AND CLINICAL IMPORTANCE: The combination of narasin with Tris-EDTA or disodium EDTA is a promising strategy to inhibit the intrinsic resistance elements of Gram-negative bacteria. These novel combinations potentially could be useful as a multimodal approach to treat mixed infections in canine OE.

Matched MeSH terms: Pseudomonas aeruginosa

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