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Fulltext Pseudomonas Aeruginosa and Streptococcus Pyogenes Exposed to Malaysian Trigona Honey In Vitro Demonstrated Downregulation of Virulence Factor

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
Fulltext Preliminary Screening of Antibacterial Activity Using Crude Extracts of Hibiscus rosa sinensis

Arullappan S, Zakaria Z, Basri DF

Trop Life Sci Res, 2009 Dec;20(2):109-18.
PMID: 24575183 MyJurnal

Hibiscus rosa sinensis, a member of the Malvaceae family, is widely cultivated in the tropics as an ornamental plant. It is often planted as a fence or hedge plant, and has several forms of flowers with varying colours. It is also used in traditional medicine to induce abortion, ease menstrual cramps, assist in childbirth and relieve headache, fever and inflammation. In this study, we evaluated the antibacterial activity of H. rosa sinesis extract using a disc diffusion method. Crude petroleum ether extract, ethyl acetate extract and methanol extract from the leaves, stems and flowers of the plant were prepared using a cold extraction technique. These extracts were tested at concentrations ranging from 4 mg/disc to 0.017 mg/disc against methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia. The petroleum ether extract from the leaves, stems and flowers and methanol extract from the leaves showed inhibition zones with diameters > 12 mm against MRSA. Overall, the petroleum ether extract from flowers at concentrations of 4 mg/disc and 2 mg/disc displayed the strongest inhibition zones of 18.6 ± 2.85 mm and 18.5 ± 0.29 mm, respectively, as compared to vancomycin (30 μg/ml), which did not differ significantly from the 18.0 ± 0.10 mm size of the vancomycin (30 μg/ml) inhibition zone (p < 0.05). In conclusion, H. rosa sinensis extract is a potential antibacterial agent for treating MRSA infection.

Matched MeSH terms: Pseudomonas aeruginosa
Fulltext The Antibacterial Activity of Dayak Onion (Eleutherine palmifolia (L.) Merr) towards Pathogenic Bacteria

Harlita TD, Oedjijono, Asnani A

Trop Life Sci Res, 2018 Jul;29(2):39-52.
PMID: 30112140 DOI: 10.21315/tlsr2018.29.2.4

Antibacterial activity of indigenous Dayak onion (Eleutherine palmifolia (L.) Merr) was investigated. The Dayak onion was solvent extracted with n-hexane, ethyl acetate, and ethanol 96% consecutively. Each extract was tested its antibacterial activity towards methicillin-resistant Staphylococcus aureus (MRSA), Bacillus cereus, Shigella sp., and Pseudomonas aeruginosa using disc diffusion method. The test results showed that the n-hexane, ethyl acetate, and ethanol 96% extracts positively inhibited the growth of MRSA, B. cereus, Shigella sp., and P. aeruginosa. The highest inhibition activity of each extract was obtained with 10 mg/mL of extract concentration; whereas the minimum inhibitory concentration (MIC) of each extract was 2 mg/mL. Extract with the highest inhibition activity was ethyl acetate extract against B. cereus (139.58%). TLC evaluation of ethyl acetate extract showed four spots and bioautography indicated that ethyl acetate extract contained four types of compounds with inhibition activity against B. cereus, in which two compounds have higher antibacterial activity than the other two.

Matched MeSH terms: Pseudomonas aeruginosa
Fulltext Population Pharmacokinetics of Doripenem in Critically Ill Patients with Sepsis in a Malaysian Intensive Care Unit

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
Antimicrobial resistance patterns and genotypic diversity between clinical and water systems isolates of Pseudomonas aeruginosa in Cali, Colombia

Chávez M, Cabezas AF, Ferauds M, Castillo JE, Caicedo LD

Trop Biomed, 2020 Sep 01;37(3):650-662.
PMID: 33612779 DOI: 10.47665/tb.37.3.650

Pseudomonas aeruginosa is considered an opportunistic pathogen, causing a wide variety of infections in compromised hosts, also frequently develops multi-resistance to antibiotics and can colonize various habitats, including water systems. The main aim of this study was to investigate antibiotics susceptibility pattern, genotypic diversity and detection of resistence genes in P. aeruginosa isolates from clinical and aquatic environment sources. Of the 220 P. aeruginosa isolates examined, 48 were clinical isolates and 172 isolates from wastewater and freshwater. Susceptibility to eight antimicrobial agents was carried out by disk diffusion method. Clinical and environmental isolates were screened for the presence of the genes encoding blaKPC-2, blaCTX-M-9, blaPER-1, blaOXA-10, blaIMP-1, blaVIM-2 and blaampC by polymerase chain reaction (PCR). Isolates were examined with PCR-SSCP analysis of partial DNAr 16S sequence. Isolates were mainly resistant to cefoxitin. Multidrug-resistant P. aeruginosa (MDRPA) strains were found in 70% and 90.3% of the clinical and environmental isolates, respectively. The prevalence rates of â-lactamase genes were recorded (blaKPC-2 41.3%, blaVIM-2 36.8%, blaIMP-1 13.6%, blaCTX-M-9 10.9% and blaampC 10.5%,). The PCR-SSCP analysis showed three conformational patterns. All clinical isolates and most environmental isolates were grouped into a single cluster. In this study, we found that P. aeruginosa strains recovered from city water systems must be considered potential reservoir for ESBL genes, especially blaKPC-2 and blaVIM-2.

Matched MeSH terms: Pseudomonas aeruginosa
Chemical compositions and antibacterial activity of the leaf and stem oils of Piper porphyrophyllum (Lindl.) N.E. Br

Salleh WM, Ahmad F, Sirat HM, Yen KH

EXCLI J, 2012;11:399-406.
PMID: 27418915

The essential oils obtained by hydrodistillation from the fresh leaf and stem of Piper porphyrophyllum N.E. Br. were analyzed by GC and GC/MS. Thirty four constituents were identified in the leaf oil, while thirty eight constituents were identified in the stems oil. The most abundant components in the leaf oil included bicyclogermacrene (14.7 %), α-copaene (13.2 %) and β-phellandrene (9.5 %) while sabinene (15.5 %), bicyclogermacrene (12.3 %) and α-copaene (8.1 %) were the main constituents in the stem oil. The evaluation of antibacterial activity by using micro-dilution method revealed that both oils were moderately active against all the Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Pseudomonas aeruginosa, Pseudomonas putida and Escherichia coli) with minimum inhibitory concentration (MIC) values in the range 125-1000 µg/ml.

Matched MeSH terms: Pseudomonas aeruginosa
Fulltext Transcriptome analysis of Pseudomonas aeruginosa PAO1 grown at both body and elevated temperatures

Chan KG, Priya K, Chang CY, Abdul Rahman AY, Tee KK, Yin WF

PeerJ, 2016;4:e2223.
PMID: 27547539 DOI: 10.7717/peerj.2223

Functional genomics research can give us valuable insights into bacterial gene function. RNA Sequencing (RNA-seq) can generate information on transcript abundance in bacteria following abiotic stress treatments. In this study, we used the RNA-seq technique to study the transcriptomes of the opportunistic nosocomial pathogen Pseudomonas aeruginosa PAO1 following heat shock. Samples were grown at both the human body temperature (37 °C) and an arbitrarily-selected temperature of 46 °C. In this work using RNA-seq, we identified 133 genes that are differentially expressed at 46 °C compared to the human body temperature. Our work identifies some key P. aeruginosa PAO1 genes whose products have importance in both environmental adaptation as well as in vivo infection in febrile hosts. More importantly, our transcriptomic results show that many genes are only expressed when subjected to heat shock. Because the RNA-seq can generate high throughput gene expression profiles, our work reveals many unanticipated genes with further work to be done exploring such genes products.

Matched MeSH terms: Pseudomonas aeruginosa
Quorum quenching properties of Actinobacteria isolated from Malaysian tropical soils

Devaraj K, Tan GYA, Chan KG

Arch Microbiol, 2017 Aug;199(6):897-906.
PMID: 28364274 DOI: 10.1007/s00203-017-1371-4

In this study, a total of 147 soil actinobacterial strains were screened for their ability to inhibit response of Chromobacterium violaceum CV026 to short chain N-acyl homoserine lactone (AHL) which is a quorum sensing molecule. Of these, three actinobacterial strains showed positive for violacein inhibition. We further tested these strains for the inhibition of Pseudomonas aeruginosa PAO1 quorum sensing-regulated phenotypes, namely, swarming and pyocyanin production. The three strains were found to inhibit at least one of the quorum sensing-regulated phenotypes of PAO1. Phylogenetic analysis of the 16S rRNA gene sequences indicated that these strains belong to the genera Micromonospora, Rhodococcus and Streptomyces. This is the first report presenting quorum quenching activity by a species of the genus Micromonospora. Our data suggest that Actinobacteria may be a rich source of active compounds that can act against bacterial quorum sensing system.

Matched MeSH terms: Pseudomonas aeruginosa
Fulltext Antibacterial activity of Andrographis paniculata and Euphorbia hirta methanol extracts

Ahmad Zorin Sahalan, Nazahiyah Sulaiman, Nihayah Mohammed, Kaswandi Md. Ambia, Hing, Hian Lian

Jurnal Sains Kesihatan Malaysia, 2007;5(2):1-8.
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
Fulltext Antibacterial activity of extracted hemolymph from larvae and pupae of local fly species, Musca domestica and Chrysomya megacephala

Ahmad Zorin Sahalan, Baharudin Omar, Aima Yusirah Mohamed, Jeffery, John

Jurnal Sains Kesihatan Malaysia, 2006;4(2):1-11.
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
Fulltext In vitro antibacterial activity of eurycoma longifolia jack (tongkat ali) root extract

Faisal, G.G., Zakaria, S.M., Najmuldeen, G.F.

International Medical Journal Malaysia, 2015;14(1):77-81.
MyJurnal

ntroduction: Currently, researchers are aiming to explore herbal plants to replace synthetic drugs because herbal plants contain high active compounds and fewer side effects. Our study was done to determine the antibacterial activity of Eurycoma longifolia Jack (E. longifolia) root using ethanol based extract. Methods: Five types of pathogenic bacterial strains were used; Gram-positive (Staphylococcus aureus and Bacillus ce- reus) and Gram-negative (Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa). Disc diffusion assay and Minimum Inhibitory Concentration (MIC) tests were used to determine the inhibition zone and turbidity of suspension which reflects the antibacterial activity of the extract. Results: The ethanolic extract of E. longifolia Jack root extract showed positive results against Gram-positive bacteria (S. aureus and B. cereus) and Gram- negative (S. typhi). B.cereus and S.typhi showed inhibition zone values of 11.76mm and 14.33mm at the extract concentration of 150mg/ml that were higher than the positive control values (9.00, 12.67mm) respectively. However, E. coli and P. aeruginosa did not show any inhibition by the ethanol-based extract. Conclusion: From the results we can conclude that E.Longifolia root extract possesses antibacterial activity that can be further explored to produce new medicinal products.

Matched MeSH terms: Pseudomonas aeruginosa
Fulltext Antimicrobial activities of three different seed extracts of Lansium varieties

Alimon, H, Abdullah Sani, A., Syed Abdul Azziz, S. S., Daud, N., Mohd Arriffin, N., Mhd Bakri, Y.

Pertanika Journal of Science & Technology, 2014;22(2):529-540.
MyJurnal

Lansium domesticum Corr. is a fruit tree of the Meliaceae family, which is commonly found in SouthEast Asia with a wide range of varieties. This study investigated three varieties of L. domesticum; Duku, Langsat and Dokong for the phytochemical screening and antimicrobial activity. Seeds from the matured fruits were extracted using hexane, methanol and water. The crude extracts were screened for antimicrobial activities toward three bacteria, namely, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. The findings showed that Langsat seed extracts contained more groups of compounds compared with the other two varieties, and its methanol extract demonstrated the highest inhibition zones against the three bacteria. The crude methanol extract of Duku seeds showed inhibition zones only towards Bacillus subtilis at a high concentration (1.0 mgL-1), whilst the seed extracts of Dokong showed no inhibition zones towards any of the tested bacteria.

Matched MeSH terms: Pseudomonas aeruginosa
Rational use of intravenous polymyxin B and colistin: A review

Zakuan ZD, Suresh K

Med J Malaysia, 2018 10;73(5):351-359.
PMID: 30350826 MyJurnal

Polymyxin B and colistin (polymyxin E) were introduced in clinical practice to treat Gram-negative infections in 1950s but their parenteral use waned in 1970s due to toxicity concerns. Resurgence of polymyxins use in Malaysia began approximately in 2009 due to a lack of treatment options for MDR Gram negative superbugs such as Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. However, limited experience and a lack of widespread availability of up-to-date dosing guidelines could potentially result in incorrect use of these last resort antibiotics by managing doctors. The recent report of polymyxin resistant strains is also a cause of concern. Herein, we discuss the importance of preserving the efficacy of polymyxins in hospitals, the similarities and differences between polymyxin B and colistin, issues pertaining to current use of polymxyins and strategies to improve polymyxins' prescription. Polymyxins should only be used to treat significant infections, in optimum doses and if possible, in combination with other antibiotics.

Matched MeSH terms: Pseudomonas aeruginosa
Detection of toluene degradation in bacteria isolated from oil contaminated soils

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 aeruginosa
The potential of endophytic bacteria as a biological control agent for ganoderma disease In oil palm

Nur Rashyeda Ramli, Maizatul Suriza Mohamed, Idris Abu Seman, Madihah Ahmad Zairun, Nasyaruddin Mohamad

Sains Malaysiana, 2016;45:401-409.

This study was conducted to screen the endophytic bacteria as a biological control agent (BCA) against Ganoderma boninense. A total of 581 endophytic bacteria were successfully isolated from symptomless oil palm root tissues at Teluk Intan, Perak, Malaysia. Three endophytic bacteria, Pseudomonas aeruginosa GanoEB1, Burkholderia cepacia GanoEB2, and Pseudomonas syringae GanoEB3 were found to have a potential as BCA based on their percentage inhibition of radial growth (PIRG) in dual culture and culture filtrate tests. Two nursery trials were conducted to evaluate the capability of these bacteria to suppress Ganoderma disease in oil palm seedlings that were artificially infected with G. boninense using rubber wood block (RWB) sitting technique. The percentage of disease incidence (DI), severity of foliar symptoms (SFS) and dead seedlings were used as the assessment tools. As a result, DI and SFS have developed much slower in the seedlings that were pre-treated with bacteria compared to untreated seedlings. After 6 months of inoculation, Ganoderma disease incidence was reduced from 62-75% in the seedlings treated with P. aeruginosa GanoEB1, followed by B. cepacia GanoEB2 (31-59%) and P. syringae GanoEB3 (30-31%). Among these three endophytic bacteria, P. aeruginosa GanoEB1 was the most effective in controlling Ganoderma disease and the dead seedlings were in the range of 13.3-26.7%, followed by B. cepacia GanoEB2 (33.3% for both trials) and P. syringae GanoEB3 (33.3-40.0%) compared to untreated seedlings at 60% for both trials. A field study needs to be conducted to verify their effectiveness in controlling Ganoderma in oil palm.

Matched MeSH terms: Pseudomonas aeruginosa
Enhancing biodegradation of crude oil in soil using fertilizer and empty fruit bunch of oil palm

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
Isolation and characterization of bacteria degrading Sumandak and South Angsi Oils

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
Fulltext Antimicrobial susceptibility and virulence genes of clinical and environmental isolates of Pseudomonas aeruginosa

Liew SM, Rajasekaram G, Puthucheary SA, Chua KH

PeerJ, 2019;7:e6217.
PMID: 30697478 DOI: 10.7717/peerj.6217

Background: Pseudomonas aeruginosa is ubiquitous, has intrinsic antibiotic resistance mechanisms, and is associated with serious hospital-associated infections. It has evolved from being a burn wound infection into a major nosocomial threat. In this study, we compared and correlated the antimicrobial resistance, virulence traits and clonal relatedness between clinical and fresh water environmental isolates of P. aeruginosa.
Methods: 219 P. aeruginosa isolates were studied: (a) 105 clinical isolates from 1977 to 1985 (n = 52) and 2015 (n = 53), and (b) 114 environmental isolates from different fresh water sources. All isolates were subjected to ERIC-PCR typing, antimicrobial susceptibility testing and virulence factor genes screening.
Results: Clinical and environmental isolates of P. aeruginosa were genetically heterogenous, with only four clinical isolates showing 100% identical ERIC-PCR patterns to seven environmental isolates. Most of the clinical and environmental isolates were sensitive to almost all of the antipseudomonal drugs, except for ticarcillin/clavulanic acid. Increased resistant isolates was seen in 2015 compared to that of the archived isolates; four MDR strains were detected and all were retrieved in 2015. All clinical isolates retrieved from 1977 to 1985 were susceptible to ceftazidime and ciprofloxacin; but in comparison, the clinical isolates recovered in 2015 exhibited 9.4% resistance to ceftazidime and 5.7% to ciprofloxacin; a rise in resistance to imipenem (3.8% to 7.5%), piperacillin (9.6% to 11.3%) and amikacin (1.9% to 5.7%) and a slight drop in resistance rates to piperacillin/tazobactam (7.7% to 7.5%), ticarcillin/clavulanic acid (19.2% to 18.9%), meropenem (15.4% to 7.5%), doripenem (11.5% to 7.5%), gentamicin (7.7% to 7.5%) and netilmicin (7.7% to 7.5%). Environmental isolates were resistant to piperacillin/tazobactam (1.8%), ciprofloxacin (1.8%), piperacillin (4.4%) and carbapenems (doripenem 11.4%, meropenem 8.8% and imipenem 2.6%). Both clinical and environmental isolates showed high prevalence of virulence factor genes, but none were detected in 10 (9.5%) clinical and 18 (15.8%) environmental isolates. The exoT gene was not detected in any of the clinical isolates. Resistance to carbapenems (meropenem, doripenem and imipenem), β-lactamase inhibitors (ticarcillin/clavulanic acid and piperacillin/tazobactam), piperacillin, ceftazidime and ciprofloxacin was observed in some of the isolates without virulence factor genes. Five virulence-negative isolates were susceptible to all of the antimicrobials. Only one MDR strain harbored none of the virulence factor genes.
Conclusion: Over a period of 30 years, a rise in antipseudomonal drug resistance particularly to ceftazidime and ciprofloxacin was observed in two hospitals in Malaysia. The occurrence of resistant environmental isolates from densely populated areas is relevant and gives rise to collective anxiety to the community at large.

Matched MeSH terms: Pseudomonas aeruginosa
Comparative analysis of metabolites and antioxidant potentials from different plant parts of curcuma aeruginosa roxb.

Sanimah Simoh, Sew YS, Fazri Abd Rahim, Muhammad Aizuddin Ahmad, Alizah Zainal

Sains Malaysiana, 2018;47:3031-3041.

A comparative analysis of metabolites from different parts of Curcuma aeruginosa, i.e. leaves, stems, adventitious
roots and rhizomes was performed by GC-MS/MS coupled with multivariate statistical analysis. The GC-MS/MS analysis
confirmed the occurrence of 26 metabolites belonged to terpenoids in almost all the samples. The Principal Component
Analysis (PCA) indicated that there was a clear distinction between rhizomes and other plant parts, i.e. stems, leaves,
and adventitious roots that could be explained by relatively higher contents of terpenoids including curzerene, alphafarnesen, furanocoumarin, velleral, germacrone cineole, borneol, beta- and gamma- elemene and methenolone. The
results of Hierarchical Clustering Analyses (HCA) corresponded with the PCA results where many terpenoids found
abundantly high in rhizome were clustered together. This was supported by the Pearson correlation analysis that
showed a significantly good relationship between those terpenoids. The adventitious roots demonstrated the strongest
antioxidant activity as compared to the other plant parts which could be attributed to its highest Total Phenolic
Contents (TPC). Total phenolic contents of all the plant parts were positively correlated with their antioxidant activities
which indicate that phenolic compounds may play a role in the overall antioxidant activities of the plants. The results
of the study highlighted the potential of this underexploited Curcuma species which could serve as a new source of
important phytochemicals and natural antioxidant that could be incorporated in functional foods and nutraceuticals.
In addition, chemical and biological evidence shown in the present work has rationalised the different uses of various
plant parts of C. aeruginosa.

Matched MeSH terms: Pseudomonas aeruginosa
Development of biofilm-targeted antimicrobial wound dressing for the treatment of chronic wound infections

Ng SF, Leow HL

Drug Dev Ind Pharm, 2015;41(11):1902-9.
PMID: 25758412 DOI: 10.3109/03639045.2015.1019888

It has been established that microbial biofilms are largely responsible for the recalcitrance of many wound infections to conventional antibiotics. It was proposed that the efficacy of antibiotics could be optimized via the inhibition of bacterial biofilm growth in wounds. The combination of antibiofilm agent and antibiotics into a wound dressing may be a plausible strategy in wound infection management. Xylitol is an antibiofilm agent that has been shown to inhibit the biofilm formation. The purpose of this study was to develop an alginate film containing xylitol and gentamicin for the treatment of wound infection. Three films, i.e. blank alginate film (SA), alginate film with xylitol (F5) and alginate film with xylitol and gentamicin (AG), were prepared. The films were studied for their physical properties, swelling ratio, moisture absorption, moisture vapor transmission rate (MVTR), mechanical and rheology properties, drug content uniformity as well as in vitro drug release properties. Antimicrobial and antibiofilm in vitro studies on Staphylococcus aureus and Pseudomonas aeruginosa were also performed. The results showed that AG demonstrates superior mechanical properties, rheological properties and a higher MVTR compared with SA and F5. The drug flux of AG was higher than that of commercial gentamicin cream. Furthermore, antimicrobial studies showed that AG is effective against both S. aureus and P. aeruginosa, and the antibiofilm assays demonstrated that the combination was effective against biofilm bacteria. In summary, alginate films containing xylitol and gentamicin may potentially be used as new dressings for the treatment of wound infection.

Matched MeSH terms: Pseudomonas aeruginosa

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