2-Octylcyclopentanone Inhibits Beta Lactam Resistant Diabetic Wound Pathogens.

Microbial infection is a frequent complication of diabetic foot ulcers, with up to 82% of ulcers being infected at the initial stage of diabetes. Furthermore, the emergence of beta lactam resistant pathogens managed to eliminate the use of beta lactam antibiotics as a chemotherapeutic alternative. This further increases the amputation and mortality rate. Hence, the aim of this study is to evaluate antimicrobial efficacy of a ketone derivative 2-octylcyclopentanone against diabetic wound pathogens. The inhibitory activity of the compound was determined using disc diffusion and broth microdilution assay. Generally, 2-octylcyclopentanone showed broad-spectrum antimicrobial activity, particularly against beta lactam resistant pathogens. The compound showed comparably better antimicrobial activity than all reference antibiotics, including chloramphenicol, streptomycin, ampicillin and penicillin. In addition, the same compound also inhibits a clinically isolated Pseudonomas aeruginosa that was resistant to all reference antibiotics. The activity was microbicidal based on the low minimal lethality concentration recorded, particularly on MRSA, P. aeruginosa and Candida utilis. The killing efficiency of the compound was concentration dependent. During kill curve analysis, the inhibitory activity of 2-octylcyclopentanone was concentration and time-dependent. 99.9% of reduction of bacterial growth was observed. MRSA and P. aeruginosa, two significant diabetic wound infections, are totally inhibited by the molecule at a concentration of minimum lethality concentration. In short, 2-octylcyclopentanone exhibited significant inhibitory towards wide range of diabetic wound pathogens. Which is considered crucial since it will provide a safe and effective alternative treatment for diabetic ulcer infection.

Jangkitan mikrob adalah komplikasi ulser yang kerap dijangkiti pada kaki pesakit diabetes, yang boleh mencapai sehingga 82% jangkitan pada peringkat awal diabetes. Kemunculan patogen tahan beta laktam berjaya menghapuskan penggunaan antibiotik beta laktam sebagai alternatif kemoterapi. Ini meningkatkan lagi kadar amputasi dan kematian. Oleh itu, tujuan kajian ini adalah untuk menilai keberkesanan antimikrob bagi derivatif keton 2-octylcyclopentanone terhadap patogen luka diabetes. Aktiviti perencatan sebatian ditentukan menggunakan resapan cakera dan ujian cerakinan mikrodilusi. Secara amnya, 2-octylcyclopentanone menunjukkan aktiviti antimikrob spektrum luas, terutamanya terhadap patogen tahan beta laktam. Kompaun tersebut menunjukkan aktiviti antimikrob yang lebih baik berbanding semua antibiotik rujukan, termasuk kloramfenikol, streptomisin, ampisilin dan penisilin. Di samping itu, sebatian yang sama juga menghalang Pseudonomas aeruginosa yang diasingkan secara klinikal yang tahan terhadap semua antibiotik rujukan. Aktiviti ini adalah mikrobisida berdasarkan kepekatan kematian minimum yang rendah yang direkodkan, terutamanya pada MRSA, P. aeruginosa dan Candida utilis. Kecekapan membunuh kompaun adalah bergantung kepada kepekatan. Semasa analisis keluk bunuh, aktiviti perencatan 2-octylcyclopentanone adalah kepekatan dan bergantung kepada masa. 99.9% pengurangan pertumbuhan bakteria diperhatikan. MRSA dan P. aeruginosa, dua jangkitan luka diabetes yang ketara, dihalang sepenuhnya oleh molekul pada kepekatan kepekatan maut minimum. Ringkasnya, 2-octylcyclopentanone menunjukkan perencatan yang ketara terhadap pelbagai patogen luka diabetes. Yang dianggap penting kerana ia akan menyediakan rawatan alternatif yang selamat dan berkesan untuk jangkitan ulser diabetik.

Naringenin-Grafted Polyvinyl Alcohol (Na/PVA) Nanoparticles: Synthesis, Characterisation and In Vitro Evaluation of Its Antimicrobial Efficiency on Fresh Beef.

Food preservatives are commonly used to guarantee the safety and quality of food. Naturally-derived preservatives are preferred by the consumers as chemical preservatives are associated with adverse side effects. The application of naringenin as a food preservative is restricted due to its high volatility, albeit known for its good efficacy in inhibiting microbial growth on food. Thus, this study aimed to synthesis and characterise naringenin-grafted PVA (Na/PVA) nanoparticles as potential meat preservative. The nano-size of naringenin was characterised by transmission electron microscopy. Finally, the antibacterial efficiency of Na/PVA nanoparticles substance was evaluated on disc diffusion assay, broth microdilution assay and using fresh beef as food model. The naringenin nanoparticles appeared in globule and smooth structure, with an average size of less than 200 nm. In total, 11.08% of naringenin nanoparticles was successfully encapsulated into PVA nanoparticles. Based on Fourier transform infrared spectra, naringenin was successfully encapsulated into PVA nanoparticles. The release of naringenin from Na/PVA nanoparticles was slow and gradual, with an initial burst release effect observed. The property was ideal for application in food model. It gained a plateau at 48 h. The Na/PVA nanoparticles depicted its antibacterial efficiency on all the test foodborne bacteria, except E. coli. It was represented by the presence of inhibition zones, which were ranged from 10 mm to 14 mm. The activity was concentration-dependent, and a higher concentration of nanoparticles was needed to kill the test bacteria. The meat coated with Na/PVA nanoparticles displayed a 100% reduction in bacterial load, where no bacterial growth was detected at the sample throughout the incubation period. The coating of nanoparticles also improved the organoleptic property of fresh beef, by maintain the meat colour. The developed nanoparticles can be potentially used nano-preservative to maintain the microbiological quality of fresh beef.

Pengawet makanan biasanya digunakan untuk menjamin keselamatan dan kualiti makanan. Pengawet semulajadi yang diperoleh ialah pilihan oleh pengguna kerana pengawet kimia dikaitkan dengan kesan sampingan yang buruk. Penggunaan naringenin sebagai pengawet makanan adalah terhad kerana turun naik yang tinggi, walaupun dikenali kerana keberkesanan yang baik dalam menghalang pertumbuhan mikrob pada makanan. Oleh itu, kajian ini bertujuan untuk mensintesis dan mencirikan nanozarah PVA (Na/PVA) naringenin sebagai pengawet daging yang berpotensi. Saiz nano naringenin dicirikan oleh mikroskopi elektron penghantaran. Akhirnya, kecekapan antibakteria bahan nanozarah Na/PVA dinilai pada disc diffusion assay, broth microdilution assay dan menggunakan daging lembu segar sebagai model kajian. Naringenin nanozarah muncul dalam globul dan struktur licin, dengan saiz purata kurang daripada 200 nm. Secara keseluruhan, 11.08% daripada naringenin nanozarah telah berjaya dimasukkan ke dalam nanozarah PVA. Berdasarkan pengubah spektra inframerah Fourier, naringenin berjaya dikapsulkan dalam nanozarah PVA. Pelepasan naringenin dari Na/PVA nanozarah adalah perlahan dan beransur-ansur, dengan kesan pelepasan mendadak diperhatikan pada fasa awal kajian. Sifat ini sesuai digunakan untuk menghalang pertumbuhan mikrob pada makanan. Ia mendapat dataran tinggi pada 48 h. Nanozarah Na/PVA menggambarkan kecekapan antibakteria pada semua bakteria bawaan makanan ujian, kecuali E. coli. Ia diwakili oleh kehadiran zon perencatan, yang berkisar dari 10 mm hingga 14 mm. Aktiviti ini bergantung kepada kepekatan, dan kepekatan nanozarah yang lebih tinggi diperlukan untuk membunuh bakteria ujian. Daging yang disalut dengan Na/PVA nanozarah menunjukkan pengurangan 100% dalam beban bakteria, di mana tiada pertumbuhan bakteria dikesan pada sampel sepanjang tempoh inkubasi. Lapisan nanozarah juga meningkatkan sifat organoleptik daging lembu segar, dengan mengekalkan warna daging. Nanozarah yang dibangunkan berpotensi digunakan nano-pengawet untuk mengekalkan kualiti mikrobiologi daging lembu segar.

Carvacrol-loaded polyvinyl alcohol/montmorillonite clay nanocomposite (PVA/MONT/Carva) as an antimicrobial agent for wound dressing

Aims@#This research was conducted to develop and characterize polyvinyl alcohol (PVA)/montmorillonite (MONT) clay incorporated with carvacrol (Carva) nanocomposite film as a potential material in wound dressing.@*Methodology and results@#Organophilic MONT clay, which was initially modified from commercial MONT clay by cetyltrimethylammonium bromide (CTAB), was used in the polymerization process using PVA. The synthesized nanocomposites were visualized via transmission electron microscopy (TEM). The developed film (PVA/MONT/Carva nanocomposite film) was characterized via Fourier transform infrared (FTIR). The investigation on mechanical property and antimicrobial activity of the film was also performed. All nanocomposites are spherical, with a size of 92.8 ± 22.1 nm. The -OH stretch, C-H stretch, aromatic group, SiO stretch, and C-O from acetyl group were identified in the PVA/MONT/Carva nanocomposite films. During the chemical release test, carvacrol attained a plateau at 24 h, with a total release of 62.3%. This nanocomposite exhibited a severe detrimental influence on the growth of Gram-bacteria and yeasts, which represented a broad spectrum of antimicrobial agents. All test microorganisms showed approximately up to 82% reduction of microbial growth during the Hohenstein challenge test. Physically, the nanocomposite films were yellowish and apparent. The film was sturdy, flexible, elastic and consisted of excellent water holding capacity.@*Conclusion, significance and impact of study@#PVA/MONT/Carva nanocomposite film may have a useful potential to be merged in the pharmaceutical application, especially in wound dressing production.

Antimicrobial wound dressing film utilizing nano-cellulose and gelatin as drug delivery system for Garcinia mangostana L extract

Aims@#Diabetic patients with foot ulcer showed 150-fold increased risk of amputation, which is primarily caused by microbial infection. Silver ions are commonly incorporated into wound dressing to enhance the antimicrobial property. However, concerns have been expressed about the development of bacterial resistance to heavy metals. In this study, we extracted the nano-cellulose from medical cotton and reinforced with gelatin to develop a film for wound dressing. @*Methodology and results@#Garcinia mangostana L pericarp extract was incorporated into the nano-cellulose film as antimicrobial finishing. The efficacy of the developed nano-cellulose film was evaluated on diabetic wound microorganisms. We observed cellulose nano crystals with an average length of 133.71 nm under transmission electron microscope. The developed film showed gradual release of the extract over a period of 48 h and no burst effect was observed. The film exhibited significant inhibitory activity on three Gram positive bacteria, three Gram negative and all filamentous fungi tested. On Hohenstein challenge test, all test microorganisms showed significant growth reduction, with the treatment of the film. We also noticed that the antimicrobial activity of the film sustained even after 20 washes. @*Conclusion, significance and impact of study@#Our results indicate that the G. mangostana L pericarp extract loaded nano-cellulose films exhibited significant inhibitory activity on diabetic wound microorganisms. The developed film can be potentially used to prevent foot ulcer infection among diabetic patients.

Chemical Composition and Antimicrobial Efficiency of Swietenia macrophylla Seed Extract on Clinical Wound Pathogens

Microbial wound infection prolonged the hospitalization and increase the cost for wound management. Silver is commonly used as antimicrobial wound dressing. However, it causes several adverse side effects. Hence, this study was aimed to evaluate the antimicrobial efficiency of Swietenia macrophylla seed extract on clinical wound pathogens. Besides, the bioactive constituents of the seed extract were also determined. S. macrophylla seeds were extracted with methanol by maceration method. The seed extract inhibited 5 test bacteria and 1 yeast on disc diffusion assay. The antibacterial activity was broad spectrum, as the extract inhibited both Gram positive and Gram negative bacteria. On kill curve analysis, the antibacterial activity of the seed extract was concentration-dependent, the increase of extract concentration resulted in more reduction of bacterial growth. The extract also caused 99.9% growth reduction of Bacillus subtilis relative to control. A total of 21 compounds were detected in gas chromatography-mass spectrometry analysis. The predominant compounds present in the extract were oleic acid (18.56%) and linoleic acid (17.72%). In conclusion, the methanolic extract of S. macrophylla seeds exhibited significant antimicrobial activity on clinical wound pathogens. Further investigations should be conducted to purify other bioactive compounds from the seeds of S. macrophylla.

Chemical compositions and in vitro antimicrobial activity of Cymbopogon nardus on food borne microorganisms

Aims@#Food borne infections are routinely observed and frequently reported. Cymbopogon nardus, or commonly known as citronella is a tropical plant widely used for aromatherapy and insect repellant. This study aimed to evaluate the phytochemical compositions of C. nardus ethanol extract and its antimicrobial activity on food borne microorganisms. @*Methodology and results@#The plant materials were extracted with ethanol using maceration technique. The ethanol extract obtained was analysed using GC-MS and the most abundant compounds were 6-methyloctahydrocoumarin (31.5%) and 2,4-di-tert-butylphenol (28.7%). On Kirby Bauer assay, the extract showed wide spectrum inhibitory effect on one Gram-positive bacteria (Bacillus coagulans), two Gram-negative bacteria (Proteus mirabilis and Escherichia coli), and one yeast (Candida albicans). All the test microorganisms showed different susceptibility to the extract, where the minimal inhibitory concentrations were ranged from 63 to 250 μg/mL. The inhibitory effect of the extract was bactericidal. In addition, the time kill analysis of the extract exhibited inhibitory effect on P. mirabilis which was concentration-dependent. The C. nardus extract exhibited rapid bactericidal effect on P. mirabilis and lower bacterial counts were obtained with increased extract concentration. Besides, the extract did not exert significant toxicity effect to Artemia salina on brine shrimp lethality assay. @*Conclusion, significance and impact of study@#Therefore C. nardus can be a potential source of safe and effective antimicrobial agent to combat food borne infections.

Garcinexanthone G, a Selective Butyrylcholinesterase Inhibitor from the Stem Bark of Garcinia atroviridis

The present study was undertaken to investigate the isolated compounds from the stem bark of Garcinia atroviridis as potential cholinesterase inhibitors and the ligand-enzyme interactions of selected bioactive compounds in silico. The in vitro cholinesterase results showed that quercetin (3) was the most active AChE inhibitor (12.65 ± 1.57 µg/ml) while garcinexanthone G (6) was the most active BChE inhibitor (18.86 ± 2.41 µg/ml). It is noteworthy to note that compound 6 was a selective inhibitor with the selectivity index of 11.82. Molecular insight from docking interaction further substantiate that orientation of compound 6 in the catalytic site which enhanced its binding affinity as compared to other xanthones. The nature of protein-ligand interactions of compound 6 is mainly hydrogen bonding, and the hydroxyl group of compound 6 at C-10 is vital in BChE inhibition activity. Therefore, compound 6 is a notable lead for further drug design and development of BChE selective inhibitor.

Chemical Composition and Antimicrobial Efficacy of Helminthostachys zeylanica against Foodborne Bacillus cereus

Helminthostachys zeylanica is a rare plant grows in lightly shaded areas. The fern was traditionally used as antipyretic and antiphlogistic agents. This study was aimed to evaluate the antibacterial potential of H. zeylanica on foodborne Bacillus cereus. The chemical composition of its ethanolic extract was also determined. The plant samples were collected at Kampung Kebun Relong, Kedah, Malaysia. The ethanolic extract showed significant inhibitory activity on B. cereus with a sizeable clear zone detected on disc diffusion assay. On broth microdilution assay, the MIC of the extract on B. cereus was 6.25 mg/ml and the MBC was 12.5 mg/ml. The inhibitory activity of the extract on B. cereus was bactericidal. In the growth dynamic study, the antibacterial efficacy of the extract was concentration dependent, where a lower colony forming unit count was obtained with increased extract concentration. The SEM micrograph of extract treated B. cereus cells showed invaginations of cell wall. The bacterial cell structure collapsed after 24 h exposure to the extract. The GCMS analysis of the extract showed that the major constituents of the extract were phenol (36.26%) and quercetin (29.70%). This study is important as it shows the potential use of H. zeylanica as an effective agent to control B. cereus related infections.

Antimicrobial activity of Aspergillus sp. IBRL MP15 CCL, an endophytic fungus isolated from Swietenia macrophylla leaf against human pathogens

@#Aims: Endophytes are microorganisms residing in the living tissues of the host plant and may contribute to their hostplant by producing a plethora of bioactive compounds that provide survival value to the plant. This study aimed toevaluate the antimicrobial activity of Aspergillus sp. IBRL MP15 CCL, an endophytic fungus isolated from Swieteniamacrophylla leaf.Methodology and results: The antimicrobial activity was evaluated with disc diffusion and a colorimetric brothmicrodilution test against 15 organisms comprising of 4 Gram-positive bacteria and 4 Gram-negative bacteria, 4 fungiand 3 yeast. On disc diffusion assay, the fungal extract was shown to inhibit the growth of 7 test bacteria and 3 testyeast. The antibacterial activity was more pronounced with extract from fungal culture with host plant extractsupplementation with significantly larger inhibition zones on all susceptible test microorganisms. The minimal inhibitoryconcentration of the extract ranged from 250 to 4000 μg/mL indicating different level of susceptibility of the testedpathogens against the fungal extract. The killing kinetic study shows that antimicrobial activity of the fungal extract isconcentration dependent and it can act as bactericidal at higher concentration.Conclusion, significance and impact of study: The findings of this study suggest that Aspergillus sp. IBRL MP15CCL can be a promising source of antimicrobial agent to be further studied and developed

Anthocyanins from Clitoria ternatea Attenuate Food-Borne Penicillium expansum and its Potential Application as Food Biopreservative

Clitoria ternatea or Commonly known blue pea, is a perennial climber crop native to Asian countries. The current study was aimed to evaluate the antimicrobial activity C. ternatea extract on food borne microorganisms and its antifungal effect on Penicillium expansum. The extract showed significant antimicrobial activity against 3 Gram positive bacteria, 2 Gram negative bacteria and 1 filamentous fungus on disc diffusion assay. The extract also showed good biocidal effect on all Gram positive bacteria tested and P. expansum. However, the kill curve analysis revealed that the fungicidal activity of the extract against P. expansum conidia was depend on the concentration of the extract and the time of exposure of the conidia to the extract. The scanning electron micrograph of the extract treated P. expansum culture showed alterations in the morphology of fungal hyphae. The germination of P. expansum conidia was completely inhibited and conidial development was totally suppressed by the extract, suggesting the possible mode of action of anthocyanin. Besides, the extract also exhibited 5.0-log suppression of microbial growth relative to control in the rice model. The results indicate the potential use of the C. ternatea anthocyanin as food biopreservative.