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In vitro antimicrobial activity of ethanol and water extracts of Cassia alata

Somchit MN, Reezal I, Nur IE, Mutalib AR

J Ethnopharmacol, 2003 Jan;84(1):1-4.
PMID: 12499068

Crude ethanol and water extract of leaves and barks from Cassia alata were tested in vitro against fungi, (Aspergillus fumigatus and Microsporum canis), yeast (Candida albicans) and bacteria (Staphylococcus aereus and Escherichia coli). C. albicans showed concentration-dependent susceptibility towards both the ethanol and water extracts from the barks, but resistant towards the extracts of leaves. The degree of susceptibility varied, the water extract from barks showed bigger inhibition zone than the ethanol extracts (12-16 and 10-14 mm, diameter respectively). The growth of Aspergillus fumigatus and Microsporum canis were not affected by all types of the plant extracts. Results were comparable to standard antifungal drug Tioconazole (18 mm diameter) at equivalent concentration. The anti-bacterial activity of C. alata extracts on S. aureus was detected with only the leaves extracts using water and ethanol. The water extract exhibited higher antibacterial activity than the ethanol extract from leaves (inhibition zones of 11-14 and 9-11 mm, respectively). E. coli showed resistance to all types of extracts. Based on the current findings, it can be concluded that this plant has antimicrobial activity, which is as potent as standard antimicrobial drugs against certain microorganisms.

Matched MeSH terms: Aspergillus fumigatus/drug effects
Fulltext Efficacy of metabolites of a Streptomyces strain (AS1) to control growth and mycotoxin production by Penicillium verrucosum, Fusarium verticillioides and Aspergillus fumigatus in culture

Danial AM, Medina A, Sulyok M, Magan N

Mycotoxin Res, 2020 May;36(2):225-234.
PMID: 31960351 DOI: 10.1007/s12550-020-00388-7

The objectives of this study were to determine the efficacy of metabolites of a Streptomyces strain AS1 on (a) spore germination, (b) mycelial growth, (c) control of mycotoxins produced by Penicillium verrucosum (ochratoxin A, OTA), Fusarium verticillioides (fumonisins, FUMs) and Aspergillus fumigatus (gliotoxin) and (d) identify the predominant metabolites involved in control. Initial screening showed that the Streptomyces AS1 strain was able to inhibit the mycelial growth of the three species at a distance, due to the release of secondary metabolites. A macroscopic screening system showed that the overall Index of Dominance against all three toxigenic fungi was inhibition at a distance. Subsequent studies showed that the metabolite mixture from the Streptomyces AS1 strain was very effective at inhibiting conidial germination of P. verrucosum, but less so against conidia of A. fumigatus and F. verticillioides. The efficacy was confirmed in studies on a conducive semi-solid YES medium in BioScreen C assays. Using the BioScreen C and the criteria of Time to Detection (TTD) at an OD = 0.1 showed good efficacy against P. verrucosum when treated with the Streptomyces AS1 extract at 0.95 and 0.99 water activity (aw) when compared to the other two species tested, indicating good efficacy. The effective dose for 50% control of growth (ED50) at 0.95 and 0.99 aw were approx. 0.005 ng/ml and 0.15 μg/ml, respectively, with the minimum inhibitory concentration (MIC) at both aw levels requiring > 40 μg/ml. In addition, OTA production was completely inhibited by 2.5 μg/ml AS1 extract at both aw levels in the in vitro assays. Ten metabolites were identified with four of these being predominant in concentrations > 2 μg/g dry weight biomass. These were identified as valinomycin, cyclo(L-Pro-L-Tyr), cyclo(L-Pro-L-Val) and brevianamide F.

Matched MeSH terms: Aspergillus fumigatus/drug effects
Clinical effectiveness of early posaconazole suspension pre-emptive therapy in lung transplant recipients: The Alfred's experience

Jeong W, Snell GI, Levvey BJ, Westall GP, Morrissey CO, Ivulich S, et al.

J Antimicrob Chemother, 2017 Jul 01;72(7):2089-2092.
PMID: 28369489 DOI: 10.1093/jac/dkx085

Objectives: This study describes the clinical outcomes and therapeutic drug monitoring (TDM) following posaconazole suspension pre-emptive therapy in lung transplant (LTx) recipients.
Methods: This was a single-centre, retrospective cohort study evaluating posaconazole suspension pre-emptive therapy in LTx recipients between January 2009 and December 2015.
Results: Forty-two LTx recipients were prescribed posaconazole suspension pre-emptively. Aspergillus fumigatus was the most commonly isolated fungal organism. Of the patients receiving posaconazole suspension as the initial antifungal post-LTx, 93% had eradication of colonization at 6 months after commencing therapy. In contrast, only 61% had eradication of fungal colonization when posaconazole suspension was administered following initial therapy with voriconazole. Posaconazole suspension appeared to be well tolerated, although one case was curtailed following concern about abnormal liver function and another due to nausea/vomiting. TDM was performed in 37 patients. The initial median (IQR) trough plasma concentration ( C min ) following 400 mg twice-daily posaconazole suspension was 0.78 (0.46-1.19) mg/L. Doses beyond 800 mg daily did not appear to result in a higher median C min.
Conclusions: Early initiation of posaconazole suspension pre-emptive therapy in LTx recipients appears to be well tolerated and may potentially afford favourable clinical outcomes.

Matched MeSH terms: Aspergillus fumigatus/drug effects*
Synthesis, Structural Characterization, and Bioactivity of the Stable Peptide RCB-1 from Ricinus communis

Boldbaatar D, Gunasekera S, El-Seedi HR, Göransson U

J Nat Prod, 2015 Nov 25;78(11):2545-51.
PMID: 26509914 DOI: 10.1021/acs.jnatprod.5b00463

The Ricinus communis biomarker peptides RCB-1 to -3 comprise homologous sequences of 19 (RCB-1) or 18 (RCB-2 and -3) amino acid residues. They all include four cysteine moieties, which form two disulfide bonds. However, neither the 3D structure nor the biological activity of any of these peptides is known. The synthesis of RCB-1, using microwave-assisted, Fmoc-based solid-phase peptide synthesis, and a method for its oxidative folding are reported. The tertiary structure of RCB-1, subsequently established using solution-state NMR, reveals a twisted loop fold with antiparallel β-sheets reinforced by the two disulfide bonds. Moreover, RCB-1 was tested for antibacterial, antifungal, and cytotoxic activity, as well as in a serum stability assay, in which it proved to be remarkably stable.

Matched MeSH terms: Aspergillus fumigatus/drug effects