Effect of chito-oligosaccharides with different degrees of polymerization on Botrytis cinerea and Mucor piriformis

acceptedVersio

Effect of chito-oligosaccharides with different degrees of polymerization on Botrytis cinerea and Mucor piriformis

acceptedVersio

Adherence Inhibition of Enteropathogenic Escherichia coli by Chitooligosaccharides with Specific Degrees of Acetylation and Polymerization

acceptedVersio

Antibiotic saving effect of combination therapy through synergistic interactions between well-characterized chito-oligosaccharides and commercial antifungals against medically relevant yeasts

Combination therapies can be a help to overcome resistance to current antifungals in humans. The combined activity of commercial antifungals and soluble and well-defined low molecular weight chitosan with average degrees of polymerization (DPn) of 17–62 (abbreviated C17 –C62) and fraction of acetylation (FA) of 0.15 against medically relevant yeast strains was studied. The minimal inhibitory concentration (MIC) of C32 varied greatly among strains, ranging from > 5000 μg mL-1 (Candida albicans and C. glabrata) to < 4.9 (C. tropicalis). A synergistic effect was observed between C32 and the different antifungals tested for most of the strains. Testing of several CHOS preparations indicated that the highest synergistic effects are obtained for fractions with a DPn in the 30–50 range. Pre-exposure to C32 enhanced the antifungal effect of fluconazole and amphotericin B. A concentration-dependent post-antifungal effect conserved even 24 h after C32 removal was observed. The combination of C32 and commercial antifungals together or as part of a sequential therapy opens new therapeutic perspectives for treating yeast infections in humans

Antifungal activity of well-defined chitooligosaccharide preparations against medically relevant yeasts

publishedVersio

Effect of the reducing end sugars (GlcN vs GlcNAc) on the ability of CHOS to inhibit germination of <i>B. cinerea</i> (measured 24 hours after inoculation).

<p>Squares: chitosan, DP_n 206, 85 % D at the reducing end; circles: CHOS generated by ScCsn46A, DP_n 33.5, >90% GlcN at the reducing end; triangles: CHOS generated by ChiA, DP_n 34.6, about 35% GlcNAc at the reducing end. Data points represent the mean of three replicate wells.</p

Préface

<p>Effect of combinations of chitosan (DP_n 206) or CHOS (DP_n 30) and Signum on cumulative <i>Botrytis cinerea</i> infection of detached chickpea leaves.</p

Effect of combinations of chitosan (DP_n 206) or chito-oligosaccharides (CHOS DP_n30) and Switch on <i>Botrytis cinerea</i> infection of detached chickpea leaves.

<p>Disease development was scored daily up to eight days after inoculation.</p>a<p>All data are the mean of three replicates (each replicate contained three compound leaves with 6 inoculated leaflets) ± standard deviation.</p>b<p>The AUDPC was used to calculate the protection index.</p>c<p>E_obs/E_exp 1 indicates additivity; E_obs/E_exp>1 indicates synergy.</p>d<p>Conidia in sterile water.</p>e<p>Recommended dose.</p

Inhibition of disease development in strawberry flowers inoculated with a mixture of <i>Botrytis cinerea</i> conidia and chitooligosaccharides (CHOS DP_n 23) and/or synthetic fungicides.

<p>Disease development and protection index were scored as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093192#pone-0093192-t003" target="_blank">Table 3</a>. The synergistic effect was calculated by determining the ratio between the observed efficacy E_obs (% inhibition) and the expected efficacy (E_exp) (see materials and methods). An E_obs/E_exp value of 1 indicates additivity, while E_obs/E_exp>1 indicates synergy.</p>a<p>The recommended doses for the synthetic fungicides are 1500, 500, 1000 and 1000 μg mL⁻¹ for Teldor, Switch, Amistar and Signum, respectively.</p>b<p>All data are the mean of two experiments ± standard deviation, with 6×3 flowers in each treatment.</p>c<p>The AUDPC was used to calculate the protection index.</p>d<p>Conidia in sterile water.</p