Effects of theFusariumspp. mycotoxins fusaric acid and deoxynivalenol on the growth ofRuminococcus albusandMethanobrevibacter ruminantium

2000 ◽  
Vol 46 (8) ◽  
pp. 692-699 ◽  
Author(s):  
Harold D May ◽  
Qingzhong Wu ◽  
Cheryl K Blake

The Fusarium spp. mycotoxins fusaric acid and deoxynivalenol (DON) were tested for antimicrobial activity against Ruminococcus albus and Methanobrevibacter ruminantium. The growth of both organisms was inhibited by fusaric acid as low as 15 µg/mL (84 µM) but not by DON, at levels as high as 100 µg/mL (338 µM). No synergistic inhibitory effect was observed with DON plus fusaric acid. Neither organism was able to adapt to the fusaric acid and responses of each organism to the compound were different. The optical density (OD) maximum for R. albus, but not for M. ruminantium, was diminished after 28 days incubation at concentrations of fusaric acid below 240 µg/mL. Inhibition of R. albus started before significant growth had occurred, while M. ruminantium doubled twice before the onset of inhibition. Responses to picolinic acid, an analog of fusaric acid, were also dramatically different between the two microorganisms with M. ruminantium exhibiting a severe lag followed by a complete recovery of growth, while R. albus was only slightly inhibited with no lag. These results suggest that the mechanism of fusaric acid inhibition is specific to each microorganism. This is the first demonstration of the common mycotoxin fusaric acid inhibiting the growth of rumen bacteria.Key words: mycotoxins, fusaric acid, deoxynivalenol, Ruminococcus albus, Methanobrevibacter ruminantium.

2009 ◽  
Vol 6 (2) ◽  
pp. 354-360
Author(s):  
Baghdad Science Journal

The Antimicrobial activity of Probiotic Bifidobacterium sp and Prebiotics : chicory roots ( Hot water extract ) and Inulin ( 10 % ) against some Pathogenic bacteria (Esherichia coli , Proteus mirabilis , Klebsiella sp , Pseudomonas aeruginosa , Serratia marcescens was studied . The combination of Probiotic and Prebiotics (Synbiotic) (Bifidobacterium sp + chicory ) and (Bifidobacterium sp + Inulin ) also tested for their antimicrobial activity against Pathogenic bacteria . Results showed that Bifidobacterium sp had good antimicrobial activity against all the Pathogenic bacteria tested , followed by chicory and inulin . The synergistic inhibitory effect of Synbiotic (Bifidobacterium sp + chicory ) and ( Bifidobacterium sp + inulin ) on Pathogenic bacteria was higher than the effect of Bifidobacterium sp alone, chicory alone and inulin alone.


2012 ◽  
Vol 47 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Nasima Akhtar ◽  
Monzur Morshed Ahmeda ◽  
Nishat Sarker ◽  
Khandaker Rayhan Mahbuba ◽  
Abdul Matin Sarker

Growth response of Spirulina platensis in papaya skin extract media and their antimicrobial activity were studied. Five different concentrations  e.g. 10gm/L, 8gm/L, 6 gm/L, 4 gm/L and 2gm/L of Papaya (Carica papaya) skin extract media and BD1 (control) medium were used  in this study. After 8 days of cultivation, the optical density (0.33) was recorded in BD1 medium and among the five different concentrations  of papaya skin extract media the maximum was found (0.31) in 6gm/L. Antimicrobial activity of Spirulina platensis grown in three  media namely Zarrouk, BD1 media and media made from papaya skin extract was also studied. Only freeze dried Spirulina platensis powder  extract showed inhibitory effect against bacteria and no antifungal activity was observed. DOI: http://dx.doi.org/10.3329/bjsir.v47i2.11445 Bangladesh J. Sci. Ind. Res. 47(2), 147-152, 2012  


2018 ◽  
Vol 115 (42) ◽  
pp. 10672-10677 ◽  
Author(s):  
Stephanie A. Heusser ◽  
Marie Lycksell ◽  
Xueqing Wang ◽  
Sarah E. McComas ◽  
Rebecca J. Howard ◽  
...  

Theories of general anesthesia have shifted in focus from bulk lipid effects to specific interactions with membrane proteins. Target receptors include several subtypes of pentameric ligand-gated ion channels; however, structures of physiologically relevant proteins in this family have yet to define anesthetic binding at high resolution. Recent cocrystal structures of the bacterial protein GLIC provide snapshots of state-dependent binding sites for the common surgical agent propofol (PFL), offering a detailed model system for anesthetic modulation. Here, we combine molecular dynamics and oocyte electrophysiology to reveal differential motion and modulation upon modification of a transmembrane binding site within each GLIC subunit. WT channels exhibited net inhibition by PFL, and a contraction of the cavity away from the pore-lining M2 helix in the absence of drug. Conversely, in GLIC variants exhibiting net PFL potentiation, the cavity was persistently expanded and proximal to M2. Mutations designed to favor this deepened site enabled sensitivity even to subclinical concentrations of PFL, and a uniquely prolonged mode of potentiation evident up to ∼30 min after washout. Dependence of these prolonged effects on exposure time implicated the membrane as a reservoir for a lipid-accessible binding site. However, at the highest measured concentrations, potentiation appeared to be masked by an acute inhibitory effect, consistent with the presence of a discrete, water-accessible site of inhibition. These results support a multisite model of transmembrane allosteric modulation, including a possible link between lipid- and receptor-based theories that could inform the development of new anesthetics.


PPAR Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Wen Bao ◽  
Rui Kong ◽  
Nan Wang ◽  
Wei Han ◽  
Jie Lu

At present, there are more and more patients with acute hypertriglyceridemia pancreatitis in clinical practice. Common treatment measures include fasting and water withdrawal, fluid resuscitation, and somatostatin. In recent years, studies have pointed out that the PPARa agonist fenofibrate may help improve the condition of such patients. Therefore, through clinical research and analysis, we reported for the first time that fenofibrate combined with octreotide acetate has a more excellent effect in the treatment of patients with acute hypertriglyceridemia pancreatitis, and from the perspective of signal pathways, we revealed that the combination of the two drugs has an effect on NF-κB P65. The synergistic inhibitory effect proves that the combined treatment is beneficial to control inflammation, protect liver function, and improve the prognosis of patients. It is worthy of clinical promotion.


Author(s):  
PAULA ALEJANDRA GIRALDO VILLAMIL ◽  
ANDRÉS CAMILO ANDRADE BURBANO ◽  
LUIS POMBO OSPINA ◽  
JANETH ARIAS PALACIOS ◽  
ÓSCAR EDUARDO RODRÍGUEZ AGUIRRE

Objective: The objective of the study was to determine the antimicrobial activity of leaf and flower extract in Chromolaena scabra (L. f.) R.M. King and H. Rob., against selected strains of bacteria and fungi. Methods: The agar diffusion method with plate perforation was developed; the microorganisms used were strains of Staphylococcus aureus and Escherichia coli, Aspergillus niger, and Penicillium digitatum. Rifampicin was used as a positive control. The evaluation was performed by measuring the diameter of the growth inhibition zones around the holes. The inhibitory effect of the plant extracts was obtained by its efficiency compared to the positive control. A comparison with fluconazole and ketoconazole was performed to determine how much of the extract is required to cause inhibition of fungal growth from the standard. Results: IC50 was determined by relating the ln of mass evaluated with respect to the square of the inhibition halo; ethanolic extracts of leaves and flowers of petroleum ether with IC50 values of 85.8 mg/ml and 50.3 mg/ml showed the highest inhibitory effect against S. aureus; the extract of petroleum ether and ethanol from leaves with IC50 of 64 mg/ml and 60 mg/ml, respectively. They were effective with A. niger. Leaf petroleum ether extract showed the best relative antifungal activity against A. niger with respect to fluconazole equivalent to 459.51 when fluconazole is 1.0. Conclusion: The extracts with high potential to inhibit the growth of microorganisms were determined to be ether flowers of petroleum and ethanol leaf extracts.


Author(s):  
Kokkaiah Irulandi ◽  
Sethupandian Geetha ◽  
Palanichamy Mehalingam

Objective: To determine antimicrobial activity of methanol, ethyl acetate and acetone extracts of Myristica fatua, Alstonia boonei, Helicteres isora, Vitex altissima and Atalantia racemosa  against different species of pathogens, Streptococcus feacalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Staphyllococcus aureus, and Candida albicans.Methods: Antimicrobial activity of plant extracts was measured by agar well diffusion method.Results: Acetone extracts of Alstonia boonei showed the highest inhibitory effect against Escherichia coli (21.00 ± 1.00 mm) and Streptococcus faecalis (19.00 ± 1.00 mm). All the extracts of Heliteres isora leaves showed different zone of inhibition observed in all the tested pathogens ranges between (8.13 ± 1.53 – 15.25 ± 1.23 mm). Ethyl acetate extract of Vitex altissima showed highest activity against Bacillus sublilis (19.67 ± 1.53 mm). Methanol and acetone leaves extracts of Atalantia racemosa have good fungal activity against the Candida albicans (19.33 ± 1.26 mm - 16.00 ± 1.00 mm). Methanol extract of Myristica fatua showed high antimicrobial activity against Pseudomonas aeruginosa (15.10 ± 0.17 mm) and Bacillus subtilis (14.23 ± 0.21 mm).Conclusion: The results from the study suggest that the leaves Myristica fatua, Alstonia boonei, Helicteres isora, Vitex altissima and Atalantia racemosa showed good antimicrobial activity against the different pathogens. They are used as the alternative source for the control and treatment of microbial infections.Keywords: Antimicrobial activity, Leaves extracts,  Well diffusion method, Pathogenic strains.


2019 ◽  
Vol 82 (3) ◽  
pp. 441-453 ◽  
Author(s):  
ZHENHONG GAO ◽  
ERIC BANAN-MWINE DALIRI ◽  
JUN WANG ◽  
DONGHONG LIU ◽  
SHIGUO CHEN ◽  
...  

ABSTRACT Foodborne pathogens are serious challenges to food safety and public health worldwide. Fermentation is one of many methods that may be used to inactivate and control foodborne pathogens. Many studies have reported that lactic acid bacteria (LAB) can have significant antimicrobial effects. The current review mainly focuses on the antimicrobial activity of LAB, the mechanisms of this activity, competitive growth models, and application of LAB for inhibition of foodborne pathogens.


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