Testing of glyceryl monoesters for their antimicrobial susceptibility and their influence in emulsions.

Natural anti-microbial agents have received great attention in the cosmetic preservation area due to their well-documented safety profile. The anti-microbial activities of palm-based glyceryl monoesters (monolaurin, monocaprylin and monocaprin) were compared with commercially available tea tree oil and potassium sorbate against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Aspergillus niger, using the anti-microbial susceptibility testing procedure. Monolaurin was found to exhibit excellent inhibitory activity against S. aureus and Asp. niger, whereas potassium sorbate and tea tree oil had no activity against Asp. niger and S. aureus, respectively. Monocaprylin was shown to have low inhibitory activity against E. coli, and no inhibitory activity towards P. aeruginosa. On the other hand, tea tree oil had a higher inhibitory activity than monolaurin at 2% against E. coli but showed no activity against P. aeruginosa. Similar trends were observed for monocaprin and monolaurin which showed no anti-microbial activity towards P. aeruginosa as well as E. coli. Interestingly, the presence of monolaurin was not only effective as a preservative, but was also found to induce the formation of liquid crystals at concentrations as low as 0.5%. The formation of liquid crystals is said to enhance the stability and functionality of cosmetic emulsions

Isolation, Identification, Modification, and Biological Analysis of extracts of A. Mexicana

Argemone mexicana is a member of the Papaveraceae family of plants that has been used for centuries in traditional medicine by indigenous communities in Mexico and the United States. Through a collaborative project, we have explored separation of key components of the seeds and leaves of this plant to isolate the source of their biological activity. We have already identified two key molecules which give this plant anti-microbial properties against the gram-positive bacteria. Furthermore, we have chemically modified one of these molecules to observe variations on activity. We hope this leads to the discovery of new antibiotic drugs

An In Vitro Pipeline for Screening and Selection of Citrus-Associated Microbiota with Potential Anti-"Candidatus Liberibacter asiaticus" Properties.

Huanglongbing (HLB) is a destructive citrus disease that is lethal to all commercial citrus plants, making it the most serious citrus disease and one of the most serious plant diseases. Because of the severity of HLB and the paucity of effective control measures, we structured this study to encompass the entirety of the citrus microbiome and the chemistries associated with that microbial community. We describe the spatial niche diversity of bacteria and fungi associated with citrus roots, stems, and leaves using traditional microbial culturing integrated with culture-independent methods. Using the culturable sector of the citrus microbiome, we created a microbial repository using a high-throughput bulk culturing and microbial identification pipeline. We integrated an in vitro agar diffusion inhibition bioassay into our culturing pipeline that queried the repository for antimicrobial activity against Liberibacter crescens, a culturable surrogate for the nonculturable "Candidatus Liberibacter asiaticus" bacterium associated with HLB. We identified microbes with robust inhibitory activity against L. crescens that include the fungi Cladosporium cladosporioides and Epicoccum nigrum and bacterial species of Pantoea, Bacillus, and Curtobacterium Purified bioactive natural products with anti-"Ca. Liberibacter asiaticus" activity were identified from the fungus C. cladosporioides Bioassay-guided fractionation of an organic extract of C. cladosporioides yielded the natural products cladosporols A, C, and D as the active agents against L. crescens This work serves as a foundation for unraveling the complex chemistries associated with the citrus microbiome to begin to understand the functional roles of members of the microbiome, with the long-term goal of developing anti-"Ca Liberibacter asiaticus" bioinoculants that thrive in the citrus holosystem.IMPORTANCE Globally, citrus is threatened by huanglongbing (HLB), and the lack of effective control measures is a major concern of farmers, markets, and consumers. There is compelling evidence that plant health is a function of the activities of the plant's associated microbiome. Using Liberibacter crescens, a culturable surrogate for the unculturable HLB-associated bacterium "Candidatus Liberibacter asiaticus," we tested the hypothesis that members of the citrus microbiome produce potential anti-"Ca Liberibacter asiaticus" natural products with potential anti-"Ca Liberibacter asiaticus" activity. A subset of isolates obtained from the microbiome inhibited L. crescens growth in an agar diffusion inhibition assay. Further fractionation experiments linked the inhibitory activity of the fungus Cladosporium cladosporioides to the fungus-produced natural products cladosporols A, C, and D, demonstrating dose-dependent antagonism to L. crescens

Evaluation of anti-microbial potential of hydroxycoumarins

Coumarins comprise a very large class of substances found in plants and are made of fused benzene and α-pyrone rings. More than 1300 coumarins have been identified, principally as secondary metabolites in green plants but also in fungi and bacteria. Coumarin and its derivatives are considered nowadays an important class of organic compounds due to their wide spectrum of biological activities and therapeutic applications, including anticoagulant, estrogenic, dermal photosensitising, vasodilator, molluscucidal, antihelmintic, sedative and hypnotic, analgesic and hypothermic activity. A number of studies have reported anti-microbial activities of various coumarins. In contrast, there are few reports of anti-microbial potential of hydroxycoumarins. In this contest, six hydroxycoumarins were tested. The anti-microbial properties were evaluated by two different methods using Fusarium oxysporum (CCMI866), Aspergillus niger (CCMI296), Cladosporium 7F1 and Trichoderma (CCMI783) to access the antimicrobial spectrum of active compounds

New market perspectives using herbs and berries in organic meat products

The aim of the project is to extend the range of organic meat products by introducing new interesting flavour variants. The novelty is to utilize herbs and berries for biological preservation and to provide the products with a new and interesting flavour profile and appearance. The project is consumerdriven as MAPP will study how ecological consumers relate to a new preservation technology in the form of berries and herbs. They will also study how the consumers relate to the new products by evaluations and when buying the products. Among Danish berries and herbs, AU-IHP will select and produce the cultivars which are to be screened at DMRI for anti-microbial activity and favourable flavour characteristics in meat products. Furthermore, AU-IHP will optimize cultivation and storage conditions, preserving the desired characteristics after harvest in the best possible way. DMRI will combine the selected berries and herbs to obtain the best result. The work includes an investigation of how berries and herbs should be added to the meat products and it must be clarified how different raw materials and meat processing affect the anti-microbial activity. The results from DMRI will be validated at test productions at the two participating plants. Finally, we will document that the selected berries and herbs can guarantee food safety and favourable eating quality throughout the entire shelf-life. Economic estimates for total production costs will be made

Antimicrobially active microorganisms associated with marine bryozoans

Bryozoans are sessile colonial animals that can be found in various aquatic and mainly in marine environments. Due to their sessile nature, bryozoans compete for surfaces they can colonize but, on the other hand, are confronted with microbial colonizers on their surfaces. Interactions of the bryozoan with its associates, as well as within the microbial community, are mediated chemically. Biofilm formation and composition is mainly influenced by the use of chemical compounds. Studies on the bryozoan-associated microbial diversity are scarce, and surveys on the antimicrobial potential of these associated bacteria are missing. The present study focused on isolating bryozoan-associated bacteria, assessing their antimicrobial properties and classifying them phylogenetically. Various bryozoan specimens were collected in the Baltic (10 specimens) and the Mediterranean Sea (11 specimens). Bacteria were isolated using a variety of nutrient media and tested for their antimicrobial abilities against Gram-positive and Gram-negative indicator strains, as well as against the yeast Candida glabrata. 30% of all isolates displayed activity and were phylogenetically classified on the basis of 16S rDNA gene sequences. Whereas all isolates were active against Gram-positive indicators, four isolates exhibited additional anti-Escherichia coli activity, the phylogenetic analysis revealed affiliation to Gram-negative phyla (Flavobacteria, Alpha- and Gammaproteobacteria). One isolate belonged to the Gram-positive Actinobacteria. Both species- and strain-specific activity patterns were revealed. Furthermore, site-specific distribution patterns of associated bacteria were found. Of these antibiotically active isolates, the strain B390 was described as type strain of the novel species Tenacibaculum adriaticum. Also, specimens of the bryozoan Membranipora membranacea were sampled in the Baltic Sea for the first more detailed analysis on antimicrobially active isolates. Low-nutrient media featuring “artificial” or “natural” ingredients were used for isolation of bacteria. Additionally, the antibiotic test panel was extended to six different production media. The impact of these media on the phylogenetic diversity, as well as on activity patterns was determined. Although bacteria were affiliated with same phyla (Alpha- and Gammaproteobacteria, Actinobacteria, additionally Bacilli), the isolates of this sampling were more diverse as far as genus or phylotype affiliation was concerned. Especially within the Alphaproteobacteria, several probably novel bacterial species were found. Furthermore, the use of six different media for activity testing resulted in a more than twofold higher hit rate of active isolates in comparison to only one single medium

Lactoferrin. A natural glycoprotein involved in iron and inflammatory homeostasis

Human lactoferrin (hLf), an iron-binding multifunctional cationic glycoprotein secreted by exocrine glands and by neutrophils, is a key element of host defenses. HLf and bovine Lf (bLf), possessing high sequence homology and identical functions, inhibit bacterial growth and biofilm dependently from iron binding ability while, independently, bacterial adhesion to and the entry into cells. In infected/inflamed host cells, bLf exerts an anti-inflammatory activity against interleukin-6 (IL-6), thus up-regulating ferroportin (Fpn) and transferrin receptor 1 (TfR1) and down-regulating ferritin (Ftn), pivotal actors of iron and inflammatory homeostasis (IIH). Consequently, bLf inhibits intracellular iron overload, an unsafe condition enhancing in vivo susceptibility to infections, as well as anemia of inflammation (AI), re-establishing IIH. In pregnant women, affected by AI, bLf oral administration decreases IL-6 and increases hematological parameters. This surprising effect is unrelated to iron supplementation by bLf (80 µg instead of 1-2 mg/day), but to its role on IIH. AI is unrelated to the lack of iron, but to iron delocalization: cellular/tissue overload and blood deficiency. BLf cures AI by restoring iron from cells to blood through Fpn up-expression. Indeed, anti-inflammatory activity of oral and intravaginal bLf prevents preterm delivery. Promising bLf treatments can prevent/cure transitory inflammation/anemia/oral pathologies in athletes

Effect of locally available spices on the organoleptic and storage periods of Heterotis niloticus

Investigation were carried out on the effect of some locally available species in the enhancement of the organoleptic quality and the storage periods of smoked Heterotis niloticus using Pprosopis africana as common smoke sources. Samples of fresh H. niloticus were bought, cut into chunks while extract juice from pepper, ginger rhizomes, garlic, onion bulb were used as sources of spices. Samples of fish were divided randomly into five (5) batches dipped into spice extract juices for 10 minutes drained and smoked with common firewood. Treatment without spice extract juice served as control. Each batch of fish was smoked for 7 hours on a drum-made smoking kiln products were individually packaged in polythene bag stored at room temperature and used for sensory evaluation and microbial analysis. Results of the sensory evaluation indicated that there was significant difference (P0.05) in the microbial analysis. The garlic juice extract had the longest storage period with minimum total plate and mould count after 8 week

Role of lactobacilli and lactoferrin in the mucosal cervicovaginal defense

Human lactoferrin is an iron-binding glycoprotein present at high concentrations in breast milk and colostrum. It is produced by many exocrine glands and widely distributed in a variety of body fluids. This protein has antimicrobial, immunomodulatory, antioxidant, and anticancer properties. Two important hLf receptors have been identified: LDL receptor related protein (LRP1), a low specificity receptor, and intelectin-1 (ITLN1), a high specificity receptor. No data are present on the role of hLf on the biliary epithelium. Our aims have been to evaluate the expression of Lf and its receptors in human and murine cholangiocytes and its effect on proliferation. Immunohistochemistry and immunofluorescence (IF) were conducted on human healthy and primary biliary cholangitis (PBC) liver samples as well as on liver samples obtained from normal and bile duct ligated (BDL) mice to evaluate the expression of Lf, LRP1 and ITLN1. Cell proliferation in vitro studies were performed on human cholangiocyte cell lines via 3-(4,5-dimetiltiazol-2-il)-2,5-diphenyltetrazolium assay as well as IF to evaluate proliferating cell nuclear antigen (PCNA) expression. Our results show that mouse and human cholangiocytes express Lf, LRP1 and ITLN1, at higher extent in cholangiocytes from BDL and PBC samples. Furthermore, the in vitro addition of bovine Lf (bLf) has a proliferative effect on human cholangiocyte cell line. The results support a proliferative role of hLf on the biliary epithelium; this pro-proliferative effect of hLf and bLf on cholangiocytes could be particularly relevant in human cholangiopathies such as PBC, characterized by cholangiocyte death and ductopenia

Prevention of enteroxigenic Escherichia coli infections in pigs by dairy-based nutrition

Abstract Postweaning diarrhea (PWD) is a significant enteric disease causing considerable economic losses for the pig industry. Among several aetiological risk factors, enterotoxigenic Escherichia coli (ETEC) is considered to be a major cause. After being routinely used for several decades to control bacterial disease outbreaks in piglet, the use of antibiotics at subtherapeutic concentrations has been banned in the European Union because of the increasing prevalence of resistance to antibiotics in pigs. The removal of in-feed antibiotics from piglet diets has negative economic consequences as it dramatically increases the rate of morbidity and mortality due to ETEC as well as the use of antibiotics for therapeutic purposes. Other than subtherapeutic antibiotics, zinc oxide (ZnO) had been reported to ameliorate and/or prevent the development of PWD in piglets, but its excretion may have negative impacts on the environment. Thus, other alternatives that control ETEC infections in piglets postweaning will be of great advantage. A number of nutritional strategies have been proposed as alternative means of preventing ETEC infections, of which feeding dairy-based products to piglets could be one of such strategies. It is apparent that colostrums, milk and milk fractions such as whey and casein contain several biologically active compounds with anti-microbial and immunomodulatory properties. Recently, these dairy products and their isolated compounds such as lactoferrin and oligosaccharides have been employed as anti-infective agents against ETEC infections in iglets postweaning. The dairy by-products (e.g. whey or whey permeate) may also be fermented to further improve the anti-infective potential of the products. Overall, the anti-infective activities of dairy-based products against ETEC could be attributed to the improvement of the intestinal barrier functions, microbial ecosystem and immunity of the piglets. Keywords : Dairy-based product; Anti-microbial; Immunomodulation; Anti-infective; Enterotoxigenic Escherichia coli; Postweaning diarrhea; Pigle