1,720,959 research outputs found
PROBIOTIC, PREBIOTIC, AND SYNBIOTIC APPROACHES IN SUSTAINABLE POULTRY PRODUCTION THROUGH MICROBIOME MODULATION
No full textCampylobacter is one of the prominent causative agents of acute gastroenteritis in the US and more than 70% of Campylobacter infections, known as Campylobacteriosis, are occurred through raw or undercooked poultry consumption or improper handling of contaminated poultry products. Moreover, reports show that the antibiotic resistance pattern of Campylobacter is persistent and in the absence of sub-therapeutic antibiotic growth promoter, colonization of this bacterial pathogen in poultry gut or on skin and the potential risk of cross-contamination of the finished poultry products are increasing, Therefore, both conventional and organic/pasture poultry farmers are searching for sustainable alternative to synthetic antibiotics which can reduce colonization and cross-contamination of poultry products with poultry-borne bacterial pathogens specifically Campylobacter. On the other hand, due to the consumers’ demand, majority poultry farmers are growing their chicks without sub-therapeutic growth promotor which leads to slow growth and higher mortality rates. Therefore, to make the poultry farming sustainable, farmers need alternative feed or water supplement which can promote poultry health and growth. Probiotics, prebiotics, or a combination of these two referred to as synbiotics, have emerged as a promising natural and alternative approach to sustainable animal farming. Probiotics and their metabolites such as conjugated linoleic acids (CLAs) play a crucial role in improving host health and act as antimicrobials against enteric pathogens. Our lab developed a genetically engineered probiotic, LC+mcra that can convert more CLA by over-expressing the mcra (myosin-cross-reactive-antigen) in Lactobacillus casei (LC). Further, prebiotic-like components such as bioactive phenolic extracts (BPEs) from berry pomace can stimulate the growth of beneficial microbes including LC, competitively inhibit growth of enteric bacterial pathogens, and promote the growth of chickens in a concentration-dependent manner when applied throughout the growth period. In our previous study, we observed that LC+mcra effectively eliminated Campylobacter jejuni (CJ) in co-culture condition as well as the cell free culture supernatants (CFCS) of LC+mcra was effective in growth reduction of CJ. LC+mcra and its CFCSs also reduced the adherence and invasion ability of CJ to both HD-11 and HeLa cells. Physicochemical properties and gene expressions related to CJ virulence were also altered by CFCSs treatments. These findings suggested, LC+mcra can be an alternative in controlling CJ growth along with other beneficial attributes of LC. Then, we aimed to enhance the efficiency of antimicrobial/beneficial activities of LC+mcra by combining BPEs. In mixed culture condition, LC+mcra in the presence of BPE reduced the growth of CJ more efficiently as well as the CFCS of LC+mcra in the presence of BPE. Interaction of CJ with cultured DF-1, HD-11, and HeLa were altered significantly. Further, combined treatments altered the physicochemical properties and expression of multiple virulence genes such as ciaB, cdtB, cadF, flaA, flaB of CJ. This finding indicates that BPE and LC+mcra in combination might be able to prevent colonization of CJ in poultry. So, in our present study at simulated gut conditions, we evaluated combined effect of LC+mcra and BPE in reducing growth of Campylobacter in cecum contents. Cecum contents were collected from chickens pre-inoculated with kanamycin resistant CJ (CJ-Km), incubated over 48h time period, while being supplemented with either BPE, CFCS from LC+mcra, or their combination. It was found that combined treatments were able to reduce both inoculated and naturally colonized Campylobacter more effectively. Microbiome analysis using 16S rRNA sequencing also revealed that combined treatments were capable of altering natural microflora positively within chicken cecum contents. Then, the effect of sustainable probiotics on CJ colonization and gut microbiome composition was evaluated using chicken as a model. A total of 120 chickens were used in duplicate trials to investigate the effectiveness of LC+mcra in decreasing CJ colonization by means of CJ-Km compared to the control group. We observed that LC+mcra could efficiently colonize various parts of the chicken gut and competitively reduce colonization of natural and challenged Campylobacter. Furthermore, 16S rRNA compositional analysis revealed lower abundance of Proteobacteria, higher abundance of Firmicutes, along with enriched bacterial genus diversity in gut of LC+mcra fed chicken. Outcomes of this study reveal high potential of LC+mcra as sustainable approach to decrease colonization of Campylobacter in poultry gut along with other beneficial attributes. So, we further evaluated the combined effect of LC+mcra and a low dose of BPE on Campylobacter colonization in chicken gut using a day-old chick model. Colonization of CJ-Km as well as the natural colonization of Campylobacter was reduced by the combined effect of LC+mcra and BPEs significantly at all time points. In the cecum contents of the LC+mcra and BPEs treatment group, there was notable change at phylum level microbiome compared to the control group. At genus level colonization of Lactobacillus was significantly higher (1.7 folds), Campylobacter colonization was reduced significantly (6.3 folds), and other microflora remained balanced due to the combined treatment of LC+mcra and BPEs. Therefore, LC+mcra with BPEs could be an alternative to improve the safety of poultry products and reduce campylobacteriosis in humans sustainably. The application period of this synbiotic compositions could be extended to improve the poultry growth rate as an additional benefit of the LC+mcra and BPEs
BIOACTIVE LACTOBACILLUS CASEI IN REDUCING GROWTH AND COLONIZATION OF CAMPYLOBACTER JEJUNI
No full textCampylobacter jejuni (CJ) is one of the pre-dominant causative agents of acute gastroenteritis in the US and occurs commonly through handling/consumption of contaminated poultry products. Probiotics with enhanced bioactive metabolites such as conjugated linoleic acids (CLAs) play crucial role in improving host health and act as antimicrobials. Further, prebiotic like components such as bioactive phenolics from berry pomace extract (BPE) can stimulate growth of beneficial microbes including Lactobacillus casei (LC) and inhibit bacterial pathogens in vitro. In this study, we aimed to assess efficiency of CLA overproducing LC (LC+mcra) alone or in presence of BPE against CJ. LC+mcra alone or LC+mcra with BPE reduced CJ growth, adhesion and invasion efficiency to cultured cells and also altered physicochemical properties, gene expressions related to virulence. These findings suggest, BPE and LC+mcra in combination may able to prevent CJ colonization in poultry and reduce cross-contamination, hence control foodborne infections with CJ in human
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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