1,721,237 research outputs found
Antibiotic usage practices and its drivers in commercial chicken production in Bangladesh
Get PDFIrrational and inappropriate use of antibiotics in commercial chicken production can contribute to the development of antimicrobial resistance. We aimed to assess antibiotic usage in commercial chicken production in Bangladesh, and identify factors associated with this practice. We conducted a large-scale cross-sectional study to collect information on antibiotic usage in commercial chickens from January to May 2021. Structured interviews were conducted with 288 broiler, 288 layer and 192 Sonali (locally-produced cross-bred) farmers in 20 sub-districts across Bangladesh. The frequency of antibiotic usage, the types of antibiotics and purpose of usage were estimated for each production type. Adjusted odds ratios (aOR) were calculated to measure the association between antibiotic usage and factors related to the characteristics of the farms and farmers using multivariable logistic regression models. The proportion of farms, irrespective of their production type, reporting usage of antibiotics in the 24 hours preceding the interview was 41% (n = 314, 95% CI: 37–44%). Forty-five percent (n = 344, 41–48%) reported antibiotic usage in the last 72 hours, 86% (n = 658, 83–88%) in the last 14 days, and almost all farms, 98% (n = 753, 97–99%), had used antibiotics since the start of their production cycle. Use of antibiotics in the 24 hours preceding an interview was more frequently reported in broiler (OR 1.91, 95% CI: 1.36–2.69) and Sonali (OR 1.94, 95% CI: 1.33–2.33) than layer farms. Oxytetracycline (23–31%, depending on production type), doxycycline (18–25%), ciprofloxacin (16–26%) and amoxicillin (16–44%) were the most frequently used antibiotics. Antibiotics were reported to be used for both treatment and prophylactic purposes on most farms (57–67%). Usage of antibiotics in the 24h preceding an interview was significantly associated with the occurrence of any illnesses in chickens (aOR broiler: 41.22 [95% CI:13.63–124.62], layer: aOR 36.45[9.52–139.43], Sonali: aOR 28.47[4.97–162.97]). Antibiotic usage was mainly advised by veterinary practitioners (45–71%, depending on production type), followed by feed dealers (21–40%) and farmers (7–13%). Improvement of chicken health through good farming practices along with changes in key stakeholders (feed dealers and practitioners) attitudes towards antibiotic recommendations to farmers, may help to reduce the levels of antibiotic usage and thus contribute to mitigate antimicrobial resistance
Weaning U.S. food-animals off antimicrobials: What can we learn from state- and city-level policies?
Get PDFAntimicrobials are widely used worldwide in food animal production for controlling and preventing disease and for improving feed conversion efficiency and growth promotion. Inappropriate use of antimicrobials in animal agriculture has the potential to promote antimicrobial resistance, which represents a threat to human, animal, and environmental health. State and municipal policies in the United States have recently been implemented to improve antimicrobial use and reporting in this sector. This study analyzed the implementation of two state-level policies (California (CA) and Maryland (MD)) and a city-level policy in San Francisco (SF), California that aimed to reduce the use of antimicrobials in food-animals and increase transparency of antimicrobial use. A qualitative analysis was based on in-depth interviews with key informants (KIs) (n = 19) who had direct experience implementing or working in the context of these sub-national policies. Interviews were recorded and transcriptions were analyzed independently by two researchers using a three-stage, grounded theory coding procedure. This study identified four major findings, including 1) vague language on antimicrobial use within policies reduces policy effectiveness; 2) the lack of reporting by producers challenges the ability to evaluate the impact of the policies on actual use; 3) diverse stakeholders need to be involved in order to develop a more effective policy; and 4) funding should be linked to the policy to provide for reporting and data analysis. This analysis provides insights on the successes and failures of existing policies and serves to inform future sub-national policies aiming to improve the judicious use of antimicrobials in food-animals
Methicillin-resistant Staphylococcus aureus in pigs: prevalence, transmission dynamics and host-pathogen interaction.
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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
Het gebruik van desinfectantia en bacteriofagen om aviaire colibacillose te reduceren
No full textAvian pathogenic Escherichia coli (APEC) cause yearly a huge economic damage to the poultry industry due to mortality, slower growth, a lower feed conversion efficiency and condemnation of carcasses at the abattoir. Inhalation of dust contaminated with high concentrations of Escherichia coli can infect the air sacs and lungs, whereafter bacteria can enter the bloodstream, causing systemic disease (known as colibacillosis). The disease is traditionally treated with antibiotics, but due to frequent use of antibiotics many APEC strains have become multidrug resistant. The use of antibiotics raises a public health concern, due to transfer of resistance genes/resistant bacteria from animals to humans. Therefore in this study the use of disinfectants and bacteriophage therapy were tested as alternative prophylaxis/treatment for colibacillosis in chickens. First, antibiotic resistance of a selection of APEC strains (n = 97), representative for the Belgian laying hen industry, was determined since APEC isolates from laying hens are less studied than isolates from broilers. Furthermore, it was determined if these APEC isolates were resistant against the most included active ingredients (formaldehyde, glutaraldehyde, glyoxal, hydrogen peroxide (H2O2), and a quaternary ammonium compound (QAC)) in routinely used disinfectants in the poultry industry. The biofilm-forming capacity of the strains was determined on materials frequently used in poultry barns, since biofilm formation can have an effect on the efficacy of disinfectants. High resistance percentages were found against antibiotics frequently used in the poultry industry (ampicillin, nalidixic acid, sulfonamides and trimethoprim). However, no phenotypically detectable acquired resistance against routinely used disinfectants could be found, while resistance genes were present. Most APEC strains were only moderate biofilm producers on polystyrene, while on polypropylene and polyvinyl chloride they were strong biofilm producers. Hence, the efficacy of two of the five selected active ingredients in disinfectants (H2O2 and QAC) was tested to eliminate sessile cells. H2O2 and QAC were able to eliminate all adhering cells at a concentration of 1% and 0.01%, respectively. Normally, disinfectants are used in poultry houses to prevent disease carry-over between sequential flocks, whereby the number of specific pathogens is lowered as much as possible. However, during this study the efficacy of nebulization of low concentrations of H2O2 to reduce infection pressure in the presence of chickens was determined. Chickens respiratorily exposed to APEC and subsequently to 2% H2O2 had nonetheless a higher chance of developing a high lesion score associated with APEC, than chickens that were exposed to APEC and subsequently to 1% H2O2 or distilled water, contraindicating H2O2 nebulization in the presence of chickens. During the second part of the study, a bioluminescent APEC strain (CH2-lux) was developed by transposition of the lux operon of Photorhabdus luminescens in the strain used for infection studies (CH2). The transposition of the lux operon into the chromosome of the APEC isolate did not affect the virulence of the latter strain, nor its sensitivity for lytic bacteriophages (phages). Ex vivo correlations were found between the luminescence and bacterial numbers in the homogenized heart, liver and lung of four-week-old CH2-lux infected chickens. The marked strain can also be used to increase knowledge on the pathogenesis of the disease, in order to find targeted treatments against colibacillosis. A bacteriophage cocktail composed of four phages was developed after an in vitro selection of the phages. They were administered to experimentally infected chickens intratracheally, intra-esophageally or via the drinking water. However, treated groups did not show a significant decrease in mortality, lesion scores or weight loss compared to infected/untreated groups. The results indicate that even though in vitro the phage cocktail efficiently lysed the infecting strain, the phage cocktail could not cure experimentally infected chickens. More research is needed to analyze the in vivo therapeutic and prophylactic effect of phages. The developed luminescent APEC strain can thereby possibly provide solutions. During this study various experiments were performed to evaluate the application of disinfectants and bacteriophages to reduce avian colibacillosis, even though many valuable results were found, still much research is needed to expand knowledge on the use of disinfectants and bacteriophages in the battle against colibacillosis.status: Publishe
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
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