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Antimicrobial susceptibility of Staphylococcus aureus causing bovine mastitis
No full textFil: Russi, Norma Beatriz. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentina.Se determinó la susceptibilidad in vitro frente a antimicrobianos de 95 cepas de Staphylococcus aureus aislados de mastitis bovina en la cuenca lechera central de Argentina utilizando el método de la concentración inhibitoria mínima (CIM) y el método de difusión en agar. Las CIM50 de penicilina, oxacilina, gentamicina, eritromicina, enrofloxacina y florfenicol fueron de 0,06, 0,25, 0,19, 0,125, 0,19 y 4 µg/ml, respectivamente, mientras que las CIM90 fueron de 4, 0,25, 0,38, 0,25, 0,38 y 8 µg/ml, respectivamente. El mayor porcentaje de resistencia se observó frente a penicilina con un alto número de cepas productoras de beta-lactamasa, lo cual coincide con hallazgos previos en nuestro país, no detectándose cepas oxacilina resistente. Además, se evaluaron los puntos de corte actualmente utilizados en las pruebas de difusión en agar para la eritromicina para clasificar a cepas de S. aureus aisladas de mastitis bovina en nuestro país. Los puntos de corte establecidos en el presente estudio permitieron categorizar a los aislamientos en susceptibles, intermedios y resistentes, no detectándose errores mayores y arrojando una menor cantidad de errores menores que con los criterios de interpretación del NCCLS. Asimismo, a partir de estudios cinéticos de disposición de eritromicina en leche luego de la administración intramuscular, se establecieron puntos de corte de CIM para este antimicrobiano, no detectándose errores mayores y arrojando un número de errores similar al anterior. Estos resultados justifican la revisión de los puntos de corte del método de difusión en agar para eritromicina frente a S. aureus aislados de mastitis.The in vitro activity of selected antimicrobial agents against 95 Staphylococcus aureus strains causing both clinical and subclinical bovine mastitis belonging to 61 dairy farms from the Central dairy area of Argentina was assessed using both minimal inhibitory concentration (MIC) and agar diffusion method. MIC50 and MIC90 were as follows: penicillin, 0.05 and 4 µg/ml; oxacillin, 0.25 and 0.25 µg/ml; gentamicin, 0.25 and 0.5 µg/ml; erythromycin 0.125 and 0.25 µg/ml; enrofloxacin 0.25 and 0.5 µg/ml, and florfenicol 4 and 8 µg/ml. No resistant isolates to oxacillin, enrofloxacin and florfenicol were detected by the agar diffusion method, while 48.4, 2.1 and 2.1% were resistant to penicillin, gentamicin and erythromycin, respectively. Beta-lactamase activity was detected in 89% of penicillin-resistant strains. In addition, interpretative breakpoints used in agar diffusion tests for erythromycin were evaluated using S. aureus isolated from bovine mastitis in Argentina. Breakpoints established in the present study allowed classification of isolates in susceptible, intermediate and resistant categories, finding no major errors and less minor errors than those detected using NCCLS interpretative criteria. MIC breakpoints were established based on kinetic studies following intramuscular administration of erythromycin. Using these MIC breakpoints, agar diffusion interpretative breakpoints were estimated obtaining lack of major errors and an acceptable percentage of minor errors. These results underscore the importance of revising interpretative criteria for agar diffusion method used for erythromycin against S. aureus isolated from bovine mastitis in Argentina.Instituto Nacional de Tecnología AgropecuariaUniversidad Nacional del Litora
Antimicrobial susceptibility of Staphylococcus aureus causing bovine mastitis
No full textFil: Russi, Norma Beatriz. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentina.Se determinó la susceptibilidad in vitro frente a antimicrobianos de 95 cepas de Staphylococcus aureus aislados de mastitis bovina en la cuenca lechera central de Argentina utilizando el método de la concentración inhibitoria mínima (CIM) y el método de difusión en agar. Las CIM50 de penicilina, oxacilina, gentamicina, eritromicina, enrofloxacina y florfenicol fueron de 0,06, 0,25, 0,19, 0,125, 0,19 y 4 µg/ml, respectivamente, mientras que las CIM90 fueron de 4, 0,25, 0,38, 0,25, 0,38 y 8 µg/ml, respectivamente. El mayor porcentaje de resistencia se observó frente a penicilina con un alto número de cepas productoras de beta-lactamasa, lo cual coincide con hallazgos previos en nuestro país, no detectándose cepas oxacilina resistente. Además, se evaluaron los puntos de corte actualmente utilizados en las pruebas de difusión en agar para la eritromicina para clasificar a cepas de S. aureus aisladas de mastitis bovina en nuestro país. Los puntos de corte establecidos en el presente estudio permitieron categorizar a los aislamientos en susceptibles, intermedios y resistentes, no detectándose errores mayores y arrojando una menor cantidad de errores menores que con los criterios de interpretación del NCCLS. Asimismo, a partir de estudios cinéticos de disposición de eritromicina en leche luego de la administración intramuscular, se establecieron puntos de corte de CIM para este antimicrobiano, no detectándose errores mayores y arrojando un número de errores similar al anterior. Estos resultados justifican la revisión de los puntos de corte del método de difusión en agar para eritromicina frente a S. aureus aislados de mastitis.The in vitro activity of selected antimicrobial agents against 95 Staphylococcus aureus strains causing both clinical and subclinical bovine mastitis belonging to 61 dairy farms from the Central dairy area of Argentina was assessed using both minimal inhibitory concentration (MIC) and agar diffusion method. MIC50 and MIC90 were as follows: penicillin, 0.05 and 4 µg/ml; oxacillin, 0.25 and 0.25 µg/ml; gentamicin, 0.25 and 0.5 µg/ml; erythromycin 0.125 and 0.25 µg/ml; enrofloxacin 0.25 and 0.5 µg/ml, and florfenicol 4 and 8 µg/ml. No resistant isolates to oxacillin, enrofloxacin and florfenicol were detected by the agar diffusion method, while 48.4, 2.1 and 2.1% were resistant to penicillin, gentamicin and erythromycin, respectively. Beta-lactamase activity was detected in 89% of penicillin-resistant strains. In addition, interpretative breakpoints used in agar diffusion tests for erythromycin were evaluated using S. aureus isolated from bovine mastitis in Argentina. Breakpoints established in the present study allowed classification of isolates in susceptible, intermediate and resistant categories, finding no major errors and less minor errors than those detected using NCCLS interpretative criteria. MIC breakpoints were established based on kinetic studies following intramuscular administration of erythromycin. Using these MIC breakpoints, agar diffusion interpretative breakpoints were estimated obtaining lack of major errors and an acceptable percentage of minor errors. These results underscore the importance of revising interpretative criteria for agar diffusion method used for erythromycin against S. aureus isolated from bovine mastitis in Argentina.Instituto Nacional de Tecnología AgropecuariaUniversidad Nacional del Litora
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
Identificación de factores de riesgos asociados a la presentación de endometritis en bovinos lecheros
Get PDFEl objetivo del presente trabajo fue identificar factores asociados a la presentación de endometritis en vacas lecheras posparto. Se muestrearon 152 vacas (aproximadamente con 40 días posparto) pertenecientes a cuatro establecimientos de producción lechera de Argentina. Los sistemas productivos se caracterizaban por ser de tipo pastoriles base alfalfa con suplementación estratégica, con un promedio diario de 19 litros/animal. La metodología del muestro consistió en higienizar la zona vulvar con yodo povidona y papel descartable. Seguidamente se tomó la muestra del contenido uterino introduciendo el Metrichecktm y se lo observó clínicamente para efectuar una clasificación en grados de endometritis (escala de 0 a 3). De cada vaca se tomaron datos sobre número de lactancia, genética, tipo de parto, condición corporal, sexo de las crías para la identificación de los factores asociados a la presencia de endometritis. Para dichas asociaciones se empleó Chi-cuadrado, test exacto de Fisher, T-student y regresión logística. El 70% de las vacas no presentaron anormalidades en el flujo uterino o mostraron un grado leve de endometritis. Las endometritis con grado mayor a dos estuvieron asociadas a partos distócicos (Odds Ratio=OR= 9,6), retención de membranas fetales (OR= 4,4) y vacas melliceras (OR= 5,1). El registro de los factores de riesgo, la revisión sistemática posparto, la utilización de herramientas que facilitan la inspección (Ej.: Metricheck) y la capacitación continua de todos los actores que intervienen en el sistema productivo, son aspectos relevantes a considerar para emitir un diagnóstico certero de endometritis y aplicar medidas de profilaxis y/o curativas tendientes a lograr un corto intervalo entre partos.Fil: Recce, Sebastian. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Russi, Norma Beatriz. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Massera, A.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Signorini Porchietto, Marcelo Lisandro. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Departamento de Salud Pública Veterinaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin
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