Browsing by Subject "Oxytetracycline"

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    Open Access
    Susceptibility of caprine mastitis pathogens to tildipirosin, gamithromycin, oxytetracycline, and danofloxacin: effect of serum on the in vitro potency of current macrolides
    (Springer, 2022-09-13) Galecio Naranjo, Juan Sebastian; Escudero Pastor, Elisa; Corrales, Juan Carlos; García-Romero, Edgar; Fe, Christian de la; Hernandis Belenguer, Verónica; Marín Carrillo, Pedro; Farmacología
    Mastitis is a significant disease in dairy ruminants, causing economic losses to the livestock industry and severe risks to public health. Antibiotic therapy is one of the most crucial practices to treat mastitis, although the susceptibility of caprine mastitis pathogens to current antibiotics has not been tested under standard or modified incubation conditions. This work evaluated the in vitro activity of tildipirosin, gamithromycin, oxytetracycline, and danofloxacin against caprine mastitis pathogens incubated following standard conditions of Clinical and Laboratory Standards Institute (CLSI) and deviation method by 25% supplementation with goat serum. Mycoplasma agalactiae, Escherichia coli, Staphylococcus aureus, Streptococcus spp., and coagulase-negative Staphylococci (CNS) were isolated from dairy goats with mastitis in Spain. Minimum inhibitory concentrations (MICs) were determined using the broth microdilution technique. The lowest MIC90 under standard conditions was obtained with danofloxacin for mastitis-causing pathogens. An exception was M. agalactiae, where danofloxacin and oxytetracycline obtained low values. However, after adding serum, gamithromycin showed the lowest MIC50 for S. aureus, Streptococcus spp., and CNS. The lowest MIC50 was obtained with all the antibiotics tested (< 0.125 µg/ml) against M. agalactiae. Supplementing with serum resulted in a significant variation in tildipirosin and gamithromycin MIC values for CNS, S. aureus, M. agalagtiae, and E. coli. In brief, the MIC for antibiotics used against mastitis should be determined under conditions closely resembling intramammary infections to obtain representative susceptibility patterns against mastitis pathogens. Caprine mastitis pathogens were broadly susceptible to danofloxacin under standard conditions. The potency of macrolides against caprine mastitis pathogens increases when serum is present in culture media.
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    Open Access
    Use of digital image analysis to improve rigor and efficiency of physeal bone growth measurements
    (Universidad de Murcia, Departamento Histología e Histopatología, 2025) Jay Byrd; Bria Foley; Alexander Farell; Garret Williams; Max Twedt; James Sypherd; Ellen Leiferman; Cameron Jeffers; Matthew A. Halanski; Grant Ozaki; Histología e Histopatología
    In larger, translational animal models, manual measurements of longitudinal bone growth using fluorochrome labels is tedious and may be prone to less rigor due to variations in reader experience, sampling differences, and photobleaching that limits the repeatability of measurements. This study assesses the reliability of three different digital methods to assist in measurement of distance between pulsed fluorochrome labels. Forty-five tibial physes from skeletally immature New Zealand White rabbits were pulsed with fluorochrome labels and measured using Fully Manual Technique (FMT), Manual Digital Measurement (MDM), Computer Assisted Image Processing (AIP), and Fully Automated Measurement (FAM). Pearson’s correlation coefficient and Bland-Altman analysis were used to analyze the different methods. Intraclass correlation coefficient (ICC) assessed inter- and intrareader reliability. Regardless of the method, all growth rate measurement techniques exhibited excellent agreement and reliability. The computer assisted methods allowed rapid data acquisition without compromising reliability, thereby improving efficiency in bone growth research. Clinical Significance: Distances between fluorochrome bone labels on large samples can be reliably measured using digital imaging and processing techniques.