Biochemistry, Biophysics, and Structural Biology | Open Access Articles

Tulathromycin Metaphylaxis Increases Nasopharyngeal Isolation Of Multidrug Resistant Mannheimia Haemolytica In Stocker Heifers, William B. Crosby, Brandi B. Karisch, Lari M. Hiott, Lee J. Pinnell, Alexandra Pittman, Jonathan G. Frye, Charlene R. Jackson, John Dustin Loy, William B. Epperson, John Blanton Jr., Sarah F. Capik, Paul S. Morley, Amelia R. Woolums

School of Veterinary and Biomedical Sciences: Faculty Publications

Bovine respiratory disease (BRD) is a leading cause of disease in feedlot and stocker calves with Mannheimia haemolytica (MH) as one of the most common etiologies. One of the most effective means of controlling BRD is through metaphylaxis, which involves administering antimicrobials to all animals at high risk of developing BRD. However, increasing prevalence of multidrug resistant (MDR) MH may reduce efficacy of metaphylaxis due to decreased susceptibility to drugs used for metaphylaxis. Primarily, this study aimed to determine the effect of tulathromycin metaphylaxis and subsequent BRD treatment on antimicrobial resistance (AMR) in MH isolated from stocker calves. Secondary objectives …

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Detection Of Mannheimia Haemolytica-Specific Igg, Igm And Iga In Sera And Their Relationship To Respiratory Disease In Cattle, Korakrit Poonsuk, Carita Kordik, Matthew M. Hille, Ting-Yu Cheng, William B. Crosby, Amelia R. Woolums, Michael L. Clawson, Carol G. Chitko-Mckown, Bruce Brodersen, John Dustin Loy

School of Veterinary and Biomedical Sciences: Faculty Publications

Mannheimia haemolytica is one of the major causes of bovine respiratory disease in cattle. The organism is the primary bacterium isolated from calves and young cattle affected with enzootic pneumonia. Novel indirect ELISAs were developed and evaluated to enable quantification of antibody responses to whole cell antigens using M. haemolytica A1 strain P1148. In this study, the ELISAs were initially developed using sera from both M. haemolytica-culture-free and clinically infected cattle, then the final prototypes were tested in the validation phase using a larger set of known-status M. haemolytica sera (n = 145) collected from feedlot cattle. The test …

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Does Swab Type Matter? Comparing Methods For Mannheimia Haemolytica Recovery And Upper Respiratory Microbiome Characterization In Feedlot Cattle, William B. Crosby, Lee Pinnell, John T. Richeson, Cory Wolfe, Jake Castle, John Dustin Loy, Sheryl P. Gow, Keun Seok Seo, Sarah F. Capik, Amelia R. Woolums, Paul S. Morley

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: Bovine respiratory disease (BRD) is caused by interactions among host, environment, and pathogens. One standard method for antemortem pathogen identification in cattle with BRD is deep-guarded nasopharyngeal swabbing, which is challenging, costly, and waste generating. The objective was to compare the ability to recover Mannheimia haemolytica and compare microbial community structure using 29.5 inch (74.9 cm) deep-guarded nasopharyngeal swabs, 16 inch (40.6 cm) unguarded proctology swabs, or 6 inch (15.2 cm) unguarded nasal swabs when characterized using culture, real time-qPCR, and 16S rRNA gene sequencing. Samples for aerobic culture, qPCR, and 16S rRNA gene sequencing were collected from the …

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School of Veterinary and Biomedical Sciences: Faculty Publications

School of Veterinary and Biomedical Sciences: Faculty Publications

School of Veterinary and Biomedical Sciences: Faculty Publications