| Autor: |
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, Sarah F. Capik, Paul S. Morley, Amelia R. Woolums |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
Frontiers in Veterinary Science, Vol 10 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2297-1769 |
| DOI: |
10.3389/fvets.2023.1256997 |
| Popis: |
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 included evaluating the effect of metaphylaxis and treatment for BRD on animal health and comparing the genetic relationship of MH isolated. Crossbred beef heifers (n = 331, mean weight = 232, SD = 17.8 kg) at high risk for BRD were randomly assigned to receive tulathromycin metaphylaxis (META, n = 167) or not (NO META, n = 164). Nasopharyngeal swabs were collected for MH isolation, antimicrobial susceptibility testing and whole genome sequencing at arrival and 3 (WK3) and 10 (WK10) weeks later. Mixed-effects logistic regression was used to identify risk factors for isolation of MH and MDR MH (resistant to ≥3 antimicrobial drug classes) at 3 and 10 weeks, BRD morbidity, and crude mortality. Animals in the META group had higher odds of isolation of MDR MH at 3 weeks [OR (95% CI) = 13.08 (5–30.9), p |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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