Morgan Bustamante Brittany L, Chigerwe Munashe, Martínez-López Beatriz, Aly Sharif S, McArthur Gary, ElAshmawy Wagdy R, Fritz Heather, Williams Deniece R, Wenz John, Depenbrock Sarah
Public Health Sciences, School of Medicine, University of California, Davis, Davis, CA 95616, USA.
Center for Animal Disease Modeling and Surveillance, Department of Veterinary Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616, USA.
Antibiotics (Basel). 2024 Jan 4;13(1):50. doi: 10.3390/antibiotics13010050.
Weaned dairy heifers are a relatively understudied production group. Bovine respiratory disease (BRD) is the most common cause of antimicrobial drug (AMD) use, morbidity, and mortality in this production group. The study of antimicrobial resistance (AMR) is complicated because many variables that may affect AMR are related. This study generates hypotheses regarding the farm- and animal-level variables (e.g., vaccination, lane cleaning, and AMD use practices) that may be associated with AMR in respiratory isolates from weaned dairy heifers. A cross-sectional study was performed using survey data and respiratory isolates (, , and ) collected from 341 weaned dairy heifers on six farms in California. Logistic regression and Bayesian network analyses were used to evaluate the associations between farm- and animal-level variables with minimum inhibitory concentration (MIC) classification of respiratory isolates against 11 AMDs. Farm-level variables associated with MIC classification of respiratory isolates included the number of source farms of a calf-rearing facility, whether the farm practiced onsite milking, the use of lagoon water for flush lane cleaning, and respiratory and pinkeye vaccination practices. Animal-level variables associated with a MIC classification included whether the calf was BRD-score-positive and time since the last phenicol treatment.
断奶后的奶牛小母牛是一个相对较少被研究的生产群体。牛呼吸道疾病（BRD）是该生产群体中使用抗菌药物（AMD）、发病和死亡的最常见原因。抗菌药物耐药性（AMR）的研究很复杂，因为许多可能影响AMR的变量是相关的。本研究针对可能与断奶奶牛小母牛呼吸道分离株中的AMR相关的农场和动物水平变量（例如疫苗接种、通道清洁和AMD使用做法）提出了假设。利用从加利福尼亚州六个农场的341头断奶奶牛小母牛收集的调查数据和呼吸道分离株（、和）进行了一项横断面研究。使用逻辑回归和贝叶斯网络分析来评估农场和动物水平变量与呼吸道分离株对11种AMD的最低抑菌浓度（MIC）分类之间的关联。与呼吸道分离株的MIC分类相关的农场水平变量包括犊牛饲养设施的来源农场数量、农场是否实行现场挤奶、是否使用泻湖水进行通道冲洗清洁以及呼吸道和红眼病疫苗接种做法。与MIC分类相关的动物水平变量包括犊牛的BRD评分是否为阳性以及自上次使用氯霉素治疗以来的时间。
