Food Animal Health and Management Program, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA.
Texas A&M AgriLife Research, Texas A&M University System, Amarillo, TX.
Am J Vet Res. 2023 Aug 14;84(11). doi: 10.2460/ajvr.23.06.0140. Print 2023 Nov 1.
Evaluate agreement among the antimicrobial susceptibility profiles of Mannheimia haemolytica or Pasteurella multocida obtained by transtracheal wash, nasal swab, nasopharyngeal swab, and bronchoalveolar lavage.
100 Holstein and Holstein-cross bull calves with bovine respiratory disease.
Calves > 30 days old with naturally occurring bovine respiratory disease were sampled sequentially by nasal swab, nasopharyngeal swab, transtracheal wash, and then bronchoalveolar lavage. Samples were cultured, and for each antimicrobial, the MIC of 50% and 90% of isolates was calculated, and isolates were categorized as susceptible or not. Categorical discrepancies were recorded. Percent positive agreement and kappa values were calculated between isolates for each of the sampling methods.
Antimicrobial susceptibility varied by pathogen and resistance to enrofloxacin, florfenicol, tilmicosin, and spectinomycin was detected. Minor discrepancies were seen in up to 29% of classifications, with enrofloxacin, penicillin, and florfenicol more frequently represented than other drugs. Very major and major discrepancies were seen when comparing florfenicol (1.9%) and tulathromycin (3.8 to 4.9%) across sampling methods. Some variability was seen in agreement for enrofloxacin for several comparisons (8.3 to 18.4%).
Susceptibility testing of isolates from 1 location of the respiratory tract can reliably represent susceptibility in other locations. Nevertheless, the potential for imperfect agreement between sampling methods does exist. The level of restraint available, the skill level of the person performing the sampling, the age and size of the animal, disease status, and treatment history all must be factored into which test is most appropriate for a given situation.
评估通过气管冲洗、鼻拭子、鼻咽拭子和支气管肺泡灌洗获得的溶血曼海姆菌或多杀巴斯德氏菌的抗菌药敏谱之间的一致性。
100 头患有牛呼吸道疾病的荷斯坦和荷斯坦杂交公牛犊。
对 30 日龄以上患有自然发生的牛呼吸道疾病的牛犊进行连续采样，依次进行鼻拭子、鼻咽拭子、气管冲洗，然后进行支气管肺泡灌洗。对样品进行培养，并计算每种抗菌药物的 50%和 90%分离株的 MIC，并对分离株进行敏感或不敏感分类。记录分类差异。计算每种采样方法分离株之间的阳性符合率和kappa 值。
抗菌药敏性因病原体而异，检测到对恩诺沙星、氟苯尼考、替米考星和大观霉素的耐药性。在多达 29%的分类中出现了轻微差异，恩诺沙星、青霉素和氟苯尼考比其他药物更常见。在比较不同采样方法时，氟苯尼考（1.9%）和泰拉霉素（3.8%至 4.9%）出现了非常大的和主要的差异。在几种比较中，恩诺沙星的一致性也存在一些差异（8.3%至 18.4%）。
呼吸道某一部位分离株的药敏试验可以可靠地代表其他部位的药敏情况。然而，不同采样方法之间确实存在不一致的可能性。可用的限制程度、进行采样的人员的技能水平、动物的年龄和大小、疾病状态和治疗史都必须考虑到哪种测试最适合特定情况。
