Capik Sarah F, White Brad J, Lubbers Brian V, Apley Michael D, DeDonder Keith D, Larson Robert L, Harhay Greg P, Chitko-McKown Carol G, Harhay Dayna M, Kalbfleisch Ted S, Schuller Gennie, Clawson Michael L
Am J Vet Res. 2017 Mar;78(3):350-358. doi: 10.2460/ajvr.78.3.350.
OBJECTIVE To compare predictive values, extent of agreement, and gamithromycin susceptibility between bacterial culture results of nasopharyngeal swab (NPS) and bronchoalveolar lavage fluid (BALF) samples obtained from calves with bovine respiratory disease (BRD). ANIMALS 28 beef calves with clinical BRD. PROCEDURES Pooled bilateral NPS samples and BALF samples were obtained for bacterial culture from calves immediately before and at various times during the 5 days after gamithromycin (6 mg/kg, SC, once) administration. For each culture-positive sample, up to 12 Mannheimia haemolytica, 6 Pasteurella multocida, and 6 Histophilus somni colonies underwent gamithromycin susceptibility testing. Whole-genome sequencing was performed on all M haemolytica isolates. For paired NPS and BALF samples collected 5 days after gamithromycin administration, the positive and negative predictive values for culture results of NPS samples relative to those of BALF samples and the extent of agreement between the sampling methods were determined. RESULTS Positive and negative predictive values of NPS samples were 67% and 100% for M haemolytica, 75% and 100% for P multocida, and 100% and 96% for H somni. Extent of agreement between results for NPS and BALF samples was substantial for M haemolytica (κ, 0.71) and H somni (κ, 0.78) and almost perfect for P multocida (κ, 0.81). Gamithromycin susceptibility varied within the same sample and between paired NPS and BALF samples. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated culture results of NPS and BALF samples from calves with BRD should be interpreted cautiously considering disease prevalence within the population, sample collection relative to antimicrobial administration, and limitations of diagnostic testing methods.
目的 比较从患有牛呼吸道疾病（BRD）的犊牛获取的鼻咽拭子（NPS）和支气管肺泡灌洗（BALF）样本的细菌培养结果之间的预测值、一致程度和加米霉素敏感性。动物 28 头患有临床 BRD 的肉牛犊。程序 在加米霉素（6 mg/kg，皮下注射，一次）给药前及给药后 5 天内的不同时间，立即从犊牛获取合并的双侧 NPS 样本和 BALF 样本用于细菌培养。对于每个培养阳性样本，对多达 12 个溶血曼氏杆菌、6 个多杀巴斯德菌和 6 个睡眠嗜组织菌菌落进行加米霉素敏感性测试。对所有溶血曼氏杆菌分离株进行全基因组测序。对于加米霉素给药 5 天后采集的配对 NPS 和 BALF 样本，确定 NPS 样本相对于 BALF 样本培养结果的阳性和阴性预测值以及采样方法之间的一致程度。结果 溶血曼氏杆菌的 NPS 样本阳性和阴性预测值分别为 67%和 100%，多杀巴斯德菌为 75%和 100%，睡眠嗜组织菌为 100%和 96%。NPS 和 BALF 样本结果之间的一致程度对于溶血曼氏杆菌（κ，0.71）和睡眠嗜组织菌（κ，0.78）为实质性，对于多杀巴斯德菌（κ，0.81）几乎为完美。加米霉素敏感性在同一样本内以及配对的 NPS 和 BALF 样本之间存在差异。结论和临床意义 结果表明，考虑到群体内的疾病患病率、相对于抗菌药物给药的样本采集以及诊断检测方法的局限性，对于患有 BRD 的犊牛的 NPS 和 BALF 样本的培养结果应谨慎解释。
