Department of Veterinary Clinical Sciences, College of Veterinary Medicine, West Lafayette, Indiana, USA.
State of Indiana Animal Disease Diagnostic Laboratory, West Lafayette, Indiana, USA.
J Vet Intern Med. 2023 Jan;37(1):323-327. doi: 10.1111/jvim.16586. Epub 2022 Nov 25.
It is important to determine if a horse is shedding Salmonella spp., but a complete culture series can be cost prohibitive.
Determine the optimal pooling technique to maintain high sensitivity of Salmonella spp. culture using spiked samples, and then demonstrate the efficacy of this protocol on clinical submissions.
Pooled fecal samples are as sensitive as 5 individual cultures for the detection of Salmonella shedding.
A single Salmonella-negative horse from the university herd, and 19 hospitalized horses.
Salmonella-free fecal samples were spiked with different amounts of Salmonella spp. (10 , 10 , 10 , and 10 colony forming units [cfu]) and homogenized to evaluate pooled samples. Five individual fecal samples were collected from 19 hospitalized horses. Ten-gram aliquots of each individual sample were combined to make a pooled sample. Both individual and pooled samples were cultured for Salmonella spp. The identity of bacterial isolates was confirmed by matrix-assisted laser desorption-ionization time of flight mass spectrometry.
A 10 cfu concentration of Salmonella spp. could be recovered from a spiked Salmonella-free fecal sample. Homogenization protocols indicated that the addition of 20 mL of broth to the pooled sample improved recovery, whereas homogenization time did not. Of the 19 horses tested, 5 were positive for Salmonella. In all instances, Salmonella spp. were recovered from the fecal pool as well as individual samples.
Pooling of 5 fecal samples for Salmonella culture is a sensitive and cost-effective diagnostic approach to detect horses that are shedding the organism.
确定马是否排出沙门氏菌很重要，但进行完整的培养系列可能费用过高。
确定使用加标样本维持沙门氏菌培养高灵敏度的最佳混合技术，然后在临床标本上证明该方案的功效。
混合粪便样本在检测沙门氏菌排出方面与 5 个单独培养物一样敏感。
大学畜群中单一的沙门氏菌阴性马和 19 匹住院马。
用不同数量的沙门氏菌（10 、10 、10 和 10 菌落形成单位 [cfu]）对无沙门氏菌的粪便样本进行加标，并进行匀浆以评估混合样本。从 19 匹住院马中采集 5 个单独的粪便样本。将每个单独样本的 10 克等分试样合并制成混合样本。对单个和混合样本进行沙门氏菌培养。通过基质辅助激光解吸电离飞行时间质谱确认细菌分离物的身份。
可从加标无沙门氏菌粪便样本中回收 10 cfu 浓度的沙门氏菌。匀浆方案表明，将 20 mL 肉汤加入混合样本中可提高回收率，而匀浆时间没有影响。在测试的 19 匹马中，有 5 匹对沙门氏菌呈阳性。在所有情况下，均从粪便混合样本以及单个样本中回收了沙门氏菌。
混合 5 个粪便样本进行沙门氏菌培养是一种敏感且具有成本效益的诊断方法，可用于检测正在排出该病原体的马匹。
