Papillomatous digital dermatitis (PDD) is a foot disease causing lameness in dairy cattle. It is regarded as a polymicrobial infection, although its etiology is not fully understood. PDD is treated by the topical or systemic administration of antibiotics such as lincomycin (LCM); however, the milk of the cows cannot be marketed during the treatment and withdrawal period due to the residual antibiotics in milk. Allyl isothiocyanate (AITC), an extract of Wasabia japonica (known as wasabi or Japanese horseradish) widely employed as a food additive, can be used as an alternative antimicrobial agent that overcomes this problem. We previously showed that AITC is as effective as LCM in PDD treatment. Here, using the samples obtained in the previous clinical study, we analyzed changes in the bacterial population in the PDD‐associated microbiota after AITC treatment and compared those with that following LCM treatment by 16S ribosomal RNA (rRNA)‐based amplicon analysis. Both treatments induced major changes in the bacterial population, and Treponema species, which have been regarded as the major causative agents of PDD, were efficiently eliminated by both agents. However, the AITC‐treated samples exhibited higher diversity compared with pretreatment samples, but this trend was not observed for LCM treatment, probably reflecting different antibacterial activities of the two agents. Importantly, this analysis detected population changes before morphological changes in PDD lesions (clinical signs of healing) became evident, indicating that 16S rRNA‐based amplicon analysis represents an efficient strategy for analyzing and monitoring the treatment efficiency of PDD as well as other polymicrobial diseases.

中文翻译：

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基于16S rRNA的扩增子分析，对异硫氰酸烯丙酯进行局部处理后，乳牛乳头状指皮炎的细菌种群变化。

乳头状数字性皮炎（PDD）是一种脚病，可导致奶牛la行。尽管尚未完全了解其病因，但仍被视为多微生物感染。通过局部或全身施用抗生素（例如林可霉素（LCM））来治疗PDD；但是，由于牛奶中残留的抗生素，在治疗和停药期间无法销售奶牛的牛奶。异硫氰酸烯丙酯（AITC），山葵提取物（被称为芥末或日本辣根）被广泛用作食品添加剂，可用作克服该问题的替代抗菌剂。我们之前已经证明AITC在PDD治疗中与LCM一样有效。在这里，我们使用先前临床研究中获得的样本，分析了AITC处理后PDD相关微生物群中细菌种群的变化，并通过基于16S核糖体RNA（rRNA）的扩增子分析将其与LCM处理后的细菌种群进行了比较。两种处理均引起细菌种群和梅毒螺旋体的重大变化被认为是PDD的主要病原体的两种物种均被两种病原体有效地消除了。但是，与预处理样品相比，经AITC处理的样品表现出更高的多样性，但LCM处理未观察到这种趋势，可能反映了两种药物的不同抗菌活性。重要的是，该分析在PDD病变的形态学改变（临床治愈迹象）变得明显之前就检测到了种群变化，这表明基于16S rRNA的扩增子分析代表了一种有效的策略，可以分析和监测PDD以及其他多种微生物疾病的治疗效率。