Laboratory of Veterinary Public Health, Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan.
Vet Microbiol. 2010 Jul 14;143(2-4):352-62. doi: 10.1016/j.vetmic.2009.12.009. Epub 2009 Dec 24.
Although it is suspected that papillomatous digital dermatitis (PDD), an infectious foot disease of cattle, is caused by multiple bacteria, it remains unclear precisely which ones are involved in the etiology. To study the bacterial community, we used 16S rRNA gene sequencing of randomly selected clones based on PCR with minimum amplification cycles to search for organisms present in PDD lesions but not in healthy foot skin. The nucleotide sequences of 1525 clones from 5 PDD lesions (836 clones) and 4 samples of healthy foot skin (689 clones) were determined and grouped into 316 operational taxonomic units (OTUs) with a cut-off value of >99% sequence identity. Two OTUs, P-01 (143 clones; 100% nucleotide sequence identity with Treponema phagedenis) and P-02 (112 clones; 86% identity with Bacteroidetes), were detected most frequently in all PDD samples examined. In contrast, OTU N-01 (87 clones), showing 99% nucleotide sequence identity with Moraxella phenylpyruvica, was the most prevalent in the normal samples examined. Spirochaetes were detected in only 1 sample. Phylogenetic analysis showed that T. denticola-like and T. phagedenis-like spirochetes were the predominant groups in the PDD lesions. Detection of multiple treponemes and an unknown bacterium close to Bacteroides sp. at high rates by a culture-independent approach could be evidence of the association of these organisms with PDD.
虽然怀疑乳头状数字皮炎（PDD）是一种牛的传染性足部疾病，但确切的病因仍然不清楚。为了研究细菌群落，我们使用了基于最小扩增循环的 PCR 随机选择克隆的 16S rRNA 基因测序，以寻找存在于 PDD 病变但不存在于健康足部皮肤中的生物体。从 5 个 PDD 病变（836 个克隆）和 4 个健康足部皮肤样本（689 个克隆）中随机选择的 1525 个克隆的核苷酸序列被确定，并分为 316 个操作分类单元（OTU），截断值为> 99%序列同一性。在所有检查的 PDD 样本中，两个 OTU，P-01（143 个克隆；与 Treponema phagedenis 的核苷酸序列完全一致）和 P-02（112 个克隆；与拟杆菌的 86%同一性）检测到的频率最高。相比之下，OTU N-01（87 个克隆）与莫拉氏菌属苯基丙酮酸最常见于正常样本。仅在 1 个样本中检测到螺旋体。系统发育分析表明，T. denticola-like 和 T. phagedenis-like 螺旋体是 PDD 病变中的主要群体。通过非培养方法检测到高比率的多种密螺旋体和一种接近拟杆菌的未知细菌，可能表明这些生物体与 PDD 有关。
