数字皮炎(DD),一种常见的牛足溃疡性疾病,导致跛行,降低生产力和动物福利,与螺旋体螺旋体细菌感染有关。外用四环素,最常见的治疗方法,治愈率不一致;因此,需要新的治疗方案。我们比较了局部使用土霉素和维生素D3对受DD影响的皮肤先天免疫的影响。用土霉素或维生素D3局部治疗具有活动性DD病变的奶牛,并从病变处收集皮肤活检。组织样本进行组织学检查,促炎细胞因子的转录表达,Toll样受体(TLRs),和宿主防御肽评估,并确定了特定螺旋体物种的存在。在螺旋体感染的人角质形成细胞模型中研究了机械水平的治疗效果。土霉素促进溃疡性DD病变中增生性结痂的形成,并降低Cxcl-8(中性粒细胞化学引诱物)的转录表达。土霉素还减少了密螺旋体和足T.ponema的数量,并增强了Tlr2mRNA的表达。维生素D3没有改变细胞因子或Tlrs的表达,或者细菌负荷,但增强了气管抗菌肽(Tap)的转录,一种关键的牛β-防御素.结合土霉素和维生素D3在通过组合抗菌药物控制DD方面提供了互补的临床益处,免疫调节,和促进愈合的活动。
Digital dermatitis (DD), a common ulcerative disease of the bovine foot causing lameness and reducing productivity and animal welfare, is associated with infection by spirochete Treponema bacteria. Topical tetracycline, the most common treatment, has inconsistent cure rates; therefore, new therapeutic options are needed. We compared effects of topical oxytetracycline and vitamin D3 on innate immunity in DD-affected skin. Cows with active DD lesions were treated topically with oxytetracycline or vitamin D3 and skin biopsies were collected from lesions. Tissue samples were examined histologically, transcriptional expression of pro-inflammatory cytokines, Toll-like receptors (TLRs), and host defense peptides assessed, and the presence of specific treponeme species determined. Effects of treatments at a mechanistic level were studied in a human keratinocyte model of treponeme infection. Oxytetracycline promoted hyperplastic scab formation in ulcerated DD lesions and decreased transcriptional expression of Cxcl-8 (neutrophil chemoattractant). Oxytetracycline also reduced numbers of Treponema phagedenis and T. pedis and enhanced Tlr2 mRNA expression. Vitamin D3 did not modify expression of cytokines or Tlrs, or bacterial loads, but enhanced transcription of tracheal antimicrobial peptide (Tap), a key bovine β-defensin. Combing oxytetracycline and vitamin D3 provides complementary clinical benefits in controlling DD through a combination of antimicrobial, immunomodulatory, and pro-healing activities.