title: An ultrastructural study of Trichophyton rubrum induced onychomycosis.
abstract: BACKGROUND
  Trichophyton rubrum (T.rubrum) caused onychomycosis is the most common nail fungal disease. The common diagnostic methods are direct microscopic examination and fungal culture. In this study we used scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to study the subungual ultrastructural changes in T. rubrum induced onychomycosis.
  
  
  METHODS
  Six outpatients with onychomycosis were recruited and T.rubrum infection was confirmed by fungal culture. Six toenail samples were collected and prepared for SEM characterization. The cultured fugal colonies were prepared for SEM and TEM characterization.
  
  
  RESULTS
  1) SEM showed significant structural damages and the formation of a thin layer or a single layer of keratinocytes in all infected nail plates. Hyphae (piercing or penetrating keratinocytes layers), arthrospores and local bacterial aggregation were observed on the ventral surface of the nail plates. 2) SEM of the cultured fungal colony showed relatively straight, highly branched hyphae and microconidias; TEM showed branching hyphae that were composed of double-layer cell walls. Hyphae had nucleus, mitochondria, liposomes, lysosomes, scattered rough endoplasmic reticulum, myeloid bodies and aggregated ribosomes. There were high-density particles outside the hyphae.
  
  
  CONCLUSIONS
  SEM showed a large number of hyphae penetrated the keratinocytes layer, suggesting that T. rubrum can cause severe damage to the stratum corneum. TEM showed the ultrastructural features of T. rubrum-induced infection before treatment.
authors.affiliation: Department of Dermatology and Venereology, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100050, P. R. China. yuexpyue123@126.com.
authors.forename: Xueping
authors.initials: X
authors.lastname: Yue
authors.affiliation: Department of Dermatology and Venereology, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100050, P. R. China. bjttpfk6650@hotmail.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Dermatology and Venereology, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100050, P. R. China. 1795428369@qq.com.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Ultrastructural Pathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, 100050, P. R. China. sunyilin@hotmail.com.
authors.forename: Yilin
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Dermatology, Peking University First Hospital, Peking University, Beijing, 100034, P. R. China. wangap@medmail.com.cn.
authors.forename: Aiping
authors.initials: A
authors.lastname: Wang
authors.affiliation: Department of Ultrastructural Pathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, 100050, P. R. China. zhangqi5706@163.com.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Ultrastructural Pathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, 100050, P. R. China. grassgrenn@163.com.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Zhang
mesh_terms: D005260:Female; D005533:Foot Dermatoses / Q000382:microbiology / Q000473:pathology*; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D009262:Nails / Q000382:microbiology* / Q000648:ultrastructure*; D014009:Onychomycosis / Q000382:microbiology / Q000473:pathology*; D014249:Trichophyton / Q000472:pathogenicity* / Q000648:ultrastructure