Related Experiment Video

Updated: Jan 4, 2026

In Vivo Confocal Microscopy: A Standard Operating Procedure for the Detection of Demodex Mites at the Eyelid Margin
05:21

In Vivo Confocal Microscopy: A Standard Operating Procedure for the Detection of Demodex Mites at the Eyelid Margin

Published on: July 3, 2025

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Corynebacterium kroppenstedtii subsp. demodicis is the endobacterium of Demodex folliculorum

B M Clanner-Engelshofen1, L E French1, M Reinholz1

  • 1Department of Dermatology and Allergy, University Hospital, LMU Munich, Munich, Germany.

Journal of the European Academy of Dermatology and Venereology : JEADV
|November 13, 2019
PubMed
Abstract

Insights

Researchers identified Corynebacterium kroppenstedtii subsp. demodicis as the true endobacterium of Demodex folliculorum mites. This finding advances understanding of the Demodex mite, its bacterial symbiont, and human skin interactions.

Area of Science:

  • Microbiology
  • Dermatology
  • Microbiome research

Background:

  • Demodex mites are complex members of the human skin microbiome, often commensal but implicated in inflammatory skin conditions.
  • Limited knowledge exists regarding Demodex mite life cycle and physiology due to challenges in in vitro cultivation.
  • Previous studies suggested various Bacillus species as potential endosymbionts.

Purpose of the Study:

  • To definitively identify the true bacterial endosymbiont of human Demodex mites.
  • To elucidate the tripartite microbe-host interaction involving Demodex mites, their endosymbiont, and the human host.

Main Methods:

  • Utilized DNA sequencing, PCR, MALDI-TOF, and DNA-DNA hybridization for genetic and phenotypic analysis.
  • Conducted fatty and mycolic acid analyses and antibiotic resistance testing to characterize the endobacterium.
  • Compared type strains with native isolates to confirm findings.

Main Results:

  • Identified Corynebacterium kroppenstedtii subsp. demodicis as the true endobacterium of Demodex folliculorum.
  • This identification was consistent across different mite sampling sources and life stages.
  • Characterized the genetic and phenotypic profile of the identified endosymbiont.

Conclusions:

  • The identification of Corynebacterium kroppenstedtii subsp. demodicis provides a foundation for further research.
  • This discovery is expected to deepen the understanding of the Demodex mite-bacterial endosymbiont-human host relationship.
  • Future studies can explore therapeutic strategies targeting this tripartite interaction.

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