Invited Speaker Australian Society for Microbiology Annual Scientific Meeting 2023

Exploring the scabies-associated microbiota to understand the pathobiology of scabies-related secondary skin infections (94055)

Sara Taylor 1 , Martha Zakrzewski 1 , Charlotte Bernigaud 2 , Deepani D Fernando 1 , Francoise Botterel 2 , Nuzhat Surve 3 , Pallavi Surase 3 , M.G. Karmarkar 3 , Troy Darben 4 , Olivier Chosidow 2 , Katja Fischer 1
  1. Infection and Inflammation Program, QIMR Berghofer, Brisbane, QLD, Australia
  2. UPE-Université Paris-Est, Service de Dermatologie, Hôpital Henri Mondor, Cretail, Paris, France
  3. Seth G.S Medical College & KEM Hospital, Parel, Mumbai, India
  4. Robina Skin Specialist Centre, Robina, QLD, Australia

Introduction:

Scabies is a debilitating, truly neglected infectious disease affecting low and medium-income overcrowded populations worldwide. In the tropics, scabies promotes opportunistic bacterial infections, leading to cellulitis/necrotizing fasciitis, bacteraemia, kidney disease and rheumatic heart disease, causing globally substantial morbidity and mortality. Pathobiology is poorly understood, due to an absence of molecular information on mite infestation, bacterial co-infection and the interactions thereof.

 

Objectives:

We undertake a unique microbiome research program, applying meta-omics to a multinational set of samples, to provide fundamental insights into the interaction between mites and skin microbiota. The program covers four themes, (a) microbial profiling of common scabies, (b) throughout acaricide treatment, (c) of crusted scabies and (d) investigating the mite-internal microbiome. 

 

Materials and Method:

We collected 750 skin samples and clinical data from consenting patients presenting with confirmed common scabies during routine dermatological consultations in Australia, India and France. From every patient several epidermal skin scrapings were taken from single lesions along with control samples from corresponding co- and contra-lateral healthy sites. Microbial DNA was purified and 16S/ITS long read amplicon PacBio sequencing was performed. Bioinformatics analysis included quality control using ‘R’, taxonomic grouping and assignment with the Dada2 pipeline and statistical analysis.

 

Results:

Across all collected samples, scabies infection impacted the overall microbial community composition and lead to a significantly decreased microbial diversity in mite-infected lesions compared to respective uninfected sites. In mite-infected lesions the abundance of opportunistic pathogens was increased, while a commensal species appeared to be decreased. Further analysis will gain insight in potential correlations of specific microbes with clinical findings including impetigo, itch and scabies severity.

 

Conclusions:

This large-scale, global study is the first to assess the scabies-associated microbiome at a molecular level. The data and knowledge gained will be useful to support new treatment strategies for scabies and associated secondary bacterial infections.