Propionibacterium (Cutibacterium) granulosum Extracellular DNase BmdE Targeting Propionibacterium (Cutibacterium) acnes Biofilm Matrix, a Novel Inter-Species Competition Mechanism

Abstract

Acne vulgaris is the most common dermatological disorder worldwide affecting more than 80% of adolescents and young adults with a global prevalence of 231 million cases in 2019. The involvement of the skin microbiome disbalance in the pathophysiology of acne is recognized, especially regarding the relative abundance and diversity of Propionibacterium acnes a well-known dominant human skin commensal. Biofilms, where bacteria are embedded into a protective polymeric extracellular matrix, are the most prevalent life style for microorganisms. P. acnes and its biofilm-forming ability is believed to be a contributing factor in the development of acne vulgaris, the persistence of the opportunistic pathogen and antibiotic therapy failures. Degradation of the extracellular matrix is one of the strategies used by bacteria to disperse the biofilm of competitors. In this study, we report the identification of an endogenous extracellular nuclease, BmdE, secreted by Propionibacterium granulosum able to degrade P. acnes biofilm both in vivo and in vitro. This, to our knowledge, may represent a novel competitive mechanism between two closely related species in the skin. Antibiotics targeting P. acnes have been the mainstay in acne treatment. Extensive and long-term use of antibiotics has led to the selection and spread of resistant bacteria. The extracellular DNase BmdE may represent a new bio-therapeutical strategy to combat P. acnes biofilm in acne vulgaris.

Detailed protocol for germ-free Drosophila melanogaster colonization with Propionibacterium spp. biofilms

“…We have used our in vivo biofilm model system to investigate Propionibacterium spp. biofilm in different conditions ( Bronnec and Alexeyev, 2021 ; Bronnec et al., 2022 ). In those publications, the fruit fly food was supplemented with a lipid solution.…”

“…Fruit flies infected with Propionibacterium spp. biofilm were also orally treated with biofilm dispersing enzymes to evaluate their biofilm degrading activity in vivo ( Bronnec and Alexeyev, 2021 ; Bronnec et al., 2022 ). These alternatives are not reported in this protocol.…”

“…As described in the publications, Bronnec and Alexeyev (2021) and Bronnec et al. (2022) , unprocessed slides visualization was the main method used to evaluate the biofilm formation.…”

“…biofilms in the fruit fly’s gut using an easy to carry out method. For complete details on the use and execution of this protocol, please refer to Bronnec and Alexeyev (2021) and Bronnec et al. (2022) .…”

“…For complete details on the use and execution of this protocol, please refer to Bronnec and Alexeyev (2021) and Bronnec et al. (2022) .…”