Antimicrobial activity of thermophilin 110 against the opportunistic pathogen Cutibacterium acnes

The quorum sensing peptide BlpC regulates the transcription of genes outside its associated gene cluster and impacts the growth of Streptococcus thermophilus

“…The mutant still inhibited the growth of S. thermophilus ST113, P. acidilactici, and C. acnes. These results suggest that thermophilin 110 alone is responsible for the unique broad-spectrum activities previously reported for strain B59671, which include activities against Enterococcus faecalis, Enterobacter faecium, Streptococcus mutans, Streptococcus pyogenes, Streptococcus salivarius, Lactobacillus acidophilus, Lactobacillus helveticus, and Cutibacterium acnes Somkuti, 2013, 2017;Renye and Steinberg, 2021;Renye et al, 2023). The optimal intraspecies activity of this strain may be due to the production of both thermophilins since our results suggest they are both expressed.…”

“…YtrA was reported to regulate cell envelope stress responses in response to cell wall antibiotics in B. subtilis ( Salzberg et al, 2011 ) and repress the transcription of its own operon and a specific subset of genes encoding membrane proteins in S. solfataricus ( Lemmens et al, 2019 ). Bacteriocins encoded within the S. thermophilus blp gene cluster are believed to exert their antimicrobial activity by forming pores within the target cell membrane ( Gilbreth and Somkuti, 2005 ; Renye et al, 2023 ). Therefore, it is reasonable to hypothesize that the YtrA-family regulator in S. thermophilus is part of a stress response associated with the production of bacteriocins.…”