Frontiers in Microbiology (Apr 2022)

Bacteriocin-Like Inhibitory Substances in Staphylococci of Different Origins and Species With Activity Against Relevant Pathogens

  • Rosa Fernández-Fernández,
  • Carmen Lozano,
  • Paula Eguizábal,
  • Laura Ruiz-Ripa,
  • Sandra Martínez-Álvarez,
  • Idris Nasir Abdullahi,
  • Myriam Zarazaga,
  • Carmen Torres

DOI
https://doi.org/10.3389/fmicb.2022.870510
Journal volume & issue
Vol. 13

Abstract

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Bacteriocins are antimicrobial peptides with relevance in the modulation of human and animal microbiota that have gained interest in biomedical and biotechnological applications. In this study, the production of bacteriocin-like inhibitory substances (BLIS) was tested among a collection of 890 staphylococci of different origins (humans, animals, food, and the environment) and species, both coagulase-positive (CoPS, 238 isolates of 3 species) and coagulase-negative staphylococci (CoNS, 652 isolates of 26 species). Of the 890 staphylococci, 60 (6.7%) showed antimicrobial activity by the spot-on-lawn method against at least one of the 25 indicator bacteria tested. BLIS-producer (BLIS+) isolates were detected in 8.8% of CoPS and 6.0% of CoNS. The staphylococcal species with the highest percentages of BLIS+ isolates were S. chromogenes (38.5%), S. pseudintermedius (26.7%), and S. warneri (23.1%). The production of BLIS was more frequently detected among isolates of pets, wild animals, and food. Moreover, 13 BLIS+ isolates showed wide antimicrobial activiy spectrum, and 7 of these isolates (of species S. aureus, S. pseudintermedius, S. sciuri, and S. hominis) demonstrated antimicrobial activity against more than 70% of the indicator bacteria tested. The genetic characterization (by PCR and sequencing) of the 60 BLIS+ isolates revealed the detection of (a) 11 CoNS and CoPS isolates carrying putative lantibiotic-like genes; (b) 3 S. pseudintermedius isolates harboring the genes of BacSp222 bacteriocin; and (c) 2 S. chromogenes isolates that presented the gene of a putative cyclic bacteriocin (uberolysin-like), being the first report in this CoNS species. Antimicrobial susceptibility testing was performed in BLIS+ isolates and one-third of the CoNS isolates showed susceptibility to all antibiotics tested, which also lacked the virulence genes studied. These BLIS+ CoNS are good candidates for further characterization studies.

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