Poster Presentation 50th Lorne Proteins Conference 2025

Flexible and contractile Herelleviridae bacteriophage JS1 showing cross-species activity against Staphylococci (#110)

Sabrina Suhani 1 , Yan Li 1 , Laura Perlaza-Jiménez 2 , Denis Korneev 3 4 , Tze Young Thung 1 , Han Lee 5 , Joshua J. Iszatt 6 7 , Christopher J. Stubenrauch 1 , Rhys A. Dunstan 1 , Anthony Kicic 6 7 8 9 , Trevor Lithgow 1
  1. Infection Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
  2. Monash Bioinformatics Platform, Monash University, Clayton, Victoria, Australia
  3. Ramaciotti Centre for Cryo-EM, Monash University, Clayton, Victoria, Australia
  4. School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
  5. Monash Proteomics & Metabolomics Platform, Monash University, Clayton, Victoria, Australia
  6. Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, Western Australia, Australia
  7. Wal-yan Respiratory Research Centre, Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
  8. Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, Western Australia, Australia
  9. Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, The University of Western Australia and Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia

Using a selective plating strategy for Staphylococci, we surveyed local community wastewater and purified 16 independent isolates representing six species of Staphylococcus: S. cohnii, S. equorum, S. lentus, S. nepalensis, S. sciuri and S. xylosus. We did not detect the Golden Staph/ MRSA superbug species S. aureus. The wastewater also served as a source to identify a bacteriophage (phage) referred to here as JS1 that could infect all of these species of Staphylococcus, as well as a range of clinical S. aureus strains including methicillin-resistant (MRSA) isolates. Phage JS1 could not be classified into any of the three recognized morphotypes: the Myo-like (long, straight, contractile tails), Sipho-like (long, flexible, non-contractile tails) or Podo-like (very short rigid tails). Electron microscopy showed instead that JS1 virions have long, flexible, contractile tails. Curvature analysis shows that this represents a range of flexion with a 1/R value of 7.6±1.3 mm-1, where R is the radius of curvature. Based on this analysis, and comparisons to the curvature of three other related phages, we suggest that JS1 and the Herelleviridae family to which it belongs represent a new fourth morphology of the Caudoviricetes phages. Phage JS1 also encodes five membrane proteins of unknown function that were found to be conserved in other phages in the Herelleviridae family and predicted to have transmembrane segments sufficient to span a bacterial membrane. Four of the JS1 proteins were annotated to be involved in hydrolysis of cell wall and generated high-confidence structural predictions with conserved domains of relevant lysis function. Future studies aim for the purification of the hydrolases and assessing the effective degradation of drug-resistant and phage-resistant Staphylococcus cell surfaces in vitro.