Analysis host-recognition mechanism of staphylococcal kayvirus ɸSA039 reveals a novel strategy that protects Staphylococcus aureus against infection by Staphylococcus pseudintermedius Siphoviridae phages

Abstract

1 reveals a novel strategy that protects Staphylococcus aureus against infection 2 by Staphylococcus pseudintermedius Siphoviridae phages 3 4 5 6 Abstract 21Following the emergence of antibiotic resistant bacteria such as methicillin-resistant 22 Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius 23 (MRSP), phage therapy has attracted significant attention as an alternative to antibiotic 24 treatment. Bacteriophages belonging to kayvirus (previously known as Twort-like phages) have 25 broad host range and are strictly lytic in Staphylococcus spp. Previous work revealed that 26 kayvirus ɸSA039 has a host-recognition mechanism distinct from those of other known 27 kayviruses: most of kayviruses use the backbone of wall teichoic acid (WTA) as their receptor; 28 by contrast, ɸSA039 uses the β-N-acetylglucosamine (β-GlcNAc) residue in WTA. In this study, 29 we found that ɸSA039 could switch its receptor to be able to infect S. aureus lacking the β- 30 GlcNAc residue by acquiring a spontaneous mutation in open reading frame (ORF) 100 and 31 ORF102. Moreover, ɸSA039 could infect S. pseudintermedius, which has a different WTA 32 structure than S. aureus. By comparison with newly isolated S. pseudintermedius-specific phage 33 (SP phages), we determined that glycosylation in WTA of S. pseudintermedius is essential for 34 adsorption of SP phages, but not ɸSA039. Finally, we describe a novel strategy of S. aureus 35 which protects the bacteria from infection of SP phages. Notably, glycosylation of ribitol 36 phosphate (RboP) WTA by TarM or/and TarS prevents infection of S. aureus by SP phages. 37 These findings could help to establish a new strategy for treatment of S. aureus and S. 38 pseudintermedius infection, as well as provide valuable insights into the biology of phage-host 39 interactions. 40 Keyword: Kayvirus, phage therapy, host-recognition mechanism, Staphylococcus 41 pseudintermedius, Staphylococcus aureus 42 43Staphylococcus is a Gram-positive bacterium that causes many kinds of infections. Two 45 representative species, S. aureus and S. pseudintermedius, are coagulase-positive bacteria that 46 are notoriously pathogenic in humans and animals (Kloos and Bannerman 1994; Pompilio et al. 47 2015). S. aureus is a commensal found on the skin and mucosae of humans, whereas S. 48 pseudintermedius commonly inhabits dog skin. Both are common bacterial pathogens associated 49 with chronic and recurrent skin infections that require long-term systemic antimicrobial therapy. 50Infection by S. aureus and S. pseudintermedius is becoming problematic due to the emergence of 51 antibiotic-resistant strains, including methicillin-resistant (MRSA and MRSP) and vancomycin-52 resistant strains (VRSA) (Enright et al. 2002; Sakoulas et al. 2005). Virulent bacteriophages that 53 can kill a wide range of S. aureus hosts represent promising alternatives to conventional 54 antibiotic treatment (Alves et al. 2014; Iwano et al. 2018; Azam and Tanji 2019a). The success 55 of p...