Thanks to their wide host range and virulence, staphylococcal bacteriophages (phages) belonging to the genus Twortlikevirus (staphylococcal Twort-like phages) are regarded as ideal candidates for clinical application for Staphylococcus aureus infections due to the emergence of antibiotic-resistant bacteria of this species. To increase the usability of these phages, it is necessary to understand the mechanism underlying host recognition, especially the receptor-binding proteins (RBPs) that determine host range. In this study, we found that the staphylococcal Twort-like phage ⌽SA012 possesses at least two RBPs. Genomic analysis of five mutant phages of ⌽SA012 revealed point mutations in orf103, in a region unique to staphylococcal Twort-like phages. Phages harboring mutated ORF103 could not infect S. aureus strains in which wall teichoic acids (WTAs) are glycosylated with ␣-N-acetylglucosamine (␣-GlcNAc). A polyclonal antibody against ORF103 also inhibited infection by ⌽SA012 in the presence of ␣-GlcNAc, suggesting that ORF103 binds to ␣-GlcNAc. In contrast, a polyclonal antibody against ORF105, a short tail fiber component previously shown to be an RBP, inhibited phage infection irrespective of the presence of ␣-GlcNAc. Immunoelectron microscopy indicated that ORF103 is a tail fiber component localized at the bottom of the baseplate. From these results, we conclude that ORF103 binds ␣-GlcNAc in WTAs, whereas ORF105, the primary RBP, is likely to bind the WTA backbone. These findings provide insight into the infection mechanism of staphylococcal Twort-like phages. IMPORTANCE Staphylococcus phages belonging to the genus Staphylococcus aureus, a Gram-positive coccus, is a commensal and pathogenic bacterium that causes opportunistic infections in humans and animals. Currently, antibiotic resistance in this species poses a threat to public health. Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital-acquired infections around the world (1). The emergence of such antibiotic-resistant bacteria requires development of alternatives to antibiotic-based therapies. One promising alternative is phage therapy, in which bacteriophages (phages) are used to treat bacterial infections (2, 3). In preclinical trials performed in mice, S. aureus infections (including MRSA infections) were successfully treated by use of phages (4). Therefore, phage therapy has attracted great interest as an alternative to antibiotics.Previously, we isolated the virulent staphylococcal phage ⌽SA012, which exerts lytic effects on a wide range of S. aureus isolates from bovine mastitis cases (5). Genomic analysis of ⌽SA012 revealed that it belongs to the genus Twortlikevirus, which contains the Staphylococcus phages Twort, K, and G, whereas the genus SPO1likevirus contains the Bacillus phage SPO1 as well as Listeria phages P100 and A511. Lactobacillus phage LP65 and Enterococcus phage ⌽EF24C were classified as orphans within the subfamily (6). Representatives of the two genera share the following features: they (i) hav...

The ionic conductivity of a solid electrolyte for sodium-ion batteries is a hot topic nowadays. The lattice distortion introduced into the solid electrolyte produces high ionic conductivity. In this work, we attempted to introduce lattice distortion into Na3OBr, a solid electrolyte for the sodium-ion batteries, by synthesizing Na3O1-SBr in which the oxygen ions are partially replaced by sulfur ions. The solid electrolyte Na3OBr has anti-perovskite structure, which makes it easy to manipulate the crystal structure. We have succeeded in synthesizing high purity Na3O1-SBr (=0 ,0.05 ,0.1 ,0.15 ,0.2). The lattice distortions have been introduced to Na3OBr.