Impetigo is a contagious skin infection predominantly caused by Staphylococcus aureus. Decontamination of S. aureus from the skin is becoming more difficult because of the emergence of antibiotic-resistant strains. Bacteriophage endolysins are less likely to invoke resistance and can eliminate the target bacteria without disturbance of the normal microflora. In this study, we investigated the therapeutic potential of a recombinant endolysin derived from kayvirus S25-3 against staphylococcal impetigo in an experimental setting. First, the recombinant S25-3 endolysin required an incubation period of over 15 minutes to exhibit efficient bactericidal effects against S. aureus. Second, topical application of the recombinant S25-3 endolysin decreased the number of intraepidermal staphylococci and the size of pustules in an experimental mouse model of impetigo. Third, treatment with the recombinant S25-3 endolysin increased the diversity of the skin microbiota in the same mice. Finally, we revealed the genus-specific bacteriolytic effect of recombinant S25-3 endolysin against staphylococci, particularly S. aureus, among human skin commensal bacteria. Therefore, topical treatment with recombinant S25-3 endolysin can be a promising disease management procedure for staphylococcal impetigo by efficient bacteriolysis of S. aureus while improving the cutaneous bacterial microflora.

The skin is the largest human organ and a site of substantial disease burden, yet its cellular and molecular organization across the body is largely undefined. Here we construct an organ-wide single-cell spatial atlas of ~1.2 million cells from normal adult human skin, resolving the location of 45 cell types across 114 samples encompassing 15 anatomic sites. We uncover site-specific stereotypic cell-type composition and their organization into ten multicellular neighborhoods, most notably a perivascular neighborhood reminiscent of skin-associated lymphoid tissue. Within this neighborhood, ligand–receptor (L–R) analyses identify a central role for tumor necrosis factor in maintaining CCL19⁺ perivascular fibroblasts, highlighting homeostatic immune–stromal crosstalk. Finally, comparing neighborhood dynamics in spatial transcriptomics of skin disease, we find pan-disease immune alterations in this perivascular neighborhood, suggesting spatial compartmentalization of pathogenic activity. Thus, multicellular neighborhoods underlie the skin’s multiscale molecular to macroanatomic organization, orchestrate cell–cell interactions and anatomic site specialization and exhibit architectural disruption in disease.

Background: Streptococcus caniscauses deep pyoderma in canines, which raises concerns about the risk of isolates from lesions acquiring an antibiotic-resistant phenotype. It is necessary to identify effective antibiotics and the characteristics of the pathogenic cluster forS. canis-associated deep pyoderma.Results: The signalment, molecular typing, and antibiotic-resistant status ofS. canisisolated from deep pyoderma lesions (27 strains) and oral cavities (26 strains) were analyzed. Older dogs tended to haveS. canis-associated deep pyoderma (15 of 27 dogs over 10 years old). Veterinarians chose quinolones for 10/16 cases (63%), even though the rate of quinolone-resistant strains ofS. canisis 38–59%. Although 70% of the strains showed resistance to three or more antibiotic classes (37/53), 94% (50/53) strains showed sensitivity for penicillins. We also identified β-lactamase activity among penicillin-resistant strains ofS. canis. Clonal complex 13 (CC13) was detected only in lesions and formed independent clusters in the phylogenetic tree. One strain of CC13 was resistant to the anti-methicillin-resistantStaphylococcus aureusdrugs, vancomycin and linezolid.Conclusion: Although antibiotic-resistant strains ofS. canisare isolated at a high rate, they can currently be treated with β-lactamase-inhibiting penicillins. CC13 may be a pathogenic cluster with high levels of antibiotics resistance.

Background: Little is known about the epidemic status of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in cats in Japan due to insufficiently reliable seroepidemiological analysis methods that are easy to use in cats. Results: We developed a protein-A/G-based enzyme-linked immunosorbent assay (ELISA) to detect antibodies against SARS-CoV-2 in cats. The assay was standardized using positive rabbit antibodies against SARS-CoV-2. The ELISA results were consistent with those of a conventional anti-feline-immunoglobulin-G (IgG)-based ELISA. To test the protein-A/G-based ELISA, we collected blood samples from 1,969 cats that had been taken to veterinary clinics in Japan from June to July 2020 and determined the presence of anti-SARS-CoV-2 antibodies. Nine cats were found to have SARS-CoV-2 S1-specific IgG, of which 4 had recombinant receptor-binding domain-specific IgG. Of those 9 samples, one showed neutralizing activity. Based on these findings, we estimated that the prevalence of SARS-CoV-2 neutralizing antibodies in cats in Japan was 0.05% (1/1,969 samples). This prevalence was consistent with the prevalence of neutralizing antibodies against SARS-CoV-2 in humans in Japan according to research conducted at that time. Conclusions: Protein-A/G-based ELISA has the potential to be a standardized method for measuring anti-SARS-CoV-2 antibodies in cats. The infection status of SARS-CoV-2 in cats in Japan might be linked to that in humans.

Background Little is known about the epidemic status of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in cats living in Japan, and about the influence of cat lifestyles on the SARS-CoV-2 infection epidemic in cats. Results We developed protein A/G-based ELISA, which was standardized using positive rabbit antibodies. The measured values of this ELISA were consistent with those of conventional anti-feline IgG-based ELISA. We then collected blood samples from 1,969 cats that visited veterinary clinics in Japan from June to July 2020 and examined for the presence of anti-SARS-CoV-2 antibodies. Using protein A/G-based ELISA, nine cats were found to have SARS-CoV-2 S1-specific IgG, among which four had RBD-specific IgG. Among those nine samples, one showed neutralizing activity. Based on these, we estimated that the prevalence of SARS-CoV-2 neutralizing antibodies in cats living in Japan was 0.05% (1/1,969 samples). This prevalence did not differ much from the prevalence of neutralizing antibodies for SARS-CoV-2 in humans conducted in Japan at that time. Furthermore, we searched for factors associated with the prevalence of neutralizing antibodies in cats using our data and information from five countries (China, Croatia, France, Germany, and Italy). The prevalence of SARS-CoV-2 in cats was correlated with the rate of keeping indoor-only. Conclusions Protein A/G-based ELISA has the potential to be a standardized method to measure anti-SARS-CoV-2 antibodies in cats. The infection status of SARS-CoV-2 in cats in Japan is linked to that in humans, and the epidemic of SARS-CoV-2 infection in cats may be controlled by their living environment.