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In Japan, trematodes of the family Ochetosomatidae are not naturally distributed. However, the introduced ochetosomatid Ochetosoma kansense (Crow, 1913) has been reported from the oral cavity of native snakes in western Japan since 2010. In this study, trematodes were isolated from the oral cavities of the native Japanese snakes, Elaphe quadrivirgata (Boie, 1826), E. climacophora (Boie, 1826), and Rhabdophis tigrinus (Boie, 1826), in the central Kanto region of eastern Japan. Morphological and molecular analyses of the isolated trematodes revealed that all trematodes were identifiable to a newly introduced ochetosomatid species to Japan, O. elongatum (Pratt, 1903), which originated from North America; Lechriorchis tygarti was synonymized with O. elongatum based on identical molecular data and morphological similarity. To identify first intermediate hosts of O. elongatum, seven freshwater snail species were examined in eastern Japan. Molecular analysis was used to identify O. elongatum sporocysts in the freshwater snail Physella acuta (Draparnaud, 1805), which also originated from North America. The other six species did not host O. elongatum, suggesting that Ph. acuta is the only first intermediate host of O. elongatum in Japan. Although O. elongatum has been detected in Japan, its invasion route and period of introduction are unclear. Frequent imports of freshwater snails and wild snakes from North America, after the 1990s and 2005, respectively, presumably introduced O. elongatum in Japan.
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Introduction: The diffusion of cell components such as proteins is crucial to the function of all living cells. The abundance of macromolecules in cells is likely to cause a state of macromolecular crowding, but its effects on the extent of diffusion remain poorly understood. Methods: Here we investigate the diffusion rate in three distinct locations in mesenchymal cell types, namely the open cytoplasm, the stress fibers in the open cytoplasm, and those below the nucleus using three kinds of biologically inert green fluorescent proteins (GFPs), namely a monomer, dimer, and trimer GFP. Fluorescence correlation spectroscopy (FCS) was used to determine the diffusion coefficients. Results: We show that diffusion tends to be lowered on average in stress fibers and is significantly lower in those located below the nucleus. Our data suggest that the diffusive properties of GFPs, and potentially other molecules as well, are hindered by macromolecular crowding. However, although the size dependence on protein diffusion was also studied for monomer, dimer, and trimer GFPs, there was no significant difference in the diffusion rates among the GFPs of these sizes. These results could be attributed to the lack of significant change in protein size among the selected GFP multimers. Conclusion: The data presented here would provide a basis for better understanding of the complex protein diffusion in the nonuniform cytoplasm, shedding light on cellular responses to mechanical stress, their local mechanical properties, and reduced turnover in senescent cells.
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Type I interferons (IFN-Is) play a significant role in systemic lupus erythematosus (SLE) pathogenesis. Double-filtration plasmapheresis (DFPP) is a treatment option for SLE; however, its effect on IFN-Is remains unclear. Therefore, we investigated the effects of DFPP on IFN-Is. Plasma from patients with SLE (n = 11) who regularly underwent DFPP was analysed using a cell-based reporter system to detect the bioavailability and inducing activity of IFN-I. The concentration of plasma dsDNA was measured, and western blotting analysis was used to assess the phosphorylation of the STING pathway. A higher IFN-I bioavailability and inducing activity were observed in patients compared to healthy controls, and both parameters decreased after DFPP. The reduction in IFN-I-inducing activity was particularly prominent in patients with high disease activity. Notably, this reduction was not observed in STING-knockout reporter cells. Additionally, plasma dsDNA levels decreased after DFPP treatment, suggesting that inhibition of the STING pathway was responsible for the observed decrease in activity. Western blotting analysis revealed suppression of STING pathway phosphorylation after DFPP. DFPP reduced IFN-I bioavailability and the inducing activity of plasma. This reduction is likely attributable to the inhibition of the STING pathway through the elimination of dsDNA.
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Glypthelmins quieta is a frog trematode native to North and Central America. This trematode was recently detected in Japan in the American bullfrog Lithobates catesbeianus, which was introduced from North America to Japan. As the first intermediate host of G. quieta, typically a snail, has not yet been identified in Japan, we conducted a snail survey in eastern Japan to screen for an intermediate host using DNA barcoding based on the nuclear 28S ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1. We sampled 3 different snail species, Orientogalba ollula, Physella acuta, and Sinotaia quadrata histrica (157 individuals in total), and only the freshwater snail Physella acuta, which is also believed to have been introduced from North America to Japan, had sporocysts of G. quieta in its hepatopancreas. The introduction of the intermediate and definitive hosts from North America may have facilitated the invasion of G. quieta into Japan.
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Caracoles , Trematodos , Animales , Japón , Trematodos/genética , Caracoles/parasitología , Especies Introducidas , Interacciones Huésped-Parásitos , ARN Ribosómico 28S/genéticaRESUMEN
Dissipative structures often appear as an unstable counterpart of ordered structures owing to fluctuations that do not form a homogeneous phase. Even a multiphase mixture may simultaneously undergo one chemical reaction near equilibrium and another one that is far from equilibrium. Here, we observed in real time crystal seed formation and simultaneous nanocrystal aggregation proceeding from CeIV complexes to CeO2 nanoparticles in an acidic aqueous solution, and investigated the resultant hierarchical nanoarchitecture. The formed particles exhibited two very different size ranges, resulting in further pattern formation with opalescence. The hierarchically assembled structures in solutions were CeO2 colloids, viz. primary core clusters (1-3 nm) of crystalline ceria and secondary clusters (20-30 nm) assembled through surface ions. Such self-assembly is widespread in multi-component complex fluids, paradoxically moderating hierarchical reactions. Stability and instability are not only critical but also complementary for co-optimisation around the nearby free energy landscape prior to bifurcation.
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Extraction ability of N,N-dioctylthiodiglycolamic acid (T-DODGAA), a soft-base sulfur donor ligand with an amide group and a carboxylic acid connected by a thioether chain, for 56 metal ions have been comprehensively investigated and compared with that of N,N-dioctyldiglycolamic acid (DODGAA) with an etheric oxygen atom, a hard-base donor. The acid dissociation constant (pKa) of the thiodiglycolamic acid framework was determined to be 3.71 ± 0.06 in water (0.1 M LiCl, 25 °C) by potentiometric titration, indicating that T-DODGAA is a slightly weaker acid than DODGAA (pKa = 3.54 ± 0.03). T-DODGAA can quantitatively extract various metal ions from the 56 metal ions into the organic phase (isooctane) through a proton-exchange reaction. T-DODGAA provided higher extraction performance than DODGAA for Hf(IV), Cr(III), Fe(III), Ni(II), Cu(II), Pd(II), Ag(I), Au(III), Hg(II), Al(III), and Ga(III), especially for soft metal ions. Furthermore, to demonstrate the practical feasibility of T-DODGAA for hydrometallurgy and metal recycling, we performed selective separation tests of rare metal ions such as Sc(III), Ni(II), Co(II), Pd(II), Au(III), In(III), and Ga(III) in metal-mixed extraction systems.
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This study examined the psychogenic stress (PS) effects on changes in oxidative stress and the antioxidant capacity of an organism at different growth stages. The experimental animals were male Wistar rats of five different ages from growth periods (GPs) to old age. The growth stages were randomly classified into control (C) and experimental (PS) groups. The PS was performed using restraint and water immersion once daily for 3 h for 4 weeks. Reactive oxygen metabolites (d-ROMs) and the biological antioxidant potential (BAP) were measured before and after the experiment. In addition, the liver and adrenal glands were removed, and the wet weight was measured. The d-ROM and BAP of all growth stages given PS increased significantly. The d-ROM in the C group without PS increased significantly in GPs while decreased significantly in old-aged rats. In addition, the BAP of the C group in GP and early adulthood were all significantly elevated. There were significant differences in organ weights between the C and PS groups at all growth stages. Oxidative stress and antioxidant capacity differed depending on the organism's developmental status and growth stage, and PS also showed different effects. In particular, the variability in oxidative stress was remarkable, suggesting that the effect of PS was more significant in the organism's immature organs.
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Antioxidantes , Estrés Oxidativo , Ratas Wistar , Estrés Psicológico , Animales , Antioxidantes/metabolismo , Masculino , Ratas , Estrés Psicológico/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Hígado/metabolismo , Tamaño de los Órganos , Glándulas Suprarrenales/metabolismo , Glándulas Suprarrenales/crecimiento & desarrolloRESUMEN
Understanding radioactive Cs contamination has been a central issue at Fukushima Daiichi and other nuclear legacy sites; however, atomic-scale characterization of radioactive Cs in environmental samples has never been achieved. Here we report, for the first time, the direct imaging of radioactive Cs atoms using high-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). In Cs-rich microparticles collected from Japan, we document inclusions that contain 27 - 36 wt% of Cs (reported as Cs2O) in a zeolite: pollucite. The compositions of three pollucite inclusions are (Cs1.86K0.11Rb0.19Ba0.22)2.4(Fe0.85Zn0.84X0.31)2.0Si4.1O12, (Cs1.19K0.05Rb0.19Ba0.22)1.7(Fe0.66Zn0.32X0.41)1.4Si4.6O12, and (Cs1.27K0.21Rb0.29Ba0.15)1.9(Fe0.60Zn0.32X0.69)1.6Si4.4O12 (X includes other cations). HAADF-STEM imaging of pollucite, viewed along the [111] zone axis, revealed an array of Cs atoms, which is consistent with a simulated image using the multi-slice method. The occurrence of pollucite indicates that locally enriched Cs reacted with siliceous substances during the Fukushima meltdowns, presumably through volatilization and condensation. Beta radiation doses from the incorporated Cs are estimated to reach 106 - 107 Gy, which is more than three orders of magnitude less than typical amorphization dose of zeolite. The atomic-resolution imaging of radioactive Cs is an important advance for better understanding the fate of radioactive Cs inside and outside of nuclear reactors damaged by meltdown events.
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BACKGROUND: The recent coronavirus disease 2019 (COVID-19) pandemic and school closures were reported to have negatively impacted the mental health of children and adolescents. This study aimed to examine the change in the number and severity of pediatric suicide attempts before and after the COVID-19 pandemic. METHODS: This study enrolled 54 patients (26 vs. 28 patients before and after the COVID-19 pandemic, respectively) under 19 years of age who were transported to the emergency department as a result of suicide attempts between April 2017 and December 2021. The primary outcome includes the rate of serious suicide attempts (SSAs). RESULTS: The SSA rates were 19% (5/26) and 43% (12/28) before and after the COVID-19 pandemic, respectively (p = 0.62). The average number of transported suicide attempts per month almost doubled (0.72 vs. 1.33, respectively) and suicide attempts as a percentage of all ambulance transportations of individuals under 19 years old increased significantly from 0.95% (26/2729)to 1.98% (28/1414) (p = 0.006). CONCLUSIONS: The COVID-19 pandemic increased the severity of pediatric suicide attempts but not to a statistically significant degree. Social preventive support and early psychological intervention are therefore needed currently and in the future.
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COVID-19 , Adolescente , Humanos , Niño , Adulto Joven , Adulto , COVID-19/epidemiología , Pandemias , Intento de Suicidio , Ambulancias , Servicio de Urgencia en HospitalRESUMEN
Revealing the mechanisms of glucose transport is crucial for studying pathological diseases caused by glucose toxicities. Numerous studies have revealed molecular functions involved in glucose transport in the nematode Caenorhabditis elegans, a commonly used model organism. However, the behavior of glucose in the intestinal lumen-to-cell remains elusive. To address that, we evaluated the diffusion coefficient of glucose in the intestinal apical brush border of C. elegans by using fluorescent glucose and fluorescence recovery after photobleaching. Fluorescent glucose taken in the intestine of worms accumulates in the apical brush border, and its diffusion coefficient of â¼10-8 cm2/s is two orders of magnitude slower than that in bulk. This result indicates that the intestinal brush border is a viscous layer. ERM-1 point mutations at the phosphorylation site, which shorten the microvilli length, did not significantly affect the diffusion coefficient of fluorescent glucose in the brush border. Our findings imply that glucose enrichment is dominantly maintained by the viscous layer composed of the glycocalyx and molecular complexes on the apical surface.
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Caenorhabditis elegans , Mucosa Intestinal , Animales , Microvellosidades , Caenorhabditis elegans/genética , Glucosa , IntestinosRESUMEN
BACKGROUND: It is important to assess whether the early detection of breast cancer affects medical care costs. However, research remains scant on the actual medical care costs associated with breast cancer treatment in Japan. This study aimed to determine the medical care costs of breast cancer treatment based on its stage using national health insurance claims data. METHODS: This was an observational study including patients with breast cancer who had undergone breast cancer treatment, as defined by the disease name and related treatment codes. Between August 2013 and June 2016, patients who underwent surgical treatment without axillary lymph node dissection and other radical treatment were classified as the curable group, while those who underwent palliative treatment were classified as the non-curable group. Patients were further stratified by subtype. The total and treatment-specific medical care costs for the five years were calculated using the national health insurance claims data of Hachioji City between August 2013 and May 2021. RESULTS: The mean total medical care costs for the curable and non-curable groups for the 5 years were JPY 3958 thousand (standard deviation 2664) and JPY 8289 thousand (8482), respectively. The mean medical care costs for specific breast cancer treatment for the curable and non-curable groups were JPY 1142 (728) thousand and JPY 3651 thousand (5337), respectively. Further, human epidermal growth factor receptor 2 + , Hormone + patients had the highest mean cost over the 5 years. CONCLUSIONS: The results suggest that the early detection of breast cancer may reduce medical care costs at the patient level.
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Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/cirugía , Japón , Costos de la Atención en Salud , Escisión del Ganglio LinfáticoRESUMEN
Ancient lakes are a hotspot of biodiversity. Freshwater species often experience spectacular species radiation after colonizing lakes from riverine habitats. Therefore, the relationship between the fauna of the ancient lakes and the surrounding riverine system has a special significance in understanding their origin and evolutionary history. The study of ancient lake species often focused on the lake colonization of riverine species. In contrast, far less attention has been placed on the reverse direction: the riverine colonization of the lake species, despite its importance in disentangling their complex evolutionary history. The freshwater snails in the genus Semisulcospira involve endemic groups that radiated in the ancient Lake Biwa. Using genetics and fossil records, we inferred that the ancestors of these lake-endemic Semisulcospira snails historically colonized the riverine habitats at least three times during the Middle Pleistocene. Each colonization resulted in the formation of a new lineage that was genetically and morphologically distinct from other lineages. Further, one of these colonizations was followed by hybridization with a cosmopolitan riverine species, which potentially facilitated the population persistence of the colonizers in the new environment. Despite their complex histories, all these colonizers were currently grouped within a single species, Semisulcospira kurodai, suggesting cryptic diversity in this species. This study highlights the significance of the riverine colonizations of the lake species to fully understand the diversification history of freshwater fauna in and around the ancient lakes.
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Evolución Biológica , Lagos , Animales , Filogenia , Caracoles/genética , Caracoles/anatomía & histología , EcosistemaRESUMEN
Understanding the growth and evolution of social networks is an important area of study, as these networks form the foundation for many popular online services such as social networking sites (SNS) and online games. However, previous models developed to explain the growth mechanisms of these networks have struggled to accurately reproduce certain behaviors that are frequently observed in real data, such as waves of novelty, in which new individuals or topics receive more attention than existing ones for a short period of time. In this study, we introduce a new model that incorporates context information into existing agent-based models in order to more accurately capture the structure and growth dynamics of these networks. Context information is introduced through labels based on the timing of appearance and relationships with antecedent agents. New agents are first added to the network when they are called by existing agents, and at this time they are also given a label. Agents added to the network at the same time by the same agent will have the same label. These labels are used to classify agents and give them different selection probabilities. This newly introduced selection probability creates a mechanism in which new agents receive attention beyond preferential attachment. By comparing the results of our model with real data on ten metrics, we demonstrate that it is able to produce behavior that more closely resembles real data. This improved understanding of the dynamics of social networks has important implications for designing effective interventions, including strategies for user acquisition and retention.
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Red Social , Humanos , ProbabilidadRESUMEN
[Purpose] Oxidative stress is regulated by antioxidant capacity in vivo. However, its impact on aging characteristics remains debatable. This study is first to report oxidative stress, antioxidant capacity, and their ratio in five age groups of rats, and aimed to provide basic data useful for disease prevention. [Materials and Methods] Sixty male Wistar rats of different ages were used as experimental animals, grouped as follows: weaned (three weeks), growth (eight weeks), adulthood (six months), middle-age (12 months), and old-age (24 months). To assess oxidative stress and antioxidant capacity, derivatives of reactive oxygen metabolites and biological antioxidant potential were measured. [Results] The lowest level of oxidative stress and the highest level of antioxidant capacity were observed during the weaning stage, and remarkable dynamic changes were observed until adulthood. The highest oxidative stress and lowest antioxidant capacity were observed in the old-age group. [Conclusion] In vivo oxidative stress and antioxidant capacity are largely reflected in the characteristics of aging, and this ratio is greatly influenced by the dynamics of oxidative stress and antioxidant capacity with age.
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IMPORTANCE: USA300 is an MRSA clone producing PVL, a toxin associated with SSTIs. ΨUSA300 is a USA300 variant recently identified in Japan by Takadama et al. (15). Here, we found that the prevalence rate of PVL-positive MRSA in S. aureus was elevated in the Japanese community, and ΨUSA300 accounted for most of them. ΨUSA300 strains have been isolated from several areas in Japan and were associated with deep-seated SSTIs. This study highlighted the emerging threat posed by ΨUSA300 in Japan.
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Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Humanos , Staphylococcus aureus Resistente a Meticilina/genética , Japón/epidemiología , Staphylococcus aureus/genética , Prevalencia , Infecciones Estafilocócicas/epidemiología , Exotoxinas/genéticaRESUMEN
AbstractHost shifts represent the advancement of a novel niche and often lead to speciation in symbionts. However, its mechanisms are not well understood. Here, we focused on the alga Pseudocladophora conchopheria growing on the shells of intertidal snails. Previous surveys have shown that the alga has host specificity-only attaching to the shell of Lunella correensis-but we discovered that the alga attaches to the shells of multiple sympatric snails. A genome-wide single-nucleotide polymorphism analysis (MIG-seq) was performed to determine whether host-associated speciation occurred in the algae. As a result, there was no gene flow or limited gene flow among the algae from different hosts, and some algae were genetically differentiated among hosts. In addition, the demographic estimate revealed that speciation with gene flow occurred between the algae from different hosts. Therefore, these results support the idea that host-shift speciation gradually proceeded with gene flow in the algae, providing insight into the early evolution of host shifts.
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Chlorophyta , Flujo Génico , Especiación Genética , Exoesqueleto , Chlorophyta/genética , Polimorfismo de Nucleótido SimpleRESUMEN
Aggregation of humic acids (HAs) was studied by small-angle neutron and X-ray scattering techniques. The combination of these techniques enables us to examine the aggregation structures of HA particles. Two HAs with distinctive compositions were examined: a commercial HA (PAHA) and a HA extracted from deep sedimentary groundwater (HHA). While macroscopic coagulation tests showed that these HAs were stable in solutions except for HHA at pH < 6, small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS) revealed that they formed aggregates with sizes exceeding the sub-micrometer length scale. The SAXS curves of PAHA remarkably varied with pD = log aD+, where aD+ stands for the activity of deuterium ions, whereas the SANS curves did not. With the help of theoretical fittings, it was revealed that PAHA aggregates consisted of two domains: poorly hydrated cores and well-hydrated proton-rich shells. The cores were (dis)aggregated with pD inside the aggregates of the shells. The SANS and SAXS curves of HHA resembled each other, and their intensities at low q, where q stands for the scattering vector, increased with a decrease of pD, indicating the formation of homogeneous aggregates within the spatial resolutions of SANS and SAXS. This study revealed that distinctive aggregation behaviors exist in humic substances with nm-scale heterogeneous structures like PAHA, which is important for their roles in the fate of contaminants or nutrients in aqueous environments.
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Sustancias Húmicas , Difracción de Neutrones , Dispersión del Ángulo Pequeño , Rayos X , Difracción de Neutrones/métodos , Difracción de Rayos XRESUMEN
OBJECTIVE: To practically apply level 2 automated driving in complex traffic conditions, it is necessary to prompt driver behaviors to prevent potential accidents in areas where manual interventions are frequently required. METHODS: A driving simulator experiment with 20 participants was conducted to evaluate the impact of different human machine interfaces (HMIs) on drivers' interventions in terms of braking to avoid rear-end collisions during level 2 automated driving when a motorcycle abruptly cut in near intersections. Two types of HMIs were tested: a static HMI that informed drivers about approaching intersections, and a sensor HMI that displayed real-time object recognition results. Each driver participated in five experimental conditions, which varied the presence or absence of the static and sensor HMIs during level 2 automated driving, with manual driving serving as the baseline condition. RESULTS: The maximum deceleration in terms of braking to avoid rear-end collisions was significantly larger when level 2 automated driving was used without any HMI, compared to that of manual driving. However, when the sensor HMI was applied together with the static HMI during level 2 automated driving, a comparable time to collision could be achieved with a significantly smaller deceleration, compared to that without any HMI. Drivers' eye-gaze behaviors revealed that no significant difference existed in the percentages of gaze to the road center area, indicating that they were not distracted by the HMIs. Finally, drivers' attention levels to surrounding traffic and feeling of safety were significantly higher when level 2 automated driving was used in combination with the static and sensor HMIs. CONCLUSIONS: The results demonstrated that the combination of static and sensor HMIs successfully aided drivers in ensuring driving safety with a significantly smaller deceleration to avoid rear-end collisions during level 2 automated driving. Furthermore, drivers' attention levels were maintained, and their feeling of safety was improved when both HMIs were used in combination.
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Conducción de Automóvil , Humanos , Accidentes de Tránsito/prevención & control , Atención , Fijación OcularRESUMEN
Studies are underway on the adsorption reactions of metal ions in confined spaces at the solid-water interface, but it is unclear how the effects of confinement differ for different types of ions. We investigated the effect of the pore size on the adsorption of two cations with different valence, Cs+ and Sr2+, on mesoporous silicas with different pore size distributions. The amount of Sr2+ adsorbed per unit surface area did not differ significantly among the silicas, whereas that of Cs+ was particularly high for silicas with a larger fraction of micropores. The results of X-ray absorption fine structure analysis showed that both ions form outer-sphere complexes with the mesoporous silicas. The results of adsorption experiments were analyzed by fitting using a surface complexation model with the cylindrical Poisson-Boltzmann equation and optimized capacitance of the Stern layer for different pore sizes, and we found that the intrinsic equilibrium constant for the adsorption of Sr2+ is constant regardless of the pore size, whereas that of Cs+ increases as the pore size decreases. The decrease in the relative permittivity of water inside pores with a decrease of the pore size can be interpreted to cause a change in the hydration energy of Cs+ in the second coordination sphere upon adsorption. The reasons for the different confinement effects on the adsorption reactions of Cs+ and Sr2+ were discussed based on the distance of the adsorbed ions from the surface and the chaotropic and kosmotropic nature of Cs+ and Sr2+, respectively.
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OBJECTIVES: Some MRSA strains produce Panton-Valentine leucocidin (PVL) and/or toxic shock syndrome toxin 1 (TSST-1), which are associated with severe infectious diseases. Although PVL- or TSST-1-positive strains have been isolated worldwide, strains carrying both PVL and TSST-1 genes are rare and sporadic. The objective of this study was to characterize these strains from Japan. METHODS: A total of 6433 MRSA strains isolated in Japan between 2015 and 2021 were analysed. Molecular epidemiological and comparative genomic analyses were conducted on PVL- and TSST-1-positive MRSA strains. RESULTS: A total of 26 strains from 12 healthcare facilities were PVL positive and TSST-1 positive, and all were classified as clonal complex (CC) 22. These strains exhibited similar genetic features to each other and were named as ST22-PT according to a previous report. Twelve and one of the ST22-PT strains were identified in patients with deep-seated skin infections and toxic shock syndrome-like symptoms, which are typical clinical features of PVL-positive and TSST-1-positive Staphylococcus aureus, respectively. Whole-genome comparative analysis revealed that the ST22-PT strains were highly similar to PVL- and TSST-1-positive CC22 strains isolated in several countries. Evaluation of the genome structure showed that ST22-PT possessed ΦSa2 harbouring PVL genes and a unique S. aureus pathogenicity island harbouring the TSST-1 gene. CONCLUSIONS: ST22-PT strains have recently emerged from several healthcare facilities in Japan, and ST22-PT-like strains have been identified in several countries. Our report highlights that the risk of international spread of PVL- and TSST-1-positive MRSA clone ST22-PT needs to be further investigated.