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Objectives: Although Clostridium perfringens sporulation is a key event in the pathogenesis of food-borne illness, the molecules and underlying mechanisms responsible for regulating sporulation are incompletely understood. The present study sought to identify amino acids that affect sporulation in C. perfringens strain SM101., Methods: A C. perfringens strain was cultured in the chemically defined medium deficient in an amino acid. The bacterial growth was determined by spectrophotometrically measuring culture turbidity and by calculating colony-forming unit. Morphological characteristics were assessed by phase-contrast microscopy with fluorescent staining and by electron microscopy., Results: The amino acids Arg, Cys, Gly, His, Ile, Leu, Met, Phe, Thr, Trp, Tyr, and Val were important for sporulation, and furthermore, Ser reduced sporulation. The mechanism underlying Ser-induced prevention of sporulation was assessed morphologically. The numbers of bacterial cells in sporulation stage II were significantly higher in the presence than in the absence of Ser. In the presence of Ser, almost all cells were in stage II-III, characterized by polar septation-early engulfment, and did not proceed to late engulfment., Conclusions: These results suggest that Ser accelerated the early stage of sporulation of C. perfringens strain SM101, but disturbed the engulfment process, resulting in reduction of sporulation. To the best of our knowledge, this is the first study reporting that an amino acid affects engulfment during the C. perfringens sporulation process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

As a commercially available esterified compound derived from sucrose and palmitoyl acids, sucrose ester palmitic acid (SEPA) has been used as an emulsifier in food processing. It possesses antibacterial activity against vegetative and spore-forming bacteria, including Clostridium, Moorella, Bacillus, and Geobacillus species, prompting the food industry to use it as a food additive to achieve a desirable shelf life; however, the precise mechanism by which the compound affects the physiological processes of bacteria and how it inhibits bacterial growth remains unclear. In this study, we focused on the inhibitory effect of SEPA on the germination-to-outgrowth process of Clostridium perfringens SM101 spores, a strain widely used as a model of C. perfringens. When the isolated spores were exposed to ≧ 20 μg/ml of SEPA on brain heart infusion agar, bacterial colony formation was completely inhibited. Time-resolved phase-contrast microscopy was employed to visualize the effect of SEPA on the entire regrowth process of SM101 spores. SEPA did not affect the "germination stage," where each spore changes its optical density from phase-bright to phase-dark. In contrast, the presence of SEPA completely blocked the "outgrowth stage," in which the newly synthesized vegetative cell body emerges from the cracked spore shell. The results demonstrate that SEPA inhibits the revival process of the spores of a pathogenic strain of C. perfringens and that the site of its action is the "outgrowth stage" and not the "germination stage," as evidenced by single- cell analysis., Competing Interests: Declaration of competing interest Satoshi Sekimoto is an employee of Mitsubishi Chemical Corporation. The other authors declare no potential conflicts of interest. The funder played no role in the study design, data collection and interpretation, or the decision to submit the work for publication., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Periodontal disease is an inflammatory disease caused by infection with periodontopathogenic bacteria. Oral care is essential to prevent and control periodontal disease, which affects oral and systemic health. However, many oral hygiene products currently on the market were developed as disinfectants, and their intense irritation makes their use difficult for young children and older people. This study investigated the antibacterial effects of prunin laurate (Pru-C12) and its analogs on periodontopathogenic bacteria, Porphyromonas gingivalis ( P. gingivalis ). Pru-C12 and its analogs inhibited in vitro bacterial growth at more than 10 μM and biofilm formation at 50 µM. Among its analogs, only Pru-C12 showed no cytotoxicity at 100 µM. Three of the most potent inhibitors also inhibited the formation of biofilms. Furthermore, Pru-C12 inhibited alveolar bone resorption in a mouse experimental periodontitis model by P. gingivalis infection. These findings may be helpful in the development of oral hygiene products for the prevention and control of periodontal disease and related disorders.

Curcumin has been reported to exert its anti-SARS-CoV-2 activity by inhibiting the binding of spike receptor-binding domain (RBD) to angiotensin-converting enzyme-2 (ACE2). To identify more potent compounds, we evaluated the antiviral activities of curcumin and its analogs in SARS-CoV-2-infected cells. An artificial intelligence-supported activity prediction system was used to select the compounds, and 116 of the 334 curcumin analogs were proposed to have spike RBD-ACE2 binding inhibitory activity. These compounds were narrowed down to eight compounds for confirmatory studies. Six out of the eight compounds showed antiviral activity with EC 50 values of less than 30 µM and binding inhibitory activity with IC 20 values of less than 30 µM. Structure-activity relationship analyses revealed that the double bonds in the carbon chain connecting the two phenolic groups were essential for both activities. X-ray co-crystallography studies are needed to clarify the true binding pose and design more potent derivatives.

SARS-CoV-2 serological studies suggest that individual serum antibody repertoires can affect neutralisation breadth. Herein, we asked whether a BNT162b2 vaccine-induced epitope dominance pattern (i.e., predominant viral structural domain targeted by serum antibodies for virus neutralisation) affects cross-variant neutralisation. When a neutralisation assay against the ancestral strain was carried out using 16 vaccine sera preabsorbed with a recombinant receptor-binding domain (RBD) or an N-terminal domain (NTD) protein, three and 13 sera, respectively, showed lower neutralisation under NTD and RBD protein-preabsorbed conditions than under the other protein-preabsorbed conditions. This suggests that the NTD was responsible for virus neutralisation in three sera, whereas the other 13 sera elicited RBD-dominant neutralisation. The results also suggest the presence of infectivity-enhancing antibodies in four out of the 13 RBD-dominant sera. A neutralisation assay using SARS-CoV-2 variants revealed that NTD-dominant sera showed significantly reduced neutralising activity against the B.1.617.2 variant, whereas RBD-dominant sera retained neutralising activity even in the presence of infectivity-enhancing antibodies. Taken together, these results suggest the followings: (i) epitope dominance patterns are divided into at least two types: NTD-dominant and RBD-dominant; (ii) NTD-dominant sera have less potential to neutralise the B.1.617.2 variant than RBD-dominant sera; and (iii) infectivity-enhancing antibodies play a limited role in cross-variant neutralisation against the five variants tested., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Adding bevacizumab to first-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) prolonged the progression-free survival (PFS), but limited data are available for second-generation EGFR-TKIs. AfaBev-CS is a randomized, phase II trial comparing afatinib plus bevacizumab and afatinib alone as first-line treatment., Patients and Methods: Untreated patients with non-squamous non-small cell lung cancer (NSCLC) harboring EGFR mutations (Del19 or L858R) were enrolled and randomly assigned to receive either afatinib (30 mg) plus bevacizumab (AfaBev group) or afatinib (40 mg) monotherapy (Afa group). The primary endpoint was PFS. The power was >50% under the assumptions of a median PFS of 12 months for the Afa group and hazard ratio (HR) of 0.6 for the AfaBev group., Results: Between August 2017 and September 2019, 100 patients were enrolled. There was no significant difference in PFS between the groups. The median PFS was 16.3 and 16.1 months for the AfaBev and Afa groups, respectively, with an HR of 0.865 (95% confidence interval [CI], 0.539 to 1.388; p = 0.55). In terms of overall survival, there was no significant difference between the groups (HR, 0.84; 95% CI, 0.39 to 1.83; p = 0.67). The overall response rate was 82.6% and 76.6% in the AfaBev and Afa groups, respectively (p = 0.61). Grade ≥ 3 diarrhea, hypertension, acneiform rash, paronychia, and stomatitis were frequently observed in the AfaBev group., Conclusions: This study failed to show efficacy of AfaBev over Afa for improving PFS in untreated patients with EGFR-mutated NSCLC., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dr. Ninomiya reports receiving personal fees from Boehringer Ingelheim, Chugai Pharmaceutical Co., AstraZeneca, Eli Lilly Japan and Eisai. Dr. Ishikawa reports receiving personal fees from Boehringer Ingelheim. Dr. Kozuki reports receiving grants from Chugai Pharmaceutical Co., AstraZeneca, Eli Lilly Japan, Taiho Pharmaceutical Co., Bristol-Myers Squibb, Ono Pharmaceutical Co, MSD, Kyowa Hakko Kirin, Merck Biopharma, Daiichi-Sankyo, AMGEN, Abbvie. Sanofi, Eisai and Labcorp Development Japan; and personal fees from Chugai Pharmaceutical Co., AstraZeneca, Ono Pharmaceutical Co., Pfizer Japan, Daiichi-Sankyo, Bayer, Abbvie, Eli Lilly Japan, Taiho Pharmaceutical Co., Bristol-Myers Squibb, MSD, Kyowa Hakko Kirin, Nippon Boehringer Ingelheim, Merck Biopharma, Nippon Kayaku, Novartis, Takeda Pharmaceutical Co., Bayer, Sawai and AMGEN. Dr. Kuyama reports receiving personal fees from Chugai Pharmaceutical Co., AstraZeneca, Pfizer Japan, Daiichi-Sankyo, Eli Lilly Japan, Taiho Pharmaceutical Co., Bristol-Myers Squibb, MSD, Kyowa Hakko Kirin, Boehringer Ingelheim, Nippon Kayaku, Novartis, Sanofi and Hisamitsu pharmaceutical Co. Inc. Dr. Yokoyama reports receiving grants from MSD, Chugai Pharmaceutical Co. Ltd., Bristol-Myers Squibb Co. Ltd., Boehringer Ingelheim Japan Inc., Takeda Pharmaceutical Co. Ltd., Delta-Fly Pharma and Janssen Pharmaceutical K.K.; and personal fees from AstraZeneca K.K., Chugai Pharmaceutical Co. Ltd., Eli Lilly Japan K.K., Pfizer Japan Inc, Bristol-Myers Squibb Co. Ltd., Ono Pharmaceutical Co. Ltd., Takeda Pharmaceutical Co. Ltd. and Nippon Kayaku Co. Ltd. Dr. Shibayama reports receiving grants from Ono Pharmaceutical Co.; and personal fees from AstraZeneca, Nippon Boehringer Ingelheim and Daiichi-Sankyo. Dr. Aoe reports receiving grants from Ono Pharmaceutical Co., AstraZeneca, Eli Lilly Japan, Bristol-Myers Squibb, MSD, Novartis and Pfizer; and personal fees from Ono Pharmaceutical Co., Bristol-Myers Squibb. Dr. Bessho reports receiving grants from Chugai Pharmaceutical Co., AstraZeneca, MSD, Abbvie and Pfizer; and personal fees from Chugai Pharmaceutical Co., AstraZeneca, Eli Lilly Japan, Taiho Pharmaceutical Co, Bristol-Myers Squibb, Ono Pharmaceutical Co., Nippon Boehringer Ingelheim, Novartis and Pfizer. Dr. Hotta reports receiving grants from Chugai Pharmaceutical Co., AstraZeneca, Eli Lilly Japan, Bristol-Myers Squibb, MSD and Abbvie; and personal fees from Chugai Pharmaceutical Co., AstraZeneca, Eli Lilly Japan, Taiho Pharmaceutical Co., Bristol-Myers Squibb, Ono Pharmaceutical Co., MSD, Pfizer Japan, Takeda Pharmaceutical Co. and Nippon Boehringer Ingelheim. Dr. Kiura reports receiving grants from Chugai Pharmaceutical Co., Taiho Pharmaceutical Co., Ono Pharmaceutical Co., Nippon Boehringer Ingelheim, Nippon Kayaku Co. Ltd., Bristol-Myers Squibb K.K., MSD K.K., Pfizer Japan, TEIJIN Pharma Limited., SHIONOGI Co. Ltd., KYORIN Pharmaceutical Co. Ltd. and Merck Biopharma Co. Ltd. The remaining authors declare no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

To facilitate selfish replication, viruses halt host gene expression in various ways. The nuclear export of mRNA is one such process targeted by many viruses. SARS-CoV-2, the etiological agent of severe acute respiratory syndrome, also prevents mRNA nuclear export. In this study, Nsp14, a bifunctional viral replicase subunit, was identified as a novel inhibitor of mRNA nuclear export. Nsp14 induces poly(A)+ RNA nuclear accumulation and the dissolution/coalescence of nuclear speckles. Genome-wide gene expression analysis revealed the global dysregulation of splicing and 3'-end processing defects of replication-dependent histone mRNAs by Nsp14. These abnormalities were also observed in SARS-CoV-2-infected cells. A mutation introduced at the guanine-N7-methyltransferase active site of Nsp14 diminished these inhibitory activities. Targeted capillary electrophoresis-mass spectrometry analysis (CE-MS) unveiled the production of N7-methyl-GTP in Nsp14-expressing cells. Association of the nuclear cap-binding complex (NCBC) with the mRNA cap and subsequent recruitment of U1 snRNP and the stem-loop binding protein (SLBP) were impaired by Nsp14. These data suggest that the defects in mRNA processing and export arise from the compromise of NCBC function by N7-methyl-GTP, thus exemplifying a novel viral strategy to block host gene expression., (© The Author(s) 2023. Published by Oxford University Press on behalf of Nucleic Acids Research.)

The emergence of mcr plasmid-mediated colistin-resistant extended-spectrum β-lactamase (ESBL)-producing Enterobacterales among companion dogs and cats poses a risk of the animals acting as reservoirs for cross-species transmission. However, current knowledge of mcr-harboring ESBL-producing Enterobacterales in companion dogs and cats is still limited; thus, the genetic and phenotypic characteristics of the bacterial isolates and plasmids, in companion dogs and cats, remain to be elucidated. Here, we identified mcr gene-harboring ESBL-producing Escherichia coli isolates during whole-genome sequencing of ESBL-producing E. coli isolates from a dog and a cat in Osaka, Japan. Colistin-resistant MY732 isolate from a dog carried two plasmids: mcr-1.1-harboring IncI2 plasmid and bla CTX-M-14 -harboring IncFIB plasmid. Conjugation assays revealed that both plasmids can be co-transferred even though the IncFIB plasmid lacked a conjugal transfer gene cassette. The other isolate MY504 from a cat harbored two bla genes and mcr-9 on the identical IncHI2 plasmid. This isolate was not resistant to colistin, which is likely to be due to deletion of the regulatory two-component QseBC system associated with the mcr-9 expression. To the best of our knowledge, this is the first report of a colistin-resistant ESBL-producing E. coli isolate harboring mcr-1 from a companion dog in Japan. Given that the mcr gene-harboring IncI2 and IncHI2 plasmids in this study shared high homology with plasmids from human or animal-derived Enterobacterales, companion dogs and cats may act as important reservoirs for cross-species transmission of the mcr gene in the community, in Japan., Competing Interests: Conflict of interest We have no competing interests to declare., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Cross-neutralizing capacity of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants is important in mitigating (re-)exposures. Role of antibody maturation, the process whereby selection of higher affinity antibodies augments host immunity, to determine SARS-CoV-2 neutralizing capacity was investigated., Methods: Sera from SARS-CoV-2 convalescents at 2, 6, or 10 months postrecovery, and BNT162b2 vaccine recipients at 3 or 25 weeks postvaccination, were analyzed. Anti-spike IgG avidity was measured in urea-treated ELISAs. Neutralizing capacity was assessed by surrogate neutralization assays. Fold change between variant and wild-type neutralization inferred the breadth of neutralizing capacity., Results: Compared with early-convalescent, avidity indices of late-convalescent sera were significantly higher (median, 37.7 [interquartile range 28.4-45.1] vs 64.9 [57.5-71.5], P < .0001). Urea-resistant, high-avidity IgG best predicted neutralizing capacity (Spearman r = 0.49 vs 0.67 [wild-type]; 0.18-0.52 vs 0.48-0.83 [variants]). Higher-avidity convalescent sera better cross-neutralized SARS-CoV-2 variants (P < .001 [Alpha]; P < .01 [Delta and Omicron]). Vaccinees only experienced meaningful avidity maturation following the booster dose, exhibiting rather limited cross-neutralizing capacity at week 25., Conclusions: Avidity maturation was progressive beyond acute recovery from infection, or became apparent after the booster vaccine dose, granting broader anti-SARS-CoV-2 neutralizing capacity. Understanding the maturation kinetics of the 2 building blocks of anti-SARS-CoV-2 humoral immunity is crucial., Competing Interests: Conflict of Interest. Y. N. and Y. K. report equity ownership of Quantum Molecular Diagnostics, an Osaka Metropolitan University spinout targeting infectious diseases to develop innovative diagnostics. Y. N. and Y. K. also report receiving financial support outside of this work from Abbott Japan LLC, Japan., (© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

This paper proposes an optical system for aquatic display that shows an image in water. The aquatic image is formed by utilizing aerial imaging by retro-reflection, which converges light by a retro-reflector and a beam splitter. Refraction on intersection between air and another material causes spherical aberration, which changes light-converging distance. In order to reduce the converging distance change, the light-source component is filled with water so that the optical system becomes conjugate including the medium. We analyzed converging of light in water by simulations. Furthermore, we have confirmed effectiveness of conjugated optical structure experimentally by use of a prototype.

Teleost fishes exhibit complex sexual characteristics in response to androgens, such as fin enlargement and courtship display. However, the molecular mechanisms underlying their evolutionary acquisition remain largely unknown. To address this question, we analyse medaka (Oryzias latipes) mutants deficient in teleost-specific androgen receptor ohnologs (ara and arb). We discovered that neither ar ohnolog was required for spermatogenesis, whilst they appear to be functionally redundant for the courtship display in males. However, both were required for reproductive success: ara for tooth enlargement and the reproductive behaviour eliciting female receptivity, arb for male-specific fin morphogenesis and sexual motivation. We further showed that differences between the two ar ohnologs in their transcription, cellular localisation of their encoded proteins, and their downstream genetic programmes could be responsible for the phenotypic diversity between the ara and arb mutants. These findings suggest that the ar ohnologs have diverged in two ways: first, through the loss of their roles in spermatogenesis and second, through gene duplication followed by functional differentiation that has likely resolved the pleiotropic roles derived from their ancestral gene. Thus, our results provide insights into how genome duplication impacts the massive diversification of sexual characteristics in the teleost lineage., (© 2023. The Author(s).)

Although a certain level of efficacy and safety of several vaccine products against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have been established, unmet medical needs for orally active small molecule therapeutic drugs are still very high. As a key drug target molecule, SARS-CoV-2 main protease (M pro ) is focused and large number of in-silico screenings, a part of which were supported by artificial intelligence (AI), have been conducted to identify M pro inhibitors both through drug repurposing and drug discovery approaches. In the many drug-repurposing studies, docking simulation-based technologies have been mainly employed and contributed to the identification of several M pro binders. On the other hand, because AI-guided INTerprotein's Engine for New Drug Design (AI-guided INTENDD), an AI-supported activity prediction system for small molecules, enables to propose the potential binders by proprietary AI scores but not docking scores, it was expected to identify novel potential M pro binders from FDA-approved drugs. As a result, we selected 20 potential M pro binders using AI-guided INTENDD, of which 13 drugs showed M pro -binding signal by surface plasmon resonance (SPR) method. Six (6) compounds among the 13 positive drugs were identified for the first time by the present study. Furthermore, it was verified that vorapaxar bound to M pro with a K d value of 27 µM by SPR method and inhibited virus replication in SARS-CoV-2 infected cells with an EC 50 value of 11 µM. Communicated by Ramaswamy H. Sarma.

Background: The standard of care for unresectable, locally advanced non-small-cell lung cancer (LA-NSCLC) is chemoradiotherapy (CRT) followed by durvalumab, based on the PACIFIC study. Although multiple Japanese phase II studies have shown high efficacy and tolerability of CRT with cisplatin plus S-1 (SP), no prospective study using durvalumab after SP-based CRT has been reported., Objectives: We conducted a multicenter phase II study of this approach, the interim analysis of which showed a high transition rate to durvalumab consolidation therapy. Here, we report the primary analysis results., Design: In treatment-naïve LA-NSCLC, cisplatin (60 mg/m 2 , day 1) and S-1 (80-120 mg/body, days 1-14) were administered with two 4-week cycles with concurrent thoracic radiotherapy (60 Gy) followed by durvalumab (10 mg/kg) every 2 weeks for up to 1 year., Methods: The primary endpoint was 1-year progression-free survival (PFS). The expected 1-year PFS and its lower limit of the 80% confidence interval (CI) were set as 63% and 47%, respectively, based on the results of TORG1018 study., Results: In all, 59 patients were enrolled, with 51 (86.4%) proceeding to durvalumab. The objective response rate throughout the study was 72.9% (95% CI: 59.7-83.6%). After median follow-up of 21.9 months, neither median PFS nor OS was reached. The 1-year PFS was 72.5% (80% CI: 64.2-79.2%, 95% CI: 59.1-82.2%), while the 1-year overall survival was 91.5% (95% CI: 80.8-96.4%). No grade 5 adverse events were observed throughout the study. The most common adverse event during the consolidation phase was pneumonitis (any grade, 78.4%; grade ⩾3, 2.0%). Eventually, 52.5% of patients completed 1-year durvalumab consolidation therapy from CRT initiation., Conclusion: This study of durvalumab after SP-based CRT met its primary endpoint and found a 1-year PFS of 73% from CRT initiation. This study provides the first prospective data on the prognosis and tolerability of durvalumab consolidation from the initiation of CRT., Trial Registration: Japan Registry of Clinical Trials, jRCTs031190127, registered 1 November, 2019, https://jrct.niph.go.jp/latest-detail/jRCTs031190127., Competing Interests: H.T. received personal fees as honoraria from Boehringer Ingelheim, AstraZeneca, Pfizer, Chugai Pharmaceutical, Bristol-Myers Squibb, and Ono Pharmaceutical. S.T. received research funding from AstraZeneca, and personal fees as honoraria from AstraZeneca, Chugai Pharmaceutical, Taiho Pharmaceutical, and Eli Lilly. T.Misu. received personal fees as honoraria from Chugai Pharmaceutical and AstraZeneca. S.K. received personal fees as honoraria from Chugai Pharmaceutical, Bristol-Myers Squibb, Boehringer Ingelheim, AstraZeneca, Pfizer, Eli Lilly, MSD, Taiho Pharmaceutical, Sanofi, Kyowa Kirin, Hisamitsu Pharmaceutical, Daiichi Sankyo, Nippon Kayaku, and Novartis. N.I. received personal fees as honoraria from AstraZeneca. K.Kusa. received personal fees as honoraria from AstraZeneca, Chugai Pharmaceutical, Ono Pharmaceutical, and Nippon Kayaku. N.F. received personal fees as honoraria from Bristol-Myers Squibb, Ono Pharmaceutical, Boehringer Ingelheim, and AstraZeneca. Y.F. received personal fees as honoraria from Bristol-Myers Squibb, Ono Pharmaceutical, Chugai Pharmaceutical, AstraZeneca, Novartis, Merck Biopharma, MSD, Boehringer Ingelheim, Taiho Pharmaceutical, and Daiichi Sankyo. T.T. received personal fees as honoraria from Chugai Pharmaceutical. K.Shib. received personal fees as honoraria from AstraZeneca, Taiho Pharmaceutical, Chugai Pharmaceutical, Bristol-Myers Squibb, and Ono Pharmaceutical. A.B. received research funding from AstraZeneca and personal fees as honoraria from AstraZeneca and Taiho Pharmaceutical. K.Kair. received research funding from AstraZeneca and Nihon Medi-Physics and personal fees as honoraria from Ono Pharmaceutical, Boehringer Ingelheim, Chugai Pharmaceutical, Taiho Pharmaceutical, Eli Lilly, AstraZeneca, and Pfizer. N.S. received research funding from Ono Pharmaceutical, Boehringer Ingelheim, Taiho Pharmaceutical, Chugai Pharmaceutical, Eisai, Daiichi Sankyo, Takeda Pharmaceutical, Shionogi, Nippon Kayaku, and Pfizer, and personal fees as honoraria from Ono Pharmaceutical, Taiho Pharmaceutical, Chugai Pharmaceutical, Eli Lilly, AstraZeneca, Boehringer Ingelheim, MSD, Daiichi Sankyo, Novartis, Bristol-Myers Squibb, Pfizer, Takeda Pharmaceutical, and Nippon Kayaku. No potential conflicts of interest were disclosed by the other authors., (© The Author(s), 2022.)

Predator-prey interactions based on laterality have recently been observed between fishes and their prey populations. Maintenance of antisymmetric dimorphism by frequency-dependent selection has been reported in fish, but has not been observed in invertebrates. Over 10 years, we investigated long-term changes in the "ratio of laterality" (frequency of righty morphs in a population) in the cuttlefish Sepia recurvirostra and its potential prey prawns Penaeus semisulcatus and Metapenaeus endeavouri in the Visayan Sea, the Philippines. The morphological laterality of cuttlefish and prey prawns was defined by measuring the asymmetry of the cuttlebone and carapace, respectively. Cuttlefish and prey prawns showed morphological antisymmetry, being composed with righty morphs and lefty morphs. The ratio of laterality of cuttlefish and one prey prawn oscillated significantly, but the oscillation was not strongly synchronized. The ratio of laterality of cuttlefish followed that of the prey prawn, indicating that predation biased to each laterality occurred in relation to their laterality. These results suggest that the lateral dimorphism of cuttlefish is maintained through frequency-dependent selection on lateral morphs of the predator cuttlefish and prey prawns. Our findings provide new insight into the ecological significance and antisymmetry maintenance mechanism in relation to interspecific interactions in marine invertebrates.

The water flea, Daphnia magna, is a representative zooplankton that lives in freshwater environments. It primarily propagates via asexual reproduction in normal and healthy environmental conditions. Unsuitable environmental conditions induce D. magna to change its mode of reproduction from asexual to sexual reproduction. During sexual reproduction, D. magna produces special tough eggs (resting eggs) that can survive severe environmental conditions. Despite an increase in our understanding of their mating behavior, the sex-specific characteristics of swimming behavior among daphnid species are poorly understood. In this study, we analysed the swimming patterns and dynamics of female and male adult D. magna using computer modeling. Males displayed laterally biased diffusion in contrast to the homogeneous, nondirectional diffusion of females. Computer modeling analysis using a discrete-time Markov chain simulation, in which the frequencies of turning behavior were evaluated as probability distributions, explained the greater diffusion of males in the horizontal direction. We presumed that high diffusion in the horizontal direction would increase the probability of encountering a distant mate. Our findings suggest that male D. magna increases genotypic heterogeneity by effectively selecting certain motion parameters., (© 2022 Wiley Periodicals LLC.)

A novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), suddenly emerged in China in 2019, spread globally and caused the present COVID-19 pandemic. Therefore, to mitigate SARS-CoV-2 infection effective measures are essential. Chlorous acid (HClO 2 ) has been shown to be an effective antimicrobial agent. However, at present there is no experimental evidence showing that HClO 2 can inactivate SARS-CoV-2. Therefore, in this study, we examined the potential of HClO 2 to inactivate SARS-CoV-2 in presence or absence of organic matter and the results were compared with that of sodium hypochlorite (NaClO), another potent antimicrobial agent. When concentrated SARS-CoV-2 was incubated with 10 ppm HClO 2 for 10 s, viral titre was decreased by 5 log of 50% tissue culture infective dose per mL (TCID 50 ml -1 ). However, the same concentration of NaClO could not inactivate SARS-CoV-2 as effectively as HClO 2 did even after incubation for 3 min. Furthermore, 10 ppm HClO 2 also inactivated more than 4.0 log of TCID 50 within 10 s in the presence of 5 % fetal bovine serum used as mixed organic matters. Our results obtained with HClO 2 are more effective against SARS-CoV-2 as compared to NaClO that can be used for disinfectant against SARS-CoV-2 ., Competing Interests: This study was performed as a collaborative research of Sankei Co., Ltd., and financially supported by this company., (© 2022 The Authors.)

Staphylococcus argenteus has been recently established as a novel species of Staphylococcus aureus complex. It is known to cause various human diseases, such as skin and soft-tissue infections, sepsis, and staphylococcal food poisoning, although the source of infection has not been clearly described. In food poisoning cases, the source of bacterial contamination in food is unknown. This study examined the prevalence of S. argenteus among retail fresh food and poultry slaughterhouses in Japan. Among 642 food samples examined, successful isolation of S. argenteus was achieved in 21 of 151 (13.9%) chicken samples. No isolations from pork, beef, fish, or vegetables in retail markets were confirmed. Multiple-locus sequence typing revealed that the 21 isolates were classified into four sequence types (ST) that were divided into 14 subtypes using spa-typing. All food isolates were susceptible to methicillin and did not show positivity for the Panton-Valentine leukocidin gene. When bacteria were isolated from two poultry slaughterhouses in the same region, 14 S. argenteus strains were successfully isolated from only one slaughterhouse. Thirteen of 14 strains were isolated from a poultry carcass and slaughterhouse environments during a certain sampling period and were all classified as ST5961 with identical spa-type. Also, the number of single nucleotide variants (SNVs) detected on the core genomes of the same 13 strains were between 0 and 17, suggesting a long-term inhabitation of an S. argenteus strain inside the facility. Furthermore, one isolate from chicken meat was also genetically linked with the same lineage of slaughterhouse isolates, with ≤15 SNVs being detected. Additionally, one slaughterhouse isolate from chiller water and three chicken isolates were classified into the same cluster by phylogenetic analysis, although the number of pairwise SNVs ranged from 62 to 128. To the best of the authors' knowledge, this is the first study that demonstrated S. argenteus in a food processing facility and the possible bacterial contamination on food during food processing., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Aim: A novel coronavirus, termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) suddenly appeared in Wuhan, China, and has caused pandemic. In this study, we evaluated antiviral activity of purified hypochlorous acid (HClO) against coronaviruses such as SARS-CoV-2 and transmissible gastroenteritis virus (TGEV) responsible for pig diseases., Materials and Results: In a suspension test, 28.1 ppm HClO solution inactivated SARS-CoV-2 in phosphate-buffered saline with the reduction of 10 4 of 50% tissue culture infectious dose per ml (TCID 50 per ml) within 10 s. When its concentration increased to 59.4 ppm, the virus titre decreased to below the detection limit (reduction of 5 logs TCID 50 ) within 10 s even in the presence of 0.1% foetal bovine serum. In a carrier test, incubation with 125 ppm HClO solution for 10 min or 250 ppm for 5 min inactivated SARS-CoV-2 by more than 4 logs TCID 50 per ml or below the detection limit. Because the titre of TGEV was 10-fold higher, TGEV was used for SARS-CoV-2 in a suspension test. As expected, 56.3 ppm HClO solution inactivated TGEV by 6 logs TCID 50 within 30 s., Conclusions: In a carrier test, 125 ppm HClO solution for 10 min incubation is adequate to inactivate 4 logs TCID 50 per ml of SARS-CoV-2 or more while in a suspension test 56.3 ppm HClO is adequate to inactivate 5 logs TCID 50 per ml of SARS-CoV-2 when incubated for only 10 s regardless of presence or absence of organic matter., Significance and Impact of the Study: Effectiveness of HClO solution against SARS-CoV-2 was demonstrated by both suspension and carrier tests. HClO solution inactivated SARS-CoV-2 by 5 logs TCID 50 within 10 s. HClO solution has several advantages such as none toxicity, none irritation to skin and none flammable. Thus, HClO solution can be used as a disinfectant for SARS-CoV-2., (© 2021 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.)

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a serious global issue. To prevent viral transmission, it is important to disinfect contaminated environmental surfaces and aerosols. We previously demonstrated that nano-sized electrostatic atomized water particles (NEAWPs) inactivate SARS-CoV-2. Herein, we focused on the underlying mechanisms. Morphological observation by transmission electron microscopy revealed that compared with NEAWPs-untreated virus, the shapes of particles corresponding to the size of SARS-CoV-2 particles were distorted significantly when exposed to NEAWPs. The amounts of viral RNA and protein in NEAWPs-treated SARS-CoV-2 showed a significantly greater decline than those in viruses unexposed to NEAWPs. Furthermore, much less NEAWPs-treated SARS-CoV-2 than NEAWPs-untreated virus bound to host cells. These results strongly suggest that NEAWPs damage the viral envelope, as well as viral protein and RNA, thereby impairing the ability of the virus to bind to host cells. Reactive oxygen species in NEAWPs may be involved in the inactivating effects on SARS-CoV-2., Supplementary Information: The online version contains supplementary material available at 10.1007/s11051-022-05485-5., Competing Interests: Conflict of interestThis study was performed in collaboration with Panasonic Corporation Living Appliances and Solutions Company, and was financially supported by the company., (© The Author(s), under exclusive licence to Springer Nature B.V. 2022.)