Faecalibacterium taiwanense sp. nov., isolated from human faeces.

Two Gram-stain-negative, straight rods, non-motile, asporogenous, catalase-negative and obligately anaerobic butyrate-producing strains, HLW78T and CYL33, were isolated from faecal samples of two healthy Taiwanese adults. Phylogenetic analyses of 16S rRNA and DNA mismatch repair protein MutL (mutL) gene sequences revealed that these two novel strains belonged to the genus Faecalibacterium. On the basis of 16S rRNA and mutL gene sequence similarities, the type strains Faecalibacterium butyricigenerans AF52-21T(98.3-98.1 % and 79.0-79.5 % similarity), Faecalibacterium duncaniae A2-165T(97.8-97.9 % and 70.9-80.1 %), Faecalibacterium hattorii APC922/41-1T(97.1-97.3 % and 80.3-80.5 %), Faecalibacterium longum CM04-06T(97.8-98.0% and 78.3 %) and Faecalibacterium prausnitzii ATCC 27768T(97.3-97.4 % and 82.7-82.9 %) were the closest neighbours to the novel strains HLW78T and CYL33. Strains HLW78T and CYL33 had 99.4 % both the 16S rRNA and mutL gene sequence similarities, 97.9 % average nucleotide identity (ANI), 96.3 % average amino acid identity (AAI), and 80.5 % digital DNA-DNA hybridization (dDDH) values, indicating that these two strains are members of the same species. Phylogenomic tree analysis indicated that strains HLW78T and CYL33 formed an independent robust cluster together with F. prausnitzii ATCC 27768T. The ANI, AAI and dDDH values between strain HLW78T and its closest neighbours were below the species delineation thresholds of 77.6-85.1 %, 71.4-85.2 % and 28.3-30.9 %, respectively. The two novel strains could be differentiated from the type strains of their closest Faecalibacterium species based on their cellular fatty acid compositions, which contained C18 : 1 ω7c and lacked C15 : 0 and C17 : 1 ω6c, respectively. Phenotypic, chemotaxonomic and genotypic test results demonstrated that the two novel strains HLW78T and CYL33 represented a single, novel species within the genus Faecalibacterium, for which the name Faecalibacterium taiwanense sp. nov. is proposed. The type strain is HLW78T (=BCRC 81397T=NBRC 116372T).

Key issues in Japan's public health centers to prepare for future pandemics: a text mining study using a topic model.

BACKGROUND: In Japan, over 450 public health centers played a central role in the operation of the local public health system in response to the COVID-19 pandemic. This study aimed to identify key issues for improving the system for public health centers for future pandemics. METHODS: We conducted a cross-sectional study using an online questionnaire. The respondents were first line workers in public health centers or local governments during the pandemic. We solicited open-ended responses concerning improvements needed for future pandemics. Issues were identified from these descriptions using morphological analysis and a topic model with KHcoder3.0. The number of topics was estimated using Perplexity as a measure, and Latent Dirichlet Allocation for meaning identification. RESULTS: We received open-ended responses from 784 (48.6%) of the 1,612 survey respondents, which included 111 physicians, 330 nurses, and 172 administrative staff. Morphological analysis processed these descriptions into 36,632 words. The topic model summarized them into eight issues: 1) establishment of a crisis management system, 2) division of functions among public health centers, prefectures, and medical institutions, 3) clear role distribution in public health center staff, 4) training of specialists, 5) information sharing system (information about infectious diseases and government policies), 6) response to excessive workload (support from other local governments, cooperation within public health centers, and outsourcing), 7) streamlining operations, and 8) balance with regular duties. CONCLUSIONS: This study identified key issues that need to be addressed to prepare Japan's public health centers for future pandemics. These findings are vital for discussions aimed at strengthening the public health system based on experiences from the COVID-19 pandemic.

Vallitalea longa sp. nov., an anaerobic bacterium isolated from marine sediment.

A novel bacterium, strain SH18-1T, was isolated from marine sediment collected near Sado Island in the Sea of Japan. This strain was strictly anaerobic, Gram-stain-negative, non-spore-forming, rod-shaped, motile, and mesophilic. It grew at 15-40 °C (optimum, 30-35 °C), at a NaCl concentration of 0.2-5.0 % (w/v; optimum, 1.5-2.5 %), and at pH 5.5-8.5 (optimum, pH 7.0). Results of 16S rRNA gene phylogenetic analysis showed a similarity value of 97.49 % between strain SH18-1T and Vallitalea guaymasensis Ra1766G1T, which was the most closely related species. The genome size of strain SH18-1T was 5.71 Mb and its G+C content was 30.2 mol%. Genome sequence analyses for comparison between strain SH18-1T and V. guaymasensis Ra1766G1T showed values lower than the threshold for species demarcation determined using the Genome-to-Genome Distance Calculator and the Average Nucleotide Identity Calculator. Elemental sulphur, sulphate, thiosulphate, sulphite, fumarate, nitrate, and nitrite were not used as terminal electron acceptors. The major fatty acids in strain SH18-1T were iso-C15 : 0, anteiso-C15 : 0, and C16 : 0, and the detected polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid, glycolipid, three unidentified phospholipids, and one unidentified polar lipid. From these results, strain SH18-1T (=NBRC 115488T=DSM 114058T) is suggested to represent a novel species of the genus Vallitalea and the name Vallitalea longa sp. nov. is proposed.

Physiological and genomic analyses of cobalamin (vitamin B12)-auxotrophy of Lysobacter auxotrophicus sp. nov., a methionine-auxotrophic chitinolytic bacterium isolated from chitin-treated soil.

A novel bacterium, designated 5-21aT, isolated from chitin-treated upland soil, exhibits methionine (Met) auxotrophy and chitinolytic activity. A physiological experiment revealed the cobalamin (synonym, vitamin B12)(Cbl)-auxotrophic property of strain 5-21aT. The newly determined complete genomic sequence indicated that strain 5-21aT possesses only the putative gene for Cbl-dependent Met synthase (MetH) and lacks that for the Cbl-independent one (MetE), which implies the requirement of Cbl for Met-synthesis in strain 5-21aT. The set of genes for the upstream (corrin ring synthesis) pathway of Cbl synthesis is absent in the genome of strain 5-21aT, which explains the Cbl-auxotrophy of 5-21aT. This strain was characterized via a polyphasic approach to determine its taxonomic position. The nucleotide sequences of two copies of the 16S rRNA gene of strain 5-21aT indicated the highest similarities to Lysobacter soli DCY21T(99.8 and 99.9 %) and Lysobacter panacisoli CJ29T(98.7 and 98.8 %, respectively), whose Cbl-auxotrophic properties were revealed in this study. The principal respiratory quinone was Q-8. The predominant cellular fatty acids were iso-C15:0, iso-C16:0 and iso-C17:1 ω9c. The complete genome sequence of strain 5-21aT revealed that the genome size was 4 155 451 bp long and the G+C content was 67.87 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain 5-21aT and its most closely phylogenetic relative L. soli DCY21T were 88.8 and 36.5%, respectively. Based on genomic, chemotaxonomic, phenotypic and phylogenetic data, strain 5-21aT represents a novel species in the genus Lysobacter, for which the name Lyobacter auxotrophicus sp. nov. is proposed. The type strain is 5-21aT (=NBRC 115507T=LMG 32660T).

Fructobacillus papyriferae sp. nov., Fructobacillus papyrifericola sp. nov., Fructobacillus broussonetiae sp. nov. and Fructobacillus parabroussonetiae sp. nov., isolated from paper mulberry in Taiwan.

Five Gram-stain-positive strains (M1-10T, M1-13, M1-21T, M2-14T and S1-1T) were isolated from paper mulberry (Broussonetia papyrifera) in Taiwan. Cells were rod-shaped, non-motile, non-haemolytic, asporogenous, facultatively anaerobic, heterofermentative, and did not exhibit catalase and oxidase activities. Phylogenetic analysis of the 16S rRNA gene sequences revealed that these novel strains belonged to the genus Fructobacillus. On the basis of 16S rRNA gene sequence similarities, the type strains of Fructobacillus fructosus and Fructobacillus durionis were the closest neighbours to strains M1-10T, M1-13, M1-21T, M2-14T and S1-1T. Sequence analyses of concatenated two partial housekeeping genes, the RNA polymerase beta subunit (rpoC) and recombinase A (recA) also indicated that the novel strains belonged to the genus Fructobacillus. The 16S rRNA and concatenated rpoC and recA gene sequence similarities between strains M1-10T and M1-13 were 100 %, respectively. The average nucleotide identity values of M1-10T, M1-21T, M2-14T and S1-1T with F. fructosus and F. durionis were 75.1-78.9% and 76.5-77.5 %, respectively. The digital DNA-DNA hybridization values were 19.7-21.5% and 19.6-20.4 %, respectively. Phenotypic and genotypic test results demonstrated that these strains represent four novel species of the genus Fructobacillus, for which the names Fructobacillus papyriferae sp. nov., Fructobacillus papyrifericola sp. nov., Fructobacillus broussonetiae sp. nov. and Fructobacillus parabroussonetiae sp. nov. are proposed with the type strains M1-10T (=BCRC 81237T=NBRC 114433T), M1-21T (=BCRC 81239T=NBRC 114435T), M2-14T (=BCRC 81240T=NBRC 114436T) and S1-1T (=BCRC 81241T=NBRC 114437T), respectively.

Effect of COVID-19 infection related experiences on social behaviors when a state of emergency is declared: a cohort study.

BACKGROUND: Restricting the movement of the public to gathering places and limiting close physical contact are effective measures against COVID-19 infection. In Japan, states of emergency have been declared in specific prefectures to reduce public movement and control COVID-19 transmission. We investigated how COVID-19 infection related experiences including people with a history of infection, people with a history of close contact, and people whose acquaintances have been infected, affected self-restraint from social behaviors during the second state of emergency in Japan. METHODS: A prospective cohort study was conducted among workers aged 20-65 years using data from an internet survey. The baseline survey was conducted on December 22-25, 2020, and a follow-up survey was on February 18-19, 2021. There were 19,051 participants who completed both surveys and were included in the final analysis. We identified eight social behaviors: (1) eating out (4 people or fewer); (2) eating out (5 people or more); (3) gathering with friends and colleagues; (4) day trip; (5) overnight trip (excluding visiting home); (6) visiting home; (7) shopping for daily necessities; and (8) shopping for other than daily necessities. We set self-restraint regarding each social behavior after the second state of emergency was declared in January 2021 as the dependent variable, and COVID-19 infection related experiences as independent variables. Odds ratios were estimated using multilevel logistic regression analyses nested in the prefecture of residence. RESULTS: Significant differences by COVID-19 infection related experiences were identified: compared to people without COVID-19 related experiences, people with a history of COVID-19 were less likely self-restraint from most social behaviors. People whose acquaintance had been diagnosed with COVID-19 were significantly more likely to refrain from most social behaviors. There was no significant difference in any social behaviors for people with a history of close contact only. CONCLUSION: To maximize the effect of a state of emergency, health authorities should disseminate information for each person in the target population, taking into account potential differences related to the infection related experiences.

What is the role of occupational physicians in the workplace during the COVID-19 pandemic in Japan? A qualitative interview study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had various impacts on businesses and workers worldwide. The spread of infection has been reported through cluster outbreaks in the workplace, and World Health Organization has emphasized workplace infection control measures. Occupational physicians (OPs) are expected to actively support employers' efforts to minimize the damage of the pandemic. However, there is little research on the role of these specialists during a pandemic. Clarification of the contributions of OPs to health and safety at the workplace in the COVID-19 pandemic would be beneficial to ensure that OPs can be effectively deployed in the next pandemic. METHODS: We employed semi-structured interviews and qualitative content analysis of the interview transcripts. Twenty OPs were selected as priority candidates from among 600 OPs certificated of the JSOH, and thirteen who met the eligibility criteria agreed to participate. The online interviews were conducted in November and December 2020 with thirteen OPs. We extracted meaning units (MUs) from interview transcripts according to the research question: "What was the role of OP in the COVID-19 pandemic?" and condensed and abstracted them into codes and categorized them. Validity was confirmed by additional 5 OPs interviews. RESULTS: A total of 503 MUs were extracted from the transcripts. These were abstracted into 10 sub-categories and two categories. Categories 1 and 2 dealt with "Role in confronting the direct effects of the pandemic" and "Role in confronting the indirect effects of the pandemic" and accounted for 434 (86.3%) and 69 (13.7%) MUs, respectively. These results were validated by another 5 interviews. CONCLUSION: This study identified the role of OPs in Japan in the COVID-19 pandemic. The results showed that they made a wide range of contributions to the direct and indirect effects of the pandemic. We hope our findings will help OPs during future pandemics or other long-term emergency situations.

Qualitative study of barriers and facilitators encountered by individuals with physical diseases in returning and continuing to work.

BACKGROUND: The number of employees with physical diseases is increasing, and there is a need for support to help them return and continue to work. To provide effective support, it is important to identify barriers and facilitators for individuals in returning and continuing to work. Previous studies have reported barriers and facilitators for specific diseases. However, few reports have dealt with these issues across various diseases. To identify a range of barriers and facilitators that may apply to different physical diseases, we conducted a qualitative analysis by interviewing patients with diverse characteristics being treated for diseases. METHODS: We conducted semi-structured interviews based on the criteria for qualitative research. We investigated three disease groups to obtain details of barriers and facilitators: impairments that were visible to other people (mainly stroke); impairments invisible to others (mainly heart disease); and impairments that changed over time (mainly cancer). Interview transcripts were analyzed and the results reported using systematic text condensation. RESULTS: We extracted 769 meaning units from 28 patient interviews. We categorized barriers and facilitators that were generalizable to various diseases into three themes (personal factors, workplace factors, and inter-sectoral collaboration and social resources) and 10 sub-themes (work ability, psychological impacts, health literacy, social status, family background, workplace structure, workplace system, workplace support, inter-sectoral collaboration, and social resources). CONCLUSIONS: This study identified 10 sub-themes that can be applied for workers with physical diseases; those sub-themes may be used as a basis for communicating with those individuals about returning and continuing to work. Our results suggest that various barriers and facilitators for workers with physical diseases should be understood and addressed at medical institutions, workplaces, and support sites.

The effects of alendronate on the suppression of bone resorption and the promotion of cartilage formation in the human mosaicplasty donor site: A randomized, double-blind, placebo-controlled prospective study.

BACKGROUND: We previously reported that early alendronate administration accelerated bone formation and improved the quality of repaired cartilage in the donor site in rabbits. To investigate whether alendronate administration has effects in humans similar to those observed in rabbits. METHODS: The study cohort included 35 patients over the age of 12-years old who underwent mosaicplasty without osteoporotic therapy from March 2011 to October 2012. The donor sites were medial or lateral in the patellofemoral joint. Placebo (P) or Bonalon containing 35 mg of alendronate (A) was administered orally every week for 8 weeks. The cohort comprised 15 male and 20 female, including 14 right and 21 left knees. The mean age at the time of surgery was 57.1 years. Bone formation was examined using computer tomography and lateral knee radiography, and cartilage formation was examined using magnetic resonance imaging (MRI), second-look assessment, and intraoperative acoustic evaluation. The clinical outcomes were assessed using the Japanese Orthopaedic Association knee score and visual analog scale (VAS). Bone and cartilage formation in the donor site and clinical outcomes were assessed at 3, 6, and 12 months after mosaicplasty. RESULTS: The ratio of TRAP-5b in group A was significantly smaller than that in group P at 2 and 8 weeks after mosaicplasty. The extent of bone formation in the donor sites in group A was significantly greater than that in group P at 3 and 6 months after mosaicplasty. Cartilage formation did not differ significantly between the two groups as determined by MRI, macroscopic assessment, and intraoperative acoustic evaluation. Clinical outcomes did not differ significantly between the two groups, and no negative clinical outcomes were observed. CONCLUSION: Early alendronate administration accelerated bone formation but not cartilage formation in the mosaicplasty donor site in humans.

COVID-19 vaccination coverage by company size and the effects of workplace vaccination program in Japan: a cohort study.

BACKGROUND: Vaccination is considered the most effective control measure against COVID-19. Vaccine hesitancy and equitable vaccine allocation are important challenges to disseminating developed vaccines. To promote COVID-19 vaccination coverage, the government of Japan established the workplace vaccination program. However, while it appears that the program was effective in overcoming vaccine hesitancy, the program may have hindered the equitable allocation of vaccines because it mainly focused on employees of large companies. We investigated the relationship between company size and COVID-19 vaccination completion status of employees and the impact of the workplace vaccination program on this relationship. METHODS: We conducted an internet-based prospective cohort study from December 2020 (baseline) to December 2021. The data were collected using a self-administered questionnaire survey. Briefly, 27,036 workers completed the questionnaire at baseline and 18,560 at follow-up. After excluding ineligible respondents, we finally analyzed the data from 15,829 participants. At baseline, the participants were asked about the size of the company they worked for, and at follow-up they were asked about the month in which they received their second COVID-19 vaccine dose and the availability of a company-arranged vaccination opportunity. RESULTS: In each month throughout the observation period, the odds of having received a second COVID-19 vaccine dose were significantly lower for small-company employees than for large-company employees in the sex- and age-adjusted model. This difference decreased after adjusting for socioeconomic factors, and there was no significant difference after adjusting for the availability of a company-arranged vaccination opportunity. CONCLUSIONS: The workplace vaccination program implemented in Japan to control the COVID-19 pandemic may have been effective in overcoming vaccine hesitancy in workers; however, it may have caused an inequitable allocation of vaccines between companies of different sizes. Because people who worked for small companies were less likely to be vaccinated, it will be necessary to enhance support of vaccination for this population in the event of future infectious disease outbreaks. TRIAL REGISTRATION: Not applicable.

Subjective and objective assessments after a change from a 4-crew, 12-h shift to a 3-crew, 12-h shift schedule: an observational study.

PURPOSE: To clarify the subjective and objective impacts of a change in a 12-h shift schedule, involving a reduction in the number of crews, on workers at an electronic parts production company. METHODS: Forty-two workers participated in this study. Subjective indicators (e.g. questionnaires) and objective indicators [e.g., psychomotor vigilance task (PVT)], as well as an activity monitor-based sleep assessment, were measured during a > 1-year period that encompassed the shift schedule change. The study outcome was a comparison of work-related injury rates measured 1 year before and after the change in shift schedule. RESULTS: After the shift schedule change, questionnaire scores regarding work-related burdens and PVT performance parameters, including mean response time and number of lapses, increased significantly. However, we also observed divergences in the trends of the subjective and objective measures 1 year after the change. Despite these variations in both types of measures, we observed no significant differences in work-related injury rates measured before and after the shift schedule change. CONCLUSION: This study revealed that a reduction in the number of crews in a 12-h shift schedule has a negative impact on the subjective and objective indicator after the change in shift schedule; only indicators of alertness did not recover at 1 year after the change. Assessments of the workers' performances and the regular implementation of health and safety programs for more than 1 year are needed to maintain workers' health after the change in shift schedule.

Diabetes severity measured by treatment control status and number of anti-diabetic drugs affects presenteeism among workers with type 2 diabetes.

BACKGROUND: The number of people with diabetes is increasing and resulting in major economic losses. Presenteeism accounts for the majority of economic losses, so measures against presenteeism are important. This study investigated the relationship between severity of type 2 diabetes and presenteeism. METHODS: A cross-sectional study was conducted among workers over 40 years of age. Participants were classified as normal group or diabetic treatment group using their medical examination results and health insurance claims data. Diabetic treatment groups were described by degree of treatment control: Good (HbA1c < 7%), Intermediate (7% ≤ HbA1c < 8%), and Poor (8% ≤ HbA1c). Therapy type was also divided into monotherapy and combination therapy. Logistic regression analysis was performed to predict presenteeism loss using the Quantity and Quality method. RESULTS: Data on 13,271 workers were analyzed. Presenteeism loss was significantly higher in all treatment control groups compared with the normal group, particularly for the intermediate and poor control groups. The monotherapy group did not differ from the normal group, but presenteeism loss was significantly higher in the combination therapy group than the normal group. CONCLUSIONS: Presenteeism loss in workers with diabetes may be affected by diabetes severity, and even if treatment control were good, presenteeism loss could occur when the number of anti-diabetic drugs was high. Therefore, it is important to provide early intervention and continuous support as a preventive measure against not only diabetes and diabetes-related complications but also presenteeism.

Association between overtime work hours and preventive dental visits among Japanese workers.

BACKGROUND: This study aimed to examine the association between overtime work and the frequency of preventive dental visits among workers in Japan. METHODS: A self-administered questionnaire was completed by 14,847 daytime-workers. We used a logistic regression model stratified by sex and age and adjusted for marital status, occupation, education, and oral status to investigate the association between overtime work hours and the frequency of preventive dental visits. RESULTS: In total 1037 men (9.3%) and 511 women (13.9%) attended quarterly preventive dental visits, and 2672 men (23.9%) and 1165 women (31.8%) attended annual preventive dental visits. Overtime work was statistically significantly associated with quarterly preventive dental visits among men aged 50-59 years, with adjusted odds ratios (aOR) and 95% confidence intervals (CI) of 0.73 (0.56-0.95), 0.75 (0.54-1.04), and 0.55 (0.34-0.90) for < 20, 20-39, and ≥40 h overtime/month, respectively. No such trends were observed for men aged < 50 years and women of all ages. Overtime work of < 20, 20-40, and ≥40 h overtime/month was statistically significantly associated with annual preventive dental visits among men aged 40-49 years (aOR [95%CI]: 0.76 [0.61-0.95], 0.84 [0.65-1.09], and 0.72 [0.51-1.00], respectively) and 50-59 years (aOR [95%CI]: 0.75 [0.61-0.91], 0.76 [0.59-0.97], and 0.63 [0.45-0.88], respectively). No such trends were observed in men < 40 years and women of all ages. CONCLUSIONS: Our study revealed associations between overtime and preventive dental visits among male workers aged in their 40s and 50s.

Relationship Between Work Engagement and the Onset of Long-term Sickness Absence Due to Mental Disorders: A 4-year Retrospective Cohort Study.

The aim of the present study was to investigate the association between work engagement and long-term sickness absence due to mental disorders such as mood disorders and anxiety, and whether the relationship differs between men and women, during a 4-year follow-up period. Data were obtained from 21,293 workers at four pharmaceutical companies belonging to the Collabo-Health Study Group in 2014. The baseline data were collected by self-administered questionnaires. We obtained information about long-term sickness absence from the personnel records of the surveyed companies from the baseline survey in 2014 until March 2018. Hazard ratios (HRs) and 95% confidence intervals (CIs) using the low work engagement group as a reference were calculated by Cox proportional hazards analysis as the outcome, defined as the period leading to mental health-related sick leave. A total of 12,025 participants had complete data for analysis, and 123 exhibited long-term sickness absence during a 4-year follow-up period. The high work engagement group for men had a significantly lower HR (0.52, 95% CI: 0.31-0.88, P = 0.015) compared with the low work engagement group. Conversely, among women, the moderate work engagement group had a significantly higher HR (2.44, 95% CI: 1.03-5.84, P = 0.043) compared with the low work engagement group. Work engagement in men may predict the occurrence of long-term sickness absence due to mental disorders in the subsequent four years, but this relationship was different in women. Further research is needed to clarify this issue.

Improved Sleep Quality and Work Performance Among Shift Workers Consuming a "Foods with Function Claims" Containing Asparagus Extract.

The purpose of this study was to examine whether Foods with Function Claims (FFC) containing asparagus extract effectively improved sleep quality and work performance in shift workers. An intervention study with a before-and-after intervention design was conducted on nurses engaged in two-shift work at a hospital, ingesting a FFC containing asparagus extract. The evaluation period lasted at least two weeks, including three nights shifts during the period. Before and after ingestion, Pittsburgh Sleep Questionnaire Index (PSQI), Utrecht Work Engagement Scale (UWES), Sleep quality (VAS-rated), impaired work functioning, and psychiatric symptoms were evaluated. A diary record, wearing of an activity meter, and a Psychomotor vigilance test were also performed at baseline and after intervention. Data were analyzed by the paired t-test or the Wilcoxon rank sum test. Among 34 participants, 33 completed the study. The results of the primary outcome measures showed significant improvements in PSQI and Sleep Quality in the night of the day after a night shift (PSQI total score: base line 7.41/ post intervention 6.03: P < 0.001; sleep quality: base line 4.48/post intervention 6.00: P < 0.001). The results of the secondary outcome measures showed significant improvements in UWES and feeling of fatigue. There was also trend of improvement in sleep efficiency and the reaction time. There was no significant improvement in impaired work functioning. This study showed that regular consumption of an FFC containing asparagus extract could improve sleep quality, feeling of fatigue, and work engagement among shift workers. Some caution, however, is needed when interpreting the results because of the before-and-after intervention design without a control group.

Work-Related Factors Affecting the Occurrence of Presenteeism － Recent Research Trends and Future Directions.

Productivity loss due to presenteeism accounts for a large proportion of economic losses caused by workers' health problems. To reduce presenteeism, it is necessary to identify its causes, but, in contrast to the large amount of research on the effects of diseases and lifestyles, there is not enough research on the effects of work-related factors on presenteeism. In this study, those factors include the work environment and the work-related psychological status of workers. The purpose of this review was to identify research trends in presenteeism, defined as work-related productivity loss, and to examine future directions for presenteeism research. We conducted a search with only the keyword "presenteeism" using MEDLINE/PubMed for the last 5 years and extracted 30 relevant articles, most of which were cross-sectional studies. The articles were categorized into the following themes: 1) studies on the associations of various stress models and factors with presenteeism; 2) studies on the mediators and the pathways of association between stress factors and presenteeism; 3) studies on the relationships between organizational factors and presenteeism; and 4) studies on the link between workers' positive and negative psychological status and presenteeism. Our findings showed that, over the last 5 years, the relationship between psychological stress and presenteeism has been extended to include a variety of stress models and stressors. In addition, by putting many models and factors into a single statistical model and adjusting for their interrelationships, important factors have been examined by ensuring that a significant relationship with presenteeism remains. As there is still a lack of longitudinal studies necessary to discuss causality, more research of higher quality is needed.

Effect of Psychological Distress on the Association of Workplace Social Capital with Presenteeism and Sickness Absence.

Greater workplace social capital (WSC) can be related to workers' health and productivity. We sought to clarify the association between horizontal WSC and presenteeism and sickness absence (SA) and to examine the effects of psychological distress on these associations among Japanese workers. A cross-sectional study was conducted in 2017 at seven large Japanese companies. Logistic regression analysis was performed with presenteeism and SA as the dependent variables, horizontal WSC as an independent variable, and sociodemographic characteristics and psychological distress as covariates. After adjustment for sociodemographic characteristics, the results showed that greater horizontal WSC was associated with lower presenteeism and SA. The odds ratios for the relationship between horizontal WSC and presenteeism and that between horizontal WSC and SA dropped moderately after adjustment for psychological distress but remained significant. Further exploration of the factors underlying the relationship between WSC and productivity is needed to confirm if WSC enhances workers' health and productivity and to inform the development of effective occupational health initiatives.

Protocol for a Nationwide Internet-based Health Survey of Workers During the COVID-19 Pandemic in 2020.

The ever-changing social implications of the COVID-19 pandemic have resulted in an urgent need to understand the working environments and health status of workers. We conducted a nationwide Internet-based health survey of Japanese workers in December 2020, in the midst the country's "third wave" of COVID-19 infection. Of 33,087 surveys collected, 6,051 were determined to have invalid responses. The 27,036 surveys included in the study were balanced in terms of geographical area, sex of participants, and type of work, according to the sampling plan. Men were more likely than women to have telecommuted, while women were more likely to have resigned since April 2020. Forty percent and 9.1% of respondents had a K6 score of 5 or higher and 13 or higher, respectively, and they did not exhibit extremely poor health. The present study describes the protocol used to conduct an Internet-based health survey of workers and a summary of its results during a period when COVID-19 was spreading rapidly in Japan. In the future, we plan to use this survey to examine the impact of COVID-19 on workers' work styles and health.

Changes in Presenteeism Six Months After Returning from Sick Leave Due to Mental Illness.

This study examines how psychological distress (measured by the K10 screening test) and presenteeism (measured by the quality and quantity method) change in the six months after returning to work from having taken a sick leave because of a mental illness. In a manufacturing company with approximately 2,600 employees, 23 employees returned to work after experiencing mental illness between April 2015 and March 2016, and all 23 agreed to participate in the study. We analyzed 18 cases for which we had sufficient data. Two of the employees were absent from work in the sixth month. We performed multilevel analysis for K10 and presenteeism over time on the 16 without recurrence. A significant decreasing trend was observed for both K10 and presenteeism. Eleven of the 16 employees were consistently below the K10 cutoff value of 10 for six months, and 5 had zero presenteeism in the sixth month, whereas 6 employees showed improvement in presenteeism that stopped midway through the study. An occupational physician judged that the employees could work normally with presenteeism of zero. After returning to work, it is important to monitor not only psychiatric symptoms but also presenteeism.

Aquabacterium pictum sp. nov., the first aerobic bacteriochlorophyll a-containing fresh water bacterium in the genus Aquabacterium of the class Betaproteobacteria.

A strictly aerobic, bacteriochlorophyll a-containing betaproteobacterium, designated strain W35T, was isolated from a biofilm sampled at Tama River in Japan. The non-motile and rod-shaped cells formed pink-beige pigmented colonies on agar plates containing organic compounds, and showed an in vivo absorption maximum at 871 nm in the near-infrared region, typical for the presence of bacteriochlorophyll a. The new bacterial strain is Gram-negative, and oxidase- and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain W35T was closely related to species in the genus Aquabacterium. The closest phylogenetic relatives of strain W35T were Aquabacterium commune B8T (97.9 % sequence similarity), Aquabacterium citratiphilum B4T (97.2 %) and Aquabacterium limnoticum ABP-4T (97.0 %). The major cellular fatty acids were C16  :  1ω7c (50.4 %), C16  :  0 (22.7 %), summed feature 8 (C18  :  1ω7c/C18  :  1ω6c; 9.7 %), C18  :  3ω6c (5.5 %), C12  :  0 (5.3 %) and C10  :  0 3OH (2.7 %). The respiratory quinone was ubiquinone-8. Predominant polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The G+C content of the genomic DNA was 70.4 mol% (genome data) and 71.4 mol% (HPLC). The genome size of strain W35T is 6.1 Mbp and average nucleotide identity analysis indicated genome similarities of strain W35T and related Aquabacterium type strains to be 78-79 %. The results of polyphasic comparisons showed that strain W35T was clearly distinguishable from other members of the genus Aquabacterium. Therefore, we propose a new species in the genus Aquabacterium, namely, Aquabacterium pictum sp. nov. The type strain is W35T (=DSM 106757T=NBRC 111963T). The description of the genus Aquabacterium is also emended.