Identification of glycosylation genes and glycosylated amino acids of flagellin in Pseudomonas syringae pv. tabaci

A glycosylation island is a genetic region required for glycosylation. The glycosylation island of flagellin in Pseudomonas syringae pv. tabaci 6605 consists of three orfs: orf1, orf2 and orf3. Orf1 and orf2 encode putative glycosyltransferases, and their deletion mutants, Delta orf1 and Delta orf2, exhibit deficient flagellin glycosylation or produce partially glycosylated flagellin respectively. Digestion of glycosylated flagellin from wild-type bacteria and non-glycosylated flagellin from Delta orf1 mutant using aspartic N-peptidase and subsequent HPLC analysis revealed candidate glycosylated amino acids. By generation of site-directed Ser/Ala-substituted mutants, all glycosylated amino acid residues were identified at positions 143, 164, 176, 183, 193 and 201. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) analysis revealed that each glycan was about 540 Da. While all glycosylation-defective mutants retained swimming ability, swarming ability was reduced in the Delta orf1, Delta orf2 and Ser/Ala-substituted mutants. All glycosylation mutants were also found to be impaired in the ability to adhere to a polystyrene surface and in the ability to cause disease in tobacco. Based on the predicted tertiary structure of flagellin, S176 and S183 are expected to be located on most external surface of the flagellum. Thus the effect of Ala-substitution of these serines is stronger than that of other serines. These results suggest that glycosylation of flagellin in P. syringae pv. tabaci 6605 is required for bacterial virulence. It is also possible that glycosylation of flagellin may mask elicitor function of flagellin molecule

Chronic Nonspecific Jejunitis - A -

A 29-yr-old Japanese man presented with left lumbar pain. Laboratory tests were suggestive of an inflammatory disease but serological, bacteriological, and markers of auto immunity were all negative. Gastroduodenal endoscopy showed slight mucosal congestion of the gastric antrum but the duodenum showed normal villi. Colonoscopy showed no abnormalities, and small bowel enema and jejunoscopy were normal. Abdominal ultrasonography and CT scans showed wall thickening of the small intestine. At laparoscopically-assisted wedge biopsy of jejunum, focal edema was noted mainly affecting the midjejunum together with enlarged mesenteric nodes. Histopathological examination of the surgical biopsy material showed focal neutrophilic infiltration in the mucosa and submucosa without granuloma. The lymph node showed nonspecific changes with no granulomas. Although the etiology could not be identified, the patient responded well to clarythromycin treatment

Effect of COVID-19 vaccination on household transmission of SARS-CoV-2 in the Omicron era: The Vaccine Effectiveness, Networking, and Universal Safety (VENUS) study

Objectives: To evaluate the effectiveness of vaccination on reducing household transmission of SARS-CoV-2 among common household types in Japan during the Omicron variant wave. Methods: This retrospective study was conducted using vaccination records, COVID-19 infection data, and resident registry data from two Japanese municipalities. Households that experienced their first COVID-19 case between January and April 2022 were categorized into two groups according to the presence/absence of children aged ≤11 years. We constructed multivariable logistic regression models with generalized estimating equations to calculate the odds ratios (ORs) and 95% confidence intervals for household transmission according to the vaccination statuses of primary cases and household contacts. Results: We analyzed 7326 households with 17,586 contacts. In all households, the OR for household transmission was <0.6 (P <0.001) when the primary case and/or contact were vaccinated. In households with children aged ≤11 years, the OR was 0.71 (P <0.001) when only the contact was vaccinated. In households with all members aged ≥12 years, the OR was <0.5 (P <0.001) when the primary case and/or contact were vaccinated. Conclusion: COVID-19 vaccination effectively reduced household transmission in Japan during the Omicron variant wave

Acute and delayed psychiatric sequelae among patients hospitalised with COVID-19: a cohort study using LIFE study data

Background Characterising the psychiatric sequelae of coronavirus disease 2019 (COVID-19) can inform the development of long-term treatment strategies. However, few studies have examined these sequelae at different time points after COVID-19 infection.Aims The study aimed to investigate the incidences and risks of acute and delayed psychiatric sequelae in patients hospitalised with COVID-19 in Japan.Methods This retrospective cohort study was conducted using a database comprising healthcare claims data from public health insurance enrollees residing in a Japanese city. We analysed a primary cohort comprising patients hospitalised with COVID-19 between March 2020 and July 2021 and two control cohorts comprising patients hospitalised with influenza or other respiratory tract infections (RTI) during the same period. We calculated the incidences of acute (1–3 months after infection) and delayed (4–6 months after infection) psychiatric sequelae. These sequelae were identified using diagnosis codes and categorised as mood/anxiety/psychotic disorder, mood disorder, anxiety disorder, psychotic disorder or insomnia. Multivariable logistic regression models were used to estimate the odds ratios (ORs) of psychiatric sequelae occurrence after COVID-19 infection compared with influenza and other RTI.Results The study population with acute psychiatric sequela consisted of 662 patients with COVID-19, 644 patients with influenza, and 7369 patients with RTI who could be followed for 3 months; the study population with delayed psychiatric sequelae consisted of 371 patients with COVID-19, 546 patients with influenza, and 5397 patients with RTI who could be followed for 6 months. In the analysis of acute psychiatric sequelae, COVID-19 had significantly higher odds of mood/anxiety/psychotic disorder (OR: 1.39, p=0.026), psychotic disorder (OR: 2.13, p&lt;0.001), and insomnia (OR: 2.59, p&lt;0.001) than influenza, and significantly higher odds of insomnia (OR: 1.44, p=0.002) and significantly lower odds of anxiety disorder (OR: 0.56, p&lt;0.001) than other RTI. In the analysis of delayed psychiatric sequelae, COVID-19 had significantly higher odds of psychotic disorder (OR: 2.25, p=0.007) than influenza, but significantly lower odds of anxiety disorder (OR: 0.55, p=0.011) than other RTI.Conclusions COVID-19 was generally associated with an increased risk of psychiatric sequelae occurring within 3 months after infection, but had a lower risk of new psychiatric sequelae developing 4–6 months after infection

Effectiveness of messenger RNA vaccines against infection with SARS-CoV-2 during the periods of Delta and Omicron variant predominance in Japan: the Vaccine Effectiveness, Networking, and Universal Safety (VENUS) study

Objectives: We aimed to evaluate COVID-19 messenger RNA vaccine effectiveness during the Delta- and Omicron-predominant periods in Japan. Methods: We conducted a population-based cohort study among individuals aged 16–64 years during two periods: the Delta-predominant period (July 1–December 31, 2021) and the Omicron-predominant period (January 1–March 29, 2022). Results: When comparing individuals who were vaccinated with those who were unvaccinated, the effectiveness of a second dose against symptomatic infection was 89.8% (95% confidence interval [CI]: 80.5–94.7%) during the Delta-predominant period and 21.2% (95% CI: 11.0–30.3%) during the Omicron-predominant period. The effectiveness of a third dose against symptomatic infection was 71.8% (95% CI: 60.1–80.1%) during the Omicron-predominant period. Conclusion: Vaccine effectiveness against symptomatic infection decreased during the Omicron-predominant period but was maintained by a third dose

Association between seasonal influenza vaccination and antimicrobial use in Japan from the 2015-16 to 2020-21 seasons : from the VENUS study

Abstract: Background Seasonal influenza vaccination might be considered an antimicrobial resistance (AMR) countermeasure because it can reduce unnecessary antimicrobial use for acute respiratory infection by mitigating the burden of such diseases.Objectives To examine the association between seasonal influenza vaccination and antimicrobial use (AMU) in Japan at the community level and to examine the impact of influenza vaccination on the frequency of unnecessary antimicrobial prescription for upper respiratory infection.Methods For patients who visited any healthcare facility in one of the 23 wards of Tokyo, Japan, due to upper respiratory infection and who were aged 65 years or older, we extracted data from the Vaccine Effectiveness, Networking, and Universal Safety (VENUS) study database, which includes all claims data and vaccination records from the 2015-16 to 2020-21 seasons. We used the average treatment effect (ATE) with 1:1 propensity score matching to examine the association of vaccination status with frequency of antibiotic prescription, frequency of healthcare facility consultation, risk of admission and risk of death in the follow-up period of the same season (from 1 January to 31 March).Results In total, 244 642 people were enrolled. Matched data included 101 734 people in each of the unvaccinated and vaccinated groups. The ATE of vaccination was -0.004 (95% CI -0.006 to -0.002) for the frequency of antibiotic prescription, -0.005 (-0.007 to -0.004) for the frequency of healthcare facility consultation, -0.001 (-0.002 to -0.001) for the risk of admission and 0.00 (0.00 to 0.00) for the risk of death.Conclusions Our results suggest that seasonal influenza vaccination is associated with lower frequencies of unnecessary antibiotic prescription and of healthcare facility consultation

Bivalent mRNA vaccine effectiveness against COVID-19 among older adults in Japan: a test-negative study from the VENUS study

Abstract Background Bivalent COVID-19 vaccines have been implemented worldwide since the booster vaccination campaigns of autumn of 2022, but little is known about their effectiveness. Thus, this study holistically evaluated the effectiveness of bivalent vaccines against infection in older adults in Japan. Methods We adopted the test-negative design using COVID-19 test data of individuals, aged ≥ 65 years, residing in three municipalities in Japan, who underwent tests in medical institutions between October 1 and December 30, 2022. Logistic regression analyses were conducted to estimate the odds of testing positive according to vaccination status. Vaccine effectiveness was defined as (1 − odds ratio) × 100%. Results A total of 3,908 positive and 16,090 negative results were included in the analyses. Receiving a bivalent dose in addition to ≥ 2 monovalent doses was 33.6% (95% confidence interval [CI]: 20.8, 44.3%) more effective than receiving no vaccination, and 18.2% (95% CI: 9.4, 26.0%) more effective than receiving ≥ 2 monovalent doses but not receiving a bivalent vaccination. In addition, the effectiveness peaked at 14–20 days after administration and then gradually declined over time. Furthermore, a bivalent booster dose provided 18.6% (95% CI: 9.9, 26.5%) additional protection among those vaccinated with ≥ 2 monovalent doses, in the absence of a previous infection history. However, we did not find sufficient evidence of effectiveness of bivalent vaccines among previously infected older adults. Conclusions Bivalent vaccines are effective against COVID-19 infections among older adults without a history of infection

Transient elevation of cytoplasmic calcium ion concentration at a single cell level precedes morphological changes of epidermal keratinocytes during cornification

Epidermal keratinocytes achieve sequential differentiation from basal to granular layers, and undergo a specific programmed cell death, cornification, to form an indispensable barrier of the body. Although elevation of the cytoplasmic calcium ion concentration ([Ca²⁺]i) is one of the factors predicted to regulate cornification, the dynamics of [Ca²⁺]i in epidermal keratinocytes is largely unknown. Here using intravital imaging, we captured the dynamics of [Ca²⁺]i in mouse skin. [Ca²⁺]i was elevated in basal cells on the second time scale in three spatiotemporally distinct patterns. The transient elevation of [Ca²⁺]i also occurred at the most apical granular layer at a single cell level, and lasted for approximately 40 min. The transient elevation of [Ca²⁺]i at the granular layer was followed by cornification, which was completed within 10 min. This study demonstrates the tightly regulated elevation of [Ca²⁺]i preceding the cornification of epidermal keratinocytes, providing possible clues to the mechanisms of cornification