Research Institute for Environmental Sciences and Public Health of Iwate Prefecture

This study was undertaken to improve the performance of Spoken Query Spoken Term Detection (SQ-STD) by introducing Self-Supervised Learning (SSL) models. To construct posteriorgrams, the SSL models are augmented with a Connectionist Temporal Classification (CTC) layer and extracted posterior probability vectors, which represent phonemes or syllables from the layer immediately preceding the CTC output layer. Posteriorgram matching is performed using posteriorgrams generated from SSL models of three types known for their high speech recognition accuracy: wav2vec 2.0, HuBERT, and WavLM. Experiment results obtained on the NTCIR evaluation sets demonstrate that our approach achieves retrieval accuracy exceeding 92 %, which is the state of the art for the evolution sets.

Escherichia albertii is an emerging enteropathogen and its distribution in various foods and environmental samples has been reported in many regions around the world. In this study, we aimed to identify effective isolation and detection methods for E. albertii in various foods and environmental water samples. E. albertii-specific polymerase chain reaction (PCR) was positive in chicken, oyster, river water, and wastewater samples, and E. albertii was isolated from these PCR-positive samples except the wastewater sample. E. albertii was not isolated from any of the samples without screening PCR; therefore, PCR is useful for the detection and isolation of E. albertii in foods and environmental water samples. The effect of two-step enrichment with four kinds of selective enrichment broth was compared with cycle threshold (Ct) values of the E. albertii-specific real-time PCR assay and the isolation results. The Ct values in three out of five samples were lower in the second enriched culture than those of the first enriched culture, and E. albertii was isolated from enriched cultures showed Ct values <25. These results suggest that the population of E. albertii in these three samples increased in the second enriched culture compared with the first enriched culture, and isolating E. albertii from an enriched culture showing Ct values <25 is an efficient method. Genetic analysis was performed to E. albertii isolates from food, environmental water, and human fecal samples, and all the isolates possessed eae, and isolates from chicken, pork, and river water samples showed the same EAOg type as E. albertii isolated from human fecal samples. Therefore, it was suggested that a continuous attention should be paid to E. albertii in food and environment.

Abstract Shiga toxin (Stx)-producingEscherichia coli(STEC) causes serious gastrointestinal illness, including hemorrhagic colitis and hemolytic uremic syndrome. Although all known Stxs (Stx1 and Stx2) are encoded by bacteriophages (Stx phages), the production of Stx2 is known to be a major risk factor for severe STEC infections. The production of Stx2, but not Stx1, is tightly coupled with the induction of Stx phages, and Stx2 production levels vary between STEC strains, even within the same serotype. Here, we analyzed the genomic diversity of all Stx phages in 71 strains representing the entire O145:H28 lineage, one of the major STECs. Our analysis revealed the highly dynamic nature of the Stx phages in O145:H28, including the independent acquisition of similar Stx phages by different sublineages and the frequent changes in Stx phages in the same sublineages due to the gain and loss of Stx phages. Analyses of Stx2 production levels in O145:H28 strains and K-12 lysogens of Stx2 phages of specific groups and types, which were defined by their early region sequences and CI repressors, respectively, revealed that short-tailed Stx2a phages (S-Stx2a phages) confer significantly greater Stx2 production to host strains than long-tailed Stx2a phages (L-Stx2a phages). However, L-Stx2a phages that encode a specific type of CI repressor promoted Stx2 production, comparable to the level of production among S-Stx2a phages, as well as promoted virulence to host strains, exceeding the level among other L-Stx2a phages. We also showed a clear link between the phage induction efficiency, which was primarily determined by the early region of each phage, and the level of Stx2 production by host strains. These results provide important insights into the diversification and dynamism of Stx phages and the relationship between the variations in Stx2 phages and the amount of Stx2 production by their host strains.Author summaryShiga toxin (Stx)-producingEscherichia coli(STEC) is an important human intestinal pathogen that causes severe illnesses. These bacteria produce Stx1, Stx2 or both toxins, but the production of Stx2 is an important measure of the virulence of STEC strains. While both types of Stx are encoded by bacteriophages (Stx phages), Stx2 production is tightly coupled with phage induction, and variations in Stx2 phages have been associated with variations in Stx2 production levels by their host O157:H7 STEC strains. However, in non-O157 STEC strains, the variation in Stx phages and its association with host strain production of Stx2 have not yet been fully analyzed. This systematic study of Stx phages in O145:H28 STEC reveals not only the marked genomic diversity and dynamism of Stx phages in this STEC lineage but also that short-tailed Stx2 phages and a specific group of long-tailed Stx2 phages induce high levels of Stx2 production by host strains, and this increased production is linked to the efficient induction of phages.

BackgroundPrevious studies have linked residential displacement as a result of the 2011 East Japan Earthquake to increases in body weight. However, no study has examined longer-term trajectories of body weight among displaced survivors. We compared body weight change between survivors relocated to temporary housing (TH) group versus other types of accommodation for up to 5 years after the Great East Japan Earthquake.MethodsLongitudinal follow-up was conducted from 2011 to 2015 in a cohort of 9,909 residents of 42,831. We compared trends in body weight in the TH group (n = 3,169) and the non-TH group (n = 6,740) using a mixed linear regression model stratified by sex (mean age, 61.0 years old; male, 38.9%).ResultsIn age-adjusted analysis, the body weight in the 2011 survey was not significantly different between two groups for either sex. In men, the TH group significantly increased body weight compared to the non-TH group since 2012. In women, body weight sharply increased in the TH group while body weight did not change in the non-TH group during survey time points. The interaction of living conditions and survey years was statistically significant in both sexes (men; F-value, 6.958; P < 0.001: women; F-value, 19.127; P < 0.001).ConclusionSurvivors relocated to temporary housing had an increased risk of weight gain. The weight gain in this group is a potential risk factor for metabolic syndrome in the post-disaster period.

Drinking water is one of the major exposure routes to Perfluoroalkyl substances (PFASs). These chemicals are scarcely removed by the conventional process in water purification plants. In the present study, four models of pitcher-type water purifiers (A-D) were tested to evaluate their removal effect on six PFASs including PFOS and PFOA. All of the water purifiers removed PFASs, but the efficiency was dependent on the models. Model C was most effective; more than 90% of all PFASs were removed through the recommended life of the filter cartridge. Model D was least effective; its removal efficiency declined below 50% by the end of the cartridge's life. When compared by the carbon chain length of PFASs, the removal efficiency was "C12 > C10 > C8 > C6" in all models. This study clearly demonstrates that household water purifiers are effective in decreasing the exposure to PFASs through drinking water.

PurposeTo clarify the relationship between daily hot water bathing (HWB) at home and glycemic control in middle-aged and elderly ambulatory patients with type 2 diabetes mellitus (T2DM).MethodsWe defined hemoglobin A1c (HbA1c) as the main outcome. We set 7.0% based on the mean value of the dependent variable as the cut-off point for analysis. Frequency of HWB was an explanatory variable. A two-sample t-test was used to compare between groups with continuous variables. Multiple logistic regression analysis was performed for frequency, adjusted age, sex, BMI, T2DM duration (Model 1), and other confounding factors (Model 2). Odds ratio (OR) and 95% confidence interval (95% CI) were calculated.ResultsAmong 838 patients, there was a significant difference (p<0.001) in age between males (n=528, 62.8±8.7 years) and females (n=310, 65.0±8.1 years). In Model 1, compared with participants who used HWB more than seven times a week, those with poorly controlled HbA1c were significantly associated with low frequency of HWB: four to six times a week (OR 1.32, 95% CI 0.87–1.99) and less than three times a week (OR 1.43, 95% CI 0.98–2.10); p-value for overall trend was 0.041. In Model 2, p-value for overall trend was 0.138.ConclusionA higher frequency of HWB was moderately associated with a decreased risk of poor glycemic control in middle-aged and elderly ambulatory patients with T2DM.

Human norovirus (HuNoV) GII.P17-GII.17 (Kawasaki2014 variant) reportedly emerged in 2014 and caused gastroenteritis outbreaks worldwide. To clarify the evolution of both VP1 and RNA-dependent RNA polymerase (RdRp) regions of GII.P17-GII.17, we analyzed both global and novel Japanese strains detected during 2013–2017. Time-scaled phylogenetic trees revealed that the ancestral GII.17 VP1 region diverged around 1949, while the ancestral GII.P17 RdRp region diverged around 2010. The evolutionary rates of the VP1 and RdRp regions were estimated at ~2.7 × 10−3 and ~2.3 × 10−3 substitutions/site/year, respectively. The phylogenetic distances of the VP1 region exhibited no overlaps between intra-cluster and inter-cluster peaks in the GII.17 strains, whereas those of the RdRp region exhibited a unimodal distribution in the GII.P17 strains. Conformational epitope positions in the VP1 protein of the GII.P17-GII.17 strains were similar, although some substitutions, insertions and deletions had occurred. Strains belonging to the same cluster also harbored substitutions around the binding sites for the histo-blood group antigens of the VP1 protein. Moreover, some amino acid substitutions were estimated to be near the interface between monomers and the active site of the RdRp protein. These results suggest that the GII.P17-GII.17 virus has produced variants with the potential to alter viral antigenicity, host-binding capability, and replication property over the past 10 years.

ABSTRACTA survey of the contamination of foods by sterigmatocystin (STC) was performed by an analytical method based on LC-MS/MS. STC was extracted from samples with acetonitrile/water (85/15, v/v) and then purified with immunoaffinity columns. The method was validated by a small-scale inter-laboratory study using spiked wheat samples. Mean recoveries of STC were 100.3% and 92.5% from two samples spiked at 0.5 and 5.0 µg/kg, respectively. A total of 583 samples were analysed between 2016 and 2018, and STC was detected in 19.9% of all samples at >0.05 μg/kg (limit of quantification). The foods that were contaminated by STC were wheat flour, Job’s tears products, rye flour, rice, buckwheat flour, white sorghum, barley products, azuki bean and corn flour. STC was not found in beer or wine. The occurrence of STC in domestic wheat flour (44.4%), Job’s tears products (41.7%) and rye flour (29.9%) accounted for the three highest values. The highest mean concentrations were obtained for Job’s tears products (0.3 μg/kg) and rye flour (0.3 μg/kg). The maximum contamination level was present in a sample of rye flour (7.1 μg/kg). Although the contamination levels were low, these results indicate that STC frequently contaminates Japanese retail foods. A continuous survey is required to assess exposure to STC in Japan.