Complete genome sequences of Escherichia coli KA0011 clinical isolate used as a quality control strain of carbapenem susceptibility testing in Japan.

Escherichia coli KA0011 had stable minimum inhibitory concentration values around the breakpoint range of meropenem and imipenem, making it suitable for use as a quality control strain for antimicrobial susceptibility testing. Here, we report the complete genomic sequence of KA0011.

Prevalence and genetic distribution of Legionella spp. in public bath facilities in Kobe City, Japan.

Legionella is an important waterborne pathogen that causes legionellosis. Public baths are considered the primary cause of legionellosis infection in Japan. We investigated the prevalence and genetic distribution of 338 Legionella spp. isolates from 81 public bath facilities, including 35 hot springs and 46 other facilities, through annual periodic surveillance in Kobe, Japan, from 2016 to 2021. In addition, the genotypes of nine clinical strains of unknown infectious source from the same period were compared to those of bathwater isolates. We elucidated the differences in the distribution of Legionella species, serogroups, and genotypes between hot springs and other public baths. Legionella israelensis, L. londiniensis, and L. micdadei colonized hot springs along with L. pneumophila. The minimum spanning tree analysis based on multiple-locus variable number tandem repeat analysis (MLVA) also identified four major clonal complexes (CCs) in L. pneumophila SG1 and found that CC1 of the four CCs is a specific novel genotype with the lag-1 gene in hot springs. The same MLVA genotypes and sequence types as those of the clinical strains were not present among the strains isolated from bath water. Thus, our surveillance is useful for estimating the sources of legionellosis infection in Japan and developing prevention strategies.

Evaluation of Legionella pneumophila SGUT Serotypes Isolated from Bath Water Using a Multiplex-PCR Serotyping Assay.

Legionella pneumophila, the primary causative agent of Legionnaires' disease, is classified into at least 15 serogroups (SGs). Before genotyping, serotyping is first performed to limit the sources of L. pneumophila infections that caused an outbreak. In addition to conventional assays using monoclonal or polyclonal antisera, serotyping using multiplex polymerase chain reaction (M-PCR) was recently developed for L. pneumophila. In this study, we applied the M-PCR system to 41 strains that remained to be SGUT (untypable) by slide agglutination tests among the 220 L. pneumophila strains isolated from bath water in Kobe City during 2016-2020, to determine SG-genotypes (SGg) by PCR amplification of the specific target gene of the SGs. Among the 41 SGUT strains, SGg4/10/14 was the most predominant (24/41, 58.5%), followed by SGg1 (7/41, 17.1%). Seven strains, except for the strains determined as SGg1, were identified as belonging to a single SGg by M-PCR serotyping (SGg5 [3/41, 7.3%], SGg8 [3/41, 7.3%], and SGg7 [1/41, 2.4%]). Furthermore, we found that the seven strains identified as SGg1 harbored particular genotypes. In conclusion, the M-PCR serotyping assay will be helpful for investigating the distribution of L. pneumophila in environmental and clinical settings.

Investigation of a Legionella pneumophila Outbreak at a Bath Facility in Japan Using Whole-Genome Sequencing of Isolates from Clinical and Environmental Samples.

Exposure to aerosols containing Legionella from artificially made water systems has been established as a primary cause of Legionnaires' disease. In this study, we investigated an outbreak of L. pneumophila serogroup 1 sequence type 138 which occurred at a bath facility in 2022. The whole-genome sequencing of isolates revealed that the colonization of L. pneumophila at the bath facility had occurred before 2013, and the patients had been exposed to multiple genetic lineages of the strain. Our study demonstrates the importance of performing a careful comparative genetic analysis of clinical and environmental isolates from LD outbreaks in order to effectively investigate and prevent future LD outbreaks.

Long-term consumption of non-fermented and fermented dairy products and risk of breast cancer by estrogen receptor status - Population-based prospective cohort study.

BACKGROUND & AIMS: The impact of dairy consumption on breast cancer development is unclear. We sought to examine associations between long-term consumption of milk and fermented dairy products and risk of breast cancer by estrogen (ER) and progesterone receptor (PR) status and assess whether these associations varied by body weight. METHODS: The population-based Swedish Mammography Cohort included 33,780 women (88.2% postmenopausal), with no history of cancer or diabetes at baseline (1997). Long-term consumption of dairy products was assessed using a self-administered food-frequency questionnaire in 1987 and 1997. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: During 16.6 years of follow-up (559,286 person-years), 1870 total breast cancer cases were diagnosed (1162 ER+/PR+; 195 ER-/PR-). High long-term non-fermented milk consumption was associated with increased ER+/PR+ breast cancer incidence, HR = 1.30, 95%CI:1.02-1.65 for the average of 1987 and 1997 intake ≥2 vs. 0 servings/day and this increased risk was limited to women with BMI<25 kg/m2 HR = 1.55, 95%CI:1.08-2.21, while no significant associations with milk consumption were observed with ER-/PR- breast cancer. In contrast, consumption of fermented dairy products was inversely associated with ER-/PR- breast cancer (for consistently high intake ≥3 vs. <1 servings/day HR = 0.28, 95%CI:0.10-0.78), but not clear association was observed for ER+/PR+ (HR = 0.89, 95%CI:0.69-1.14). CONCLUSIONS: In this cohort of mainly postmenopausal women, high long-term consumption of milk was associated with increased risk of ER+/PR+ breast cancer. In contrast, high long-term consumption of fermented dairy products was associated with decreased risk of ER-/PR- breast cancer.

Genome- and Mass Spectrometry-Guided Discovery of Ralstoamides A and B from Ralstonia solanacearum Species Complex.

Strains of Ralstonia solanacearum species complex (RSSC) are devastating plant pathogens distributed globally with a wide host range and genetic diversity. Many RSSC strains harbor the polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) hybrid gene rmyA/rmyB for ralstonin production. We report that ralstoamides A (1) and B (2), which are ralstonin-like but shorter lipopeptides, were discovered from the Japanese strains using accumulated RSSC genome data and LC/MS-based metabolite analysis. Their structures, including absolute configurations, were elucidated by spectroscopic analysis and chemical techniques. ramA, a PKS-NRPS gene for ralstoamide production, was identified from the producer strains by genome sequencing and gene-deletion experiments. Based on the analysis of biosynthetic genes of ralstoamides and ralstonins, we suggest the occurrence of NRPS-module reduction of rmyA/rmyB genes in some RSSC strains. This possible molecular evolution changed not only the structures, but also the biological activity of RSSC lipopeptides.

Effect of office-based brief high-impact exercise on bone mineral density in healthy premenopausal women: the Sendai Bone Health Concept Study.

Although there is ample evidence supporting the effectiveness of physical activity in the prevention and treatment of osteoporosis, there are no previous studies to examine the effect of office-based brief high-impact exercise (HIE) on bone mineral density (BMD) in healthy premenopausal women. This study evaluated the effects of office-based HIE on BMD in healthy premenopausal Japanese women. Ninety-one healthy premenopausal women were randomized to receive stretching exercise (SE) or HIE (stretching, along with up to 5 × 10 vertical and versatile jumps) for 12 months. The BMD of the lumbar spine and proximal femur was measured using dual-energy X-ray absorptiometry. Several cardiovascular risk factors and leg strength also were assessed. An accelerometer-based recorder was used to measure daily impact loading in four 1-week samples. The progression of the HIE program was ensured by the accelerometer. Thirty-three women (71.7%) in the SE group and 34 (75.6%) in the HIE group completed the study. There was a significant difference in the change in the femoral neck BMD between the groups in favor of the HIE group [0.6% (95% CI: -0.4, 1.7) vs. -1.0% (95% CI: -2.2, 0.2)]. Adiponectin, LDL, HDL, and the leg strength of participants in both the groups improved during the intervention. These finding suggested that office-based brief HIE can be recommended for premenopausal women for preventing bone mineral loss.

Lung cancer death rates by smoking status: comparison of the Three-Prefecture Cohort study in Japan to the Cancer Prevention Study II in the USA.

Cigarette smoking is an established risk factor for lung cancer. However, the magnitude of the relative risk (RR) on lung cancer mortality in relation to cigarette smoking is reported to be lower in Japan than in Western countries. We investigated whether this discrepancy could be explained by differences in the exposure to cigarettes smoked, by differences in sensitivity to smoking, or by differences in lung cancer mortality among non-smokers. We examined the 10-year follow-up data on 88,153 participants in a Japanese population-based prospective study conducted in three prefectures. Data used as a Western counterpart was retrieved from a published report of the US Cancer Prevention Study (CPS)-II. Although there was a significant increased risk of lung cancer death among current smokers compared with non-smokers, the observed RR in the Three-Prefecture Study were much lower than RR reported in the CPS-II. Lung cancer mortality of our Japanese sample was lower among current smokers and higher among non-smokers regardless of age and sex. Current smokers in our sample had initiated smoking at an older age and smoked fewer cigarettes per day for shorter durations than those in the CPS-II sample. The Poisson regression model (controlling for age, number of cigarettes smoked per day and duration of smoking) showed that male current smokers in our sample had a lower risk of lung cancer compared with those in the CPS-II sample (rate ratio 0.34 [95%CI 0.27-0.43]). These findings might explain why Japanese risks of lung cancer are lower than those observed in Western countries.