Objectives The increasing prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has been associated with the emergence of the CTX-M-producing sequence type 131 (ST131) ...pandemic clonal group, a member of the O25b serogroup and the B2 phylogenetic group. To assess the clonal spread of ESBL-producing E. coli in Japan, a regional surveillance programme was conducted. A total of 581 ESBL-producing clinical specimen E. coli isolates were collected between 2001 and 2010. Clonal groups, including ST131, D-ST405, D-ST393 and D-ST69, were determined using the PCR O type, phylogenetic grouping by triplex PCR, allele-specific PCR and multilocus sequence typing (MLST). A subset of clonal groups underwent PFGE. Among clonal strains, 215 isolates (37%) were identified as belonging to the ST131 group, 185 as B2-ST131-O25b (32%), 26 as B2-ST131-O16 (4%), 3 as B1-ST131-O25b (0.5%) and 1 as B2-ST131-O-non-typeable (0.1%). Forty-one isolates (7%) were identified as belonging to the D-ST405 clonal group, seven (1%) as D-ST69 and two (0.3%) as D-ST393. The B2-ST131-O16 clonal group was characterized by CTX-M-14 and a significantly lower ciprofloxacin resistance rate than the B2-ST131-O25b clonal group. The B2-ST131-O16 and B2-ST131-O25b clonal groups each made up a single PFGE cluster, with 65% similarity. The rate of ESBL-producing E. coli increased over the years (0.2% in 2001 to 9.7% in 2010) and corresponded to increases in the numbers of the B2-ST131-O25b, B2-ST131-O16 and D-ST405 clonal groups. The B2-ST131-O25b, B2-ST131-O16 and D-ST405 clonal groups have contributed to the spread of ESBL-producing E. coli in Japan.
Since phreatic eruptions often occur near the surface, it is important to understand the shallow subsurface structure of a volcano to clarify the eruption mechanism. The 2015 phreatic eruption at ...Owakudani, Hakone Volcano, Japan, was preceded by localized uplift and intensified steam activity. However, the cause of these events is unknown due to a poor understanding of the shallow subsurface structure. We report on a three‐dimensional resistivity structure inferred from dense audio‐frequency magnetotelluric surveys conducted in Owakudani that revealed a ∼100‐m thick conductive layer at the surface underlain by a resistive section, at the edge of which eruptions craters were located. This conductive layer is estimated to be a low‐permeability cap layer, because the inflation source prior to the eruption is located beneath it and the ejecta from the eruption was reported to have originated from a depth of 100 m or less.
Plain Language Summary
Phreatic eruptions occur as a result of the rapid expansion of water that is heated by a source such as magma. Ejecta from these eruptions does not contain magmatic material, but often contains hydrothermally altered rocks. Understanding the hydrothermal system that develops in shallow volcanic structures is important to understand how phreatic eruptions occur. We imaged the subsurface structure of Owakudani, Hakone Volcano, Japan, where small phreatic eruptions took place in 2015. We found that an ∼100‐m thick layer near the surface is a key structure that may have caused the phreatic eruption. Formation of this characteristic structure is useful for evaluating the potential for phreatic eruptions elsewhere.
Key Points
We estimated the 3‐D resistivity structure of Owakudani, Hakone Volcano, where phreatic eruptions occurred in 2015
A ∼100‐m thick conductive layer near the surface of Owakudani played an important role in causing the phreatic eruptions
Surveillance of
Streptococcus pneumoniae
serotypes is important for the successful implementation of vaccination strategies to prevent the spread of invasive pneumococcal diseases. The standard ...method of serotyping of pneumococcal isolates is the phenotypic Neufeld test, which is cost- and labor-intensive. Recently, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been implemented as a rapid, simple and inexpensive method for identifying species. We evaluated the performance of MALDI-TOF MS for serotyping ten major serotypes of
S. pneumoniae
in Japan (serotypes 3, 6B, 15A, 15C, 19A, 19 F, 23A, 24 F, 35B and 38) using the Biotyper and ClinProTools. After optimizing the settings, we validated their serotyping performance for serotypes 3, 15A and 19A using a separate set of isolates that were not used in the creation of the classification algorithms. A total of 574 isolates of
S. pneumoniae
collected from Japanese nationwide surveillance studies were included. Of these, 407 isolates belonged to the ten major serotypes. Biotyper and ClinProTools correctly identified 77.9 % and 84.0 %, respectively, of the ten major serotype isolates. The validation analysis included a total of 113 isolates of the serotypes 3, 15A and 19A isolates. Biotyper and ClinProTools correctly identified 85.0 % and 69.9 % of the validation cohort isolates, respectively. MALDI-TOF MS has the potential to discriminate the ten major
S. pneumoniae
serotypes prevalent in Japan.
A magma supply system is identified in the upper crust beneath Aso caldera, Japan, appearing as a conductive anomaly via three‐dimensional electrical resistivity modeling. Aso caldera contains ...numerous postcaldera volcanoes, with Naka‐dake cone recently experiencing eruptions at the first crater, including an explosive eruption that ejected volcanic ash 11,000 m into the air in October 2016. The magma supply system imaged by the resistivity model consists of four key components: a magma reservoir at ~17 km depth that corresponds to the Conrad discontinuity, a magma‐filled crack‐propagation zone that extends obliquely from the magma reservoir, another magma reservoir centered at 6 km depth, and an upright crack‐intrusion zone at 2–4 km depth. The shape of the conductive anomaly is consistent with the regional stress regime, with the locations of the low‐velocity anomalies and a deformation source found beneath the caldera. This anomaly is therefore defined as the magma supply system, which feeds magma to the first crater of the Naka‐dake eruptions. The averaged melt fractions of the upper magma reservoir are estimated to be 3%–4% for 89.3 km3 of the reservoir and 96%–99% for 6.3 km3, with resistivity thresholds of <40 and <1 Ωm, respectively. Furthermore, the resistivity model detects three conductive anomalies in Aso caldera that are associated with an aqueous fluid‐flow system in the region. The resistivity model also suggests that the resistivity distribution can play an important role in characterizing the stress regime based on the distribution of earthquake clusters in the upper crust beneath the caldera.
Key Points
Three‐dimensional electrical resistivity modeling reveals a crustal magma supply system beneath Aso caldera, Japan
The system consists of a deep magma reservoir, an inclined crack propagation zone, a magma reservoir, and an upright crack intrusion zone
The resistivity distribution may reflect the regional stress regime in the upper crust beneath the Aso caldera region
We evaluated whether quantitative PCR (qPCR) and (1 → 3)-β-d-glucan assays could be used to differentiate Pneumocystis pneumonia (PCP) from Pneumocystis jirovecii colonization in immunocompromised ...patients with pulmonary infiltrates. A total of 40 bronchoalveolar lavage samples and 107 induced sputum samples from 147 patients who were suspected of having PCP were obtained for PCR detection of P. jirovecii. Diagnoses of definite PCP, probable PCP, pneumonia with P. jirovecii colonization (colonization) and pneumonia without colonization (non-colonization) were made in 11, 42, 15 and 60 patients, respectively. A PCP diagnosis was undetermined in 19 patients. The copy numbers, determined using qPCR, were significantly higher in definite PCP and probable PCP patients than in colonized patients. The area under the receiver-operating characteristic curve (AUC), sensitivity and specificity for discriminating definite PCP from colonization were 0.96, 100.0% and 80.0%, respectively, at a cut-off value of 1300 copies/mL. The values for discriminating probable PCP from colonization were 0.71, 66.7% and 73.3%, respectively, at a cut-off value of 340 copies/mL. β-d-glucan levels were significantly higher in patients with both definite PCP and probable PCP than in colonized patients. The AUC, sensitivity and specificity for discriminating definite PCP were 0.91, 100.0% and 80.0%, respectively, at a cut-off value of 15.6 pg/mL. The values for discriminating probable PCP were 0.78, 76.2% and 73.3%, respectively, at a cut-off value of 6.0 pg/mL. Both qPCR and the β-d-glucan assay displayed high accuracy for discriminating colonization from definite PCP and displayed moderate accuracy for discriminating colonization from probable PCP.
Staphylococcus aureus bacteraemia (SAB) is a serious infection that demands prompt clinical attention for good outcome. To assess the impact of intervention by infectious diseases physicians (IDPs) ...in cases with SAB, a retrospective cohort study of patients with SAB was performed in a 1240-bed, university hospital in Japan, with the aim of comparing the management and outcome of patients during the initial and the latter half of the intervention period,. Three hundred and forty-six patients with SAB during the 7-year period, from 2002 to 2008, were included, and 194 patients in the initial half of the period (from 2002 to 2005) were compared with 152 patients in the later period (from 2006 to 2008). There was no significant difference between the two groups with respect to patient's clinical background, although more patients in the later period were receiving immunosuppressive treatment. The proportion of methicillin resistant S. aureus was lower during the later period (56.2% vs. 43.3%; p 0.02). Echocardiography was used more frequently (37.1% vs. 64.5%; p < 0.001). Infective endocarditis and metastatic infections were diagnosed more frequently (10.8% vs. 20.4%; p 0.01). Follow-up blood cultures were obtained more regularly (52.1% vs. 73.7%; p <0.001) and therapy was more frequently administered for at least 14 days (47.4% vs. 82.2%; p <0.001). The 30-day mortality improved during the intervention period (25.8% vs. 16.4%; p 0.04). The total number of blood cultures received by the laboratory increased annually and the total number of consultations increased by approximately 1.6-fold compared to 2002. Proactive intervention by IDPs raised awareness of optimal management of bacteraemia and improved the adherence to the standards of care, which subsequently resulted in an improvement in the outcome.
Dose-dense weekly paclitaxel (Taxol) and carboplatin (dd-TC) improved survival compared with conventional tri-weekly paclitaxel and carboplatin (c-TC) as a first-line chemotherapy for newly diagnosed ...stage II–IV ovarian cancer in the Japanese Gynecologic Oncology Group 3016 trial. We report the quality-of-life (QoL) results from this trial.
A total of 637 patients were randomly assigned to receive c-TC or dd-TC (c-TC, n = 319; dd-TC, n = 312) and were asked to complete a QoL assessment at baseline, just after the third and sixth chemotherapy cycles, and at 12 months after randomization. QoL was assessed using Functional Assessment of Cancer Therapy (FACT)-general (FACT-G), FACT-taxane subscale (FACT-T), and FACT-ovary subscale (FACT-Ov). The overall QoL and that according to each subscale were analyzed using mixed-effects models adjusted for treatment and time.
Baseline QoL assessment was completed by 204 out of 319 (63.9%) and 200 out of 312 (64.1%) patients in the c-TC and dd-TC groups, respectively. In these groups, the compliance rates with regard to QoL assessment were 74.5% and 73.0%, respectively, after three chemotherapy cycles; 86.8% and 86.9%, respectively, after six chemotherapy cycles; and 74.2% and 71.6%, respectively, at 12 months after randomization. The overall QoL did not differ significantly between the two treatment groups up to 12 months after randomization (P = 0.46). However, QoL according to the FACT-T subscale was significantly lower in the dd-TC group than in the c-TC group (P = 0.02).
dd-TC does not decrease overall QoL compared with c-TC.
NCT00226915.
POLARBEAR-2b (PB-2b) is the second of three cryogenic receivers of the Simons Array cosmic microwave background polarization experiment. PB-2b contains over 7500 transition-edge sensor (TES) ...bolometers cooled to 250 mK and read out using digital frequency-division multiplexing (DfMux). Stray impedance in the DfMux circuit obscures TES characterization and affects TES dynamic behavior. In order to accurately characterize TESs, it is necessary to account for stray impedance in the bias circuit. We define a stray impedance model, and we describe the technique used to measure model parameters in situ and to remove their effects on TES characterization. We use the same model to predict TES dynamic behavior and show good agreement between data and the model.
Bacillus cereus
, an opportunistic pathogen, can cause fatal infection. However,
B. cereus
bloodstream infections (BSIs) have not been well characterised. From 2008 to 2013,
B. cereus
isolates from ...all of the specimens and patients with
B. cereus
BSIs were identified. Environmental samples were collected to detect
B. cereus
contamination. We also characterised the clinical presentation of
B. cereus
BSI through analyses of risk factors for BSI and mortality. A total of 217 clinical
B. cereus
isolates was detected. Fifty-one patients with nosocomial infections were diagnosed as
B. cereus
BSI, and 37 had contaminated blood cultures. The number of
B. cereus
isolates and BSI patients was significantly greater from June to September than from January to April (4.9 vs. 1.5 per month and 1.2 vs. 0.2, respectively). All BSIs were nosocomial and related to central or peripheral vascular catheter. Urinary catheter odds ratio (OR) 6.93, 95 % confidence interval (CI) 2.40–20.0 was the independent risk factor associated with BSI patients when compared to patients regarded as contaminated. In-hospital mortality among BSI patients was 20 % and was associated with urinary catheter (OR 34.7, 95 % CI 1.89–63.6) and higher Charlson index (OR 1.99, 95 % CI 1.26–3.12). The number of
B. cereus
isolates and BSI increased during summer. Inpatients with indwelling vascular or urinary catheters should be carefully monitored for potential
B. cereus
BSIs.
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