Appropriateness of surgical antimicrobial prophylaxis in Japanese university hospitals.

BACKGROUND: Surgical antimicrobial prophylaxis (SAP) is one of the major purposes of antimicrobial use. AIM: To determine the adherence to the Japanese SAP guidelines in Japanese university hospitals. METHODS: This was a retrospective cohort study including 15 general hospitals and one dental university hospital. Up to three cases of 18 designated surgeries were evaluated regarding adherence to Japanese SAP guidelines: selection of antibiotics, timing of administration, re-dosing intervals, and duration of SAP. When all items were appropriate, surgery was defined as 'appropriate'. FINDINGS: In total, 688 cases (22-45 cases per surgery) were included. The overall appropriateness was 46.8% (322/688), and the appropriateness of each surgery ranged from 8.0% (2/25, cardiac implantable electronic device implantation) to 92.1% (35/38, distal gastrectomy). The appropriateness of each item was as follows: pre/intraoperative selections, 78.5% (540/688); timing of administrations, 96.0% (630/656); re-dosing intervals, 91.6% (601/656); postoperative selection, 78.9% (543/688); and duration of SAP, 61.4% (423/688). The overall appropriateness of hospitals ranged from 17.6% (9/51) to 73.3% (33/45). The common reasons for inappropriateness were the longer duration (38.5%, 265/688) and choice of antibiotics with a non-optimal antimicrobial spectrum before/during, and after surgery (19.0%, 131/688 and 16.9%, 116/688, respectively), compared to the guideline. CONCLUSIONS: Adherence to the guidelines differed greatly between the surgeries and hospitals. Large-scale multi-centre surveillance of SAP in Japanese hospitals is necessary to identify inappropriate surgeries, factors related to the appropriateness, and incidences of surgical site infections.

Five-year point prevalence survey of healthcare-associated infections and antimicrobial use in a Japanese university hospital.

BACKGROUND: Periodic point prevalence surveys (PPSs) provide a method for assessing changes in healthcare-associated infections (HAIs) and antimicrobial use over time. Following the introduction of an antimicrobial stewardship programme at Nagoya University Hospital (Aichi, Japan) a five-year PPS study was performed to highlight any epidemiological changes. METHODS: One-day PPSs were performed annually in July at Nagoya University Hospital. Data on patient characteristics, medical devices, active HAIs and antimicrobial use were collected using a standard data-collection form. RESULTS: A total of 4339 patients were included. Over the five-year study period the median patient age was 62 years, median duration of hospital admission was nine days, 9% of patients had an HAI and 35.2% received at least one antimicrobial. Overall there were 406 HAIs (95% confidence interval, 369-447) with surgical site infection, pneumonia and febrile neutropenia occurring most frequently. Enterobacterales were the most common pathogens (N = 78, 28.6%) and 32.1% were third-generation cephalosporin-resistant. Meropenem was the most frequently prescribed antimicrobial for HAIs. Surgical antimicrobial prophylaxis changed drastically, with shorter durations and a marked reduction in oral cephalosporin use. However, antimicrobials for medical prophylaxis gradually increased. CONCLUSIONS: This five-year PPS study shows consistent data for patient background, HAIs and causative pathogens and highlights changes in antimicrobial use during the era of the National Action Plan on Antimicrobial Resistance. To describe the epidemiology of Japanese hospitals by PPS, multicentre PPSs including in community hospitals should be performed annually.

Morphological lymphocytic reaction, patient prognosis and PD-1 expression after surgical resection for oesophageal cancer.

BACKGROUND: Immune checkpoint inhibitors, such as antibody against programmed cell death protein (PD-1), have demonstrated antitumour effects in patients with malignancies, including oesophageal cancer. A lymphocytic reaction observed by pathological examination is a manifestation of the host immune response to tumour cells. It was hypothesized that a stronger lymphocytic reaction to tumours might be associated with favourable prognosis in oesophageal cancer. METHODS: Using a database of resected oesophageal cancers, four morphological components of lymphocytic reactions (peritumoral, intranest, lymphoid and stromal) to tumours were evaluated in relation to clinical outcome, PD-1 expression by immunohistochemistry and total lymphocyte count in blood. RESULTS: Resected oesophageal cancer specimens from 436 patients were included in the study. Among the four morphological components, only peritumoral reaction was associated with patient prognosis (multivariable P for trend <0·001); patients with a higher peritumoral reaction had significantly longer overall survival than those with a lower reaction (multivariable hazard ratio 0·48, 95 per cent c.i. 0·34 to 0·67). The prognostic effect of peritumoral reaction was not significantly modified by other clinical variables (all P for interaction >0·050). Peritumoral reaction was associated with total lymphocyte count in the blood (P < 0·001), supporting the relationship between local immune response and systemic immune competence. In addition, higher morphological peritumoral reaction was associated with high PD-1 expression on lymphocytes in tumours (P = 0·034). CONCLUSION: These findings should help to improve risk-adapted therapeutic strategies and help stratify patients in the future clinical setting of immunotherapy for oesophageal cancer.

ANTECEDENTES: Los inhibidores de los puntos de control inmunitario (checkpoints) (p.ej. los anticuerpos anti-PD-1) han demostrado efectos antitumorales en pacientes con tumores malignos, incluido el cáncer de esófago. La reacción linfocítica detectada en estudios anatomopatológicos es una manifestación de la respuesta inmune del huésped a las células tumorales. Se estableció la hipótesis de que una mayor reacción linfocítica a los tumores podría asociarse con un mejor pronóstico en el cáncer de esófago. MÉTODOS: Usando una base de datos de 436 cánceres de esófago resecados, se evaluaron cuatro componentes morfológicos (peritumoral, intra-epitelial, linfoide y estromal) de las reacciones linfocíticas a tumores en relación con los resultados clínicos, la expresión inmunohistoquímica de PD-1 y el recuento total de linfocitos en sangre. RESULTADOS: De los cuatro componentes, solamente la reacción peritumoral se asoció con el pronóstico del paciente (P multivariable para tendencia < 0,001): los pacientes con mayor reacción peritumoral presentaron una supervivencia global significativamente más prolongada que aquellos pacientes con menor reacción peritumoral (cociente de riesgos instantáneos multivariable, hazard ratio, HR: 0,48; i.c. del 95%: 0,34 -0,67; P <0,001). El efecto pronóstico de la reacción peritumoral no se modificó significativamente por otras variables clínicas (todas las P para la interacción > 0,05). La reacción peritumoral se asoció con el recuento total de linfocitos en la sangre (P < 0,001), lo que respalda la relación entre la respuesta inmune local y la competencia inmune sistémica. Además, una elevada reacción morfológica peritumoral se asoció con una alta expresión de PD-1 en linfocitos tumorales (P = 0,034). CONCLUSIÓN: Estos hallazgos deberían ayudar a mejorar las estrategias terapéuticas adaptadas al riesgo y contribuir a estratificar a los pacientes en el entorno clínico futuro de la inmunoterapia para los pacientes con cáncer de esófago.

Automated detection of outbreaks of antimicrobial-resistant bacteria in Japan.

BACKGROUND: Hospital outbreaks of antimicrobial-resistant (AMR) bacteria should be detected and controlled as early as possible. AIM: To develop a framework for automatic detection of AMR outbreaks in hospitals. METHODS: Japan Nosocomial Infections Surveillance (JANIS) is one of the largest national AMR surveillance systems in the world. For this study, all bacterial data in the JANIS database were extracted between 2011 and 2016. WHONET, a free software for the management of microbiology data, and SaTScan, a free cluster detection tool embedded in WHONET, were used to analyse 2015-2016 data of eligible hospitals. Manual evaluation and validation of 10 representative hospitals around Japan were then performed using 2011-2016 data. FINDINGS: Data from 1031 hospitals were studied; mid-sized (200-499 beds) hospitals accounted for 60%, followed by large hospitals (≥500 beds; 24%) and small hospitals (<200 beds; 16%). More clusters were detected in large hospitals. Most of the clusters included five or fewer patients. From the in-depth analysis of 10 hospitals, ∼80% of the detected clusters were unrecognized by infection control staff because the bacterial species involved were not included in the priority pathogen list for routine surveillance. In two hospitals, clusters of more susceptible isolates were detected before outbreaks of more resistant pathogens. CONCLUSION: WHONET-SaTScan can automatically detect clusters of epidemiologically related patients based on isolate resistance profiles beyond lists of high-priority AMR pathogens. If clusters of more susceptible isolates can be detected, it may allow early intervention in infection control practices before outbreaks of more resistant pathogens occur.

The hydrocarbon-bearing clathrasil chibaite and its host-guest structure at low temperature.

The natural sII-type clathrasil chibaite [chemical formula SiO2·(M12,M16), where Mx denotes a guest mol-ecule] was investigated using single-crystal X-ray diffraction and Raman spectroscopy in the temperature range from 273 to 83 K. The O atoms of the structure at room temperature, which globally conforms to space group [V = 7348.9 (17) Å3, a = 19.4420 (15) Å], have anomalous anisotropic displacement parameters indicating a static or dynamic disorder. With decreasing temperature, the crystal structure shows a continuous symmetry-lowering transformation accompanied by twinning. The intensities of weak superstructure reflections increase as temperature decreases. A monoclinic twinned superstructure was derived at 100 K [A2/n, V = 7251.0 (17) Å3, a' = 23.7054 (2), b' = 13.6861 (11), c' = 23.7051 (2) Å, ß' = 109.47°]. The transformation matrix from the cubic to the monoclinic system is ai ' = (½ 1 ½ / ½ 0 -½ / ½ -1 ½). The A2/n host framework has Si-O bond lengths and Si-O-Si angles that are much closer to known values for stable silicate-framework structures compared with the averaged model. As suggested from band splitting observed in the Raman spectra, the [512]-type cages (one crystallographically unique in , four different in A2/n) entrap the hydro-carbon species (CH4, C2H6, C3H8, i-C4H10). The [51264]-type cage was found to be unique in both structure types. It contains the larger hydro-carbon mol-ecules C2H6, C3H8 and i-C4H10.

New Left Lobe Transplantation Procedure with Caval Reconstruction Using an Inverted Composite Graft for Chronic Budd-Chiari Syndrome in Living-Donor Liver Transplantation-A Case Report.

When the Budd-Chiari syndrome (BCS) lesion extends to the inferior vena cava (IVC) or the orifices of the hepatic vein, the thickened IVC and/or hepatic vein wall must be removed and IVC reconstruction is required in living-donor liver transplantation (LDLT). In various reports about IVC resection in LDLT for BCS, there are none about left lobe liver transplantation with reconstruction of the retrohepatic IVC (rhIVC). To overcome removal and reconstruction of the rhIVC in LDLT for BCS, we introduced a composite IVC graft that is applicable to both right and left lobe partial liver grafts for LDLT for BCS. Pathogenic IVC was removed together with the native liver between the lower edge of the right atrium and 5 cm above the renal vein junction with the use of venovenous bypass. The e-polytetrafluoroethylene graft was anastomosed to the suprarenal intact IVC. Then the native part was detached at the level of just above the renal junction. The composite graft was inverted and a half rim of the native part of the graft was anastomosed to the posterior wall of the right atrium. Next, the common venous orifice of the left lobe graft was anastomosed to the wall defect which was composed of the anterior wall of the right atrium and the distal end of the native part of the composite graft. In conclusion, our inverted composite graft technique will overcome the weak points of LDLT for BCS, such as incomplete removal of the pathogenic caval wall and reconstruction of the rhIVC.

The first multi-centre point-prevalence survey in four Japanese university hospitals.

BACKGROUND: The Japanese government adopted a national action plan on antimicrobial resistance, which aims to reduce drug-resistant pathogens and antimicrobial use. A point-prevalence survey (PPS) is a useful surveillance method to gain information about hospital epidemiology; however, no multi-centre PPS has previously been performed in Japan. AIM: To investigate general information about hospital epidemiology, healthcare-associated infections (HCAIs), and antimicrobial use in multiple Japanese university hospitals. METHODS: In July 2016, a multi-centre PPS was conducted using a standardized protocol at four university hospitals in Japan. FINDINGS: A total of 3199 patients were included. Median age and duration of hospital stay were 64 years and 10 days, respectively. A total of 246 (7.7%; 95% confidence interval (CI): 6.8-8.7) patients had 256 active HCAIs, and 933 (29.2%; 95% CI: 27.6-30.8) patients received 1318 antimicrobials. Pneumonia and gastrointestinal system infection were the most common HCAIs (N = 42, 16.4%), and Enterobacteriaceae (N = 49, 30.8%) were the predominant causative organisms. Carbapenems (N = 52, 17.8%), anti-MRSA medications, and cephems with antipseudomonal activity were the most frequently prescribed antimicrobials for HCAIs. As surgical prophylaxis, 46 of 278 antimicrobials (16.5%) were administered orally. Proportions of HCAI and antimicrobial use in each hospital ranged from 4.8% to 9.5% and 19.3%-35.0%, respectively. CONCLUSION: This multi-centre PPS recorded detailed HCAI data and distinct antimicrobial use in Japanese university hospitals. Further surveillance is necessary to reduce HCAIs and formulate feasible plans to achieve the national action plan on antimicrobial resistance.

Six National University Consortium in Liver Transplant Professionals Training (SNUC-LT) Program in Japan.

BACKGROUND: There has been no public structured training program for transplant surgeons in Japan. However, such a program is crucial for optimizing liver transplant surgery and training young professionals in liver transplant surgery. A comprehensive training program was recently developed and the underlying concepts, structure and curriculum, and results of this program are described here. METHODS: We developed a 3-year training program in 2014 called the Six National University Consortium in Liver Transplant Professionals Training (SNUC-LT) program supported by the Ministry of Education, Culture, Sports, Science, and Technology. This program is based on strong cooperation among 6 national universities (Kumamoto, Okayama, Nagasaki, Kanazawa, Niigata, and Chiba Universities). The program includes various courses to help trainees learn transplant theory and practice as well as to teach surgical skills required to safely perform transplant surgery. RESULTS: Three trainees completed the specially designed 3-year curriculum. They attended lectures on transplant theory for an average of 59 hours and participated in an average of 44 liver transplant surgeries and 51 liver resections for transplant practice. Trainees from low-volume centers had sufficient opportunities to attend operations in high-volume centers because of the cooperative agreement among the universities. After finishing the program, the trainees were certified as talent-proven liver transplant surgeons. CONCLUSIONS: The SNUC-LT program is the first national program in Japan to have strong professional support. Our multicenter program enables young surgeons to have more abundant knowledge, more extensive experience, better surgical skills, and smoother communication skills in the field of liver transplantation.

Label-free photoacoustic imaging of human palmar vessels: a structural morphological analysis.

We analysed the vascular morphology of the palm using a photoacoustic tomography (PAT) instrument with a hemispherical detector array. The three-dimensional (3D) morphology of blood vessels was determined noninvasively. Overall, 12 females and 11 males were recruited as healthy volunteers. Their ages were distributed almost evenly from 22 to 59 years. In all cases, many vascular networks were observed just beneath the skin and were determined to be veins anatomically. To analyse the major arteries, the layer containing the subcutaneous venous network was removed from the image. The analysis focused on the common and proper palmar digital arteries. We used the curvature of these arteries as a parameter to analyse their morphologies. There was no significant difference in the curvature between genders when comparing the subjects as a whole. The blood vessel curvature increased with age. Good agreement was found between the 3D numerical analysis results and the subjective evaluation of the two-dimensional (2D) projection image. The PAT system enabled visualization of the 3D features of blood vessels in the palm and noninvasive analysis of arterial tortuousness.

Visualization of tumor-related blood vessels in human breast by photoacoustic imaging system with a hemispherical detector array.

Noninvasive measurement of the distribution and oxygenation state of hemoglobin (Hb) inside the tissue is strongly required to analyze the tumor-associated vasculatures. We developed a photoacoustic imaging (PAI) system with a hemispherical-shaped detector array (HDA). Here, we show that PAI system with HDA revealed finer vasculature, more detailed blood-vessel branching structures, and more detailed morphological vessel characteristics compared with MRI by the use of breast shape deformation of MRI to PAI and their fused image. Morphologically abnormal peritumoral blood vessel features, including centripetal photoacoustic signals and disruption or narrowing of vessel signals, were observed and intratumoral signals were detected by PAI in breast cancer tissues as a result of the clinical study of 22 malignant cases. Interestingly, it was also possible to analyze anticancer treatment-driven changes in vascular morphological features and function, such as improvement of intratumoral blood perfusion and relevant changes in intravascular hemoglobin saturation of oxygen. This clinical study indicated that PAI appears to be a promising tool for noninvasive analysis of human blood vessels and may contribute to improve cancer diagnosis.

Intraoperative Oxygen Consumption During Liver Transplantation.

BACKGROUND: The aim of this study was to investigate the changes in oxygen consumption during liver transplantation and to examine the relationship between intraoperatively elevated systemic oxygen consumption and postoperative liver function. METHODS: This study was performed in 33 adult patients undergoing liver transplantation between September 2011 and March 2014. We measured intraoperative oxygen consumption through the use of indirect calorimetry, preoperative and intraoperative data, liver function tests, and postoperative complications and outcomes. RESULTS: The mean age of patients was 52 ± 9.7 years; 14 (42%) of them were women. Average Model for End-Stage Liver Disease scores were 20 ± 8.9. Oxygen consumption significantly increased after reperfusion from 172 ± 30 mL/min during the anhepatic phase to 209 ± 30 mL/min (P < .0001). We divided patients into 2 groups according to the increase in oxygen consumption after reperfusion (oxygen consumption after reperfusion minus anhepatic phase oxygen consumption: 40 mL/min increase as cutoff). The higher consumption group had a longer cold ischemia time and higher postoperative aspartate aminotransferase and alanine aminotransferase levels as compared with the lower oxygen consumption group. There were no statistically significant differences in major postoperative complications, but the higher oxygen consumption group tended to have shorter hospital stays than the lower consumption group (58 versus 95 days). CONCLUSIONS: We have demonstrated that oxygen consumption significantly increased after reperfusion. Furthermore, this increased oxygen consumption was associated with a longer cold ischemia time and shorter hospital stays.

Influence of surgical orthodontic treatment on masticatory function in skeletal Class III patients.

Skeletal Class III patients exhibit malocclusion characterised by Angle Class III and anterior crossbite, and their occlusion shows total or partially lateral crossbite of the posterior teeth. Most patients exhibit lower bite force and muscle activity than non-affected subjects. While orthognathic surgery may help improve masticatory function in these patients, its effects have not been fully elucidated. The aims of the study were to evaluate jaw movement and the electromyographic (EMG) activity of masticatory muscles before and after orthognathic treatment in skeletal Class III patients in comparison with control subjects with normal occlusion. Jaw movement variables and EMG data were recorded in 14 female patients with skeletal Class III malocclusion and 15 female controls with good occlusion. Significant changes in jaw movement, from a chopping to a grinding pattern, were observed after orthognathic treatment (closing angle P < 0.01; cycle width P < 0.01), rendering jaw movement in the patient group similar to that of the control group. However, the grinding pattern in the patient group was not as broad as that of controls. The activity indexes, indicating the relative contributions of the masseter and temporalis muscles (where a negative value corresponds to relatively more temporalis activity and vice versa) changed from negative to positive after treatment (P < 0.05), becoming similar to those of control subjects. Our findings suggest that orthognathic treatment in skeletal Class III patients improves the masticatory chewing pattern and muscle activity. However, the chewing pattern remains incomplete compared with controls.

Six-axis multi-anvil press for high-pressure, high-temperature neutron diffraction experiments.

We developed a six-axis multi-anvil press, ATSUHIME, for high-pressure and high-temperature in situ time-of-flight neutron powder diffraction experiments. The press has six orthogonally oriented hydraulic rams that operate individually to compress a cubic sample assembly. Experiments indicate that the press can generate pressures up to 9.3 GPa and temperatures up to 2000 K using a 6-6-type cell assembly, with available sample volume of about 50 mm(3). Using a 6-8-type cell assembly, the available conditions expand to 16 GPa and 1273 K. Because the six-axis press has no guide blocks, there is sufficient space around the sample to use the aperture for diffraction and place an incident slit, radial collimators, and a neutron imaging camera close to the sample. Combination of the six-axis press and the collimation devices realized high-quality diffraction pattern with no contamination from the heater or the sample container surrounding the sample. This press constitutes a new tool for using neutron diffraction to study the structures of crystals and liquids under high pressures and temperatures.

Posterior scissors-bite: masticatory jaw movement and muscle activity.

Scissors-bite is a malocclusion characterised by buccal inclination or buccoversion of the maxillary posterior tooth and/or linguoclination or linguoversion of the mandibular posterior tooth. This type of malocclusion causes reduced contact of the occlusal surfaces and can cause excessive vertical overlapping of the posterior teeth. This case-control study is the first to evaluate both masticatory jaw movement and masseter and temporalis muscle activity in patients with unilateral posterior scissors-bite. Jaw movement variables and surface electromyography data were recorded in 30 adult patients with unilateral posterior scissors-bite malocclusion and 18 subjects with normal occlusion in a case-control study. The chewing pattern on the scissors-bite side significantly differed from that of the non-scissors-bite side in the patients and of the right side in the normal subjects. These differences included a narrower chewing pattern (closing angle, P < 0.01; cycle width, P < 0.01), a longer closing duration (P < 0.05), a slower closing velocity (P < 0.01) and lower activities of both the temporalis (P < 0.05) and the masseter (P < 0.05) muscles on the working side. In 96% of the patients with unilateral posterior scissors-bite, the preferred chewing side was the non-scissors-bite side (P = 0.005). These findings suggest that scissors-bite malocclusion is associated with the masticatory chewing pattern and muscle activity, involving the choice of the preferred chewing side in patients with unilateral posterior scissors-bite.

Influence of maximum bite force on jaw movement during gummy jelly mastication.

It is known that maximum bite force has various influences on chewing function; however, there have not been studies in which the relationships between maximum bite force and masticatory jaw movement have been clarified. The aim of this study was to investigate the effect of maximum bite force on masticatory jaw movement in subjects with normal occlusion. Thirty young adults (22 men and 8 women; mean age, 22.6 years) with good occlusion were divided into two groups based on whether they had a relatively high or low maximum bite force according to the median. The maximum bite force was determined according to the Dental Prescale System using pressure-sensitive sheets. Jaw movement during mastication of hard gummy jelly (each 5.5 g) on the preferred chewing side was recorded using a six degrees of freedom jaw movement recording system. The motion of the lower incisal point of the mandible was computed, and the mean values of 10 cycles (cycles 2-11) were calculated. A masticatory performance test was conducted using gummy jelly. Subjects with a lower maximum bite force showed increased maximum lateral amplitude, closing distance, width and closing angle; wider masticatory jaw movement; and significantly lower masticatory performance. However, no differences in the maximum vertical or maximum anteroposterior amplitudes were observed between the groups. Although other factors, such as individual morphology, may influence masticatory jaw movement, our results suggest that subjects with a lower maximum bite force show increased lateral jaw motion during mastication.

Melting temperatures of H2O up to 72 GPa measured in a diamond anvil cell using CO2 laser heating technique.

The melting curve of H2O from 49 to 72 GPa was determined by using a laser-heated diamond anvil cell. Double-sided CO2 laser heating technique was employed in order to heat the sample directly. Discontinuous changes of the heating efficiency attributed to the H2O melting were observed between 49 and 72 GPa. The obtained melting temperatures at 49 and 72 GPa are 1200 and 1410 K, respectively. We found that the slope of the melting curve significantly decreases with increasing pressure, only 5 K/GPa at 72 GPa while 44 K/GPa at 49 GPa. Our results suggest that the melting curve does not intersect with the isentropes of Uranus and Neptune, and hence, H2O should remain in the liquid state even at the pressure and temperature conditions found deep within Uranus and Neptune.

Molecular and clinical characterization of plasmid-mediated AmpC ß-lactamase-producing Escherichia coli bacteraemia: a comparison with extended-spectrum ß-lactamase-producing and non-resistant E. coli bacteraemia.

Plasmid-mediated AmpC ß-lactamase-producing Escherichia coli (AmpC-E) bacteraemia was characterized by comparison with bacteraemia caused by extended-spectrum ß-lactamase (ESBL)-producing E. coli (ESBL-E) and non-resistant E. coli (NR-E) in the era of the worldwide spread of the CTX-M-15-producing O25b-ST131-B2 clone. Of 706 bloodstream E. coli isolates collected between 2005 and 2010 in three Japanese university hospitals, 111 ESBL screening-positive isolates were analysed for AmpC and ESBL genes by PCR. A case-control study was performed in which the cases consisted of all of the patients with AmpC-E bacteraemia. Phylogenetic groups, sequence types and O25b serotype were determined. Twenty-seven AmpC-E isolates (26 of which were of the CMY-2 type) were identified, and 54 ESBL-E and 54 NR-E isolates were selected for the controls. Nineteen AmpC-E isolates were also positive for ESBL. CTX-M-14 was the most prevalent ESBL type among both the AmpC-E and ESBL-E isolates. The O25b-ST131-B2 clone was the most prevalent among the ESBL-E isolates (26%) and the second most prevalent among the NR-E isolates (13%), but only one O25b-ST131-B2 clone was found among the AmpC-E isolates. Twenty-three different sequence types were identified among the AmpC-E isolates. When compared with bacteraemia with ESBL-E, previous isolation of multidrug-resistant bacteria and intravascular catheterization were independently associated with a lower risk for AmpC-E. When compared with NR-E bacteraemia, prior use of antibiotics was the only significant risk factor for AmpC-E. Unlike the spread of the O25b-ST131-B2 clone between ESBL-E and NR-E, the AmpC-E isolates were not dominated by any specific clone.

Application of wavelength shifting fiber to subcriticality measurements.

Static and kinetic experiments on an accelerator-driven system have been conducted at the Kyoto University Critical Assembly. A small neutron detector using wavelength shifting fiber that can be inserted into a narrow space has been developed for measuring static and kinetic parameters. This study has found that the new detector type can be applied to kinetic experiments such as subcriticality measurements with the use of a D-T pulsed neutron source.