Physicochemical parameters affecting the adhesion of ciprofloxacin-resistant Escherichia coli to activated sludge.

To investigate the physicochemical conditions necessary to stably remove antibiotic-resistant bacteria (ARB) via contact with activated sludge (AS), the adhesion of ciprofloxacin (CIP)-resistant and -susceptible Escherichia coli to AS was simulated by contact tests in the laboratory. The CIP-resistant E. coli and susceptible E. coli were removed by a 3 log smaller concentration by a 5 h contact test at maximum. Considering the hydraulic retention time of a reaction tank (∼5 h) and step-feeding operation, we considered the removal rate of E. coli in the current simulated contact test to be in agreement with the actual situation where 1-2 log concentrations of E. coli were reported to be removed from an AS reaction tank. With the increase in the AS concentration and/or dissolved oxygen, the removal rate of E. coli increased. The removal rate of CIP-resistant E. coli was greater than that of susceptible E. coli under all experimental conditions. Although the mechanism by which CIP-resistant E. coli preferably adhered to AS was not clearly understood in detail, finding optimum conditions under which bacteria, including ARB, were efficiently removed by the AS process may be possible.

[Mitral Valve Repair under Ventricular Fibrillation for Acute Mitral Valve Regurgitation in a Patient with Aortitis Syndrome].

A 73-year-old woman with a history of aortitis syndrome was referred to our hospital presenting with congestive heart failure caused by acute severe mitral regurgitation due to posterior leaflet prolapse. Upon admission, the patient fell into shock state while undergoing an examination. Medical treatment including mechanical ventilation could not alleviate circulatory collapse, so emergency surgery was performed on the day of admission. Severe calcification of the ascending aorta and severe stenosis or occlusion of the aortic arch vessels resulted from the patient's aortitis syndrome precluded aortic cannulation and aortic clamp. Therefore, mitral valve repair was performed under ventricular fibrillation at moderate hypothermia. Surgery was successful, and the patient recovered well without any cerebral complications after the surgery.

Simple enumeration of Escherichia coli concentrations in river water samples by measuring ß-d-glucuronidase activities in a microplate reader.

Monitoring of Escherichia coli concentrations in river water (RW) is essential to identify fecal pollution of the river. The objective of this study was to assess the suitability of a novel, simple and high throughput method developed in our laboratory to enumerate E. coli concentrations in RW samples. The method is based on the use of the synthetic substrate specific for the ß-d-glucuronidase (GUS) produced by E. coli. GUS activities and E. coli concentrations were monitored at eight selected sites in rivers running through Sapporo, Japan. Because the fluorescence intensities of the synthetic substrate in the RW samples increased linearly over a 4-h incubation period, we could estimate the GUS activities of the RW samples. The GUS activities were highly correlated with E. coli concentrations at >100 most probable numbers 100 mL-1 with a correlation coefficient of 0.87. The GUS activities of the RW samples collected from all sampling sites fitted well to a single correlation equation, which indicates that it was applicable to the estimation of E. coli concentrations regardless of the sampling sites. This method is simple, rapid, reliable, inexpensive, and high throughput, and is therefore useful for monitoring E. coli in RW.

[Reports of 12 Cases of Stanford Type A Acute Aortic Dissection Emergent Surgery for Jehovah's Witnesses patients].

The Jehovah's Witnesses (JW) is well known for declining blood transfusions. Especially, cardiovascular surgery on JW poses unique challenges. We herein report 12 JW emergent cases of Stanford type A acute aortic dissection which underwent graft replacement between 2003 and 2019. Graft replacement of ascending aorta was performed in all cases. Operative time and anesthetic time were 344±100 and 396±109 minutes respectively. The mean intraoperative hemoglobin nadir was 4.9±1.2 g/dl. The postoperative hemoglobin nadir was 6.3 ±2.4 g/dl. There were 2 deaths within 24 hours after surgery. We did not transfuse any packed red blood cells, fresh frozen plasma or platelets for JW patients of Stanford type A acute aortic dissection surgery.

Experimental Evidence for in Situ Nitric Oxide Production in Anaerobic Ammonia-Oxidizing Bacterial Granules.

Although nitric oxide (NO) emissions from anaerobic ammonium oxidation (anammox)-based processes were reported previously, the NO production pathways are poorly understood. Here, we investigated the NO production pathways in anammox granules in detail by combining 15N-stable isotope tracer experiments with various inhibitors, microsensor measurements, and transcriptome analysis for key genes of NO2- reduction. NO was emitted from the anammox granules, which account for 0.07% of the N2 emission. 15N-stable isotope-tracer experiments indicated that most of the N2 was produced by anammox bacteria, whereas NO was produced from NO2- reduction by anammox and denitrifying bacteria. The NO emission rate was highest at pH 8.0 and accelerated by increasing NH4+ and NO2- concentrations in the culture media. The microsensor analyses showed the in situ NO production rate was highest in the outer layer of the anammox granule where anammox activity was also highest. The detected in situ NO concentrations of up to 2.7 µM were significantly above physiological thresholds known to affect a wide range of microorganisms present in wastewater. Hence, NO likely plays pivotal roles in the microbial interactions in anammox granules, which needs to be further investigated.

Determination of Cadmium in Brown Rice Samples by Fluorescence Spectroscopy Using a Fluoroionophore after Purification of Cadmium by Anion Exchange Resin.

Simple analytical methods are needed for determining the cadmium (Cd) content of brown rice samples. In the present study, we developed a new analytical procedure consisting of the digestion of rice using HCl, Cd purification using anion exchange resin, and then determining the Cd content using fluorescence spectroscopy. Digestion with 0.1 M HCl for 10 min at room temperature was sufficient to extract Cd from the ground rice samples. The Cd in the extract was successfully purified in preference to other metals using Dowex 1X8 chloride form resin. Low concentrations of Cd in the eluate could be determined using fluorescence spectroscopy with a fluoroionophore. Overall, the actual limit of quantification value for the Cd content in rice was about 0.1 mg-Cd/kg-rice, which was sufficiently low compared with the regulatory value (0.4 mg-Cd/kg-rice) given by the Codex Alimentarius Commission. We analyzed authentic brown rice samples using our new analytical procedure and the results agreed well with those determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Since the fluoroionophore recognized Zn2+ and Hg2+ as well as Cd2+, a sample containing high concentration of Zn2+ or Hg2+ might cause a false positive result.

High spatial resolution analysis of the distribution of sulfate reduction and sulfide oxidation in hypoxic sediment in a eutrophic estuary.

Bottom hypoxia and consequential hydrogen sulfide (H2S) release from sediment in eutrophic estuaries is a major global environmental issue. We investigated dissolved oxygen, pH and H2S concentration profiles with microsensors and by sectioning sediment cores followed by colorimetric analysis. The results of these analyses were then compared with the physicochemical properties of the bottom water and sediment samples to determine their relationships with H2S production in sediment. High organic matter and fine particle composition of the sediment reduced the oxidation-reduction potential, stimulating H2S production. Use of a microsensor enabled measurement of H2S concentration profiles with submillimetre resolution, whereas the conventional sediment-sectioning method gave H2S measurements with a spatial resolution of 10 mm. Furthermore, microsensor measurements revealed H2S consumption occurring at the sediment surface in both the microbial mat and the sediment anoxic layer, which were not observed with sectioning. This H2S consumption prevented H2S release into the overlying water. However, the microsensor measurements had the potential to underestimate H2S concentrations. We propose that a combination of several techniques to measure microbial activity and determine its relationships with physicochemical properties of the sediment is essential to understanding the sulfur cycle under hypoxic conditions in eutrophic sediments.

[Tricuspid Valve Replacement without Removing Transvenous Pacemaker Lead].

Transvenous pacemaker lead occasionally impairs tricuspid valve coaptation because of the direct injury like a perforation, the direct interference with the valve, or the adhesion between the pacemaker leads and the valve leaflets, resulting in severe tricuspid regurgitation. In these situation, tricuspid valve replacement (TVR) is selected after the exchange from transvenous lead to epicardial lead. However this procedure has some problems such as poor threshold of the endcardial lead, the injury and the difficulty in transvenous lead removal. We performed successful TVR without removing transvenous pacemaker lead after the fixation to the annulus of posterior leaflet in tricuspid valve. This technique is useful in a patient with tricuspid regurgitation due to the influence of the pacemaker lead.

Ecology and physiology of anaerobic ammonium oxidizing bacteria.

Anaerobic ammonium oxidation (anammox) is a microbial process in which NH4 (+) is oxidized to N2 gas with NO2 (-) as an electron acceptor. The anammox process is mediated by bacterial members affiliated with the phylum Planctomycetes, which are ubiquitously detected from anoxic natural and man-made ecosystems and a key player in the global nitrogen cycle. In the past two decades, phylogenetically different anammox bacteria have been recognized in natural and synthetic ecosystems (i.e. 'Candidatus Kuenenia', 'Candidatus Brocadia', 'Candidatus Jettenia', 'Candidatus Anammoxoglobus' and 'Candidatus Scalindua' genera), and the geographic distributions of these anammox bacteria indicate that they have genus-specific or species-specific habitats. Recently, we revealed the physiological characteristics of 'Ca. Jettenia' in addition to 'Ca. Kuenenia', 'Ca. Brocadia' and 'Ca. Scalindua', and, as a result, it is possible to compare the physiological characteristics of the anammox bacteria and discuss their niche partitioning. Therefore, we summarize the current knowledge of anammox bacterial ecology and physiology in this review to assess the potential ecological niche partitioning of anammox bacteria in natural and synthetic ecosystems.

Hydroxylamine-dependent anaerobic ammonium oxidation (anammox) by "Candidatus Brocadia sinica".

Although metabolic pathways and associated enzymes of anaerobic ammonium oxidation (anammox) of 'Ca. Kuenenia stuttgartiensis' have been studied, those of other anammox bacteria are still poorly understood. NO2- reduction to NO is considered to be the first step in the anammox metabolism of 'Ca. K. stuttgartiensis', however, 'Ca. Brocadia' lacks the genes that encode canonical NO-forming nitrite reductases (NirS or NirK) in its genome, which is different from 'Ca. K. stuttgartiensis'. Here, we studied the anammox metabolism of 'Ca. Brocadia sinica'. (15) N-tracer experiments demonstrated that 'Ca. B. sinica' cells could reduce NO2- to NH2 OH, instead of NO, with as yet unidentified nitrite reductase(s). Furthermore, N2 H4 synthesis, downstream reaction of NO2- reduction, was investigated using a purified 'Ca. B. sinica' hydrazine synthase (Hzs) and intact cells. Both the 'Ca. B. sinica' Hzs and cells utilized NH2 OH and NH4+, but not NO and NH4+, for N2 H4 synthesis and further oxidized N2 H4 to N2 gas. Taken together, the metabolic pathway of 'Ca. B. sinica' is NH2 OH-dependent and different from the one of 'Ca. K. stuttgartiensis', indicating metabolic diversity of anammox bacteria.

Tricuspid Valve Replacement Preserving Endocardial Pacemaker Lead.

We describe a simple and reliable technique to replace the tricuspid valve preserving a permanent endocardial pacemaker lead. This technique avoids any direct contact between the pacemaker lead and the prosthetic valve, which protects the pacemaker lead from the mechanical stress of the valve prosthesis and preserves the prosthetic valve's function. doi: 10.1111/jocs.12747 (J Card Surg 2016;31:311-314).

Physiological characterization of anaerobic ammonium oxidizing bacterium 'Candidatus†Jettenia caeni'.

To date, six candidate genera of anaerobic ammonium-oxidizing (anammox) bacteria have been identified, and numerous studies have been conducted to understand their ecophysiology. In this study, we examined the physiological characteristics of an anammox bacterium in the genus 'Candidatus Jettenia'. Planctomycete KSU-1 was found to be a mesophilic (20-42.5°C) and neutrophilic (pH 6.5-8.5) bacterium with a maximum growth rate of 0.0020 h(-1) . Planctomycete KSU-1 cells showed typical physiological and structural features of anammox bacteria; i.e. (29) N2 gas production by coupling of (15) NH4 (+) and (14) NO2 (-) , accumulation of hydrazine with the consumption of hydroxylamine and the presence of anammoxosome. In addition, the cells were capable of respiratory ammonification with oxidation of acetate. Notably, the cells contained menaquinone-7 as a dominant respiratory quinone. Proteomic analysis was performed to examine underlying core metabolisms, and high expressions of hydrazine synthase, hydrazine dehydrogenase, hydroxylamine dehydrogenase, nitrite/nitrate oxidoreductase and carbon monoxide dehydrogenase/acetyl-CoA synthase were detected. These proteins require iron or copper as a metal cofactor, and both were dominant in planctomycete KSU-1 cells. On the basis of these experimental results, we proposed the name 'Ca. Jettenia caeni' sp. nov. for the bacterial clade of the planctomycete KSU-1.

Identification of key nitrous oxide production pathways in aerobic partial nitrifying granules.

The identification of the key nitrous oxide (N2O) production pathways is important to establish a strategy to mitigate N2O emission. In this study, we combined real-time gas-monitoring analysis, (15)N stable isotope analysis, denitrification functional gene transcriptome analysis and microscale N2O concentration measurements to identify the main N2O producers in a partial nitrification (PN) aerobic granule reactor, which was fed with ammonium and acetate. Our results suggest that heterotrophic denitrification was the main contributor to N2O production in our PN aerobic granule reactor. The heterotrophic denitrifiers were probably related to Rhodocyclales bacteria, although different types of bacteria were active in the initial and latter stages of the PN reaction cycles, most likely in response to the presence of acetate. Hydroxylamine oxidation and nitrifier denitrification occurred, but their contribution to N2O emission was relatively small (20-30%) compared with heterotrophic denitrification. Our approach can be useful to quantitatively examine the relative contributions of the three pathways (hydroxylamine oxidation, nitrifier denitrification and heterotrophic denitrification) to N2O emission in mixed microbial populations.

[Cardiac tamponade due to ruptured coronary artery aneurysm associated with coronary-pulmonary artery fistula; report of a case].

We report a successful operative treatment of ruptured coronary artery aneurysm associated with coronary-pulmonary artery fistula. A 67-year-old woman was diagnosed with coronary artery fistula previously but observed without any treatment. She had medical examination at a previous hospital because of sudden onset of dyspnea, and transported to our institution with a diagnosis of cardiac tamponade. Multi-detector computed tomography (MDCT) showed massive pericardial effusion, coronary-pulmonary artery fistula and giant coronary artery aneurysm. We performed emergency operation. Under cardiopulmonary bypass, coronary artery fistula and aneurysm was resected. Postoperative MDCT showed almost complete exclusion of coronary artery fistula. Postoperative course was uneventful.

Collaborative metabolisms of urea and cyanate degradation in marine anammox bacterial culture.

Anammox process greatly contributes to nitrogen loss occurring in oceanic oxygen minimum zones (OMZs), where the availability of NH4+ is scarce as compared with NO2-. Remineralization of organic nitrogen compounds including urea and cyanate (OCN-) into NH4+ has been believed as an NH4+ source of the anammox process in oxygen minimum zones. However, urea- or OCN-- dependent anammox has not been well examined due to the lack of marine anammox bacterial culture. In the present study, urea and OCN- degradation in a marine anammox bacterial consortium were investigated based on 15N-tracer experiments and metagenomic analysis. Although a marine anammox bacterium, Candidatus Scalindua sp., itself was incapable of urea and OCN- degradation, urea was anoxically decomposed to NH4+ by the coexisting ureolytic bacteria (Rhizobiaceae, Nitrosomonadaceae, and/or Thalassopiraceae bacteria), whereas OCN- was abiotically degraded to NH4+. The produced NH4+ was subsequently utilized in the anammox process. The activity of the urea degradation increased under microaerobic condition (ca. 32-42 µM dissolved O2, DO), and the contribution of the anammox process to the total nitrogen loss also increased up to 33.3% at 32 µM DO. Urea-dependent anammox activities were further examined in a fluid thioglycolate media with a vertical gradient of O2 concentration, and the active collaborative metabolism of the urea degradation and anammox was detected at the lower oxycline (21 µM DO).

Surgical repair of an aortoesophageal fistula after salvage thoracic endovascular aortic repair: a case report.

BACKGROUND: An aortoesophageal fistula can prove to be fatal. Salvage thoracic endovascular aortic repair as a bridging therapy and radical surgery with thoracotomy should be considered while treating aortoesophageal fistula without spontaneous closure. Moreover, it is essential to select a technique that reduces the risk of reinfection. Here we report a rare case of a ruptured thoracic aortic aneurysm related to esophageal perforation by a fish bone that led to massive hematemesis and shock, and the surgical treatment of an aortoesophageal fistula that developed after salvage thoracic endovascular aortic repair. CASE PRESENTATION: A 70-year-old Japanese female patient was admitted with hematemesis, thoracic pain, and shock related to esophageal perforation of a ruptured descending aortic aneurysm caused by fish bone aspiration and esophageal perforation 1 month previously. An emergency thoracic endovascular aortic repair was performed. Postoperatively, an aortoesophageal fistula that remained open and a food intake-related increase in the inflammatory response was noted. Radical blood-vessel prosthesis implantation and fistula closure were performed. The patient's postoperative course was favorable and the patient was discharged 22 days after the blood vessel prosthesis implantation. CONCLUSION: Such a case of rupture of a descending aortic aneurysm related to perforation by a fish bone and an aortoesophageal fistula is considerably rare. Thus, we report the therapeutic strategy of this particular case and review the relevant literature.

Microbiological insights into anaerobic phenol degradation mechanisms and bulking phenomenon in a mesophilic upflow anaerobic sludge blanket reactor in long-term operation.

In this study, a long-term operation of 2,747 days was conducted to evaluate the performance of the upflow anaerobic sludge blanket (UASB) reactor and investigated the degradation mechanisms of high-organic loading phenol wastewater. During the reactor operation, the maximum chemical oxygen demand (COD) removal rate of 6.1 ± 0.6 kg/m3/day under 1,680 mg/L phenol concentration was achieved in the mesophilic UASB reactor. After a significant change in the operating temperature from 24.0 ± 4.1 °C to 35.9 ± 0.6 °C, frequent observations of floating and washout of the bloated granular sludge (novel types of the bulking phenomenon) were made in the UASB reactor, suggesting that the change in operating temperature could be a trigger for the bulking phenomenon. Through the metagenomic analysis, phenol degradation mechanisms were predicted that phenol was converted to 4-hydroxybenzoate via two possible routes by Syntrophorhabdaceae and Pelotomaculaceae bacteria. Furthermore, the degradation of 4-hydroxybenzoate to benzoyl-CoA was carried out by members of Syntrophorhabdaceae and Smithellaceae. In the bulking sludge, a predominant presence of Nanobdellota, belonging to DPANN archaea, was detected. The metagenome-assembled genome of the Nanobdellota lacks many biosynthetic pathways and has several genes for the symbiotic lifestyle such as trimeric autotransporter adhesin-related protein. Furthermore, the Nanobdellota have significant correlations with several methanogenic archaea that are predominantly present in the UASB reactor. Considering the results of this study, the predominant Nanobdellota may negatively affect the growth of the methanogens through the parasitic lifestyle and change the balance of microbial interactions in the granular sludge ecosystem.

Microscopic and metatranscriptomic analyses revealed unique cross-domain parasitism between phylum Candidatus Patescibacteria/candidate phyla radiation and methanogenic archaea in anaerobic ecosystems.

To verify whether members of the phylum Candidatus Patescibacteria parasitize archaea, we applied cultivation, microscopy, metatranscriptomic, and protein structure prediction analyses on the Patescibacteria-enriched cultures derived from a methanogenic bioreactor. Amendment of cultures with exogenous methanogenic archaea, acetate, amino acids, and nucleoside monophosphates increased the relative abundance of Ca. Patescibacteria. The predominant Ca. Patescibacteria were families Ca. Yanofskyibacteriaceae and Ca. Minisyncoccaceae, and the former showed positive linear relationships (r2 ≥ 0.70) Methanothrix in their relative abundances, suggesting related growth patterns. Methanothrix and Methanospirillum cells with attached Ca. Yanofskyibacteriaceae and Ca. Minisyncoccaceae, respectively, had significantly lower cellular activity than those of the methanogens without Ca. Patescibacteria, as extrapolated from fluorescence in situ hybridization-based fluorescence. We also observed that parasitized methanogens often had cell surface deformations. Some Methanothrix-like filamentous cells were dented where the submicron cells were attached. Ca. Yanofskyibacteriaceae and Ca. Minisyncoccaceae highly expressed extracellular enzymes, and based on structural predictions, some contained peptidoglycan-binding domains with potential involvement in host cell attachment. Collectively, we propose that the interactions of Ca. Yanofskyibacteriaceae and Ca. Minisyncoccaceae with methanogenic archaea are parasitisms.IMPORTANCECulture-independent DNA sequencing approaches have explored diverse yet-to-be-cultured microorganisms and have significantly expanded the tree of life in recent years. One major lineage of the domain Bacteria, Ca. Patescibacteria (also known as candidate phyla radiation), is widely distributed in natural and engineered ecosystems and has been thought to be dependent on host bacteria due to the lack of several biosynthetic pathways and small cell/genome size. Although bacteria-parasitizing or bacteria-preying Ca. Patescibacteria have been described, our recent studies revealed that some lineages can specifically interact with archaea. In this study, we provide strong evidence that the relationship is parasitic, shedding light on overlooked roles of Ca. Patescibacteria in anaerobic habitats.

Development of an internal two-stage upflow anaerobic reactor integrating biostimulation strategies to enhance the degradation of aromatic compounds in wastewater from purified terephthalic acid and dimethyl terephthalate manufacturing processes.

In this study, we aimed to establish high-rate biological treatment of purified terephthalic acid (PTA) and dimethyl terephthalate (DMT) wastewater that minimizes the inhibitory effects of high concentration benzoate and acetate. To achieve this, we developed a novel bioreactor system and biostimulation strategy. An internal two-stage upflow anaerobic (ITUA) reactor was operated with (i) a packed bed containing green tuff medium underlying (ii) a compartment seeded with anaerobic granular sludge. Ethylene glycol was amended to stimulate syntrophic interactions. Continuous operation of the system for 1,026 days achieve an organic removal rate of 11.0 ± 0.6 kg COD/m3/d. The abundance of aromatic degraders significantly increased during operation. Thus, we successfully developed a high-rate treatment system to treat wastewater from the PTA/DMT manufacturing processes by activating syntrophs in an ITUA reactor.