Peritonitis with bacteremia due to Christensenella hongkongensis identified via ribosomal RNA sequencing in a Japanese patient with advanced colorectal adenocarcinoma: A case report

Background: Christensenella hongkongensis is an obligately anaerobic, catalase-positive, motile, non-sporulating, gram-positive coccobacillus. Human infections are rare and have not been previously reported in Japan. Herein, we report the first case of perforated peritonitis with C. hongkongensis bacteremia in Japan. Case presentation: A 61-year-old Japanese man with advanced colorectal adenocarcinoma presented with fever and abdominal pain. Abdominal computed tomography revealed a low-density area with thinning of the sigmoid colon wall and air outside the intestinal tract, which was diagnosed as perforated peritonitis. Cultures of the ascitic fluid isolated Bacteroides fragilis, Bacteroides eggerthii, Parabacteroides distasonis, Enterococcus avium, and Candida albicans. Gram-positive rods were detected in the blood culture on admission after 4 days. The isolate was identified as C. hongkongensis via 16S ribosomal RNA (16S rRNA) sequencing. The patient underwent open abdominal washout and drainage via a transverse colon bifurcation colostomy. Intravenous meropenem (3 g/day) was administered for 5 days, followed by intravenous piperacillin-tazobactam (9 g/day) for 6 days, and then levofloxacin (500 mg/day) and metronidazole (1500 mg/day) intravenously for 15 days. Postoperatively, the patient gradually recovered. He was transferred to another palliative care hospital on day 38 after admission for worsening advanced colorectal cancer condition. Conclusion: Bacteremia caused by C. hongkongensis is rare. 16S rRNA sequencing should be considered for the identification of gram-positive anaerobic rods that are difficult to diagnose by conventional methods

Effects of pyrolysis temperature and feedstock type on particulate matter emission characteristics during biochar combustion

Aiming to reduce the emission of particulate matter (PM) during biomass combustion, we investigated the effects of pyrolysis temperature and feedstock type on the chemical properties of biochar and PM emission characteristics during subsequent combustion. Wood- and manure-based char samples were prepared at pyrolysis temperatures ranging from 200 to 500 °C and combusted in a laboratory-scale tube furnace at 850 °C. Due to the removal of volatile matter (VM), the total PM emission factor (EF) of the wood char decreased with increasing pyrolysis temperature, becoming negligible with pyrolysis at temperatures over 400 °C. For manure char, although pyrolysis removed VM and reduced the total PM EF from 12.5 ± 2.7 to 5.8 ± 2.9 mg/g-fuel, the high ash content precluded any effect on the emission of ash-derived PM. The occurrence of ash-derived PM resulted from release of Na, Mg, K, and Ca and was enhanced at higher combustion temperatures. We demonstrated that the pyrolysis of low-ash biomass effectively reduces the risk of PM emission. However, the efficacy of thermal treatment of high-ash biomass is limited but might be improved with further treatment, such as ash removal

Low cellular pyridoxal 5ʹ-phosphate levels decrease neurotransmitter and glutathione concentrations and increase susceptibility to hydrogen peroxide toxicity in SH-SY5Y cells

Summary: Objectives: Pyridoxal 5ʹ-phosphate (PLP) is an active and major form of vitamin B6 (VB6) in the body. PLP is essential as a cofactor for many enzymes involved in amino acid metabolism, and VB6 deficiency is associated with neurological disorders, such as epileptic-like symptoms, depression and confusion. However, the link between neuronal dysfunction and VB6 deficiency is unclear. In this study, we investigated how neuronal cells are affected by low cellular PLP levels using the neuroblastoma SH-SY5Y cell line. Methods: SH-SY5Y cells were cultured in pyridoxine-free medium supplemented with 10% fetal bovine serum and cell viability, intracellular PLP concentration, and metabolites were evaluated. Pyridoxine-free medium supplemented with 10% FBS contained 3 nM of PLP derived from FBS. Media containing various concentration of PLP were prepared using pyridoxine-free medium. Additionally, reactive oxygen species level and cell viability were assessed when cells were treated with 100 μM of hydrogen peroxide in media containing different concentrations of PLP. Results: SH-SY5Y cells had a decreased intracellular PLP level of 38 pmol/mg protein but proliferated when cells were cultured in the PLP-non-added medium. Metabolome analysis revealed the levels of neurotransmitters such as dopamine, norepinephrine, and 4-aminobutyric acid were decreased in cells cultured in the PLP-non-added medium compared with the PLP-added medium. The concentration of glutathione, an antioxidant, was also reduced. Furthermore, when cells were cultured in the PLP-non-added medium, hydrogen peroxide treatment reduced cell viability and increased intracellular reactive oxygen species levels in a concentration-dependent manner. These findings show that a growth environment low in VB6 decreases cellular glutathione and reduces resistance to oxidative stress. Conclusions: Overall, these findings show that low VB6 not only reduces neurotransmitter production, but also reduces glutathione levels, rendering cells more susceptible to oxidative stress and increasing the risk of neurodegenerative changes

Cholangitis with bacteremia due to Pseudomonas nitroreducens in a patient with pancreatic neuroendocrine tumors: a case report

Abstract Background Pseudomonas nitroreducens is a non-fermenting, gram-negative, rod-shaped bacterium commonly inhabiting soil, particularly soil contaminated with oil brine. To our knowledge, no cases of human infection with P. nitroreducens have been previously reported. Here, we present the first documented case of cholangitis caused by P. nitroreducens in a patient with bacteremia. Case presentation A 46-year-old Japanese man with an advanced pancreatic neuroendocrine tumor was hospitalized with fever and chills. Four days before admission, the patient developed right upper abdominal pain. Two days later, he also experienced fever and chills. Endoscopic retrograde cholangiopancreatography was performed on the day of admission, and the patient was diagnosed as having cholangitis associated with stent dysfunction. Gram-negative rods were isolated from blood cultures, but attempts to identify the bacteria using VITEK2 and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with VITEK MS ver. 4.7.1 (bioMérieux Japan Co. Ltd., Tokyo, Japan) were unsuccessful. Finally, the organism was identified as P. nitroreducens using MALDI-TOF MS with a MALDI Biotyper (Bruker Daltonics Co., Ltd., Billerica, MA, USA) and 16 S ribosomal RNA sequencing. Despite thorough interviews with the patient, he denied any exposure to contaminated soil. The patient was treated with intravenous cefepime and oral ciprofloxacin for 16 days based on susceptibility results, achieving a good therapeutic outcome. At the outpatient follow-up on day 28, the patient was in good general condition. Conclusions This is the first reported human case of cholangitis with bloodstream infection caused by P. nitroreducens. This report provides clinicians with novel insights into the clinical manifestations and diagnostic methods necessary for the accurate diagnosis of P. nitroreducens, along with guidance on treatment

Design for All – Design for Disabled: How important is anthropometry?

Background: Design for All or Universal Design is a relatively new domain in Ergonomics. With globally ageing populations, it has however recently gained significant interest. Objective: This position paper summarizes the outcomes of a workshop held at the virtual 21st Triennial Congress of the International Ergonomics Association. The paper expands the horizon of traditional Ergonomics into a domain where people are differently abled and establishes a platform for the essential needs of future ergonomic standards which are required to inform inclusive design guidelines, or Design for All, extending the range of users. Methods: The paper includes contributions from Asian, Australian, European and US workshop participants who are accessibility design experts in their respective geographic regions. The paper summarizes issues related to anthropometry in the Design for All, based on recent work in the US (Access board) and actual developments in various national and international accessibility standardization bodies, such as the Standards Australia/Standards New Zealand, the European Standardization Organization (EN 17210:2021; EN 17161:2019) and the International Organization for Standardization (ISO 21542:2021 and BS ISO 7176-5:2008). Conclusions: The paper concludes that despite the identification of a significant gap in knowledge of the anthropometry of people with disabilities as far back as 1990, work towards bridging the gap and enabling ergonomic standardization has not progressed since then globally. The lack of standardization in anthropometric data on people with a physical disability continues to complicate provision of data for mobility and accessibility design and hampers accessibility standardization efforts

Femoral osteomyelitis caused by oral anaerobic bacteria with mixed bacteremia of Campylobacter rectus and Parvimonas micra in a chronic periodontitis patient: a case report

Abstract Background Campylobacter rectus is a gram-negative rod, and Parvimonas micra is a gram-positive coccus, both of which are oral anaerobes that cause chronic periodontitis. Chronic periodontitis can cause bacteremia and systemic diseases, including osteomyelitis. Hematogenous osteomyelitis caused by anaerobic bacteria is uncommon, and to date, there have been no reports of mixed bacteremia with C. rectus and P. micra. Here, we report the first case of osteomyelitis of the femur caused by anaerobic bacteria with mixed bacteremia of C. rectus and P. micra caused by chronic periodontitis. Case presentation A 75-year-old man with chronic periodontitis, hyperuricemia, and benign prostatic hyperplasia was admitted to the hospital with a fracture of the left femur. The patient had left thigh pain for 4 weeks prior to admission. Left femoral intramedullary nail fixation was performed, and a large amount of abscess and necrotic tissue was found intraoperatively. The cultures of abscess specimens were identified as P. micra, Fusobacterium nucleatum, and C. rectus. C. rectus and P. micra were also isolated from blood cultures. C. rectus was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16 S ribosomal RNA sequencing. Sulbactam-ampicillin was administered for approximately 1 month, after which it was replaced by oral clavulanic acid-amoxicillin for long-term suppressive treatment. Conclusions Only five cases of bloodstream infection with C. rectus have been reported, and this is the first report of mixed bacteremia with P. micra. Clinicians should consider that chronic periodontitis caused by rare oral anaerobic bacteria can cause systemic infections, such as osteomyelitis