Direct production of 4-hydroxybenzoic acid from cellulose using cellulase-displaying Pichia pastoris.

4-hydroxybenzoic acid (4-HBA) is an industrially important aromatic compound, and there is an urgent need to establish a bioprocess to produce this compound in a sustainable and environmentally friendly manner from renewable feedstocks such as cellulosic biomass. Here, we developed a bioprocess to directly produce 4-HBA from cellulose using a recombinant Pichia pastoris strain that displays heterologous cellulolytic enzymes on its cell surface via the glycosylphosphatidylinositol (GPI)-anchoring system. ß-glucosidase (BGL) from Aspergillus aculeatus, endoglucanase (EG) from Trichoderma reesei, and cellobiohydrolase (CBH) from Talaromyces emersonii were co-displayed on the cell surface of P. pastoris using an appropriate GPI-anchoring domain for each enzyme. The cell-surface cellulase activity was further enhanced using P. pastoris SPI1 promoter- and secretion signal sequences. The resulting strains efficiently hydrolyzed phosphoric acid swollen cellulose (PASC) to glucose. Then, we expressed a highly 4-HBA-resistant chorismate pyruvate-lyase (UbiC) from Providencia rustigianii in the cellulase-displaying strain. This strain produced 975 mg/L of 4-HBA from PASC, which corresponding to 36.8% of the theoretical maximum yield, after 96 h of batch fermentation without the addition of commercial cellulase. This 4-HBA yield was over two times higher than that obtained from glucose (12.3% of the theoretical maximum yield). To our knowledge, this is the first report on the direct production of an aromatic compound from cellulose using cellulase-displaying yeast.

Eosinopenia as a diagnostic marker of bloodstream infection in a general internal medicine setting: a cohort study.

BACKGROUND: Little is known about the potential use of the eosinophil count as a predictive marker of bloodstream infection. In this study, we aimed to assess the reliability of eosinopenia as a predictive marker of bloodstream infection. METHODS: This retrospective cohort study was performed in the outpatient department and general internal medicine department of a tertiary university hospital in Japan. A total of 189 adult patients with at least 2 sets of blood cultures obtained during the period January 1-December 31, 2018, were included; those with the use of antibiotic therapy within 2 weeks prior to blood culture, steroid therapy, or a history of haematological cancer were excluded. The diagnostic accuracies of each univariate variable and the multivariable logistic regression models were assessed by calculating the areas under the receiver operating characteristic curves (AUROCs). The primary outcome was a positive blood culture indicating bloodstream infection. RESULTS: Severe eosinopenia (< 24.4 cells/mm3) alone yielded small but statistically significant overall predictive ability (AUROC: 0.648, 95% confidence interval (CI): 0.547-0.748, P < 0.05), and only moderate sensitivity (68, 95% CI: 46-85%) and specificity (62, 95% CI: 54-69%). The model comprising baseline variables (age, sex), the C-reactive protein level, and neutrophil count yielded an AUROC of 0.729, and further addition of eosinopenia yielded a slight improvement, with an AUROC of 0.758 (P < 0.05) and a statistically significant net reclassification improvement (NRI) (P = 0.003). However, the integrated discrimination index (IDI) (P = 0.284) remained non-significant. CONCLUSIONS: Severe eosinopenia can be considered an inexpensive marker of bloodstream infection, although of limited diagnostic accuracy, in a general internal medicine setting.

Bandemia as an Early Predictive Marker of Bacteremia: A Retrospective Cohort Study.

This single-center retrospective observational study aimed to verify whether a diagnosis of bandemia could be a predictive marker for bacteremia. We assessed 970 consecutive patients (median age 73 years; male 64.8%) who underwent two or more sets of blood cultures between April 2015 and March 2016 in both inpatient and outpatient settings. We assessed the value of bandemia (band count > 10%) and the percentage band count for predicting bacteremia using logistic regression models. Bandemia was detected in 151 cases (15.6%) and bacteremia was detected in 188 cases (19.4%). The incidence of bacteremia was significantly higher in cases with bandemia (52.3% vs. 13.3%; odds ratio (OR) = 7.15; 95% confidence interval (CI) 4.91-10.5). The sensitivity and specificity of bandemia for predicting bacteremia were 0.42 and 0.91, respectively. The bandemia was retained as an independent predictive factor for the multivariable logistic regression model (OR, 6.13; 95% CI, 4.02-9.40). Bandemia is useful for establishing the risk of bacteremia, regardless of the care setting (inpatient or outpatient), with a demonstrable relationship between increased risk and bacteremia. A bandemia-based electronic alert for blood-culture collection may contribute to the improved diagnosis of bacteremia.

Safety and efficacy of outpatient follow-up for referred patients with undiagnosed fever: A retrospective cohort study.

Fever is one of the most common symptoms seen in patients. The work-up and follow-up of fever in an outpatient-only setting is a reasonable option for stable patients referred for unexplained fever; however, the safety and efficacy of outpatient follow-up for those patients remain unclear. We conducted this study to evaluate the safety and efficacy of outpatient follow-up for referred patients with unexplained fever.This study was a retrospective cohort study. We included patients referred to the outpatient department of the diagnostic medicine of our university hospital for unexplained fever between October 2016 and September 2017. Exclusion criteria were recurrent fever or admission for fever evaluation prior to referral. Main outcomes of interest were the rate of admission without diagnosis, rate of remission of fever, and the total duration of fever in undiagnosed patients.Among 84 patients included in this study, 17 (20%) were diagnosed during outpatient follow-up, 6 (7%) were admitted due to worsened condition, 5 (6%) were lost to follow-up, and 56 (67%) were followed up as outpatients without a diagnosis. Among the 56 undiagnosed patients, fever resolved in 53 during outpatient follow-up with or without treatment (95%). The total duration of resolved fever in undiagnosed patients was within 8 weeks.Follow-up of patients referred for unexplained fever in an outpatient setting is safe and effective.