bluuebunny/crossref_metadata_2025 huggingface dataset:
Ventilation Liberation Practices Among 380 International PICUs
Authors: Loberger Jeremy M. , Campbell Caitlin M. , Colleti José , Borasino Santiago , Abu-Sultaneh Samer , Khemani Robinder G. ,   on behalf of the Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network.
Published: May 2022

OBJECTIVES:

1) Characterize the prevalence of ventilator liberation protocol use in international PICUs, 2) identify the most commonly used protocol elements, and 3) estimate an international extubation failure rate and use of postextubation noninvasive respiratory support modes.

DESIGN:

International cross-sectional study.

SUBJECTS:

Nontrainee pediatric medical and cardiac critical care physicians.

SETTING:

Electronic survey.

INTERVENTION:

None.

MEASUREMENTS AND MAIN RESULTS:

Responses represented 380 unique PICUs from 47 different countries. Protocols for Spontaneous Breathing Trial (SBT) practice (50%) and endotracheal tube cuff management (55.8%) were the only protocols used by greater than or equal to 50% of PICUs. Among PICUs screening for SBT eligibility, physicians were most commonly screened (62.7%) with daily frequency (64.2%). Among those with an SBT practice protocol, SBTs were most commonly performed by respiratory therapists/physiotherapists (49.2%) and least commonly by nurses (4.9%). Postextubation respiratory support protocols were not prevalent (28.7%). International practice variation was significant for most practices surveyed. The estimated median international extubation failure was 5% (interquartile range, 2.3–10%). A majority of respondents self-reported use of planned high-flow nasal cannula in less than or equal to 50% (84.2%) and planned noninvasive ventilation in less than or equal to 20% of extubations (81.6%).

CONCLUSIONS:

Variability in international pediatric ventilation liberation practice is high, and prevalence of protocol implementation is generally low. There is a need to better understand elements that drive clinical outcomes and opportunity to work on standardizing pediatric ventilation liberation practices worldwide.
An Unmet Need: Surgical Gloves with Variable Finger Lengths
Authors: Rudolph Ross , Chopra Christina , Van Etten Susan , Glaser Dale
Published: May 2022

Background:

Sterile gloves are essential for plastic surgery, but little research has been published on glove fit. Sterile gloves are produced by all manufacturers, with finger lengths fixed for all sizes. Many wearers have fingers that are shorter or longer than usual, causing functional limitations due to incorrect glove finger length and fingertip fit.

Methods:

A multiquestion confidential electronic survey of glove finger length fit was sent to 6810 plastic surgery glove wearers from three organizations: American Society of Plastic Surgeons, International Society of Plastic and Aesthetic Nurses, and Association of Plastic Surgery Physician Assistants. Data were collected for this descriptive study in 2020–2021, and statistical analyses were performed using SPSS (version 27). Sample gloves from six brands were directly measured for finger length.

Results:

The survey yielded 500 responses, with some respondents not answering all questions. The response rate from American Society of Plastic Surgeons members was 8.2%, and was 7.3% from all groups combined. The most common reason for glove finger length dissatisfaction was fingers being too long (41.61%). Although there was variation in measured glove finger lengths, the variation was not uniform. Of all responders, 28.6% were very likely, and 16.16%, moderately likely, to want to use gloves with longer or shorter fingers if available, constituting a total of 44. 76%. Of these, 36.55% would pay increased cost (10%–25%) for such gloves.

Conclusions:

A high percentage of glove users would want gloves with variable finger lengths. Current surgical gloves do not support hand anatomy variations.
Factors Contributing to Physical Therapists’ Job and Career Satisfaction in the United States: Results From a National Survey
Authors: Briggs Matthew S. , Weber Mark D. , Olson-Kellogg Becky J. , DeWitt John J. , Hensley Craig P. , Harrington Kendra L. , Kidder Melissa S. , Farrell Joseph P. , Tichenor Carol Jo
Published: May 2022

Introduction.

Mentoring and professional development opportunities influence job and career satisfaction.

Review of the Literature.

Job and career satisfaction are multifactorial. The purpose of this study was to compare job and career satisfaction between physical therapists (PTs) who were residency trained and PTs who were neither residency nor fellowship trained and between PTs who were fellowship trained and PTs who were neither residency nor fellowship trained.

Subjects.

Licensed PTs in the United States.

Methods.

An online survey was distributed asking questions regarding job satisfaction and career satisfaction. Respondents were categorized as completing a residency, fellowship, both, or neither. Responses were respectively summed, then compared between groups: residency versus nonresidency/nonfellowship and fellowship versus nonresidency/nonfellowship. Frequency analyses and Mann–Whitney U tests were performed.

Results.

A total of 3,080 survey responses were analyzed. Residency-trained PTs had an overall higher job satisfaction score (P = .03) and higher career satisfaction score (P = .05) when compared with non–residency-trained or non–fellowship-trained PTs. Fellowship-trained PTs reported higher job satisfaction (P < .001) and career satisfaction (P = .001) compared with non–residency-trained or non–fellowship-trained PTs. Residency-trained PTs rated the importance of their work being interesting and learning/improving in their work of greater importance to their job satisfaction compared with non–residency-trained or non–fellowship-trained PTs (P < .05). Whereas, fellowship-trained PTs rated factors such as their jobs being positively challenging, fulfilling, and interesting, having sufficient independence, and were learning/improving in their work of greater importance than non–residency-trained and non–fellowship-trained PTs (P ≤ .004).

Discussion and Conclusion.

Results from the study support previous evidence that PTs overall have high job/career satisfaction and residency/fellowship training may further enhance job and career satisfaction. Findings provide valuable insight and are relevant to all PTs as well as stakeholders involved in professional and postprofessional physical therapy education and those making hiring decisions and potential employment opportunities.
The current management and biomarkers of immunotherapy in advanced gastric cancer
Authors: Chang Xiaojing , Ge Xiaohui , Zhang Yufeng , Xue Xiaoying
Published: May 2022

Background:

Gastric carcinoma (GC) is the fourth most common cause of cancer-related death worldwide. Most patients are diagnosed at later stage, because of few treatment options, the prognosis is poor. In recent years, however, Immune checkpoint inhibitors(ICIs), such as anti- programmed death-1 (PD-1), anti-PD-L1, and anti-cytotoxic T lymphocyte antigen 4, have emerged as promising therapeutic agents in GC. Here, we summary the current treatment and advances of immune checkpoint inhibitors in the advanced stage of GC.

Methods:

WANFANG MED ONLINE, CNKI, NCBI PUBMED and clinicaltrials.gov were used to search literature spanning from 2000 to 2021, and all literatures about “advanced gastric or gastro-oesophageal junction cancer, Immune checkpoint inhibitors, PD-1, PD-L1, Cytotoxic T lymphocyte antigen 4, immune therapy” with detailed data were included.

Results:

Nivolumab and pembrolizumab have been recommended for the third line or subsequent therapy in advanced GC. Nivolumab plus chemotherapy has been recommended for the first line treatment in advanced GC in China. Many other ICIs have been demonstrating encouraging efficacy. PD-L1, MSI-H, Epstein Barr virus, and tumor mutational burden (TMB) status maybe potential biomarkers for response to clinical outcomes for ICIs in GC.

Conclusion:

ICIs have shown encouraging treatment efficacy and manageable safety profile in GC. Some biomarkers including PD-L1, MSI-H, EBV, and TMB status could evaluate the efficacy of ICIs in GC.
Comparison of outcomes in emergency department revisiting patients before and after coronavirus disease 2019 epidemic
Authors: Chen Chung-Ting , Wang Tse-Yao , Shih Chia-Hui , Yen David Hung-Tsang , Tung Yu-Chi
Published: May 2022

Background and importance

The outbreak of COVID-19 challenged the global health system and specifically impacted the emergency departments (EDs). Studying the quality indicators of ED care under COVID-19 has been a necessary task, and ED revisits have been used as an indicator to monitor ED performance.

Objectives

The study investigated whether discrepancies existed among ED revisiting cases before and after COVID-19 and whether the COVID-19 epidemic was a predictor of poor outcomes of ED revisits.

Design

Retrospective study.

Settings and participants

We used electronic health records data from a tertiary medical center. Data of patients with 72-h ED revisit after the COVID-19 epidemic were collected from February 2020 to June 2020 and compared with those of patients before COVID-19, from February 2019 to June 2019.

Outcome measures and analysis

The investigated outcomes included hospital admission, ICU admission, out-of-hospital cardiac arrest, and subsequent inhospital mortality. Univariate and multivariate logistic regression models were used to identify independent predictors of 72-h ED revisit outcomes.

Main results

In total, 1786 patients were enrolled in our study – 765 in the COVID group and 1021 in the non-COVID group. Compared with the non-COVID group, patients in the COVID group were younger (53.9 vs. 56.1 years old; P = 0.002) and more often female (66.1% vs. 47.3%; P < 0.001) and had less escalation of triage level (11.6% vs. 15.0%; P = 0.041). The hospital admission and inhospital mortality rates in the COVID and non-COVID groups were 33.9% vs. 32.0% and 2.7% vs. 1.5%, respectively. In the logistic regression model, the COVID-19 period was significantly associated with inhospital mortality (adjusted odds ratio, 2.289; 95% confidence interval, 1.059–4.948; P = 0.035).

Conclusion

Patients with 72-h ED revisits showed distinct demographic and clinical patterns before and after the COVID-19 epidemic; the COVID-19 period was an independent predictor of increased inhospital mortality.
Utilization of Pediatric Psychology Services in Outpatient Pediatric Gastroenterology Within a Rural Health System
Authors: Winnick Joel B. , Focht Dean R. , Sukumar Kritika , Kuhn Benjamin R. , Muldowney Ryan , O’Dell Sean M.
Published: May 2022

Increased utilization of pediatric psychology services has been demonstrated following integration into urban pediatric gastroenterology clinics; however, examination within rural health systems is lacking. Utilization of pediatric psychology services was assessed through a retrospective analysis of Electronic Health Record data contrasting referrals occurring six months pre- and post-integration of pediatric psychology in an outpatient pediatric gastroenterology clinic within a rural setting. Significant increases in the number of referrals to pediatric psychology and number of billed initial visits were observed after integration, as was a significant decrease in time to be seen. Patients with public insurance were 3.1 times more likely to complete a billed initial visit compared with patients with nonpublic insurance. The current findings support the integration of pediatric psychology within rural outpatient pediatric gastroenterology clinics to increase utilization and allow more traditionally underserved families to benefit from these services.
Effect of BCG HSP70 Gene Transfection on Dendritic Cells Derived From Bone Marrow in Children With Acute Leukemia
Authors: Wang Junlin , Li Xiaoling , Liu Chunlei , Wang Shuli , Li Jianqin
Published: May 2022

Objectives:

In this study, immature dendritic cells (imDCs) were transfected with the Bacillé Calmette-Guérin (BCG) heat shock protein 70 (HSP70) gene to investigate the impact on the maturity and function of imDCs from the bone marrow of pediatric patients with acute leukemia.

Materials and Methods:

Bone marrow mononuclear cells were isolated from pediatric patients with acute lymphoblastic leukemia who had achieved complete remission at least 6 months prior. The recombinant vector pDisplay-HSP70 was transfected into imDCs. The test groups included 5 subgroups: imDCs (imDCs without special processing), imDC-neos (imDCs transfected with the pDisplay vector), HSP70 (imDCs transfected with the pDisplay-HSP70 vector), tumor necrosis factor α (TNF-α) (imDCs induced with rhTNF-α), and HSP70+TNF-α. Mature dendritic cells (mDCs) from different groups (HSP70, TNF-α, and HSP70+TNF-α) and T cells were cultured. An equal number of lymphocytes and mDCs were used as controls. The proliferation indices of T cells and the cytokine contents (interleukin-12 and interferon-γ) were determined.

Results:

The HSP70 group and the TNF-α group expressed higher levels of HLA-DR, CD80, and CD86 but lower levels than the HSP70+TNF-α group; there was no significant difference between the HSP70 group and the TNF-α group. The combination of HSP70 and TNF-α induced the highest levels of interleukin-12 and interferon-γ.

Conclusions:

The outcomes of this study indicated that gene transfection with BCG HSP70 evidently promoted imDC maturity and the antitumor effects of mDC-mediated T cells. It could serve as a candidate gene-modified cell vaccine for tumor immunotherapy.
Nasal-Type NK/T-Cell Lymphoma Involvement of the Vocal Cord on FDG PET/CT
Authors: Huang Mingxing , Wang Rang , Shen Guohua , Tian Rong
Published: May 2022

Nasal-type extranodal natural killer/T-cell lymphoma (ENKTL) rarely involves the vocal cord. Herein, we present a case of an ENKTL patient with vocal cord involvement revealed by FDG PET/CT. Nasopharyngoscopy showed a neoplasm in the larynx, which was eventually confirmed as ENKTL by immunohistochemical results. PET/CT was subsequently performed for staging, and intense FDG uptake in the left side of vocal cord suggested ENKTL involvement.
68Ga-FAPI-04 PET/CT in Epithelioid Hemangioendothelioma With Pleura and Bone Metastases
Authors: Chen Jie , Li Chongjiao , Tian Yueli , Wen Bing , He Yong
Published: May 2022

Epithelioid hemangioendothelioma is a low- to intermediate-grade malignant vascular tumor with a slowly progressive course and unpredictable prognosis. We report a case of epithelioid hemangioendothelioma with pleura and bone metastases on 68Ga-FAPI-04 PET/CT in a 65-year-old woman who underwent surgery and chemotherapy.
Reverse Liver Spleen Uptake on [68Ga]Ga-PSMA-11 PET/CT
Authors: Abubakar Sofiullah , Al Riyami Khulood , Jain Anjali , Jayakrishnan Vipin , Tag Naima
Published: May 2022

An 80-year-old man underwent [68Ga]Ga-PSMA-11 PET/CT for staging of high-risk prostate cancer. Homogeneously increased liver uptake, more than 3-fold the splenic uptake, was seen. There was no hepatic lesion evident on CT. A higher liver to splenic uptake is more typical of some 18F-labeled PSMA PET/CT but unusual in 68Ga-labeled PSMA PET/CT scan. Further evaluation revealed a history of impaired renal function, bilateral renal atrophy, relatively decreased renal uptake of [68Ga]Ga-PSMA-11, and prominent bowel activity. We concluded that impaired renal function and subsequent poor excretion resulted in increased hepatic excretion, hence the unusual increased homogeneous hepatic uptake.
Video Review of Simulated Pediatric Cardiac Arrest to Identify Errors/Latent Safety Threats: A Mixed Methods Study
Authors: Garcia-Jorda Dailys , Nikitovic Dejana , Gilfoyle Elaine
Published: May 2022

Introduction

Outcomes from pediatric in-hospital cardiac arrest depend on the treatment provided as well as resuscitation team performance. Our study aimed to identify errors occurring in this clinical context and develop an analytical framework to classify them. This analytical framework provided a better understanding of team performance, leading to improved patient outcomes.

Methods

We analyzed 25 video recordings of pediatric cardiac arrest simulations from the pediatric intensive care unit at the Alberta Children's Hospital. We conducted a qualitative-dominant crossover mixed method analysis to produce a broad understanding of the etiology of errors. Using qualitative framework analysis, we identified and qualitatively described errors and transformed the data coded into quantitative data to determine the frequency of errors.

Results

We identified 546 errors/error-related actions and behaviors and 25 near misses. The errors were coded into 21 codes that were organized into 5 main themes. Clinical task–related errors accounted for most errors (41.9%), followed by planning, and executing task-related errors (22.3%), distraction-related errors (18.7%), communication-related errors (10.1%), and knowledge/training-related errors (7%).

Conclusions

This novel analytical framework can robustly identify, classify, and describe the root causes of errors within this complex clinical context. Future validation of this classification of errors and error-related actions and behaviors on larger samples of resuscitations from various contexts will allow for a better understanding of how errors can be mitigated to improve patient outcomes.
Normothermic Ex Situ Heart Perfusion With the Organ Care System for Cardiac Transplantation: A Meta-analysis
Authors: Langmuur Sanne J.J. , Amesz Jorik H. , Veen Kevin M. , Bogers Ad J.J.C. , Manintveld Olivier C. , Taverne Yannick J.H.J.
Published: May 2022

Background.

Heart transplantation (HTx) is, at present, the most effective therapy for end-stage heart failure patients; however, the number of patients on the waiting list is rising globally, further increasing the gap between demand and supply of donors for HTx. First studies using the Organ Care System (OCS) for normothermic machine perfusion show promising results yet are limited in sample size. This article presents a meta-analysis of heart donation either after brain death (OCS-DBD) or circulatory death (OCS-DCD) on using OCS versus static cold storage used for HTx.

Methods.

A systematic literature search was performed for articles discussing the use of normothermic ex situ heart perfusion in adult patients. Thirty-day survival outcomes were pooled, and odds ratios were calculated using random-effects models. Long-term survival was visualized with Kaplan-Meier curves, hazard ratios were calculated and pooled using fixed-effects models, and secondary outcomes were analyzed.

Results.

A total of 12 studies were included, with 741 patients undergoing HTx, of which 260 with the OCS (173 DBD and 87 DCD). No differences were found between the 3 groups for early and late survival outcomes or for secondary outcomes.

Conclusions.

OCS outcomes, for both DBD and DCD hearts, appeared similar as for static cold storage. Therefore, OCS is a safe and effective technique to enlarge the cardiac donor pool in both DBD and DCD, with additional benefits for long-distance transport and surgically complex procedures.
Effects of ginsenoside Rg1 on proliferation and directed differentiation of human umbilical cord mesenchymal stem cells into neural stem cells
Authors: Xiao Li , Wang Maoyuan , Zou Kang , Li Zuoyong , Luo Jun
Published: May 2022

Objective

Human umbilical cord mesenchymal stem cells (hUCMSCs) can be transformed into neural stem cells (NSCs) and still maintain immunomodulatory and antioxidant effects. Transplantation of NSCs induced by hUCMSCs would be a promising therapeutic strategy for the treatment of neurological diseases. Ginsenoside Rg1 has neuroprotective effects and influences cell proliferation and differentiation. In this study, we further evaluated the effects of ginsenoside Rg1 on the proliferation and directional differentiation of hUCMSCs into NSCs.

Methods

The CCK-8 assay was used to determine the optimal dose of ginsenoside Rg1 with respect to hUCMSC proliferation and differentiation. NSCs were authenticated using immunofluorescence staining and flow cytometry and were quantified in each group. RT-PCR was used to screen the signaling pathway by which ginsenoside Rg1 promoted the differentiation of hUCMSCs into NSCs.

Results

The optimal dose of Rg1 to promote hUCMSC proliferation and differentiation to NSCs was 10 μmol/l. Flow cytometry and immunofluorescence showed that induced NSCs expressed nestin and sex-determining region Y-box 2, with higher expression levels in the Rg1 group than that in the negative control group. RT-PCR showed that Rg1 downregulates the expression of genes involved in Wnt/β-catenin and Notch signaling pathways in the induction process.

Conclusion

Ginsenoside Rg1 not only promotes the proliferation and viability of hUCMSCs in the process of differentiation into NSCs but also improves the differentiation efficiency. This study provides a basis for the development of hUCMSC-derived NSCs for the treatment of nervous system diseases and for analyses of underlying biological mechanisms.
Microstructural white matter changes in chronic migraine patients with liver-yang hyperactivity and qi-blood deficiency syndrome: a diffusion tensor imaging study
Authors: Shi Min , Yang Jie , Yang Dongdong , Yang Xuhong , Zhao Huan
Published: May 2022

White matter alterations in patients with chronic migraine (CM) have been reported. Traditional Chinese medicine (TCM) syndromes are clinical syndromes proposed by TCM doctors based on long-term clinical observation and classification of the clinical symptoms and signs of CM patients. This study aimed to analyze the whole-brain diffusion tensor imaging (DTI) data of CM patients with different types of TCM syndromes. Sixteen CM patients diagnosed with liver-yang hyperactivity (LH) syndrome and 16 CM patients with qi-blood deficiency (QD) syndrome were recruited in this study. Thirty-one healthy controls (HCs) were also enrolled. All subjects underwent DTI and T1-weighted MRI acquisition. Thirty HCs and 30 CM patients (LH group: n = 15; QD group: n = 15) were included in the final analysis. No significant difference was observed in the DTI indexes between CM patients and HCs, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). The mean FAs of the left tapetum and the mean MD values for the right medial lemniscus and the right inferior cerebellar peduncle were significantly different in the LH and HC groups. The mean AD values for the right cingulate gyrus and the left uncinate fasciculus, as well as the mean RD for the right inferior cerebellar peduncle and the left tapetum, were also significantly different between these two groups. CM patients with LH and QD syndrome showed altered FA and diffusivity in comparison to healthy controls, suggesting that there may be significant white matter microstructural alterations in these patients.
The dissociating of reward feedback on familiarity and recollection processing: evidence from event-related potential
Authors: Liu Fangfang , Jiang Yingjie , Li Songliang
Published: May 2022

Objectives

Although previous studies have explored the effect of reward feedback on recognition memory, electrophysiological evidence for reward-enhanced memory and its underlying processing mechanisms remains unclear.

Methods

This study adopts reward-learning and recognition memory tasks. Participants were asked to learn the reward values of two-color images (each color image had either reward or nonreward feedback) in the reward-learning task, and then tested their recognition memory performance with reward and nonreward feedback items.

Results

Results demonstrated that the recognition memory performance of rewarded items was better than that of nonrewarded items. During the reward-learning period, nonreward feedback elicited larger feedback-related negativity (FRN) and P300 amplitudes compared with reward feedback. The findings indicated that participants mainly engaged in prediction error processing in the early stage, followed by comparing and context update of the learned items. During the recognition memory period, reward items elicited larger FN400 amplitude and smaller LPC amplitude compared with nonreward items. This suggests that reward item retrieval has deeper memory traces and can identify items faster, relying mainly on familiarity processing. Conversely, nonreward, as a general or inhibitory item, requires more detail and cognitive resources, that is, relies on recollection processing.

Conclusions

These findings indicated that participants had different process patterns between reward and nonreward items during recognition retrieval.
A comparison of SARS-CoV-2 RNA extraction with the QuickGene-810 Nucleic Acid Isolation System compared to the EZ1 Advanced DSP Virus Kit
Authors: Phan Thuy , Stephenson Rebecca , Cai Tina , Andacic Nikol , McKew Genevieve
Published: May 2022

The QuickGene-810 Nucleic Acid Isolation System is a semi-automated extraction platform which may be used for RNA extraction. New methods were required to support the rapid increase in respiratory virus testing during the SARS-CoV-2 pandemic. The aim of this study was to assess SARS-CoV-2 RNA extraction using the QuickGene-810 kit compared to the EZ1 Advanced Extraction Platform for use on the AusDiagnostics SARS-CoV-2, Influenza and RSV 8-well RT-PCR assay. Qualitative results from all clinical samples were concordant between the QuickGene-810 and the EZ1 extraction methods, demonstrating that the QuickGene-810 kit is suitable for use in pathogen diagnostics. However, there was an average difference of approximately two cycles between the cycle threshold (Ct) values for both SARS-CoV-2 targets, suggesting that the EZ1 kit yields a higher concentration of nucleic acid extract, possibly related to its use of carrier RNA and/or smaller elution volume, which infers the possibility of false negative results for samples with very low viral loads.
The role of staphylococcal bacteriocins in nasal competition
Authors: Thomas Joshua , Ghoul Melanie , Wilson Daniel , Griffin Ashleigh
Published: May 2022

Bacteriocins are antimicrobial toxins produced by bacteria to defend and invade territories by killing unrelated strains and species. Understanding if bacteriocins shape natural populations is important for understanding the evolution of antimicrobial resistance and identifying novel antimicrobials for clinical use. Staphylococcus aureus is an opportunistic pathogen that asymptomatically colonises the nasal cavity of 1 in 3 healthy adults. S. aureus is known to produce many different bacteriocins, however we are yet to understand the extent to which they mediate the establishment of nasal populations. Here, we test the importance of bacteriocins in driving colonisation success, by screening S. aureus antimicrobial inhibition against otherS. aureus strains and three commensal species that commonly co-inhabit the nasal cavity. We use a longitudinally sampled collection of 173S. aureusnasal isolates from 14 participants over 90-months to track within-individual population changes over time. We found that 8% of allS. aureus isolates produced bacteriocins active against other species, but that between-strain bacteriocin inhibition inS. aureus was very rare, observed by only 0.5% of isolates. Therefore, while there is no evidence that intraspecific competition drives colonisation success in the nasal cavity, interspecific competition is more likely to influence strain and species dominance.
Searching for new microbial enzymes for plastic polymer degradation: Polyurethanes and Lycra
Authors: Linke Julia , Ward John
Published: May 2022

New enzymes and biocatalysis could provide routes to help limit global plastic pollution, as suggested by the example of PETases for the PET degradation. Experiments were conducted to screen soil microorganisms for enzymes able to break down the plastic polymer Lycra, which contains polyurethane linkages and could be utilized as a carbon and nitrogen source.

The methodology is based on a plate assay, which compared the growth of bacteria at 50°C and 65°C on minimal media and minimal media with a top layer, that contained DMF-dissolved Lycra. The medium provided the main nutrients required for bacterial growth, with Lycra being the only substantial carbon source. Promising candidates were identified as bacterial colonies with visibly enhanced growth on the Lycra-enriched minimal medium plate. The selected soil microorganisms were then tested with a liquid culture assay, where the strain was cultivated at 50°C or 65°C in liquid broth medium, that contained dissolved Lycra. The liquid culture samples were collected at 4 time points between 0-48h, and the aliquots tested on HPLC for detection of released Lycra monomers.

Around 50 different bacterial strains from 6 various soil and compost sources were tested with the described plate screening method and 7 bacterial thermophilic species were detected, that showed visibly enhanced growth on the Lycra-enriched plates. These results could support the development of Lycra enzymatic degradation. New enzymes could be engineered, optimized and yield a sustainable solution for the textile industry, which would not require toxic chemicals or contribute to landfill.
Dissecting meningococcal disease and carriage traits using high throughput phenotypic testing
Authors: Farzand Robeena , Mourkas Evangelos , Ste Croix Megan De , Dave Neelam , Jama Abdullahi , Oldfield Neil , Lucidarme Jay , Turner David , Borrow Ray , Martinez-Pomares Luisa , Sheppard Samuel , Bayliss Christopher
Published: May 2022

Despite on-going vaccination programmes, Neisseria meningitidisis a majorcause of septicaemia and meningitis. In 2017-18, the MenW and MenY capsular groups caused 38% of all UK invasive meningococcal disease cases. Current policy is to generate genome sequences of all meningococcal disease isolates. Using this resource, we aim to determine how genetic variation contributes to phenotypic differences between carriage and disease isolates. We have adapted assays, mimicking carriage and disease behaviours, for high-throughput phenotypic testing of 335 MenW cc11 and MenY cc23 isolates. We are currently testing MenW cc11 disease and carriage isolates for cytotoxicity in a human lung epithelial cell line, growth in media and biofilm formation. Phenotypic differences are utilised as inputs for Genome Wide Association Studies enabling linkage of specific genomic variants, or variant combinations, with phenotypic variation. Genomic data include whole genome sequences and repeat-mediated phase variation states.

The MenW cc11 isolates span two known phylogenetic clusters, original and 2013. Our preliminary data from high-throughput growth and biofilm assays showed no significant differences between these groups or sources (disease versus carriage); however, variations were observed within groups with, for example, distinctive cytotoxicity or biofilm differences between isolates. These variations may reflect physiological divergence due to minor genetic modifications between highly phylogenetically-related strains. Our assay systems are robust, reproducible, and easily scalable for efficient high-throughput genotypic and phenotypic testing. Thus, large-scale screening of phenotypic variation for infectious diseases is achievable and harnessable for cost-effective, direct evolutionary and epidemiological studies.
Making virus taxonomy accessible
Authors: Smith Donald , Orton Richard , Zerbini Murilo , Lefkowitz Elliot , Sabanadzovic Sead , Simmonds Peter , Siddell Stuart
Published: May 2022

The International Committee on Taxonomy of Viruses (ICTV) is responsible for approving changes to the taxonomy of viruses. These changes arise from proposals made to the ICTV, usually by one of its 101 Study Groups, each of which is responsible for a particular virus family or families. The result of this international, voluntary effort is a searchable and structured list of current virus taxonomy that can be accessed on the ICTV website (www.ictv.global). The website also makes available the virus metadata resource (VMR), a spreadsheet with exemplar isolates and GenBank accession numbers for members of each species, as well as the ICTV Report which provides more detail about the taxonomy, structure and biology of each virus family. The online publication mode allows taxonomic changes and relevant research findings to be quickly reflected in the Report, and also means that the sequence alignments and phylogenetic trees, upon which taxonomic decisions often depend, are available as resources for all to use. A two-page summary of each Report chapter is published as an Open Access article by the Journal of General Virology as a Virus Taxonomy Profile. It remains a challenge to make these freely available resources comprehensive because of the pace of taxonomic change; over the last decade the number of virus families has almost doubled from 87 to 168. In meeting this challenge the ICTV will continue to rely on the enthusiasm, expertise and efforts of virologists from around the world.
Antimicrobial potentials of Lantana camara montevidensis leaf extract on wounds infected with Candida isolates using animal models
Authors: Ogba Ofonime , Edim Sunday
Published: May 2022

Background

There is an increased focus in the development of antimicrobials of herbs origin because they possess active chemotherapeutic effect on different kinds of infectious diseases. Many communities in Nigeria and other African countries use plants to treat various infections, including wounds. New antimicrobial agents are being developed in response to the emergence of resistance to existing antibiotics and antifungal agents. Lantana camara leaves are easily accessible at low or no cost in resource poor communities. The aim of this study was to determine the antimicrobial activity of Lantana camaraleaf extract against selected Candida isolates from infected wounds invitro and in vivo using animal models.

Methods

Aqueous and methanol leaf extraction was done using Soxhlet apparatus. TenCandidaisolates associated with wound infectionswere re-identified and used for the study. Antifungal susceptibility testing was done using the E-Test strips. Fifteen healthy male Wistar rats were used for the study. The rats were anesthetized before making incision wounds on the neck region. The rats were treated with 100mg/ml, 50mg/ml and 25mg/ml concentration of extract topically. The skin tissues of the sacrificed rats were obtained for histological examination using Heamatoxylin and eosin technique.

Results

The susceptibility rate of the Candida isolates ranged from (0.0% - 40.0%). Fluconazole was the most effective antifungal. Isolates were most susceptible(40.0%)to 100mg/ml concentration of extract. Rats treated with 100mg/ml methanol extract had significant mean wound contractions of 70.33±0.58 withdamaged tissue repair.

Conclusion

Methanol extract of Lantana camara leafhas antimicrobial activity on Candidaisolates and topical healing effect on Candida.
Genetic manipulation of Lactobacillus to produce optically pure lactic acid following fermentation using hydrolysed organic fraction of municipal solid waste as a feedstock
Authors: Letchford-Jones Christopher , Bryant David , Hughes Alun , Puri Dhivya , Gallagher Joe
Published: May 2022

Background

Lactic acid for polymer applications must be optically pure to allow the final plastic properties to be controlled. We have isolated a strain of Lactobacillus plantarum capable of utilising a range of carbohydrates and tolerant to high sugar and organic acid concentrations. However, like most Lactobacillus plantarum, this strain produces D- and L-lactic acid. To improve the commercial application of this strain gene editing has been used to ensure only one isoform is produced.

Methods

Using two-step homologous recombination, ldhL was replaced with a truncated version interrupted by a chloramphenicol acetyltransferase resistance marker, then with an unmarked truncated version.

The optical purity shift was quantified biochemically by enzymatic assay and HPLC and fermentation performance compared against the unmodified strain using enzymatically hydrolysed municipal solid waste pulp (MSW sugars) as a feedstock.

Results

The ldhL gene was successfully deleted, leading to a dramatic shift in the optical purity of lactate produced in both synthetic media and MSW sugars. The unmodified strain produced D-lactic acid with an optical purity of 40%, while the mutant achieved 94%. In MSW sugars, the modified strain performed as well as the unmodified control, consuming all available glucose in less than 48 hours with a volumetric productivity of 1.02 g/L/h.

Conclusions

Deletion of ldhL from our strain of Lactobacillus plantarum allowed exclusive production of D-lactic acid from MSW sugars. This provides a laboratory scale demonstration of the production of optically pure lactic acid from renewable sugars for use in the production of biodegradable plastics.
Probing mycobacterial metabolism in tuberculosis and leprosy to identify vulnerable metabolic nodes for drug development
Authors: Borah Khushboo , Beyß Martin , Girardi Karina , Mendum Tom , Lara Flavio , Nöh Katharina , Beste Dany , McFadden Johnjoe
Published: May 2022

Metabolism of pathogens in infectious diseases is important for their survival, virulence and pathogenesis. Mycobacterial pathogens successfully scavenge multiple host nutrient sources in the intracellular niche. It is therefore important to identify the intracellular nutrient sources and their metabolic fates in these pathogens. Metabolic phenotype of an organism is defined by metabolic fluxes. We quantified in vivo fluxes of the pathogens and probed host-bacterial metabolic cross talks in tuberculosis (TB) and leprosy using systems-based strategies and techniques of isotopic labelling, metabolic modelling and metabolic flux analysis (MFA). We show that the TB pathogen metabolizes a number of carbon and nitrogen sources in human macrophages and identified vulnerable nodes such as glutamine and serine biosynthesis as potential drug targets. Mycobacterium leprae, the leprosy causing pathogen, uses host cell glucose in infected schwann cells and the enzyme, phoenolpyruvate carboxylase is a potential drug target. Our research provides an understanding of the intracellular diets and metabolism of these important human pathogens and identified vulnerable metabolic nodes that can be used for developing innovative chemotherapies in TB and leprosy.
Actin dynamics regulate proteasome homeostasis
Authors: Williams Thomas , Rousseau Adrien
Published: May 2022

Cells require thousands of unique proteins to be in the right place, at the right time, in the right amounts and with the right modifications. They do this through several processes collectively known as protein homeostasis. TORC1 is a principal regulator of protein homeostasis, coordinating protein synthesis and degradation. The proteasome, composed of a core particle and one or two regulatory particles, degrades unwanted protein. Diverse stresses cause a protein homeostasis imbalance: inhibiting TORC1 and the misfolded/damaged protein load. Following TORC1 inhibition, proteasome regulatory particle assembly chaperone (RPAC) translation is increased and thus cells assemble more proteasomes to degrade the damaged and misfolded proteins, thereby restoring protein homeostasis.

Using yeast, we identify an endocytic protein, Ede1, that interacts with and is critical for translation of RPAC mRNA following TORC1 inhibition. We find two further endocytic proteins important for RPAC translation regulation. Mutants of these proteins cause altered Arp2/3 activity, and hence altered formation of actin patches/endocytic sites. We show that RPAC mRNA is transported on actin cables and interacts with actin patches. TORC1 inhibition depolarises the actin cytoskeleton, causing RPAC mRNA accumulation on actin patches concurrent with translation. We demonstrate Ede1 is essential for RPAC mRNA localisation regulation following rapamycin treatment.

This work shows that, upon actin depolarisation, RPAC mRNA is recruited to actin patches, likely by Ede1, and translation occurs. Actin regulation is therefore a key element of proteasome (and therefore protein) homeostasis.
Ruminococcus gnavus GH98 substrate specificity to blood group A antigen contributes to mucin glycan foraging
Authors: Wu Haiyang , Crost Emmanuelle , Owen David , Bakel Wouter van , Martinez-Gascuena Ana , Walsh Martin , Juge Nathalie
Published: May 2022

The human gut symbiont Ruminococcus gnavus displays a strain-specific repertoire of glycoside hydrolases (GHs) contributing to its spatial location in the gut. Sequence similarity networks showed that R. gnavus GH98 (RgGH98) sequence fell in a cluster different from sequences of GH98 enzymes functionally characterised to date. We heterologously expressed and purified RgGH98, and determined its substrate and linkage specificity. We showed that RgGH98 is specific for blood group A antigen (BgA), as also confirmed by isothermal titration calorimetry (ITC) and saturation transfer difference (STD) NMR, revealing affinity for blood group A over blood group B and H antigens. The molecular basis of RgGH98 specificity was further investigated using a combination of site-directed mutagenesis and X-ray crystallography. The crystal structure of the complex between RgGH98 and BgA trisaccharide and RgGH98 inactive mutant with BgA tetrasaccharide identified residues involved in RgGH98 unique specificity. RNAseq and qPCR analysis showed that the gene encoding RgGH98 is part of an operon that is overexpresssed in vitro when R. gnavusis grown on mucin as sole carbon source. We showed that RgGH98 releases BgA trisaccharide from mucin and that pretreatment of mucin with RgGH98 conferred other R. gnavusstrains lacking this enzyme the ability to grow through BgA metabolism and access to the underlying mucin glycan chain. These data further support that the GH repertoire of R. gnavus strains enables them to colonise different nutritional niches in the gut and provide a source of enzymes with unique specificities for potential applications in diagnostic or therapeutics.
Parallel phage resistance - virulence trade - offs during clinical phage therapy and in vitro
Authors: Castledine Meaghan , Padfield Daniel , Sierocinski Pawel , Pascual Jesica Soria , Hughes Adam , Mäkinen Lotta , Friman Ville-Petri , Pirnay Jean-Paul , Vos Daniel De , Buckling Angus
Published: May 2022

With rising antibiotic resistance, modern medicine needs new approaches for tackling bacterial infections. Phage therapy uses the viruses of pathogenic bacteria to clear the infection. Unlike antibiotics, phage can evolve if bacteria become resistant to maintain or even increase their infectivity (coevolution). While laboratory studies can give insight into complex bacteria-phage interactions, whether they act as a true representation of phage therapy in patients is unknown. Here, we compared phage therapy in a patient to that of in vitro experiments. The patient had been admitted with aPseudomonas aeruginosainfection and was successfully treated with a phage cocktail. Bacteria were isolated before and during phage therapy, allowing us to follow bacteria-phage coevolution in the patient while doing experiments on the same clones in vitro. In vivo and in vitro, bacteria rapidly evolved resistance with little or no evidence of bacteria - phage coevolution. Although resistance mechanisms differed, parallel resistance - virulence trade-offs were found in vivo and in vitro. Therefore, phage resistance could increase treatment success and our results indicate to what extent bacteria - phage evolutionary dynamics can be predicted from in vitro experiments.
Isolation and characterization of bacteriophage Ib_pec2 against Shigatoxigenic E.coli
Authors: Inbaraj Sophia , Chaudhuri Pallab , Thomas Prasad , M Angappan , Kumar Manish , Verma Abhishek , Irungbam Karuna , KN Viswas , Agrawal Ravi Kant
Published: May 2022

The current study aimed to isolate and characterize bacteriophage against drug resistant, Shiga toxigenic E.coli, one of the zoonotic, food-borne organisms associated with ruminants, mainly cattle. STEC were isolated (n=35) from neonatal calves, dairy workers and the surrounding environment and their antimicrobial resistance pattern was studied. Out of the 35 isolates tested, 17 isolates were found to be multi-drug resistant to important antibiotics like as ampicillin, amoxicillin-clavulanate, ciprofloxacin, streptomycin and tetracycline. Bacteriophage namely Ib_pec2 was isolated against NM—18-040 isolate and its morphology, genetic and proteomic characterization was done. Morphological analysis by TEM revealed bacteriophage belonging to myoviridae family. The genetic characterization of g23 gene revealed that the bacteriophage belonged to Tequatrovirus of myoviridae family. SDS-PAGE analysis of structural proteins followed by LC-MS/MS analysis could able to identify five proteins identical to Tequatrovirus of myoviridae family. One step growth curve experiments revealed a latency period of 40 mins and a burst size of 893 PFU/ bacteria. Temperature and pH ranging from 40-50°C, pH 7-8, respectively were ideal for phage survival and multiplication. Phage was able to lyse 22 out of 35 STEC isolates. Thus, the study could able to characterize Ib_pec2 which could be used in control of STEC in the near future. STEC is a commensal organism in the gastrointestinal tract of ruminants but pathogenic in humans. Bacteriophages can be used as alternatives to antibiotics to control its growth in ruminants and prevent its further spillage in the environment.
Evolutionary histories and antimicrobial resistance inShigella flexneri and Shigella sonnei in Southeast Asia
Authors: The Hao Chung , Bodhidatta Ladaporn , Pham Duy Thanh , Mason Carl J. , Thanh Tuyen Ha , Vinh Phat Voong , Turner Paul , Hem Sopheak , Dance David A. B. , Newton Paul N. , Phetsouvanh Rattanaphone , Davong Viengmon , Thwaites Guy E. , Thomson Nicholas R. , Baker Stephen , Rabaa Maia A.
Published: May 2022

Conventional disease surveillance for shigellosis in developing country settingsrelies on serotyping and low-resolution molecular typing, which fails to contextualise the evolutionary history of the genus. Here, we interrogated a collection of 1,804 Shigella whole genome sequences from organisms isolated in four continental Southeast Asian countries (Thailand, Vietnam, Laos, and Cambodia) over three decades to characterise the evolution of both S. flexneri and S. sonnei. We show that S. sonnei and each major S. flexneri serotype are comprised of genetically diverse populations, the majority of which were likely introduced into Southeast Asia in the 1970s-1990s. Intranational and regional dissemination allowed widespread propagation of both species across the region. Our data indicate that the epidemiology of S. sonnei and the major S. flexneri serotypes were characterised by frequent clonal replacement events, coinciding with changing susceptibility patterns against contemporaneous antimicrobials. We conclude that adaptation to antimicrobial pressure was pivotal to the recent evolutionary trajectory of Shigella in Southeast Asia.