bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Zinc-Attenuating Compounds as Potent Broad-Spectrum Antifungal Agents with
In Vitro
and
In Vivo
Efficacy
Authors: Cohrt Karen A. O'Hanlon , Marín Laura , Kjellerup Lasse , Clausen Johannes D. , Dalby-Brown William , Calera José Antonio , Winther Anne-Marie Lund 
Published: February 2018

ABSTRACT

An increase in the incidence of rare but hard-to-treat invasive fungal pathogens as well as resistance to the currently available antifungal drugs calls for new broad-spectrum antifungals with a novel mechanism of action. Here we report the identification and characterization of two novel zinc-attenuating compounds, ZAC307 and ZAC989, which exhibit broad-spectrum
in vitro
antifungal activity and
in vivo
efficacy in a fungal kidney burden candidiasis model. The compounds were identified serendipitously as part of a drug discovery process aimed at finding novel inhibitors of the fungal plasma membrane proton ATPase Pma1. Based on their structure, we hypothesized that they might act as zinc chelators. Indeed, both fluorescence-based affinity determination and potentiometric assays revealed these compounds, subsequently termed zinc-attenuating compounds (ZACs), to have strong affinity for zinc, and their growth inhibitory effects on
Candida albicans
and
Aspergillus fumigatus
could be inactivated by the addition of exogenous zinc to fungal growth media. We determined the ZACs to be fungistatic, with a low propensity for resistance development. Gene expression analysis suggested that the ZACs interfere negatively with the expression of genes encoding the major components of the
A. fumigatus
zinc uptake system, thus supporting perturbance of zinc homeostasis as the likely mode of action. With demonstrated
in vitro
and
in vivo
antifungal activity, low propensity for resistance development, and a novel mode of action, the ZACs represent a promising new class of antifungal compounds, and their advancement in a drug development program is therefore warranted.
Pharmacokinetics of 2,000 Milligram Ertapenem in Tuberculosis Patients
Authors: Zuur M. A. , Ghimire S. , Bolhuis M. S. , Wessels A. M. A. , van Altena R. , de Lange W. C. M. , Kosterink J. G. W. , Touw D. J. , van der Werf T. S. , Akkerman O. W. , Alffenaar J. W. C. 
Published: February 2018

ABSTRACT

Ertapenem is a carbapenem antibiotic with activity against
Mycobacterium tuberculosis
. Dose simulations in a hollow-fiber infection model showed that 2,000 mg once daily is an appropriate dose to be tested in clinical studies. Before using this dose in a phase II study, the aim of this prospective pharmacokinetic study was to confirm the pharmacokinetics of 2,000 mg once daily in tuberculosis (TB) patients. Twelve TB patients received a single intravenous dose of 2,000 mg ertapenem as a 30-min infusion. Blood samples were collected at 0, 0.5, 1, 2, 3, 4, 8, 12, and 24 h postadministration. Drug concentrations were measured using a validated liquid chromatography-tandem mass spectrometry assay. A large interindividual variation in the pharmacokinetics of ertapenem was observed. The median (interquartile range) area under the plasma concentration-time curve to infinity (AUC
0–∞
) was 2,032 (1,751 to 2,346) mg · h/liter, the intercompartmental clearance (CL
12
) was 1.941 (0.979 to 2.817) liters/h, and the volume of distribution in the central compartment (
V
1
) was 1.514 (1.064 to 2.210) liters. A more than dose-proportional increase in AUC was observed compared to results reported for 1,000 mg ertapenem in multidrug-resistant TB patients. Based on a MIC of 1.0 mg/liter, 11 out of 12 patients would have reached the target value of unbound drug exceeding the MIC over 40% of the time (
f
40%
T
>MIC). In conclusion, this study shows that 2,000 mg ertapenem once daily in TB patients reached the expected
f
40%
T
>MIC for most of the patients, and exploration in a phase 2 study can be advocated.
Assembly of Synthetic Functional Cellulosomal Structures onto the Cell Surface of Lactobacillus plantarum, a Potent Member of the Gut Microbiome
Authors: Stern Johanna , Moraïs Sarah , Ben-David Yonit , Salama Rachel , Shamshoum Melina , Lamed Raphael , Shoham Yuval , Bayer Edward A. , Mizrahi Itzhak 
Published: February 2018

ABSTRACT

Heterologous display of enzymes on microbial cell surfaces is an extremely desirable approach, since it enables the engineered microbe to interact directly with the plant wall extracellular polysaccharide matrix. In recent years, attempts have been made to endow noncellulolytic microbes with genetically engineered cellulolytic capabilities for improved hydrolysis of lignocellulosic biomass and for advanced probiotics. Thus far, however, owing to the hurdles encountered in secreting and assembling large, intricate complexes on the bacterial cell wall, only free cellulases or relatively simple cellulosome assemblies have been introduced into live bacteria. Here, we employed the “adaptor scaffoldin” strategy to compensate for the low levels of protein displayed on the bacterial cell surface. That strategy mimics natural elaborated cellulosome architectures, thus exploiting the exponential features of their Lego-like combinatorics. Using this approach, we produced several bacterial consortia of
Lactobacillus plantarum
, a potent gut microbe which provides a very robust genetic framework for lignocellulosic degradation. We successfully engineered surface display of large, fully active self-assembling cellulosomal complexes containing an unprecedented number of catalytic subunits all produced
in vivo
by the cell consortia. Our results demonstrate that the enzyme stability and performance of the cellulosomal machinery, which are superior to those seen with the equivalent secreted free enzyme system, and the high cellulase-to-xylanase ratios proved beneficial for efficient degradation of wheat straw.

IMPORTANCE
The multiple benefits of lactic acid bacteria are well established in health and industry. Here we present an approach designed to extensively increase the cell surface display of proteins via successive assembly of interactive components. Our findings present a stepping stone toward proficient engineering of
Lactobacillus plantarum
, a widespread, environmentally important bacterium and potent microbiome member, for improved degradation of lignocellulosic biomass and advanced probiotics.
Enhancing the Adaptability of the Deep-Sea Bacterium Shewanella piezotolerans WP3 to High Pressure and Low Temperature by Experimental Evolution under H
2
O
2
Stress
Authors: Xie Zhe , Jian Huahua , Jin Zheng , Xiao Xiang 
Published: February 2018

ABSTRACT

Oxidative stresses commonly exist in natural environments, and microbes have developed a variety of defensive systems to counteract such events. Although increasing evidence has shown that high hydrostatic pressure (HHP) and low temperature (LT) induce antioxidant defense responses in cells, there is no direct evidence to prove the connection between antioxidant defense mechanisms and the adaptation of bacteria to HHP and LT. In this study, using the wild-type (WT) strain of a deep-sea bacterium,
Shewanella piezotolerans
WP3, as an ancestor, we obtained a mutant, OE100, with an enhanced antioxidant defense capacity by experimental evolution under H
2
O
2
stress. Notably, OE100 exhibited better tolerance not only to H
2
O
2
stress but also to HHP and LT (20 MPa and 4°C, respectively). Whole-genome sequencing identified a deletion mutation in the
oxyR
gene, which encodes the transcription factor that controls the oxidative stress response. Comparative transcriptome analysis showed that the genes associated with oxidative stress defense, anaerobic respiration, DNA repair, and the synthesis of flagella and bacteriophage were differentially expressed in OE100 compared with the WT at 20 MPa and 4°C. Genetic analysis of
oxyR
and
ccpA2
indicated that the OxyR-regulated cytochrome
c
peroxidase CcpA2 significantly contributed to the adaptation of WP3 to HHP and LT. Taken together, these results confirmed the inherent relationship between antioxidant defense mechanisms and the adaptation of a benthic microorganism to HHP and LT.

IMPORTANCE
Oxidative stress exists in various niches, including the deep-sea ecosystem, which is an extreme environment with conditions of HHP and predominantly LT. Although previous studies have shown that HHP and LT induce antioxidant defense responses in cells, direct evidence to prove the connection between antioxidant defense mechanisms and the adaptation of bacteria to HHP and LT is lacking. In this work, using the deep-sea bacterium
Shewanella piezotolerans
WP3 as a model, we proved that enhancement of the adaptability of WP3 to HHP and LT can benefit from its antioxidant defense mechanism, which provided useful insight into the ecological roles of antioxidant genes in a benthic microorganism and contributed to an improved understanding of microbial adaptation strategies in deep-sea environments.
Versatile Cas9-Driven Subpopulation Selection Toolbox for Lactococcus lactis
Authors: van der Els Simon , James Jennelle K. , Kleerebezem Michiel , Bron Peter A. 
Published: February 2018

ABSTRACT

CRISPR-Cas9 technology has been exploited for the removal or replacement of genetic elements in a wide range of prokaryotes and eukaryotes. Here, we describe the extension of the Cas9 application toolbox to the industrially important dairy species
Lactococcus lactis
. The Cas9 expression vector pLABTarget, encoding the
Streptocccus pyogenes
Cas9 under the control of a constitutive promoter, was constructed, allowing plug and play introduction of short guide RNA (sgRNA) sequences to target specific genetic loci. Introduction of a
pepN
-targeting derivative of pLABTarget into
L. lactis
strain MG1363 led to a strong reduction in the number of transformants obtained, which did not occur in a
pepN
deletion derivative of the same strain, demonstrating the specificity and lethality of the Cas9-mediated double-strand breaks in the lactococcal chromosome. Moreover, the same pLABTarget derivative allowed the selection of a
pepN
deletion subpopulation from its corresponding single-crossover plasmid integrant precursor, accelerating the construction and selection of gene-specific deletion derivatives in
L. lactis
. Finally, pLABTarget, which contained sgRNAs designed to target mobile genetic elements, allowed the effective curing of plasmids, prophages, and integrative conjugative elements (ICEs). These results establish that pLABTarget enables the effective exploitation of Cas9 targeting in
L. lactis
, while the broad-host-range vector used suggests that this toolbox could readily be expanded to other Gram-positive bacteria.

IMPORTANCE
Mobile genetic elements in
Lactococcus lactis
and other lactic acid bacteria (LAB) play an important role in dairy fermentation, having both positive and detrimental effects during the production of fermented dairy products. The pLABTarget vector offers an efficient cloning platform for Cas9 application in lactic acid bacteria. Targeting Cas9 toward mobile genetic elements enabled their effective curing, which is of particular interest in the context of potentially problematic prophages present in a strain. Moreover, Cas9 targeting of other mobile genetic elements enables the deciphering of their contribution to dairy fermentation processes and further establishment of their importance for product characteristics.
Fetal and Maternal Innate Immunity Receptors Have Opposing Effects on the Severity of Experimental Malaria in Pregnancy: Beneficial Roles for Fetus-Derived Toll-Like Receptor 4 and Type I Interferon Receptor 1
Authors: Rodrigues-Duarte Lurdes , Pandya Yash , Neres Rita , Penha-Gonçalves Carlos 
Published: February 2018

ABSTRACTMalaria in pregnancy (MiP) is a distinctive clinical form ofPlasmodiuminfection and is a cause of placental insufficiency leading to poor pregnancy outcomes. Maternal innate immunity responses play a decisive role in the development of placental inflammation, but the action of fetus-derived factors in MiP outcomes has been overlooked. We investigated the role of theTlr4andIfnar1genes, taking advantage of heterogenic mating strategies to dissect the effects mediated by maternally and fetally derived Toll-like receptor 4 (TLR4) or type I interferon receptor 1 (IFNAR1). Using a mouse infection system displaying severe MiP outcomes, we found that the expressions of TLR4 and IFNAR1 in the maternal compartment take part in deleterious MiP outcomes, but their fetal counterparts patently counteract these effects. We uncovered that fetal TLR4 contributes to thein vitrouptake of infected erythrocytes by trophoblasts and to the innate immune response in the placenta, offering robust protection of fetus viability, but had no sensible impact on the placental parasite burden. In contrast, we observed that the expression of IFNAR1 in the fetal compartment was associated with a reduced placental parasite burden but had little beneficial effect on fetus outcomes. Furthermore, the downregulation ofIfnar1expression in infected placentas and in trophoblasts exposed to infected erythrocytes indicated that the interferon-IFNAR1 pathway is involved in the trophoblast response to infection. This work unravels that maternal and fetal counterparts of innate immune pathways drive opposing responses in murine placental malaria and implicates the activation of innate receptors in fetal trophoblast cells in the control of placental infection and in the protection of the fetus.
Staphylococcal Protein A Contributes to Persistent Colonization of Mice with Staphylococcus aureus
Authors: Sun Yan , Emolo Carla , Holtfreter Silva , Wiles Siouxsie , Kreiswirth Barry , Missiakas Dominique , Schneewind Olaf 
Published: February 2018

ABSTRACTStaphylococcus aureuspersistently colonizes the nasopharynx in humans, which increases the risk for invasive diseases, such as skin infection and bacteremia. Nasal colonization triggers IgG responses against staphylococcal surface antigens; however, these antibodies cannot prevent subsequent colonization or disease. Here, we describeS. aureusWU1, a multilocus sequence type 88 (ST88) isolate that persistently colonizes the nasopharynx in mice. We report that staphylococcal protein A (SpA) is required for persistence ofS. aureusWU1 in the nasopharynx. Compared to animals colonized by wild-typeS. aureus, mice colonized with the Δspavariant mount increased IgG responses against staphylococcal colonization determinants. Immunization of mice with a nontoxigenic SpA variant, which cannot cross-link B cell receptors and divert antibody responses, elicits protein A-neutralizing antibodies that promote IgG responses against colonizingS. aureusand diminish pathogen persistence.IMPORTANCEStaphylococcus aureuspersistently colonizes the nasopharynx in about one-third of the human population, thereby promoting community- and hospital-acquired infections. Antibiotics are currently used for decolonization of individuals at increased risk of infection. However, the efficacy of antibiotics is limited by recolonization and selection for drug-resistant strains. Here, we propose a model of how staphylococcal protein A (SpA), a B cell superantigen, modifies host immune responses during colonization to support continued persistence ofS. aureusin the nasopharynx. We show that this mechanism can be thwarted by vaccine-induced anti-SpA antibodies that promote IgG responses against staphylococcal antigens and diminish colonization.
Management of suspected paediatric meningitis: a multicentre prospective cohort study
Authors: Ramasamy Roshan , Willis Louise , Kadambari Seilesh , Kelly Dominic F , Heath Paul T , Nadel Simon , Pollard Andrew J , Sadarangani Manish 
Published: February 2018

ObjectiveTo quantify delays during management of children with suspected meningitis.DesignMulticentre prospective cohort study.SettingThree UK tertiary paediatric centres; June 2011–June 2012Patients388 children aged <16 years hospitalised with suspected meningitis or undergoing lumbar puncture (LP) during sepsis evaluation.Main outcome measuresTime of prehospital and in-hospital assessments, LP, antibiotic treatment and discharge; types of prehospital medical assessment and microbiological results. Data collected from hospital records and parental interview.Results220/388 (57%) children were seen by a medical professional prehospitalisation (143 by a general practitioner). Median times from initial hospital assessment to LP and antibiotic administration were 4.8 hours and 3.1 hours, respectively; 62% of children had their LP after antibiotic treatment. Median time to LP was shorter for children aged <3 months (3.0 hours) than those aged 3–23 months (6.2 hours, P<0.001) or age ≥2 years (20.3 hours, P<0.001). In meningitis of unknown cause, cerebrospinal fluid (CSF) PCR was performed for meningococcus in 7%, pneumococcus in 10% and enterovirus in 76%. When no pathogen was identified, hospital stay was longer if LP was performed after antibiotics (median 12.5 days vs 5.0 days, P=0.037).ConclusionsMost children had LP after antibiotics were administered, reducing yield from CSF culture, and PCRs were underused despite national recommendations. These deficiencies reduce the ability to exclude bacterial meningitis, increasing unnecessary hospital stay and antibiotic treatment.
Lower limb biomechanics in femoroacetabular impingement syndrome: a systematic review and meta-analysis
Authors: King Matthew G , Lawrenson Peter R , Semciw Adam I , Middleton Kane J , Crossley Kay M 
Published: February 2018

Objective(1) Identify differences in hip and pelvic biomechanics in patients with femoroacetabular impingement syndrome (FAIS) compared with controls during everyday activities (eg, walking, squatting); and (2) evaluate the effects of interventions on hip and pelvic biomechanics during everyday activities.DesignSystematic review.Data sourcesMedline, CINAHL, EMBASE, Scopus and SPORTDiscus until February 2017.MethodsPrimary aim: studies that investigated hip or pelvic kinematics and/or joint torques of everyday activities in patients with FAIS compared with the asymptomatic contralateral limb or a control group. Secondary aim: studies that evaluated effects of conservative or surgical interventions on patients with FAIS using pre-post or controlled clinical trial designs. Biomechanical data must have been collected using three-dimensional motion capture devices. Reporting quality was assessed using the Epidemiological Appraisal Instrument and data were pooled (standardised mean difference (SMD), 95% CI) where populations and primary outcomes were similar.ResultsFourteen studies were included (11 cross-sectional and three pre/post intervention), varying between low and moderate reporting quality. Patients with FAIS walked with a lower: peak hip extension angle (SMD −0.40, 95% CI −0.71 to −0.09), peak internal rotation angle (−0.67, 95% CI −1.19 to −0.16) and external rotation joint torque (−0.71, 95% CI −1.07 to −0.35), and squatted to a lesser depth with no difference in hip flexion range. Pre/post intervention data were limited in number and quality, and to surgical cohorts.ConclusionThis review suggests that patients with FAIS may demonstrate hip biomechanical impairments during walking and squatting, with minimal literature available to comment on other tasks.Clinical relevanceThe information presented in the review provides insight into the biomechanical differences associated with FAIS; however, the between-group differences were small to moderate. This information may aid in the development of management strategies for people with the condition.PROSPEROregistration numberCRD42016038677.
How can positive and negative trainer feedback in the operating theatre impact a surgical trainee’s confidence and well-being: a qualitative study in the north of England
Authors: Kamali Dariush , Illing Jan 
Published: February 2018

ObjectiveTo identify the perception of positive feedback (PF) and negative feedback (NF) provided by trainers in the operating theatre on surgical trainees' confidence and well-being.DesignNarrative interview study.SettingTwelve hospitals that form part of one deanery within the UK.ParticipantsMaximum variation sampling of 15 higher general surgical trainees provided insight into how PF and NF from trainers in the operating theatre affect confidence and well-being.MethodsNarrative telephone interviews were conducted with general surgical trainees between April and June 2016. All interviews were recorded, transcribed and anonymised. Transcriptions were analysed using the five-step framework analysis by two independent researchers.ResultsFifteen trainees (age 28–38 years) were interviewed (median interview time: 29 min). Thematic framework analysis identified nine themes within the data. PF, which included corrective feedback, helped the trainees to relax and seemed to enhance their operative performance. All trainees reported significant and unjustified NF, some of which would be defined as undermining and bullying. Many believed this to have a negative impact on their training with minimal educational benefit. Many trainees felt NF adversely affected their performance in the operating theatre with some expressing a wish to leave the profession as a consequence.ConclusionBoth PF and NF exist in the operating theatre. Both have an important influence on the trainee, their performance and career. PF, if specific, helped aid progression of learning, increased motivation and performance of surgical trainees. In contrast, NF was perceived to have detrimental effects on trainees’ performance and their well-being and, in some, introduced a desire to pursue an alternative career.
Ten-year inhospital mortality trends for patients with trauma in Japan: a multicentre observational study
Authors: Nagata Isao , Abe Toshikazu , Uchida Masatoshi , Saitoh Daizoh , Tamiya Nanako 
Published: February 2018

ObjectivesTrauma is one of the main causes of death in Japan, and treatments and prognoses of these injuries are constantly changing. We therefore aimed to investigate a 10-year trend (2004–2013) in inhospital mortality among patients with trauma in Japan.DesignMulticentre observational study.SettingJapanese nationwide trauma registry (the Japan Trauma Data Bank) data.ParticipantsAll patients with trauma whose Injury Severity Score (ISS) were 3 and above, who were aged 15 years or older, and whose mechanisms of injury (MOI) were blunt and penetrating between 2004 and 2013 (n=90 833).Outcome measuresA 10-year trend in inhospital mortality.ResultsInhospital mortality for all patients with trauma significantly decreased over the study decade in our Cochran-Armitage test (P<0.001). Similarly, inhospital mortality for patients with ISS 16 or more and patients who scored 50% or better on the Trauma and Injury Severity Score (TRISS) probability of survival scale significantly decreased (P<0.001). In addition, the OR for inhospital mortality of these three patient groups decreased yearly after adjusting for age, gender, MOI, ISS, Glasgow Coma Scale, systolic blood pressure and respiratory rate on hospital arrival in multivariable logistic regression analyses. Furthermore, inhospital mortality for patient with blunt trauma significantly decreased in injury mechanism-stratified Mantel-extension testing (P<0.001). Finally, multivariable logistic regression analyses showed that the OR for inhospital mortality of patients with ISS 16 and over decreased each year after adding and adjusting for means of transportation and usage of whole-body CT.ConclusionInhospitalmortality for patients with trauma in Japan significantly decreased during the study decade after adjusting for patient characteristics, injury severity and the response environment after injury.