bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quorum-Sensing Mechanisms Mediated by Farnesol in Ophiostoma piceae: Effect on Secretion of Sterol Esterase
Authors: de Salas Felipe , Martínez María Jesús , Barriuso Jorge 
Published: April 2015

ABSTRACTOphiostoma piceaeCECT 20416 is a dimorphic wood-staining fungus able to produce an extracellular sterol-esterase/lipase (OPE) that is of great biotechnological interest. In this work, we have studied the morphological change of this fungus from yeast to hyphae, which is associated with the cell density-related mechanism known as quorum sensing (QS), and how this affects the secretion of OPE. The data presented here confirm that the moleculeE,E-farnesol accumulates as the cell number is growing within the population. The exogenous addition of this molecule or spent medium to the cultures increased the extracellular activity of OPE 2.5 times. This fact was related not to an increase in microbial biomass or in the expression of the gene coding for OPE but to a marked morphological transition in the cultures. Moreover, the morphological transition also occurred when a high cell density was inoculated into the medium. The results suggest thatE,E-farnesol regulates through QS mechanisms the morphological transition in the dimorphic fungusO. piceaeand that it is associated with a higher extracellular esterase activity. Furthermore, identification and transcriptional analysis of genestup1andcyr1, which are involved in the response, was carried out. Here we report enhanced production of a sterol-esterase/lipase of biotechnological interest by means of QS mechanisms. These results may be useful in increasing the production of secreted enzymes of other dimorphic fungi of biotechnological interest.
An Invasive Mammal (the Gray Squirrel, Sciurus carolinensis) Commonly Hosts Diverse and Atypical Genotypes of the Zoonotic Pathogen Borrelia burgdorferiSensu Lato
Authors: Millins Caroline , Magierecka Agnieszka , Gilbert Lucy , Edoff Alissa , Brereton Amelia , Kilbride Elizabeth , Denwood Matt , Birtles Richard , Biek Roman 
Published: April 2015

ABSTRACT

Invasive vertebrate species can act as hosts for endemic pathogens and may alter pathogen community composition and dynamics. For the zoonotic pathogen
Borrelia burgdorferi
sensu lato
, the agent of Lyme borreliosis, recent work shows invasive rodent species can be of high epidemiological importance and may support host-specific strains. This study examined the role of gray squirrels (
Sciurus carolinensis
) (
n
= 679), an invasive species in the United Kingdom, as
B. burgdorferi sensu lato
hosts. We found that gray squirrels were frequently infested with
Ixodes ricinus
, the main vector of
B. burgdorferi sensu lato
in the United Kingdom, and 11.9% were infected with
B. burgdorferi sensu lato
. All four genospecies that occur in the United Kingdom were detected in gray squirrels, and unexpectedly, the bird-associated genospecies
Borrelia garinii
was most common. The second most frequent infection was with
Borrelia afzelii
. Genotyping of
B. garinii
and
B. afzelii
produced no evidence for strains associated with gray squirrels. Generalized linear mixed models (GLMM) identified tick infestation and date of capture as significant factors associated with
B. burgdorferi sensu lato
infection in gray squirrels, with infection elevated in early summer in squirrels infested with ticks. Invasive gray squirrels appear to become infected with locally circulating strains of
B. burgdorferi sensu lato
, and further studies are required to determine their role in community disease dynamics. Our findings highlight the fact that the role of introduced host species in
B. burgdorferi sensu lato
epidemiology can be highly variable and thus difficult to predict.
Biosynthesis of
l
-Sorbose and
l
-Psicose Based on C—C Bond Formation Catalyzed by Aldolases in an Engineered Corynebacterium glutamicum Strain
Authors: Yang Jiangang , Li Jitao , Men Yan , Zhu Yueming , Zhang Ying , Sun Yuanxia , Ma Yanhe 
Published: April 2015

ABSTRACT

The property of loose stereochemical control at aldol products from aldolases helped to synthesize multiple polyhydroxylated compounds with nonnatural stereoconfiguration. In this study, we discovered for the first time that some fructose 1,6-diphosphate aldolases (FruA) and tagatose 1,6-diphosphate (TagA) aldolases lost their strict stereoselectivity when using
l
-glyceraldehyde and synthesized not only
l
-sorbose but also a high proportion of
l
-psicose. Among the aldolases tested, TagA from
Bacillus licheniformis
(BGatY) showed the highest enzyme activity with
l
-glyceraldehyde. Subsequently, a “one-pot” reaction based on BGatY and fructose-1-phosphatase (YqaB) generated 378 mg/liter
l
-psicose and 199 mg/liter
l
-sorbose from dihydroxyacetone-phosphate (DHAP) and
l
-glyceraldehyde. Because of the high cost and instability of DHAP, a microbial fermentation strategy was used further to produce
l
-sorbose/
l
-psicose from glucose and
l
-glyceraldehyde, in which DHAP was obtained from glucose through the glycolytic pathway, and some recombination pathways based on FruA or TagA and YqaB were constructed in
Escherichia coli
and
Corynebacterium glutamicum
strains. After evaluation of different host cells and combinations of FruA or TagA with YqaB and optimization of gene expression, recombinant
C. glutamicum
strain WT(pXFTY) was selected and produced 2.53 g/liter total ketoses, with a yield of 0.50 g/g
l
-glyceraldehyde. Moreover, deletion of gene
cgl0331
, encoding the Zn-dependent alcohol dehydrogenase in
C. glutamicum
, was confirmed for the first time to significantly decrease conversion of
l
-glyceraldehyde to glycerol and to increase yield of target products. Finally, fed-batch culture of strain SY14(pXFTY) produced 3.5 g/liter
l
-sorbose and 2.3 g/liter
l
-psicose, with a yield of 0.61 g/g
l
-glyceraldehyde. This microbial fermentation strategy also could be applied to efficiently synthesize other
l
-sugars.
Gene Deletions Resulting in Increased Nitrogen Release by Azotobacter vinelandii: Application of a Novel Nitrogen Biosensor
Authors: Barney Brett M. , Eberhart Lauren J. , Ohlert Janet M. , Knutson Carolann M. , Plunkett Mary H. 
Published: April 2015

ABSTRACT

Azotobacter vinelandii
is a widely studied model diazotrophic (nitrogen-fixing) bacterium and also an obligate aerobe, differentiating it from many other diazotrophs that require environments low in oxygen for the function of the nitrogenase. As a free-living bacterium,
A. vinelandii
has evolved enzymes and transporters to minimize the loss of fixed nitrogen to the surrounding environment. In this study, we pursued efforts to target specific enzymes and further developed screens to identify individual colonies of
A. vinelandii
producing elevated levels of extracellular nitrogen. Targeted deletions were done to convert urea into a terminal product by disrupting the urease genes that influence the ability of
A. vinelandii
to recycle the urea nitrogen within the cell. Construction of a nitrogen biosensor strain was done to rapidly screen several thousand colonies disrupted by transposon insertional mutagenesis to identify strains with increased extracellular nitrogen production. Several disruptions were identified in the ammonium transporter gene
amtB
that resulted in the production of sufficient levels of extracellular nitrogen to support the growth of the biosensor strain. Further studies substituting the biosensor strain with the green alga
Chlorella sorokiniana
confirmed that levels of nitrogen produced were sufficient to support the growth of this organism when the medium was supplemented with sufficient sucrose to support the growth of the
A. vinelandii
in coculture. The nature and quantities of nitrogen released by urease and
amtB
disruptions were further compared to strains reported in previous efforts that altered the
nifLA
regulatory system to produce elevated levels of ammonium. These results reveal alternative approaches that can be used in various combinations to yield new strains that might have further application in biofertilizer schemes.
Expanded Natural Product Diversity Revealed by Analysis of Lanthipeptide-Like Gene Clusters in Actinobacteria
Authors: Zhang Qi , Doroghazi James R. , Zhao Xiling , Walker Mark C. , van der Donk Wilfred A. 
Published: April 2015

ABSTRACT

Lanthionine-containing peptides (lanthipeptides) are a rapidly growing family of polycyclic peptide natural products belonging to the large class of ribosomally synthesized and posttranslationally modified peptides (RiPPs). Lanthipeptides are widely distributed in taxonomically distant species, and their currently known biosynthetic systems and biological activities are diverse. Building on the recent natural product gene cluster family (GCF) project, we report here large-scale analysis of lanthipeptide-like biosynthetic gene clusters from
Actinobacteria
. Our analysis suggests that lanthipeptide biosynthetic pathways, and by extrapolation the natural products themselves, are much more diverse than currently appreciated and contain many different posttranslational modifications. Furthermore, lanthionine synthetases are much more diverse in sequence and domain topology than currently characterized systems, and they are used by the biosynthetic machineries for natural products other than lanthipeptides. The gene cluster families described here significantly expand the chemical diversity and biosynthetic repertoire of lanthionine-related natural products. Biosynthesis of these novel natural products likely involves unusual and unprecedented biochemistries, as illustrated by several examples discussed in this study. In addition, class IV lanthipeptide gene clusters are shown not to be silent, setting the stage to investigate their biological activities.
Biotin- and Glycoprotein-Coated Microspheres as Surrogates for Studying Filtration Removal of Cryptosporidium parvum in a Granular Limestone Aquifer Medium
Authors: Stevenson M. E. , Blaschke A. P. , Toze S. , Sidhu J. P. S. , Ahmed W. , van Driezum I. H. , Sommer R. , Kirschner A. K. T. , Cervero-Aragó S. , Farnleitner A. H. , Pang L. 
Published: April 2015

ABSTRACT

Members of the genus
Cryptosporidium
are waterborne protozoa of great health concern. Many studies have attempted to find appropriate surrogates for assessing
Cryptosporidium
filtration removal in porous media. In this study, we evaluated the filtration of
Cryptosporidium parvum
in granular limestone medium by the use of biotin- and glycoprotein-coated carboxylated polystyrene microspheres (CPMs) as surrogates. Column experiments were carried out with core material taken from a managed aquifer recharge site in Adelaide, Australia. For the experiments with injection of a single type of particle, we observed the total removal of the oocysts and glycoprotein-coated CPMs, a 4.6- to 6.3-log
10
reduction of biotin-coated CPMs, and a 2.6-log
10
reduction of unmodified CPMs. When two different types of particles were simultaneously injected, glycoprotein-coated CPMs showed a 5.3-log
10
reduction, while the uncoated CPMs displayed a 3.7-log
10
reduction, probably due to particle-particle interactions. Our results confirm that glycoprotein-coated CPMs are the most accurate surrogates for
C. parvum
; biotin-coated CPMs are slightly more conservative, while unmodified CPMs are markedly overly conservative for predicting
C. parvum
removal in granular limestone medium. The total removal of
C. parvum
observed in our study suggests that granular limestone medium is very effective for the filtration removal of
C. parvum
and could potentially be used for the pretreatment of drinking water and aquifer storage recovery of recycled water.
The AngFus3 Mitogen-Activated Protein Kinase Controls Hyphal Differentiation and Secondary Metabolism in Aspergillus niger
Authors: Priegnitz Bert-Ewald , Brandt Ulrike , Pahirulzaman Khomaizon A. K. , Dickschat Jeroen S. , Fleißner André 
Published: April 2015

ABSTRACT

Adaptation to a changing environment is essential for the survival and propagation of sessile organisms, such as plants or fungi. Filamentous fungi commonly respond to a worsening of their growth conditions by differentiation of asexually or sexually produced spores. The formation of these specialized cell types is, however, also triggered as part of the general life cycle by hyphal age or density. Spores typically serve for dispersal and, therefore, translocation but can also act as resting states to endure times of scarcity. Eukaryotic differentiation in response to environmental and self-derived signals is commonly mediated by three-tiered mitogen-activated protein (MAP) kinase signaling cascades. Here, we report that the MAP kinase Fus3 of the black mold
Aspergillus niger
(AngFus3) and its upstream kinase AngSte7 control vegetative spore formation and secondary metabolism. Mutants lacking these kinases are defective in conidium induction in response to hyphal density but are fully competent in starvation-induced sporulation, indicating that conidiation in
A. niger
is triggered by various independent signals. In addition, the mutants exhibit an altered profile of volatile metabolites and secrete dark pigments into the growth medium, suggesting a dysregulation of the secondary metabolism. By assigning the AngFus3 MAP kinase pathway to the transduction of a potentially self-derived trigger, this work contributes to the unraveling of the intricate signaling networks controlling fungal differentiation. Moreover, our data further support earlier observations that differentiation and secondary metabolism are tightly linked in filamentous fungi.
Trypanosoma brucei Bloodstream Forms Depend upon Uptake of
myo
-Inositol for Golgi Complex Phosphatidylinositol Synthesis and Normal Cell Growth
Authors: González-Salgado Amaia , Steinmann Michael , Major Louise L. , Sigel Erwin , Reymond Jean-Louis , Smith Terry K. , Bütikofer Peter 
Published: April 2015

ABSTRACT

myo
-Inositol is a building block for all inositol-containing phospholipids in eukaryotes. It can be synthesized
de novo
from glucose-6-phosphate in the cytosol and endoplasmic reticulum. Alternatively, it can be taken up from the environment via Na
+
- or H
+
-linked
myo
-inositol transporters. While Na
+
-coupled
myo
-inositol transporters are found exclusively in the plasma membrane, H
+
-linked
myo
-inositol transporters are detected in intracellular organelles. In
Trypanosoma brucei
, the causative agent of human African sleeping sickness,
myo
-inositol metabolism is compartmentalized.
De novo
-synthesized
myo
-inositol is used for glycosylphosphatidylinositol production in the endoplasmic reticulum, whereas the
myo
-inositol taken up from the environment is used for bulk phosphatidylinositol synthesis in the Golgi complex. We now provide evidence that the Golgi complex-localized
T. brucei
H
+
-linked
myo
-inositol transporter (TbHMIT) is essential in bloodstream-form
T. brucei
. Downregulation of TbHMIT expression by RNA interference blocked phosphatidylinositol production and inhibited growth of parasites in culture. Characterization of the transporter in a heterologous expression system demonstrated a remarkable selectivity of TbHMIT for
myo
-inositol. It tolerates only a single modification on the inositol ring, such as the removal of a hydroxyl group or the inversion of stereochemistry at a single hydroxyl group relative to
myo
-inositol.
Using multifaceted education to improve management in acute viral bronchiolitis
Authors: Murch Hannah , Oakley Juliette , Pierrepoint Marcus , Powell Colin 
Published: April 2015

ObjectiveTo establish current bronchiolitis management across hospitals in Wales, improve compliance with national guidelines and standardise evidence-based clinical practice.DesignA complete audit cycle with implementation of a multifaceted education bundle prior to the follow-up audit.SettingTwelve acute paediatric departments between 1 November and 31 December in 2012 and 2013.PatientsAll infants under 12 months with a clinical diagnosis of bronchiolitis.InterventionsThe first audit assessed management of bronchiolitis with reference to both the Scottish Intercollegiate Guideline Network (SIGN) guidelines and local hospital guidelines. Following analysis and dissemination of these results, an education bundle was implemented nationwide, with completion of the audit cycle to assess change.Main Outcome MeasuresCompliance with SIGN recommendations for investigation, treatment and discharge. Compliance with the education bundle requirements also assessed in 2013.ResultsData were collected for 1599 infants. The education bundle was delivered in all hospitals. The level of severity, defined by oxygen saturations in air at presentation, length of stay and paediatric intensive care unit transfers, was equivalent for both years. Mean compliance percentage (95% CI) across Wales significantly improved between 2012 and 2013, with compliance with investigations increasing from 50% (46% to 53%) to 71% (68% to 74%), with management increasing from 65% (61% to 68%) to 74% (71% to 77%), and overall compliance improving from 38% (37% to 39%) to 59% (56% to 62%) in 2013.ConclusionsThis audit demonstrated a significant improvement in compliance following implementation of our educational bundle. This has enabled improvement in standardised and evidence-based patient care across Wales.
Establishing a population-based patient-reported outcomes study (PROMs) using national cancer registries across two jurisdictions: the Prostate Cancer Treatment, your experience (PiCTure) study
Authors: Drummond F J , Kinnear H , Donnelly C , O'Leary E , O'Brien K , Burns R M , Gavin A , Sharp L 
Published: April 2015

ObjectiveTo establish an international patient-reported outcomes (PROMs) study among prostate cancer survivors, up to 18 years postdiagnosis, in two countries with different healthcare systems and ethical frameworks.DesignA cross-sectional, postal survey of prostate cancer survivors sampled and recruited via two population-based cancer registries. Healthcare professionals (HCPs) evaluated patients for eligibility to participate. Questionnaires contained validated instruments to assess health-related quality of life and psychological well-being, including QLQ-C30, QLQ-PR25, EQ-5D-5L, 21-question Depression, Anxiety and Stress Scale (DASS-21) and the Decisional Regret Scale.SettingRepublic of Ireland (RoI) and Northern Ireland (NI).Primary outcome measuresRegistration completeness, predictors of eligibility and response, data missingness, unweighted and weighted PROMs.ResultsProstate cancer registration was 80% (95% CI 75% to 84%) and 91% (95% CI 89% to 93%) complete 2 years postdiagnosis in NI and RoI, respectively. Of 12 322 survivors sampled from registries, 53% (n=6559) were classified as eligible following HCP screening. In the multivariate analysis, significant predictors of eligibility were: being ≤59 years of age at diagnosis (p<0.001), short-term survivor (<5 years postdiagnosis; p<0.001) and from RoI (p<0.001). 3348 completed the questionnaire, yielding a 54% adjusted response rate. 13% of men or their families called the study freephone with queries for assistance with questionnaire completion or to talk about their experience. Significant predictors of response in multivariate analysis were: being ≤59 years at diagnosis (p<0.001) and from RoI (p=0.016). Mean number of missing questions in validated instruments ranged from 0.12 (SD 0.71; EQ-5D-5L) to 3.72 (SD 6.30; QLQ-PR25). Weighted and unweighted mean EQ-5D-5L, QLQ-C30 and QLQ-PR25 scores were similar, as were the weighted and unweighted prevalences of depression, anxiety and distress.ConclusionsIt was feasible to perform PROMs studies across jurisdictions, using cancer registries as sampling frames; we amassed one of the largest, international, population-based data set of prostate cancer survivors. We highlight improvements which could inform future PROMs studies, including utilising general practitioners to assess eligibility and providing a freephone service.
Analysis of drug interactions at the end of life
Authors: Morgan N A , Rowett D , Currow D C 
Published: April 2015

BackgroundAs death approaches, patients are at their most frail, but an increasing symptom burden often necessitates an increase in medications, putting them at higher risk for drug–drug interactions.ObjectivesTo assess the potential for drug–drug interactions in routine prescribing at the end of life.MethodsAn Australian retrospective multicentre case-note review of 266 consecutive adult patients who were referred to specialist palliative care, with data available on 166. Medications used in the last 2 weeks of life were screened for potential interactions using the ‘Stockley's Drug Interactions’ software.ResultsThe mean number of medications prescribed was 10.8, median 9 (IQR 6–14); all patients received at least one medication. In this study, 72% of patients were at risk of 1 or more potential drug–drug interaction. The mean number of potential interactions was 4.4, with a median of 2.5 (IQR 0–7) per patient. There were only 4/166 (2.4%) prescribed medications with an associated clinical record of an adverse drug reaction.ConclusionsPotential drug–drug interactions are common for this group of patients. Some interactions may be recognised as an acceptable risk when the prescription is written. Further research is necessary to determine the best way to improve recognition of potential drug–drug interactions and the rates of morbidity or accelerated mortality associated with this. It is likely that palliative care services will need to implement multiple strategies including greater use of computerised prescribing software, and greater closer liaison with clinical pharmacists.
THE RECOGNITION OF STEMI BY PARAMEDICS AND THE EFFECT OF COMPUTER INTERPRETATION (RESPECT): A CLUSTER-RANDOMISED CROSSOVER PILOT STUDY
Authors: Pilbery Richard , Teare Dawn , Goodacre Steve , Morris Francis 
Published: April 2015

BackgroundTimely diagnosis and appropriate management of patients with ST-segment elevation myocardial infarction (STEMI) depends on accurate interpretation of the 12-lead ECG by paramedics. Computer interpretation messages on ECGs are often provided, but the effect they exert on paramedics' decision making is not known. The objective of this pilot study was to assess the feasibility of a trial using an online assessment tool, to determine the effect of computer interpretation messages on paramedics' diagnosis of STEMI.MethodsThe RESPECT pilot study is a cluster-randomised crossover trial using a bespoke, web-based assessment tool. Participants were randomly allocated 12 of 48 ECGs, with an equal mix of correct and incorrect computer interpretation messages, and STEMI and STEMI-mimics. These were viewed in two phases, with message visibility reversed between phases.Results254 paramedics consented into the study, 205 completing the first phase and 150 completing phase two. The data were analysed in two subsets: computer message correct and computer message incorrect. In the subset of correct computer interpretations, accuracy was 84% (message hidden) and 87% (message visible). The subset of incorrect computer interpretations resulted in an accuracy of 77% (message hidden) and 71% (message visible). For the subset of correct computer interpretation, the unadjusted OR was 1.31 (95% CI 1.01–1.71), adjusted OR, 1.80 (95% CI 0.84–4.80), the ICC for participants was 0.36 and for ECGs, 0.18 Incorrect computer interpretations had an unadjusted OR of 0.76 (95% CI 0.61–0.93), adjusted OR, 0.58 (95% CI 0.41–0.80), the ICC for participants was 0.06 and for ECGs, 0.01.ConclusionA randomised crossover trial to determine the effect of computer interpretation messages is feasible. Pilot data have provided an indication about expected rates of discordance and suggest that incorrect computer messages have a stronger influence across participants and ECGs.