bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic Polymorphism and Zoonotic Potential of
Enterocytozoon bieneusi
from Nonhuman Primates in China
Authors: Karim Md Robiul , Wang Rongjun , Dong Haiju , Zhang Longxian , Li Jian , Zhang Sumei , Rume Farzana Islam , Qi Meng , Jian Fuchun , Sun Mingfei , Yang Guangyou , Zou Fengcai , Ning Changshen , Xiao Lihua 
Published: January 2014

ABSTRACT

Enterocytozoon bieneusi
is an important zoonotic pathogen. To assess the human-infective potential of
E. bieneusi
in nonhuman primates (NHPs), we examined the prevalence and genotype distribution of
E. bieneusi
in 23 NHP species by PCR and sequence analysis of the ribosomal internal transcribed spacer (ITS). A total of 1,386 fecal specimens from NHPs from five provinces in China were examined, and
E. bieneusi
was detected in 158 (11.4%) specimens from five NHP species, including cynomolgus monkey (67.7%), rhesus macaque (8.8%), Japanese macaque (33.3%), white-headed langur (13.6%), and golden snub-nosed monkey (3.5%) (
P
< 0.0001). The infection rates were 70.2%, 21.5%, 8.5%, 7.5%, and 5.6% in Guangdong, Yunnan, Guangxi, Henan, and Sichuan Provinces, respectively (
P
< 0.0001). The prevalence was significantly higher in captive (13.7%) than in free-range (5.0%) animals (
P
< 0.0001). Altogether, 16 ITS genotypes were observed, including nine known genotypes (IV, D, Henan V, Peru8, PigEBITS7, EbpC, Peru11, BEB6, and I) and seven new genotypes (CM1 to CM7). The common genotypes included CM1, IV, and D, which were detected in 43, 31, and 30 specimens, respectively. Phylogenetic analysis revealed that seven known genotypes (but not BEB6 and I) and four new genotypes (CM1, CM2, CM3, and CM6) belonged to the previously described group 1 with zoonotic potential. Genotypes CM5 and CM7 clustered with group 2, whereas genotype CM4 did not belong to any of the previously proposed groups. It was concluded that humans and NHPs residing in the same geographical location shared the same
E. bieneusi
genotypes, indicating a potential role of these animals in the zoonotic transmission of
E. bieneusi
.
Triacylglyceride Production and Autophagous Responses in Chlamydomonas reinhardtii Depend on Resource Allocation and Carbon Source
Authors: Davey Matthew P. , Horst Irmtraud , Duong Giang-Huong , Tomsett Eleanor V. , Litvinenko Alexander C. P. , Howe Christopher J. , Smith Alison G. 
Published: January 2014

ABSTRACT

To improve the economic viability of microalgal biodiesel, it will be essential to optimize the productivity of fuel molecules such as triacylglyceride (TAG) within the microalgal cell. To understand some of the triggers required for the metabolic switch to TAG production, we studied the effect of the carbon supply (acetate or CO
2
) in
Chlamydomonas reinhardtii
(wild type and the starchless
sta6
mutant) grown under low N availability. As expected, initial rates of TAG production were much higher when acetate was present than under strictly photosynthetic conditions, particularly for the
sta6
mutant, which cannot allocate resources to starch. However, in both strains, TAG production plateaued after a few days in mixotrophic cultures, whereas under autotrophic conditions, TAG levels continued to rise. Moreover, the reduced growth of the
sta6
mutant meant that the greatest productivity (measured as mg TAG liter
−1
day
−1
) was found in the wild type growing autotrophically. Wild-type cells responded to low N by autophagy, as shown by degradation of polar (membrane) lipids and loss of photosynthetic pigments, and this was less in cells supplied with acetate. In contrast, little or no autophagy was observed in
sta6
mutant cells, regardless of the carbon supply. Instead, very high levels of free fatty acids were observed in the
sta6
mutant, suggesting considerable alteration in metabolism. These measurements show the importance of carbon supply and strain selection for lipid productivity. Our findings will be of use for industrial cultivation, where it will be preferable to use fast-growing wild-type strains supplied with gaseous CO
2
under autotrophic conditions rather than require an exogenous supply of organic carbon.
Role for Mycobacterium tuberculosis Membrane Vesicles in Iron Acquisition
Authors: Prados-Rosales Rafael , Weinrick Brian C. , Piqué Daniel G. , Jacobs William R. , Casadevall Arturo , Rodriguez G. Marcela 
Published: January 2014

ABSTRACT

Mycobacterium tuberculosis
releases membrane vesicles packed with molecules that can modulate the immune response. Because environmental conditions often influence the production and content of bacterial vesicles, this study examined
M. tuberculosis
microvesicles released under iron limitation, a common condition faced by pathogens inside the host. The findings indicate that
M. tuberculosis
increases microvesicle production in response to iron restriction and that these microvesicles contain mycobactin, which can serve as an iron donor and supports replication of iron-starved mycobacteria. Consequently, the results revealed a role of microvesicles in iron acquisition in
M. tuberculosis
, which can be critical for survival in the host.
Lipoteichoic Acids, Phosphate-Containing Polymers in the Envelope of Gram-Positive Bacteria
Authors: Schneewind Olaf , Missiakas Dominique 
Published: January 2014

ABSTRACT

Lipoteichoic acids (LTA) are polymers of alternating units of a polyhydroxy alkane, including glycerol and ribitol, and phosphoric acid, joined to form phosphodiester units that are found in the envelope of Gram-positive bacteria. Here we review four different types of LTA that can be distinguished on the basis of their chemical structure and describe recent advances in the biosynthesis pathway for type I LTA,
d
-alanylated polyglycerol-phosphate linked to di-glucosyl-diacylglycerol. The physiological functions of type I LTA are discussed in the context of inhibitors that block their synthesis and of mutants with discrete synthesis defects. Research on LTA structure and function represents a large frontier that has been investigated in only few Gram-positive bacteria.
Global Identification of Genes Affecting Iron-Sulfur Cluster Biogenesis and Iron Homeostasis
Authors: Hidese Ryota , Mihara Hisaaki , Kurihara Tatsuo , Esaki Nobuyoshi 
Published: January 2014

ABSTRACT

Iron-sulfur (Fe-S) clusters are ubiquitous cofactors that are crucial for many physiological processes in all organisms. In
Escherichia coli
, assembly of Fe-S clusters depends on the activity of the iron-sulfur cluster (ISC) assembly and sulfur mobilization (SUF) apparatus. However, the underlying molecular mechanisms and the mechanisms that control Fe-S cluster biogenesis and iron homeostasis are still poorly defined. In this study, we performed a global screen to identify the factors affecting Fe-S cluster biogenesis and iron homeostasis using the Keio collection, which is a library of 3,815 single-gene
E. coli
knockout mutants. The approach was based on radiolabeling of the cells with [2-
14
C]dihydrouracil, which entirely depends on the activity of an Fe-S enzyme, dihydropyrimidine dehydrogenase. We identified 49 genes affecting Fe-S cluster biogenesis and/or iron homeostasis, including 23 genes important only under microaerobic/anaerobic conditions. This study defines key proteins associated with Fe-S cluster biogenesis and iron homeostasis, which will aid further understanding of the cellular mechanisms that coordinate the processes. In addition, we applied the [2-
14
C]dihydrouracil-labeling method to analyze the role of amino acid residues of an Fe-S cluster assembly scaffold (IscU) as a model of the Fe-S cluster assembly apparatus. The analysis showed that Cys37, Cys63, His105, and Cys106 are essential for the function of IscU
in vivo
, demonstrating the potential of the method to investigate
in vivo
function of proteins involved in Fe-S cluster assembly.
Assessment of the Requirements for Magnesium Transporters in Bacillus subtilis
Authors: Wakeman Catherine A. , Goodson Jonathan R. , Zacharia Vineetha M. , Winkler Wade C. 
Published: January 2014

ABSTRACT

Magnesium is the most abundant divalent metal in cells and is required for many structural and enzymatic functions. For bacteria, at least three families of proteins function as magnesium transporters. In recent years, it has been shown that a subset of these transport proteins is regulated by magnesium-responsive genetic control elements. In this study, we investigated the cellular requirements for magnesium homeostasis in the model microorganism
Bacillus subtilis
. Putative magnesium transporter genes were mutationally disrupted, singly and in combination, in order to assess their general importance. Mutation of only one of these genes resulted in strong dependency on supplemental extracellular magnesium. Notably, this transporter gene,
mgtE
, is known to be under magnesium-responsive genetic regulatory control. This suggests that the identification of magnesium-responsive genetic mechanisms may generally denote primary transport proteins for bacteria. To investigate whether
B. subtilis
encodes yet additional classes of transport mechanisms, suppressor strains that permitted the growth of a transporter-defective mutant were identified. Several of these strains were sequenced to determine the genetic basis of the suppressor phenotypes. None of these mutations occurred in transport protein homologues; instead, they affected housekeeping functions, such as signal recognition particle components and ATP synthase machinery. From these aggregate data, we speculate that the
mgtE
protein provides the primary route of magnesium import in
B. subtilis
and that the other putative transport proteins are likely to be utilized for more-specialized growth conditions.
Bacterial Flagellin-Specific Chaperone FliS Interacts with Anti-Sigma Factor FlgM
Authors: Galeva Anna , Moroz Natalia , Yoon Young-Ho , Hughes Kelly T. , Samatey Fadel A. , Kostyukova Alla S. 
Published: January 2014

ABSTRACT

Flagella are extracellular organelles that propel bacteria. Each flagellum consists of a basal body, a hook, and a filament. The major protein of the filament is flagellin. Induction of flagellin gene expression coincides with secretion of FlgM. The role of FlgM is to inhibit FliA (σ
28
), a flagellum-specific RNA polymerase responsible for flagellin transcription. To prevent premature polymerization of newly synthesized flagellin molecules, FliS, the flagellin-specific chaperone, binds flagellin and facilitates its export. In this study, the interaction between FlgM and FliS from
Salmonella enterica
serovar Typhimurium was characterized using gel shift, intrinsic tryptophan fluorescence, circular dichroism, limited proteolysis, and cross-linking. We have demonstrated that (i) FliS and FlgM interact specifically, forming a 1:1 complex, (ii) the FliS binding site on FlgM is proximal to or even overlaps the binding site for FliA, and (iii) FliA competes with FliS for FlgM binding.
Calvin Cycle Mutants of Photoheterotrophic Purple Nonsulfur Bacteria Fail To Grow Due to an Electron Imbalance Rather than Toxic Metabolite Accumulation
Authors: Gordon Gina C. , McKinlay James B. 
Published: January 2014

ABSTRACT

Purple nonsulfur bacteria grow photoheterotrophically by using light for energy and organic compounds for carbon and electrons. Disrupting the activity of the CO
2
-fixing Calvin cycle enzyme, ribulose 1,5-bisphosphate carboxylase (RubisCO), prevents photoheterotrophic growth unless an electron acceptor is provided or if cells can dispose of electrons as H
2
. Such observations led to the long-standing model wherein the Calvin cycle is necessary during photoheterotrophic growth to maintain a pool of oxidized electron carriers. This model was recently challenged with an alternative model wherein disrupting RubisCO activity prevents photoheterotrophic growth due to the accumulation of toxic ribulose-1,5-bisphosphate (RuBP) (D. Wang, Y. Zhang, E. L. Pohlmann, J. Li, and G. P. Roberts, J. Bacteriol. 193:3293-3303, 2011,
http://dx.doi.org/10.1128/JB.00265-11
). Here, we confirm that RuBP accumulation can impede the growth of
Rhodospirillum rubrum
(
Rs. rubrum
) and
Rhodopseudomonas palustris
(
Rp. palustris
) RubisCO-deficient (ΔRubisCO) mutants under conditions where electron carrier oxidation is coupled to H
2
production. However, we also demonstrate that
Rs. rubrum
and
Rp. palustris
Calvin cycle phosphoribulokinase mutants that cannot produce RuBP cannot grow photoheterotrophically on succinate unless an electron acceptor is provided or H
2
production is permitted. Thus, the Calvin cycle is still needed to oxidize electron carriers even in the absence of toxic RuBP. Surprisingly, Calvin cycle mutants of
Rs. rubrum
, but not of
Rp. palustris
, grew photoheterotrophically on malate without electron acceptors or H
2
production. The mechanism by which
Rs. rubrum
grows under these conditions remains to be elucidated.
An Archaeal Glutamate Decarboxylase Homolog Functions as an Aspartate Decarboxylase and Is Involved in β-Alanine and Coenzyme A Biosynthesis
Authors: Tomita Hiroya , Yokooji Yuusuke , Ishibashi Takuya , Imanaka Tadayuki , Atomi Haruyuki 
Published: January 2014

ABSTRACT

β-Alanine is a precursor for coenzyme A (CoA) biosynthesis and is a substrate for the bacterial/eukaryotic pantothenate synthetase and archaeal phosphopantothenate synthetase. β-Alanine is synthesized through various enzymes/pathways in bacteria and eukaryotes, including the direct decarboxylation of Asp by aspartate 1-decarboxylase (ADC), the degradation of pyrimidine, or the oxidation of polyamines. However, in most archaea, homologs of these enzymes are not present; thus, the mechanisms of β-alanine biosynthesis remain unclear. Here, we performed a biochemical and genetic study on a glutamate decarboxylase (GAD) homolog encoded by TK1814 from the hyperthermophilic archaeon
Thermococcus kodakarensis
. GADs are distributed in all three domains of life, generally catalyzing the decarboxylation of Glu to γ-aminobutyrate (GABA). The recombinant TK1814 protein displayed not only GAD activity but also ADC activity using pyridoxal 5′-phosphate as a cofactor. Kinetic studies revealed that the TK1814 protein prefers Asp as its substrate rather than Glu, with nearly a 20-fold difference in catalytic efficiency. Gene disruption of TK1814 resulted in a strain that could not grow in standard medium. Addition of β-alanine, 4′-phosphopantothenate, or CoA complemented the growth defect, whereas GABA could not. Our results provide genetic evidence that TK1814 functions as an ADC in
T. kodakarensis
, providing the β-alanine necessary for CoA biosynthesis. The results also suggest that the GAD activity of TK1814 is not necessary for growth, at least under the conditions applied in this study. TK1814 homologs are distributed in a wide range of archaea and may be responsible for β-alanine biosynthesis in these organisms.
Behavioural activation versus mindfulness-based guided self-help treatment administered through a smartphone application: a randomised controlled trial
Authors: Ly Kien Hoa , Trüschel Anna , Jarl Linnea , Magnusson Susanna , Windahl Tove , Johansson Robert , Carlbring Per , Andersson Gerhard 
Published: January 2014

ObjectivesEvaluating and comparing the effectiveness of two smartphone-delivered treatments: one based on behavioural activation (BA) and other on mindfulness.DesignParallel randomised controlled, open, trial. Participants were allocated using an online randomisation tool, handled by an independent person who was separate from the staff conducting the study.SettingGeneral community, with recruitment nationally through mass media and advertisements.Participants40 participants diagnosed with major depressive disorder received a BA treatment, and 41 participants received a mindfulness treatment. 9 participants were lost at the post-treatment.InterventionBA: An 8-week long behaviour programme administered via a smartphone application. Mindfulness: An 8-week long mindfulness programme, administered via a smartphone application.Main outcome measuresThe Beck Depression Inventory-II (BDI-II) and the nine-item Patient Health Questionnaire Depression Scale (PHQ-9).Results81 participants were randomised (mean age 36.0 years (SD=10.8)) and analysed. Results showed no significant interaction effects of group and time on any of the outcome measures either from pretreatment to post-treatment or from pretreatment to the 6-month follow-up. Subgroup analyses showed that the BA treatment was more effective than the mindfulness treatment among participants with higher initial severity of depression from pretreatment to the 6-month follow-up (PHQ-9: F (1, 362.1)=5.2, p<0.05). In contrast, the mindfulness treatment worked better than the BA treatment among participants with lower initial severity from pretreatment to the 6-month follow-up (PHQ-9: F (1, 69.3)=7.7, p<0.01); BDI-II: (F(1, 53.60)=6.25, p<0.05).ConclusionsThe two interventions did not differ significantly from one another. For participants with higher severity of depression, the treatment based on BA was superior to the treatment based on mindfulness. For participants with lower initial severity, the treatment based on mindfulness worked significantly better than the treatment based on BA.Trial registrationClinical TrialsNCT01463020.
Effectiveness of a pharmacist-based gout care management programme in a large integrated health plan: results from a pilot study
Authors: Goldfien Robert D , Ng Michele S , Yip Goldie , Hwe Alice , Jacobson Alice , Pressman Alice , Avins Andrew L 
Published: January 2014

ObjectivesThe study objective was to determine the feasibility of using a pharmacist-staffed, protocol-based structured approach to improving the management of chronic, recurrent gout.SettingThe study was carried out in the outpatient clinic of a single Kaiser Permanente medical centre. This is a community-based clinic.ParticipantsWe report on 100 consecutive patients between the ages of 21 and 94 (75% men) with chronic or recurrent gout, referred by their primary physicians for the purpose of management of urate-lowering therapy. Patients with stage 5 chronic kidney disease or end-stage kidney disease were excluded.InterventionsThe programme consisted of a trained clinical pharmacist and a rheumatologist. The pharmacist contacted each patient by phone, provided educational and dietary materials, and used a protocol that employs standard gout medications to achieve and maintain a serum uric acid (sUA) level of 6 mg/dL or less. Incident gout flares or adverse reactions to medications were managed in consultation with the rheumatologist.Primary outcome measureThe primary outcome measure was the achievement and maintenance of an sUA of 6 or less for a period of at least 3 months.ResultsIn 95 evaluable patients enrolled in our pilot programme, an sUA of 6 mg/dL or less was achieved and maintained in 78 patients with 4 still in the programme to date. Five patients declined to participate after referral, and another 13 patients did not complete the programme. (The majority of these were due to non-adherence.)ConclusionsA structured pharmacist-staffed programme can effectively and safely lower and maintain uric acid levels in a high percentage of patients with recurrent gout in a primary care setting. This care model is simple to implement, efficient and warrants further validation in a clinical trial.
To close or not to close? Analysis of 4 year's data from national surveillance of norovirus outbreaks in hospitals in England
Authors: Harris John P , Adak Goutam K , O'Brien Sarah J 
Published: January 2014

ObjectiveTo assess the impact of ward or bay closures, specifically, whether prompt closure of an affected ward shortens the duration of norovirus outbreaks and the resulting disruption in hospitals.DesignAnalysis of summary data from hospitals on outbreaks of norovirus from 2009 to 2012.MethodsUsing a large outbreak surveillance dataset, we examined the duration of outbreaks, duration of disruption, ward closures, the number of patients and staff affected and the number of lost bed-days, as functions of the timing of closure. We conducted Quasi-Poisson regression analyses to assess the effect of ward closure (timing of closure) on outcome measures, controlling for time of year (winter or summer), ward size and ward type (elderly care wards).ResultsRegression analysis indicates that after controlling for season ward size and type, the duration of outbreak and duration of disruption were shorter, fewer patients were affected by the time of closure and fewer patients were affected overall, when closure occurred promptly (within 3 days of the first case becoming ill) compared with non-prompt closure groups. However, in outbreaks where wards were not closed, the length of outbreaks were similar to the prompt closure group and also had fewer patients and staff affected and fewer cases per day of outbreak compared with prompt closure.ConclusionsClosing a bay or ward promptly in an outbreak of norovirus leads to a shorter duration of outbreaks, a shorter duration of disruption and fewer patients being affected compared with outbreaks where wards were not promptly closed. However, the interpretation of these results is not straightforward. The outbreaks where the ward was not closed at all have similar characteristics in terms of the duration of outbreak and fewer people were affected compared with the baseline prompt closure group.
Can the relationship between ethnicity and obesity-related behaviours among school-aged children be explained by deprivation? A cross-sectional study
Authors: Falconer Catherine L , Park Min Hae , Croker Helen , Kessel Anthony S , Saxena Sonia , Viner Russell M , Kinra Sanjay 
Published: January 2014

ObjectivesIt is unclear whether cultural differences or material disadvantage explain the ethnic patterning of obesogenic behaviours. The aim of this study was to examine ethnicity as a predictor of obesity-related behaviours among children in England, and to assess whether the effects of ethnicity could be explained by deprivation.SettingFive primary care trusts in England, 2010–2011.ParticipantsParents of white, black and South Asian children aged 4–5 and 10–11 years participating in the National Child Measurement Programme (n=2773).Primary outcome measuresParent-reported measures of child behaviour: low level of physical activity, excessive screen time, unhealthy dietary behaviours and obesogenic lifestyle (combination of all three obesity-related behaviours). Associations between these behaviours and ethnicity were assessed using logistic regression analyses.ResultsSouth Asian ethnic groups made up 22% of the sample, black ethnic groups made up 8%. Compared with white children, higher proportions of Asian and black children were overweight or obese (21–27% vs16% of white children), lived in the most deprived areas (24–47% vs 14%) and reported obesity-related behaviours (38% with obesogenic lifestyle vs 16%). After adjusting for deprivation and other sociodemographic characteristics, black and Asian children were three times more likely to have an obesogenic lifestyle than white children (OR 3.0, 95% CI 2.1 to 4.2 for Asian children; OR 3.4, 95% CI 2.7 to 4.3 for black children).ConclusionsChildren from Asian and black ethnic groups are more likely to have obesogenic lifestyles than their white peers. These differences are not explained by deprivation. Culturally specific lifestyle interventions may be required to reduce obesity-related health inequalities.