bluuebunny/crossref_metadata_2025 huggingface dataset:
The Efficacy of Pad Placement for Electrical Cardioversion of Atrial Fibrillation/Flutter: A Systematic Review
Authors: Kirkland Scott , Stiell Ian , AlShawabkeh Tariq , Campbell Sandy , Dickinson Garth , Rowe Brian H.
Published: August 2014

Objectives

Electrical cardioversion is commonly used to treat patients with atrial fibrillation and atrial flutter to restore normal sinus rhythm. There has been considerable debate as to whether the electrode placement affects the efficacy of electrical cardioversion. The objective of this study was to examine the effectiveness of anteroposterior (A‐P) versus anterolateral (A‐L) electrode placement to restore normal sinus rhythm.

Methods

A search of eight electronic databases, including Medline, EMBASE, CINAHL, and Cochrane was completed. Grey literature (hand‐searching, Google, and SCOPUS) searching was also conducted. Studies were included if they were controlled clinical trials comparing the effectiveness of A‐P versus A‐L pad placement to restore normal sinus rhythm in adult patients with atrial fibrillation and flutter. Two independent reviewers judged study relevance, inclusion, and quality (e.g., risk of bias). Individual and pooled statistics were calculated as relative risks (RRs) with 95% confidence intervals (CIs) using a random‐effects model, and heterogeneity (I2) was reported.

Results

From 788 citations, 13 studies were included; seven involved monophasic, five involved biphasic, and one analyzed both waveform devices. The included studies tended to report cumulative success rates to restoring normal sinus rhythm after one to five sequential shocks of increasing energy; the number of shocks and energy used differed among studies. The risk of bias of the studies was “unclear.” After the first shock, pad placement was not associated with an increased likelihood of restoring normal sinus rhythm (RR = 0.88; 95% CI = 0.73 to 1.06); however, heterogeneity was high (I2 = 63%). Subgroup comparisons revealed that the A‐L position was more effective (RR = 0.77; 95% CI = 0.59 to 1.00) at restoring normal sinus rhythm when using biphasic shocks (comparison p = 0.04). Overall, the pooled results failed to identify a difference between A‐P and A‐L pad placement in restoring normal sinus rhythm at any time (RR = 1.00; 95% CI = 0.95 to 1.05); however, heterogeneity was high (I2 = 61%). No significant subgroup differences were found. Side effects were reported in only three studies.

Conclusions

The published literature is restricted to persistent atrial fibrillation and atrial flutter, pad placement varied, and energy levels used were lower than currently recommended; however, the accumulated evidence suggests that electrical pad placement is not a critically important factor in successful cardioversion in atrial fibrillation and flutter (AF/AFL). A trial is urgently needed in recent‐onset atrial fibrillation and atrial flutter patients using biphasic devices and high energy levels to resolve the debate.
Term breech deliveries in the Netherlands: did the increased cesarean rate affect neonatal outcome? A population‐based cohort study
Authors: Vlemmix Floortje , Bergenhenegouwen Lester , Schaaf Jelle M. , Ensing Sabine , Rosman Ageeth N. , Ravelli Anita C.J. , van der Post Joris A.M. , Verhoeven Arno , Visser Gerard H. , Mol Ben W.J. , Kok Marjolein
Published: August 2014

Objective

The aim of this study was to evaluate the effect of the increased cesarean rate for term breech presentation on neonatal outcome. We also investigated whether the clinical case selection for vaginal delivery applied by Dutch obstetricians led to an optimization of neonatal outcome, or whether there is still room for improvement in terms of perinatal outcome.

Design

Retrospective cohort.

Setting

The Netherlands.

Population

Singleton term breech deliveries from 37+0 to 41+6 weeks, excluding fetuses with congenital malformations or antenatal death.

Method

We used data from the Dutch national perinatal registry from 1999 up to 2007.

Main outcome measures

Perinatal mortality and morbidity.

Results

We studied 58 320 women with a term breech delivery. There was an increase in the elective cesarean rate (from 24 to 60%). As a consequence, overall perinatal mortality decreased [1.3‰ vs. 0.7‰; odds ratio 0.51 (95% confidence interval 0.28–0.93)], whereas it remained stable in the planned vaginal birth group [1.7‰ vs. 1.6‰; odds ratio 0.96 (95% confidence interval 0.52–1.76)]. The number of cesareans done to prevent one perinatal death was 338.

Conclusions

Adjustment of the national guidelines after publication of the Term Breech Trial resulted in a shift towards elective cesarean and a decrease of perinatal mortality and morbidity among women delivering a child in breech at term. Still, 40% of these women attempt vaginal birth. The relative safety of an elective cesarean should be weighed against the consequences of a scarred uterus in future pregnancies.
Valued Lives in Violent Places: Black Urban Placemaking at a Civil Rights Memorial in New Orleans
Authors: CARTER REBECCA LOUISE
Published: August 2014

This article explores the history, use, and significance of a civil rights memorial to Martin Luther King Jr, located in the Central City neighborhood of New Orleans. Situating this memorial as an important site for black urban placemaking, I focus on a religious vigil against urban violence that was held there in late 2008. Using historical and ethnographic data, I demonstrate how participants in the vigil claim and inhabit the memorial in order to raise awareness about the impact of violence, while simultaneously asserting the social value of black people and communities. I argue that this action unfolds with particular urgency in the post‐Katrina period, to counter the perceived devaluation, criminalization, and social exclusion of black people. Participants in the vigil thus rework spatial, social, and symbolic boundaries to shift relatedness and to ensure survival and social membership. The article goes beyond traditionally territorialized understandings of place and placemaking to demonstrate how the actions, interactions, and moral frameworks emerging at this particular place are part of a larger black geography and spatial imaginary, one with the capacity to transform the conceptualization and experience of urban space, place, and community.
Identification of a Plasmodium falciparum inhibitor‐2 motif involved in the binding and regulation activity of protein phosphatase type 1
Authors: Fréville Aline , Tellier Géraldine , Vandomme Audrey , Pierrot Christine , Vicogne Jérôme , Cantrelle François‐Xavier , Martoriati Alain , Cailliau‐Maggio Katia , Khalife Jamal , Landrieu Isabelle
Published: August 2014

The regulation of Plasmodium falciparum protein phosphatase type 1 (PfPP1) activity remains to be deciphered. Data from homologous eukaryotic type 1 protein phosphatases (PP1) suggest that several protein regulators should be involved in this essential process. One such regulator, named PfI2 based on its primary sequence homology with eukaryotic inhibitor 2 (I2), was recently shown to be able to interact with PfPP1 and to inhibit its phosphatase activity, mainly through the canonical ‘RVxF’ binding motif. The details of the structural and functional characteristics of this interaction are investigated here. Using NMR spectroscopy, a second site of interaction is suggested to reside between residues D94 and T117 and contains the ‘FxxR/KxR/K’ binding motif present in other I2 proteins. This site seems to play in concert/synergy with the ‘RVxF’ motif to bind PP1, because only mutations in both motifs were able to abolish this interaction completely. However, regarding the structure/function relationship, mutation of either the ‘RVxF’ or ‘FxxR/KxR/K’ motif is more drastic, because each mutation prevents the capacity of PfI2 to trigger germinal vesicle breakdown in microinjected Xenopus oocytes. This indicates that the tight association of the PfI2 regulator to PP1, mediated by a two‐site interaction, is necessary to exert its function. Based on these results, the use of a peptide derived from the ‘FxxR/KxR/K’ PfI2 motif was investigated for its potential effect on Plasmodium growth. This peptide, fused at its N‐terminus to a penetrating sequence, was shown to accumulate specifically in infected erythrocytes and to have an antiplasmodial effect.

Structured digital abstract

PfPP1 and PfI2 bind by nuclear magnetic resonance (1, 2)

PP1 physically interacts with PfPP1 by anti tag coimmunoprecipitation (View interaction)

PfI2 binds to PfPP1 by enzyme linked immunosorbent assay (View interaction)

PfI2 binds to PfPP1 by surface plasmon resonance (1, 2, 3, 4)
Molecular characterization of the thioredoxin system from Methanosarcina acetivorans
Authors: McCarver Addison C. , Lessner Daniel J.
Published: August 2014

The thioredoxin system, composed of thioredoxin reductase (TrxR) and thioredoxin (Trx), is widely distributed in nature, where it serves key roles in electron transfer and in the defense against oxidative stress. Although recent evidence reveals Trx homologues are almost universally present among the methane‐producing archaea (methanogens), a complete thioredoxin system has not been characterized from any methanogen. We examined the phylogeny of Trx homologues among methanogens and characterized the thioredoxin system from Methanosarcina acetivorans. Phylogenetic analysis of Trx homologues from methanogens revealed eight clades, with one clade containing Trxs broadly distributed among methanogens. The Methanococci and Methanobacteria each contain one additional Trx from another clade, respectively, whereas the Methanomicrobia contain an additional five distinct Trxs. Methanosarcina acetivorans, a member of the Methanomicrobia, contains a single TrxR (MaTrxR) and seven Trx homologues (MaTrx1–7), with representatives from five of the methanogen Trx clades. Purified recombinant MaTrxR had 5,5′‐dithiobis(2‐nitrobenzoic acid) (DTNB) reductase and oxidase activities. The apparent Km value for NADPH was 115‐fold lower than that for NADH, consistent with NADPH as the physiological electron donor to MaTrxR. Purified recombinant MaTrx2, MaTrx6 and MaTrx7 exhibited dithiothreitol‐ and lipoamide‐dependent insulin disulfide reductase activities. However, only MaTrx7, which is encoded adjacent to MaTrxR, could serve as a redox partner to MaTrxR. These results reveal that M. acetivorans harbors at least three functional and distinct Trxs, and a complete thioredoxin system composed of NADPH, MaTrxR and at least MaTrx7. This is the first characterization of a complete thioredoxin system from a methanogen, which provides a foundation to understand the system in methanogens.
Specific Yield Functions for Estimating Evapotranspiration from Diurnal Surface Water Cycles
Authors: Hill A. Jason , Durchholz Brandon
Published: August 2014

The White method has been routinely used to estimate evapotranspiration using diurnal variations in groundwater levels. Applications to surface water systems (e.g., wetlands) are less common. For applications to surface water systems, a stage‐dependent specific yield function must be defined. This is especially important for small wetlands formed in topographic depressions with bowl shaped bathymetries. Existing formulations of the specific yield function include weighting factors that impact the relative importance of the soil and open water specific yields on the composite value. Three formulations of the specific yield function from the literature were compared and found to produce varied results. Based on a comparison with empirical estimates of specific yield based on observed ratios of net precipitation to water level rise, one of the existing formulations is generalized and recommended for general use. The recommended function is dependent on wetland bathymetry, magnitude of the diurnal fluctuation, spatial extent of the equilibration area, and soil‐specific yield. A sensitivity analysis was conducted to examine the relative importance of these variables. The specific yield function is independent of wetland size and is strongly dependent on the basin profile coefficient (p), an indication of wetland shape. For most natural wetlands, bathymetry strongly influences specific yield.
Follicle stimulating hormone receptor in mesenchymal stem cells integrates effects of glycoprotein reproductive hormones
Authors: Tourkova Irina L. , Witt Michelle R. , Li La , Larrouture Quitterie , Liu Li , Luo Jianhua , Robinson Lisa J. , Blair Harry C.
Published: August 2014

Previously we reported that follicle stimulating hormone (FSH) affects bone degradation in human cells and in follicle stimulating hormone receptor (FSH‐R) null mice. Here we describe a FSH‐R knockout bone‐formation phenotype. We used mesenchymal stem cells (MSCs), osteoblast precursors that express FSH‐R, to determine whether FSH regulates bone formation. FSH stimulates MSC cell adhesion 1–3 h and proliferation at 24 h after addition. On the basis of phylogenetic and clinical precedents, we also examined effects of pregnant levels of human chorionic gonadotropin (hCG) on MSCs. We found effects similar to those of FSH, and RNAi knockdown of FSH‐R abrogated both FSH and hCG effects on MSCs. In contrast to effects on MSCs, neither FSH nor hCG had significant effects on osteoblast maturation. Also in MSCs, short‐term treatment by FSH and hCG altered signaling pathways for proliferation, including Erk1/2 phosphorylation. Our results show augmentation of MSC proliferation by either FSH at menopausal levels or hCG at normal pregnant levels. We conclude that FSH‐R participates in regulation of MSC precursor pools in response to either FSH or hCG, integrating the effects of these two glycoprotein hormones.
Significant factors in family difficulties for fathers and mothers who use support services for children with hikikomori
Authors: Funakoshi Akiko , Miyamoto Yuki
Published: August 2014

Aims

Hikikomori is a new psychosociological phenomenon among youth, of almost complete withdrawal from social interaction, and it has received considerable attention in community mental health in Japan. The aims of the present study were to identify the influential factors of family difficulties of parents who use support services for children with hikikomori, and compare them between fathers and mothers.

Methods

Data were collected from 110 parents (55 couples) of children with hikikomori with regard to family difficulties, quality of life, and depression variables via self‐report questionnaires. To assess the influential factors of Family Difficulties for parents with children with hikikomori, hierarchical multiple linear regression analysis was carried out for gender.

Results

While 94.5% of mothers received some kind of family support, only 61.9% of fathers received it. For both genders, the number of services that the fathers received was significantly correlated with marital cooperation, and the number of services that the mothers received was significantly correlated with support resource utilization.

Conclusions

It is necessary for fathers to receive more support, and it is important for professionals to encourage parents to address their difficulties together.
‘Soya Milk Tris‐based Phytoextender Reduces Apoptosis in Cryopreserved Buffalo (Bubalus bubalis) Spermatozoa’
Authors: Mohan R , Atreja SK
Published: August 2014

Contents

The objective of this study was to investigate the effect of newly developed soya milk Tris (SMT)‐based phytoextender as an alternative to egg yolk Tris (EYT) extender used for cryopreservation of buffalo (Bubalus bubalis) spermatozoa on apoptosis. Fresh buffalo semen (control without dilution) was cryopreserved in conventional EYT (20% egg yolk v/v in Tris) and SMT (25% soya milk v/v in Tris) extender and used for the assessment of expression of apoptotic proteins. Proteins extracted from a total number of nine ejaculates from three individual buffalo bulls chosen at random were separated using SDS–PAGE followed by immunoblotting against caspase‐8, caspase‐9, caspase‐3, poly(ADP‐ribose)polymerase (PARP), cytochrome c and apoptosis inducing factor (AIF). In addition, fluorescence microscopy was used for the detection of mitochondrial membrane potential (JC‐1 assay) and apoptotic cells (annexin V‐FITC/PI assay). The results obtained clearly indicate the significant (p < 0.05) reduction in the expression of caspase‐3 (27 kDa), caspase‐8 (53 kDa), caspase‐9 (50 kDa) precursor and cytochrome c (17 kDa) in semen cryopreserved in SMT extender in comparison with EYT extender. A non‐significant (p > 0.05) reduction in expression of PARP‐DNA‐binding subunit (24 kDa) was observed in SMT extender. No expression of AIF was found in cryopreserved semen samples. A significant (p < 0.05) increase in the mean percentage of cells having high mitochondrial membrane potential and a non‐significant (p > 0.05) decrease in late apoptotic cells (AN+/PI+) was observed in SMT extender when compared to EYT extender. The results demonstrated that cryopreservation of buffalo semen in SMT‐based phytoextender can replace the traditional egg yolk extenders as it reduces the expression of apoptotic proteins maintaining high mitochondrial membrane potential and gives better protection to sperms in terms of its non‐animal origin.
Polymorphism in NFKBIA gene is associated with recurrent acute rejections in liver transplant recipients
Authors: Kramer K. , Thye T. , Treszl A. , Peine S. , Koch M. , Sterneck M. , Nashan B. , Thude H.
Published: August 2014

The nuclear factor of kappa light polypeptide gene enhancer B‐cells inhibitor‐alpha (NFKBIA) gene encodes a member of the nuclear factor‐kappa‐B inhibitor family. Polymorphisms in this gene might be associated with a susceptibility to acute rejection episodes following liver transplantation, as they may cause an increased activation level of the proinflammatory transcription factor nuclear factor of kappa light polypeptide gene enhancer in B‐cells (NFκB). The aim of this study was to evaluate whether the NFKBIA polymorphisms −297 C/T (rs2233409), −826 C/T (rs2233406) and 126 G/A (rs696) affect the incidence of acute liver graft rejection. A total of 199 liver transplant recipients was analyzed, 100 without (NAR) and 99 with early acute rejection (AR). Thirty‐two individuals with multiple acute rejections (MAR) were analyzed as a subgroup of AR. Polymerase chain reaction‐allele specific restriction enzyme analysis (PCR‐ASRA) and allele‐specific hybridization with fluorescence resonance energy transfer (FRET) were used for genotyping. We identified the genotype NFKBIA 126 AA (P = 0.002) as well as the haplotype NFKBIA–126A–297T–826T (P = 0.002) as a potential risk factor for the occurrence of recurrent acute rejections. Furthermore, we assessed an association between the 126 A allele and susceptibility to recurrent acute rejections (P = 0.027). Our data suggest that the NFKBIA 126 G/A polymorphism might be potentially helpful to identify liver transplant recipients with an increased susceptibility to develop recurrent acute rejections.
Pressure natriuresis and the renal control of arterial blood pressure
Authors: Ivy Jessica R. , Bailey Matthew A.
Published: August 2014

The regulation of extracellular fluid volume by renal sodium excretion lies at the centre of blood pressure homeostasis. Renal perfusion pressure can directly regulate sodium reabsorption in the proximal tubule. This acute pressure natriuresis response is a uniquely powerful means of stabilizing long‐term blood pressure around a set point. By logical extension, deviation from the set point can only be sustained if the pressure natriuresis mechanism is impaired, suggesting that hypertension is caused or sustained by a defect in the relationship between renal perfusion pressure and sodium excretion. Here we describe the role of pressure natriuresis in blood pressure control and outline the cascade of biophysical and paracrine events in the renal medulla that integrate the vascular and tubular response to altered perfusion pressure. Pressure natriuresis is impaired in hypertension and mechanistic insight into dysfunction comes from genetic analysis of blood pressure disorders. Transplantation studies in rats show that blood pressure is determined by the genotype of the kidney and Mendelian hypertension indicates that the distal nephron influences the overall natriuretic efficiency. These approaches and the outcomes of genome‐wide‐association studies broaden our view of blood pressure control, suggesting that renal sympathetic nerve activity and local inflammation can impair pressure natriuresis to cause hypertension. Understanding how these systems interact is necessary to tackle the global burden of hypertension.
5‐Hydroxytryptamine1A receptor‐activation hyperpolarizes pyramidal cells and suppresses hippocampal gamma oscillations via Kir3 channel activation
Authors: Johnston April , McBain Chris J. , Fisahn André
Published: August 2014

Key points

Rhythmic activity in the gamma frequency range (30–80 Hz) in the hippocampus is modulated by neurotransmitters such as serotonin, dopamine and histamine.

Multiple different serotonin receptors are expressed in the hippocampus.

Here we show that serotonin suppresses hippocampal gamma oscillations via activation of the receptor 5‐HT1A.

The cellular cause for suppressed gamma oscillations is the 5‐HT1A receptor‐induced hyperpolarization and afterpolarization frequency reduction of pyramidal cells, but not of parvalbumin‐positive interneurons.

The pyramidal cell hyperpolarization is mediated by an inwardly rectifying current mediated by the Kir3 potassium channel known to couple to 5‐HT1A, which also results in decreased firing frequency.

Rhythmic cortical neuronal oscillations in the gamma frequency band (30–80 Hz, gamma oscillations) have been associated with cognitive processes such as sensory perception and integration, attention, learning, and memory. Gamma oscillations are disrupted in disorders for which cognitive deficits are hallmark symptoms such as schizophrenia and Alzheimer's disease. In vitro, various neurotransmitters have been found to modulate gamma oscillations. Serotonin (5‐HT) has long been known to be important for both behavioural and cognitive functions such as learning and memory. Multiple 5‐HT receptor subtypes are expressed in the CA3 region of the hippocampus and high doses of 5‐HT reduce the power of induced gamma oscillations. Hypothesizing that 5‐HT may have cell‐ and receptor subtype‐specific modulatory effects, we investigated the receptor subtypes, cell types and cellular mechanisms engaged by 5‐HT in the modulation of gamma oscillations in mice and rats. We found that 5‐HT decreases the power of kainate‐induced hippocampal gamma oscillations in both species via the 5‐HT1A receptor subtype. Whole‐cell patch clamp recordings demonstrated that this decrease was caused by a hyperpolarization of CA3 pyramidal cells and a reduction of their firing frequency, but not by alteration of inhibitory neurotransmission. Finally, our results show that the effect on pyramidal cells is mediated via the G protein‐coupled receptor inwardly rectifying potassium channel Kir3. Our findings suggest this novel cellular mechanism as a potential target for therapies that are aimed at alleviating cognitive decline by helping the brain to maintain or re‐establish normal gamma oscillation levels in neuropsychiatric and neurodegenerative disorders.
Modeling precursor diffusion and reaction of atomic layer deposition in porous structures
Authors: Keuter Thomas , Menzler Norbert Heribert , Mauer Georg , Vondahlen Frank , Vaßen Robert , Buchkremer Hans Peter
Published: August 2014

Atomic layer deposition (ALD) is a technique for depositing thin films of materials with a precise thickness control and uniformity using the self-limitation of the underlying reactions. Usually, it is difficult to predict the result of the ALD process for given external parameters, e.g., the precursor exposure time or the size of the precursor molecules. Therefore, a deeper insight into ALD by modeling the process is needed to improve process control and to achieve more economical coatings. In this paper, a detailed, microscopic approach based on the model developed by Yanguas-Gil and Elam is presented and additionally compared with the experiment. Precursor diffusion and second-order reaction kinetics are combined to identify the influence of the porous substrate's microstructural parameters and the influence of precursor properties on the coating. The thickness of the deposited film is calculated for different depths inside the porous structure in relation to the precursor exposure time, the precursor vapor pressure, and other parameters. Good agreement with experimental results was obtained for ALD zirconiumdioxide (ZrO2) films using the precursors tetrakis(ethylmethylamido)zirconium and O2. The derivation can be adjusted to describe other features of ALD processes, e.g., precursor and reactive site losses, different growth modes, pore size reduction, and surface diffusion.
Syntrophs Dominate Sequences Associated with the Mercury Methylation-Related Gene
hgcA
in the Water Conservation Areas of the Florida Everglades
Authors: Bae Hee-Sung , Dierberg Forrest E. , Ogram Andrew
Published: August 2014

The mechanisms and rates of mercury methylation in the Florida Everglades are of great concern because of potential adverse impacts on human and wildlife health through mercury accumulation in aquatic food webs. We developed a new PCR primer set targeting
hgcA
, a gene encoding a corrinoid protein essential for Hg methylation across broad phylogenetic boundaries, and used this primer set to study the distribution of
hgcA
sequences in soils collected from three sites along a gradient in sulfate and nutrient concentrations in the northern Everglades. The sequences obtained were distributed in diverse phyla, including
Proteobacteria
,
Chloroflexi
,
Firmicutes
, and
Methanomicrobia
; however,
hgcA
clone libraries from all sites were dominated by sequences clustering within the order
Syntrophobacterales
of the
Deltaproteobacteria
(49 to 65% of total sequences).
dsrB
mRNA sequences, representing active sulfate-reducing prokaryotes at the time of sampling, obtained from these sites were also dominated by
Syntrophobacterales
(75 to 89%). Laboratory incubations with soils taken from the site low in sulfate concentrations also suggested that Hg methylation activities were primarily mediated by members of the order
Syntrophobacterales
, with some contribution by methanogens,
Chloroflexi
, iron-reducing
Geobacter
, and non-sulfate-reducing
Firmicutes
inhabiting the sites. This suggests that prokaryotes distributed within clades defined by syntrophs are the predominant group controlling methylation of Hg in low-sulfate areas of the Everglades. Any strategy for managing mercury methylation in the Everglades should consider that net mercury methylation is not limited to the action of sulfate reduction.
Molecular Basis of the Behavior of Hepatitis A Virus Exposed to High Hydrostatic Pressure
Authors: D'Andrea Lucía , Pérez-Rodríguez Francisco J. , Costafreda M. Isabel , Beguiristain Nerea , Fuentes Cristina , Aymerich Teresa , Guix Susana , Bosch Albert , Pintó Rosa M.
Published: August 2014

Food-borne hepatitis A outbreaks may be prevented by subjecting foods at risk of virus contamination to moderate treatments of high hydrostatic pressure (HHP). A pretreatment promoting hepatitis A virus (HAV) capsid-folding changes enhances the virucidal effect of HHP, indicating that its efficacy depends on capsid conformation. HAV populations enriched in immature capsids (125S provirions) are more resistant to HHP, suggesting that mature capsids (150S virions) are more susceptible to this treatment. In addition, the monoclonal antibody (MAb) K24F2 epitope contained in the immunodominant site is a key factor for the resistance to HHP. Changes in capsid folding inducing a loss of recognition by MAb K24F2 render more susceptible conformations independently of the origin of such changes. Accordingly, codon usage-associated folding changes and changes stimulated by pH-dependent breathings, provided they confer a loss of recognition by MAb K24F2, induce a higher susceptibility to HHP. In conclusion, the resistance of HAV to HHP treatments may be explained by a low proportion of 150S particles combined with a good accessibility of the epitope contained in the immunodominant site close to the 5-fold axis.
Stress Response of Salmonella enterica Serovar Typhimurium to Acidified Nitrite
Authors: Mühlig Anna , Behr Jürgen , Scherer Siegfried , Müller-Herbst Stefanie
Published: August 2014

The antimicrobial action of the curing agent sodium nitrite (NaNO2), which is added as a preservative to raw meat products, depends on its conversion to nitric oxide and other reactive nitrogen species under acidic conditions. In this study, we used RNA sequencing to analyze the acidified-NaNO2shock and adaptive responses ofSalmonella entericaserovar Typhimurium, a frequent contaminant in raw meat, considering parameters relevant for the production of raw-cured sausages. Upon a 10-min exposure to 150 mg/liter NaNO2in LB (pH 5.5) acidified with lactic acid, genes involved in nitrosative-stress protection, together with several other stress-related genes, were induced. In contrast, genes involved in translation, transcription, replication, and motility were downregulated. The induction of stress tolerance and the reduction of cell proliferation obviously promote survival under harsh acidified-NaNO2stress. The subsequent adaptive response was characterized by upregulation of NsrR-regulated genes and iron uptake systems and by downregulation of genes involved in anaerobic respiratory pathways. Strikingly, amino acid decarboxylase systems, which contribute to acid tolerance, displayed increased transcript levels in response to acidified NaNO2. The induction of systems known to be involved in acid resistance indicates a nitrite-mediated increase in the level of acid stress. Deletion ofcadA, which encodes lysine decarboxylase, resulted in increased sensitivity to acidified NaNO2. Intracellular pH measurements using a pH-sensitive green fluorescent protein (GFP) variant showed that the cytoplasmic pH ofS. Typhimurium in LB medium (pH 5.5) is decreased upon the addition of NaNO2. This study provides the first evidence that intracellular acidification is an additional antibacterial mode of action of acidified NaNO2.
Bdellovibrio and Like Organisms Enhanced Growth and Survival of Penaeus monodon and Altered Bacterial Community Structures in Its Rearing Water
Authors: Li Huanhuan , Chen Cheng , Sun Qiuping , Liu Renliang , Cai Junpeng
Published: August 2014

In this study, a 96-h laboratory reduction test was conducted with strain BDHSH06 (GenBank accession no.
EF011103
) as the test strain for
Bdellovibrio
and like organisms (BALOs) and 20 susceptible marine bacterial strains forming microcosms as the targets. The results showed that BDHSH06 reduced the levels of approximately 50% of prey bacterial strains within 96 h in the seawater microcosms. An 85-day black tiger shrimp (
Penaeus monodon
) rearing experiment was performed. The shrimp survival rate, body length, and weight in the test tanks were 48.1% ± 1.2%, 99.8 ± 10.0 mm, and 6.36 ± 1.50 g, respectively, which were values significantly (
P
< 0.05) higher than those for the control,
viz
., 31.0% ± 2.1%, 86.0 ± 11.1 mm, and 4.21 ± 1.56 g, respectively. With the addition of BDHSH06, total bacterial and
Vibrio
numbers were significantly reduced (
P
< 0.05) by 1.3 to 4.5 log CFU · ml
−1
and CFU · g
−1
in both water and shrimp intestines, respectively, compared to those in the control. The effect of BDHSH06 on bacterial community structures in the rearing water was also examined using PCR amplification of the 16S rRNA gene and denaturing gradient gel electrophoresis (DGGE). The DGGE profiles of rearing water samples from the control and test tanks revealed that the amounts of 44% of the bacterial species were reduced when BDHSH06 was added to the rearing water over the 85-day rearing period, and among these, approximately 57.1% were nonculturable. The results of this study demonstrated that BDHSH06 can be used as a biocontrol/probiotic agent in
P. monodon
culture.
Diverse Virulence Gene Content of Shiga Toxin-Producing Escherichia coli from Finishing Swine
Authors: Tseng Marion , Fratamico Pina M. , Bagi Lori , Delannoy Sabine , Fach Patrick , Manning Shannon D. , Funk Julie A.
Published: August 2014

Shiga toxin-producing
Escherichia coli
(STEC) infections are a critical public health concern because they can cause severe clinical outcomes, such as hemolytic uremic syndrome, in humans. Determining the presence or absence of virulence genes is essential in assessing the potential pathogenicity of STEC strains. Currently, there is limited information about the virulence genes carried by swine STEC strains; therefore, this study was conducted to examine the presence and absence of 69 virulence genes in STEC strains recovered previously from finishing swine in a longitudinal study. A subset of STEC strains was analyzed by pulsed-field gel electrophoresis (PFGE) to examine their genetic relatedness. Swine STEC strains (
n
= 150) were analyzed by the use of a high-throughput real-time PCR array system, which included 69 virulence gene targets. Three major pathotypes consisted of 16 different combinations of virulence gene profiles, and serotypes were determined in the swine STEC strains. The majority of the swine STEC strains (
n
= 120) belonged to serotype O59:H21 and carried the same virulence gene profile, which consisted of 9 virulence genes:
stx
2e
,
iha
,
ecs1763
,
lpfA
O113
,
estIa
(
STa
),
ehaA
,
paa
,
terE
, and
ureD
. The
eae
,
nleF
, and
nleH1-2
genes were detected in one swine STEC strain (O49:H21). Other genes encoding adhesins, including
iha
, were identified (
n
= 149). The PFGE results demonstrated that swine STEC strains from pigs raised in the same finishing barn were closely related. Our results revealed diverse virulence gene contents among the members of the swine STEC population and enhance understanding of the dynamics of transmission of STEC strains among pigs housed in the same barn.
An ArsR/SmtB Family Member Is Involved in the Regulation by Arsenic of the Arsenite Oxidase Operon in Thiomonas arsenitoxydans
Authors: Moinier Danielle , Slyemi Djamila , Byrne Deborah , Lignon Sabrina , Lebrun Régine , Talla Emmanuel , Bonnefoy Violaine
Published: August 2014

The genetic organization of the
aioBA
operon, encoding the arsenite oxidase of the moderately acidophilic and facultative chemoautotrophic bacterium
Thiomonas arsenitoxydans
, is different from that of the
aioBA
operon in the other arsenite oxidizers, in that it encodes AioF, a metalloprotein belonging to the ArsR/SmtB family. AioF is stabilized by arsenite, arsenate, or antimonite but not molybdate. Arsenic is tightly attached to AioF, likely by cysteine residues. When loaded with arsenite or arsenate, AioF is able to bind specifically to the regulatory region of the
aio
operon at two distinct positions. In
Thiomonas arsenitoxydans
, the promoters of
aioX
and
aioB
are convergent, suggesting that transcriptional interference occurs. These results indicate that the regulation of the
aioBA
operon is more complex in
Thiomonas arsenitoxydans
than in the other
aioBA
containing arsenite oxidizers and that the arsenic binding protein AioF is involved in this regulation. On the basis of these data, a model to explain the tight control of
aioBA
expression by arsenic in
Thiomonas arsenitoxydans
is proposed.
Different Effects of Transgenic Maize and Nontransgenic Maize on Nitrogen-Transforming Archaea and Bacteria in Tropical Soils
Authors: Cotta Simone Raposo , Dias Armando Cavalcante Franco , Marriel Ivanildo Evódio , Andreote Fernando Dini , Seldin Lucy , van Elsas Jan Dirk
Published: August 2014

The composition of the rhizosphere microbiome is a result of interactions between plant roots, soil, and environmental conditions. The impact of genetic variation in plant species on the composition of the root-associated microbiota remains poorly understood. This study assessed the abundances and structures of nitrogen-transforming (ammonia-oxidizing) archaea and bacteria as well as nitrogen-fixing bacteria driven by genetic modification of their maize host plants. The data show that significant changes in the abundances (revealed by quantitative PCR) of ammonia-oxidizing bacterial and archaeal communities occurred as a result of the maize host being genetically modified. In contrast, the structures of the total communities (determined by PCR-denaturing gradient gel electrophoresis) were mainly driven by factors such as soil type and season and not by plant genotype. Thus, the abundances of ammonia-oxidizing bacterial and archaeal communities but not structures of those communities were revealed to be responsive to changes in maize genotype, allowing the suggestion that community abundances should be explored as candidate bioindicators for monitoring the possible impacts of cultivation of genetically modified plants.
Axenic Culture of a Candidate Division TM7 Bacterium from the Human Oral Cavity and Biofilm Interactions with Other Oral Bacteria
Authors: Soro Valeria , Dutton Lindsay C. , Sprague Susan V. , Nobbs Angela H. , Ireland Anthony J. , Sandy Jonathan R. , Jepson Mark A. , Micaroni Massimo , Splatt Peter R. , Dymock David , Jenkinson Howard F.
Published: August 2014

The diversity of bacterial species in the human oral cavity is well recognized, but a high proportion of them are presently uncultivable. Candidate division TM7 bacteria are almost always detected in metagenomic studies but have not yet been cultivated. In this paper, we identified candidate division TM7 bacterial phylotypes in mature plaque samples from around orthodontic bonds in subjects undergoing orthodontic treatment. Successive rounds of enrichment in laboratory media led to the isolation of a pure culture of one of these candidate division TM7 phylotypes. The bacteria formed filaments of 20 to 200 μm in length within agar plate colonies and in monospecies biofilms on salivary pellicle and exhibited some unusual morphological characteristics by transmission electron microscopy, including a trilaminated cell surface layer and dense cytoplasmic deposits. Proteomic analyses of cell wall protein extracts identified abundant polypeptides predicted from the TM7 partial genomic sequence. Pleiomorphic phenotypes were observed when the candidate division TM7 bacterium was grown in dual-species biofilms with representatives of six different oral bacterial genera. The TM7 bacterium formed long filaments in dual-species biofilm communities with
Actinomyces oris
or
Fusobacterium nucleatum
. However, the TM7 isolate grew as short rods or cocci in dual-species biofilms with
Porphyromonas gingivalis
,
Prevotella intermedia
,
Parvimonas micra
, or
Streptococcus gordonii
, forming notably robust biofilms with the latter two species. The ability to cultivate TM7 axenically should majorly advance understanding of the physiology, genetics, and virulence properties of this novel candidate division oral bacterium.
Enhanced Inactivation of Food-Borne Pathogens in Ready-To-Eat Sliced Ham by Near-Infrared Heating Combined with UV-C Irradiation and Mechanism of the Synergistic Bactericidal Action
Authors: Ha Jae-Won , Kang Dong-Hyun
Published: August 2014

The objective of the study described in this article was, first, to investigate the effect of the simultaneous application of near-infrared (NIR) heating and UV irradiation on inactivation of
Escherichia coli
O157:H7,
Salmonella enterica
serovar Typhimurium, and
Listeria monocytogenes
in ready-to-eat (RTE) sliced ham and as well as its effect on product quality and, second, to elucidate the underlying mechanisms of the synergistic bactericidal action of NIR heating and UV irradiation. With the inoculation amounts used, simultaneous NIR-UV combined treatment for 70 s achieved 3.62, 4.17, and 3.43 log CFU reductions of
E. coli
O157:H7,
S
. Typhimurium, and
L. monocytogenes
, respectively. For all three pathogens, the simultaneous application of both technologies resulted in an additional log unit reduction as a result of their synergism compared to the sum of the reductions obtained after the individual treatments. To investigate the mechanisms of NIR-UV synergistic injury for a particular microorganism in a food base, we evaluated the effect of four types of metabolic inhibitors using the overlay method and confirmed that damage to cellular membranes and the inability of cells to repair these structures due to ribosomal damage were the primary factors related to the synergistic lethal effect. Additionally, NIR-UV combined treatment for a maximum of 70 s did not alter the color values or texture parameters of ham slices significantly (
P
> 0.05). These results suggest that a NIR-UV combined process could be an innovative antimicrobial intervention for RTE meat products.
Transcriptome Analysis of the Entomopathogenic Oomycete Lagenidium giganteum Reveals Putative Virulence Factors
Authors: Quiroz Velasquez Paula F. , Abiff Sumayyah K. , Fins Katrina C. , Conway Quincy B. , Salazar Norma C. , Delgado Ana Paula , Dawes Jhanelle K. , Douma Lauren G. , Tartar Aurélien
Published: August 2014

A combination of 454 pyrosequencing and Sanger sequencing was used to sample and characterize the transcriptome of the entomopathogenic oomycete
Lagenidium giganteum
. More than 50,000 high-throughput reads were annotated through homology searches. Several selected reads served as seeds for the amplification and sequencing of full-length transcripts. Phylogenetic analyses inferred from full-length cellulose synthase alignments revealed that
L giganteum
is nested within the peronosporalean galaxy and as such appears to have evolved from a phytopathogenic ancestor. In agreement with the phylogeny reconstructions, full-length
L. giganteum
oomycete effector orthologs, corresponding to the cellulose-binding elicitor lectin (CBEL), crinkler (CRN), and elicitin proteins, were characterized by domain organizations similar to those of pathogenicity factors of plant-pathogenic oomycetes. Importantly, the
L. giganteum
effectors provide a basis for detailing the roles of canonical CRN, CBEL, and elicitin proteins in the infectious process of an oomycete known principally as an animal pathogen. Finally, phylogenetic analyses and genome mining identified members of glycoside hydrolase family 5 subfamily 27 (GH5_27) as putative virulence factors active on the host insect cuticle, based in part on the fact that GH5_27 genes are shared by entomopathogenic oomycetes and fungi but are underrepresented in nonentomopathogenic genomes. The genomic resources gathered from the
L. giganteum
transcriptome analysis strongly suggest that filamentous entomopathogens (oomycetes and fungi) exhibit convergent evolution: they have evolved independently from plant-associated microbes, have retained genes indicative of plant associations, and may share similar cores of virulence factors, such as GH5_27 enzymes, that are absent from the genomes of their plant-pathogenic relatives.
Diversity and Antimicrobial Resistance of Salmonella enterica Isolates from Surface Water in Southeastern United States
Authors: Li Baoguang , Vellidis George , Liu Huanli , Jay-Russell Michele , Zhao Shaohua , Hu Zonglin , Wright Anita , Elkins Christopher A.
Published: August 2014

A study of prevalence, diversity, and antimicrobial resistance of
Salmonella enterica
in surface water in the southeastern United States was conducted. A new scheme was developed for recovery of
Salmonella
from irrigation pond water and compared with the FDA's
Bacteriological Analytical Manual
(8th ed., 2014) (BAM) method. Fifty-one isolates were recovered from 10 irrigation ponds in produce farms over a 2-year period; nine
Salmonella
serovars were identified by pulsed-field gel electrophoresis analysis, and the major serovar was
Salmonella enterica
serovar Newport (
S
. Newport,
n
= 29), followed by
S. enterica
serovar Enteritidis (
n
= 6),
S. enterica
serovar Muenchen (
n
= 4),
S. enterica
serovar Javiana (
n
= 3),
S. enterica
serovar Thompson (
n
= 2), and other serovars. It is noteworthy that the PulseNet patterns of some of the isolates were identical to those of the strains that were associated with the
S
. Thompson outbreaks in 2010, 2012, and 2013,
S
. Enteritidis outbreaks in 2011 and 2013, and an
S
. Javiana outbreak in 2012. Antimicrobial susceptibility testing confirmed 16
S
. Newport isolates of the multidrug resistant-AmpC (MDR-AmpC) phenotype, which exhibited resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (ACSSuT), and to the 1st, 2nd, and 3rd generations of cephalosporins (cephalothin, amoxicillin-clavulanic acid, and ceftriaxone). Moreover, the
S
. Newport MDR-AmpC isolates had a PFGE pattern indistinguishable from the patterns of the isolates from clinical settings. These findings suggest that the irrigation water may be a potential source of contamination of
Salmonella
in fresh produce. The new
Salmonella
isolation scheme significantly increased recovery efficiency from 21.2 (36/170) to 29.4% (50/170) (
P
= 0.0002) and streamlined the turnaround time from 5 to 9 days with the BAM method to 4 days and thus may facilitate microbiological analysis of environmental water.
Distinct Immunomodulation of Bone Marrow-Derived Dendritic Cell Responses to Lactobacillus plantarum WCFS1 by Two Different Polysaccharides Isolated from Lactobacillus rhamnosus LOCK 0900
Authors: Górska Sabina , Schwarzer Martin , Jachymek Wojciech , Srutkova Dagmar , Brzozowska Ewa , Kozakova Hana , Gamian Andrzej
Published: August 2014

The structures of polysaccharides (PS) isolated from
Lactobacillus rhamnosus
LOCK 0900 and results from stimulation of mouse bone marrow-derived dendritic cells (BM-DC) and human embryonal kidney (HEK293) cells stably transfected with Toll-like receptors (TLR) upon exposure to these antigens were studied.
L. rhamnosus
LOCK 0900 produces PS that differ greatly in their structure. The polymer L900/2, with a high average molecular mass of 830 kDa, is a branched heteropolysaccharide with a unique repeating unit consisting of seven sugar residues and pyruvic acid, whereas L900/3 has a low average molecular mass of 18 kDa and contains a pentasaccharide repeating unit and phosphorus. Furthermore, we found that both described PS neither induce cytokine production and maturation of mouse BM-DC nor induce signaling through TLR2/TLR4 receptors. However, they differ profoundly in their abilities to modulate the BM-DC immune response to the well-characterized human isolate
Lactobacillus plantarum
WCFS1. Exposure to L900/2 enhanced interleukin-10 (IL-10) production induced by
L. plantarum
WCFS1, while in contrast, L900/3 enhanced the production of IL-12p70. We conclude that PS, probably due to their chemical features, are able to modulate the immune responses to third-party antigens. The ability to induce regulatory IL-10 by L900/2 opens up the possibility to use this PS in therapy of inflammatory conditions, such as inflammatory bowel disease, whereas L900/3 might be useful in reverting the antigen-dependent Th2-skewed immune responses in allergies.