bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multilocus Sequence Typing of the Porcine and Human Gastric Pathogen Helicobacter suis
Authors: Liang Jungang , Ducatelle Richard , Pasmans Frank , Smet Annemieke , Haesebrouck Freddy , Flahou Bram 
Published: January 2013

ABSTRACT

Helicobacter suis
is a Gram-negative bacterium colonizing the majority of pigs, in which it causes gastritis and decreased daily weight gain.
H. suis
is also the most prevalent gastric non-
Helicobacter pylori Helicobacter
species in humans, capable of causing gastric disorders. To gain insight into the genetic diversity of porcine and human
H. suis
strains, a multilocus sequence typing (MLST) method was developed. In a preliminary study, 7 housekeeping genes (
atpA
,
efp
,
mutY
,
ppa
,
trpC
,
ureI
, and
yphC
) of 10
H. suis
isolates cultured
in vitro
were investigated as MLST candidates. All genes, except the
ureI
gene, which was replaced by part of the
ureAB
gene cluster of
H. suis
, displayed several variable nucleotide sites. Subsequently, internal gene fragments, ranging from 379 to 732 bp and comprising several variable nucleotide sites, were selected. For validation of the developed MLST technique, gastric tissue from 17
H. suis
-positive pigs from 4 different herds and from 1
H. suis
-infected human patient was used for direct, culture-independent strain typing of
H. suis
. In addition to the 10 unique sequence types (STs) among the 10 isolates grown
in vitro
, 15 additional STs could be assigned. Individual animals were colonized by only 1
H. suis
strain, whereas multiple
H. suis
strains were present in all herds tested, revealing that
H. suis
is a genetically diverse bacterial species. The human
H. suis
strain showed a very close relationship to porcine strains. In conclusion, the developed MLST scheme may prove useful for direct, culture-independent typing of porcine and human
H. suis
strains.
Epidemiology, Antifungal Susceptibility, and Pathogenicity of Candida africana Isolates from the United Kingdom
Authors: Borman Andrew M. , Szekely Adrien , Linton Chistopher J. , Palmer Michael D. , Brown Phillipa , Johnson Elizabeth M. 
Published: January 2013

ABSTRACT

Candida africana
was previously proposed as a new species within the
Candida albicans
species complex, together with
C. albicans
and
C. dubliniensis
, although further phylogenetic analyses better support its status as an unusual variant within
C. albicans
. Here we show that
C. africana
can be distinguished from
C. albicans
and
C. dubliniensis
by pyrosequencing of a short region of ITS2, and we have evaluated its occurrence in clinical samples by pyrosequencing all presumptive isolates of
C. albicans
submitted to the Mycology Reference Laboratory over a 9-month period. The
C. albicans
complex constituted 826/1,839 (44.9%) of yeast isolates received over the study period and included 783 isolates of
C. albicans
, 28 isolates of
C. dubliniensis
, and 15 isolates of
C. africana
. In agreement with previous reports,
C. africana
was isolated exclusively from genital specimens, in women in the 18-to-35-year age group. Indeed,
C. africana
constituted 15/251 (6%) of “
C. albicans
” isolates from female genital specimens during the study period.
C. africana
isolates were germ tube positive, grew significantly more slowly than
C. albicans
and
C. dubliniensis
on conventional mycological media, could be distinguished from the other members of the
C. albicans
complex by appearance on chromogenic agar, and were incapable of forming chlamydospores. Here we present the detailed evaluation of epidemiological, phenotypic, and clinical features and antifungal susceptibility profiles of United Kingdom isolates of
C. africana
. Furthermore, we demonstrate that
C. africana
is significantly less pathogenic than
C. albicans
and
C. dubliniensis
in the
Galleria mellonella
insect systemic infection model.
Differences and Similarities between Culture-Confirmed Human Granulocytic Anaplasmosis and Early Lyme Disease
Authors: Wormser Gary P. , Aguero-Rosenfeld Maria E. , Cox Mary E. , Nowakowski John , Nadelman Robert B. , Holmgren Diane , McKenna Donna , Bittker Susan , Zentmaier Lois , Cooper Denise , Liveris Dionysios , Schwartz Ira , Horowitz Harold W. 
Published: January 2013

ABSTRACT

Lyme disease is transmitted by the bite of certain
Ixodes
ticks, which can also transmit
Anaplasma phagocytophilum
, the cause of human granulocytic anaplasmosis (HGA). Although culture can be used to identify patients infected with
A. phagocytophilum
and is the microbiologic gold standard, few studies have evaluated culture-confirmed patients with HGA. We conducted a prospective study in which blood culture was used to detect HGA infection in patients with a compatible clinical illness. Early Lyme disease was defined by the presence of erythema migrans. The epidemiologic, clinical, and laboratory features of 44 patients with culture-confirmed HGA were compared with those of a convenience sample of 62 patients with early Lyme disease. Coinfected patients were excluded. Patients with HGA had more symptoms (
P
= 0.003) and had a higher body temperature on presentation (
P
< 0.001) than patients with early Lyme disease. HGA patients were also more likely to have a headache, dizziness, myalgias, abdominal pain, anorexia, leukopenia, lymphopenia, thrombocytopenia, or elevated liver enzymes. A direct correlation between the number of symptoms and the duration of illness at time of presentation (rho = 0.389,
P
= 0.009) was observed for HGA patients but not for patients with Lyme disease. In conclusion, although there are overlapping features, culture-confirmed HGA is a more severe illness than early Lyme disease.
A Real-Time PCR Assay for Rapid Detection and Quantification of Exserohilum rostratum, a Causative Pathogen of Fungal Meningitis Associated with Injection of Contaminated Methylprednisolone
Authors: Zhao Yanan , Petraitiene Ruta , Walsh Thomas J. , Perlin David S. 
Published: January 2013

ABSTRACT

A species-specific molecular beacon real-time PCR assay was developed for rapid diagnosis of
Exserohilum rostratum
infection. As low as 100 fg of
E. rostratum
DNA can be reliably detected in the presence of 50 ng of human DNA, with a dynamic linear quantification range from 20 ng to 200 fg.
A Mutation in the Ebola Virus Envelope Glycoprotein Restricts Viral Entry in a Host Species- and Cell-Type-Specific Manner
Authors: Martinez Osvaldo , Ndungo Esther , Tantral Lee , Miller Emily Happy , Leung Lawrence W. , Chandran Kartik , Basler Christopher F. 
Published: January 2013

ABSTRACT

Zaire Ebola virus (EBOV) is a zoonotic pathogen that causes severe hemorrhagic fever in humans. A single viral glycoprotein (GP) mediates viral attachment and entry. Here, virus-like particle (VLP)-based entry assays demonstrate that a GP mutant, GP-F88A, which is defective for entry into a variety of human cell types, including antigen-presenting cells (APCs), such as macrophages and dendritic cells, can mediate viral entry into mouse CD11b
+
APCs. Like that of wild-type GP (GP-wt), GP-F88A-mediated entry occurs via a macropinocytosis-related pathway and requires endosomal cysteine proteases and an intact fusion peptide. Several additional hydrophobic residues lie in close proximity to GP-F88, including L111, I113, L122, and F225. GP mutants in which these residues are mutated to alanine displayed preferential and often impaired entry into several cell types, although not in a species-specific manner. Niemann-Pick C1 (NPC1) protein is an essential filovirus receptor that binds directly to GP. Overexpression of NPC1 was recently demonstrated to rescue GP-F88A-mediated entry. A quantitative enzyme-linked immunosorbent assay (ELISA) demonstrated that while the F88A mutation impairs GP binding to human NPC1 by 10-fold, it has little impact on GP binding to mouse NPC1. Interestingly, not all mouse macrophage cell lines permit GP-F88A entry. The IC-21 cell line was permissive, whereas RAW 264.7 cells were not. Quantitative reverse transcription (RT)-PCR assays demonstrate higher NPC1 levels in GP-F88A permissive IC-21 cells and mouse peritoneal macrophages than in RAW 264.7 cells. Cumulatively, these studies suggest an important role for NPC1 in the differential entry of GP-F88A into mouse versus human APCs.
Role of Interactions between Autographa californica Multiple Nucleopolyhedrovirus Procathepsin and Chitinase Chitin-Binding or Active-Site Domains in Viral Cathepsin Processing
Authors: Hodgson Jeffrey J. , Arif Basil M. , Krell Peter J. 
Published: January 2013

ABSTRACT

The binding of
Autographa californica
multiple nucleopolyhedrovirus chitinase (CHIA) to viral cathepsin protease progenitor (proV-CATH) governs cellular/endoplasmic reticulum (ER) coretention of CHIA and proV-CATH, thus coordinating simultaneous cellular release of both host tissue-degrading enzymes upon host cell death. CHIA is a proposed proV-CATH folding chaperone because insertional inactivation of
chiA
causes production of proV-CATH aggregates that are incompetent for proteolytic maturation into active V-CATH enzyme. We wanted to determine whether the N-terminal chitin-binding domain (CBD, 149 residues) and C-terminal CHIA active-site domain (ASD, 402 residues) of CHIA bind to proV-CATH independently of one another and whether either domain is dispensable for CHIA's putative proV-CATH folding chaperone activity. We demonstrate that N-terminally green fluorescent protein (GFP)-fused CHIA, ASD, and CBD each colocalize with proV-CATH-RFP in ER-like patterns and that both ASD and CBD independently associate with proV-CATH
in vivo
using bimolecular fluorescence complementation (BiFC) and
in vitro
using reciprocal nickel-histidine pulldown assays. Altogether, the data from colocalization, BiFC, and reciprocal copurification analyses suggest specific and independent interactions between proV-CATH and both domains of CHIA. These data also demonstrate that either CHIA domain is dispensable for normal proV-CATH processing. Furthermore, in contrast to prior evidence suggesting that a lack of
chiA
expression causes proV-CATH to become aggregated, insoluble, and unable to mature into V-CATH, a
chiA
deletion bacmid virus we engineered to express just
v-cath
produced soluble proV-CATH that was prematurely secreted from cells and proteolytically matured into active V-CATH enzyme.
Efavirenz Enhances HIV-1 Gag Processing at the Plasma Membrane through Gag-Pol Dimerization
Authors: Sudo Sho , Haraguchi Hiyori , Hirai Yoko , Gatanaga Hiroyuki , Sakuragi Jun-ichi , Momose Fumitaka , Morikawa Yuko 
Published: January 2013

ABSTRACT
Efavirenz (EFV), a nonnucleoside reverse transcriptase (RT) inhibitor, also inhibits HIV-1 particle release through enhanced Gag/Gag-Pol processing by protease (PR). To better understand the mechanisms of the EFV-mediated enhancement of Gag processing, we examined the intracellular localization of Gag/Gag-Pol processing products and their precursors. Confocal microscopy revealed that in the presence of EFV, the N-terminal p17 matrix (p17MA) fragment was uniformly distributed at the plasma membrane (PM) but the central p24 capsid (p24CA) and the Pol-encoded RT antigens were diffusely distributed in the cytoplasm, and all of the above were observed in puncta at the PM in the absence of EFV. EFV did not impair PM targeting of Gag/Gag-Pol precursors. Membrane flotation analysis confirmed these findings. Such uniform distribution of p17MA at the PM was not seen by overexpression of Gag-Pol and was suppressed when EFV-resistant HIV-1 was used. Forster's fluorescence resonance energy transfer assay revealed that Gag-Pol precursor dimerization occurred mainly at the PM and that EFV induced a significant increase of the Gag-Pol dimerization at the PM. Gag-Pol dimerization was not enhanced when HIV-1 contained the EFV resistance mutation in RT. Bacterial two-hybrid assay showed that EFV enhanced the dimerization of PR-RT fragments and restored the dimerization impaired by the dimerization-defective mutation in the RT tryptophan repeat motif but not that impaired by the mutation at the PR dimer interface. Collectively, our data indicate that EFV enhances Gag-Pol precursor dimerization, likely after PM targeting but before complete particle assembly, resulting in uniform distribution of p17MA to and dissociation of p24CA and RT from the PM.
CD22 Is Required for Protection against West Nile Virus Infection
Authors: Ma Daphne Y. , Suthar Mehul S. , Kasahara Shinji , Gale Michael , Clark Edward A. 
Published: January 2013

ABSTRACTWest Nile virus (WNV) is a RNA virus of the familyFlaviviridaeand the leading cause of mosquito-borne encephalitis in the United States. Humoral immunity is essential for protection against WNV infection; however, the requirements for initiating effective antibody responses against WNV infection are still unclear. CD22 (Siglec-2) is expressed on B cells and regulates B cell receptor signaling, cell survival, proliferation, and antibody production. In this study, we investigated how CD22 contributes to protection against WNV infection and found that CD22 knockout (Cd22−/−) mice were highly susceptible to WNV infection and had increased viral loads in the serum and central nervous system (CNS) compared to wild-type (WT) mice. This was not due to a defect in humoral immunity, asCd22−/−mice had normal WNV-specific antibody responses. However,Cd22−/−mice had decreased WNV-specific CD8+T cell responses compared to those of WT mice. These defects were not simply due to reduced cytotoxic activity or increased cell death but, rather, were associated with decreased lymphocyte migration into the draining lymph nodes (dLNs) of infectedCd22−/−mice.Cd22−/−mice had reduced production of the chemokine CCL3 in the dLNs after infection, suggesting that CD22 affects chemotaxis via controlling chemokine production. CD22 was not restricted to B cells but was also expressed on a subset of splenic DCIR2+dendritic cells that rapidly expand early after WNV infection. Thus, CD22 plays an essential role in controlling WNV infection by governing cell migration and CD8+T cell responses.
Viral Inhibition of BAK Promotes Murine Cytomegalovirus Dissemination to Salivary Glands
Authors: Handke Wiebke , Luig Christina , Popović Branka , Krmpotić Astrid , Jonjić Stipan , Brune Wolfram 
Published: January 2013

ABSTRACT

Apoptosis induction is an important host defense mechanism to control viral infection, which is antagonized by viral proteins. Murine cytomegalovirus m41.1 encodes a viral inhibitor of BAK oligomerization (vIBO) that blocks the mitochondrial apoptosis mediator BAK. However, its importance for viral fitness
in vivo
has not been investigated. Here, we show that an m41.1-deficient virus attains reduced titers in salivary glands of wild-type but not
Bak1
−/−
mice, indicating a requirement of BAK inhibition for optimal dissemination
in vivo
.
Estimating Cytomegalovirus Growth Rates by Using Only a Single Point
Authors: Cromer Deborah , Tey Siok-Keen , Khanna Rajiv , Davenport Miles P. 
Published: January 2013

ABSTRACT

Calculation of pathogen growth rates is important in understanding the natural history of infection and effects of therapy. However, it is often difficult to estimate pathogen growth because patients are treated immediately upon the detection of infection, leaving only one nonzero untreated reading. Previous approaches have relied on the flawed assumption that pathogen loads just prior to detection are at the assay detection threshold. We have developed a novel method for estimating the pathogen growth rate from a single reading and investigated the initial growth of cytomegalovirus (CMV) in allogeneic hematopoietic stem cell transplant (HSCT) patients. We applied this approach to CMV viral loads measured at least weekly in 122 patients in the 3 months posttransplant. Viral growth rates were estimated by using a modeling approach that accounts for the viral load and the time since the last negative reading. Viral growth rates decreased rapidly within the first week, from 0.72/day (doubling time, 0.96 day) at the point of reactivation to 0.22/day (doubling time, 3.1 days) at 1 week. Results from this method correlated closely with a two-point regression analysis of a subset of 58 patients with detectable subthreshold viral loads immediately prior to overt reactivation. Patients with lymphocyte counts of ≥0.5 × 10
9
/liter had significantly slower viral growth than patients with low lymphocyte counts (0.612/day versus 0.325/day,
P
< 0.0001). Thus, our novel method of estimating pathogen growth rates reveals a rapid slowing of CMV growth during reactivation in HSCT patients and a significant impact of the lymphocyte count on CMV growth.
The Amino Terminus of Herpes Simplex Virus 1 Glycoprotein K Is Required for Virion Entry via the Paired Immunoglobulin-Like Type-2 Receptor Alpha
Authors: Chowdhury Sona , Chouljenko Vladimir N. , Naderi Misagh , Kousoulas Konstantin G. 
Published: January 2013

ABSTRACT

The herpes simplex virus 1 (HSV-1) glycoprotein K (gK)/UL20 protein complex is incorporated into virion envelopes and cellular membranes and functions during virus entry and cell-to-cell spread. To investigate the role of gK/UL20 in the context of a highly neurovirulent virus strain, the HSV-1(McKrae) genome was cloned into a bacterial artificial chromosome plasmid (McKbac) and utilized to construct the mutant virus McK(gKΔ31-68), carrying a 37-amino-acid deletion within the gK amino terminus. The McKbac virus entered efficiently into Chinese hamster ovary (CHO) cells constitutively expressing HSV-1 human receptors, nectin-1, herpesvirus entry mediator (HVEM), or paired immunoglobulin-like type-2 receptor alpha (PILRα). In contrast, the McK(gKΔ31-68) virus failed to enter into CHO-PILRα cells, while it entered CHO cells expressing HVEM and nectin-1 more efficiently than the McKbac virus. Both McKbac and McK(gKΔ31-68) viruses entered all CHO cells expressing HSV-1 receptors via a pH-independent pathway. The HSV-1(F) gBΔ28syn mutant virus, encoding a carboxyl-terminal truncated gB, causes extensive cell fusion. Previously, we showed that the gKΔ31-68 amino acid deletion abrogated gBΔ28syn virus-induced cell fusion, indicating that the amino terminus of gK is required for gB-mediated virus-induced cell fusion (V. N. Chouljenko, A. V. Iyer, S. Chowdhury, D. V. Chouljenko, and K. G. J. Kousoulas, Virology
83:
12301–12313, 2009). Surprisingly, the gKΔ31-68/gBΔ28syn virus caused extensive fusion of CHO-nectin-1 cells but limited cell fusion of CHO-PILRα cells. Coimmunoprecipitation experiments revealed that both gK and PILRα bound gB in infected cells. Collectively, these results indicate that the amino terminus of gK is functionally and physically associated with the gB-PILRα protein complex and regulates membrane fusion of the viral envelope with cellular membranes during virus entry as well as virus-induced cell-to-cell fusion.
The Virion Host Shutoff RNase Plays a Key Role in Blocking the Activation of Protein Kinase R in Cells Infected with Herpes Simplex Virus 1
Authors: Sciortino Maria Teresa , Parisi Tiziana , Siracusano Gabriel , Mastino Antonio , Taddeo Brunella , Roizman Bernard 
Published: January 2013

ABSTRACT

Earlier studies have shown that active MEK blocks the activation of protein kinase R (PKR), a component of antiviral innate immune responses. In this report we show that the herpes simplex virus 1 virion host shutoff (VHS) RNase protein and MEK (mitogen-activated protein kinase kinase) act cooperatively in blocking the activation of PKR. This conclusion is based on the following. (i) In contrast to viral gene expression in the parental cell line or a cell line expressing a constitutively active MEK, the replication of a VHS mutant is particularly impaired in cells expressing dominant negative MEK. In this cell line PKR is activated by phosphorylation, and the accumulation of several viral proteins is delayed. (ii) In transfected cells, wild-type VHS blocked the activation of PKR, whereas PKR was activated in cells transfected with a mutant VHS or with plasmids encoding the VHS RNase and VP16 and VP22, the two viral proteins that neutralize the RNase activity of VHS. The results suggest that early in infection the VHS RNase degrades RNAs that activate PKR. Coupled with published data, the results suggest that inhibition of activation of PKR or its effect on viral replication is staged early in infection by VHS, postsynthesis of VP16 and VP22 by the γ
1
34.5 protein, and very late in infection by the U
S
11 protein.
Influence of the Manchester triage system on waiting time, treatment time, length of stay and patient satisfaction; a before and after study
Authors: Storm-Versloot Marja N , Vermeulen Hester , van Lammeren Nienke , Luitse Jan SK , Goslings J Carel 
Published: January 2013

ObjectivesTo compare waiting time, treatment time, length of stay (LOS), patient satisfaction and distribution of waiting times over levels of urgency before and after the implementation of the Manchester Triage system (MTS) at an emergency department (ED).MethodsBefore and after study, by means of timeline measurements and questionnaires on satisfaction in two consecutive patient series (n=1808). Questionnaires covered aspects of provision of information, opportunity given to explain problems, waiting time and sorting out the problem. After implementation of MTS, patients were triaged between 12:00 and 22:00. Subanalysis was performed on triaging and non-triaging; and between urgency levels.ResultsWaiting time did not decrease after implementation of the MTS, however, treatment time and LOS were significantly longer. Total LOS did not differ. After implementation, waiting time was better distributed over urgency levels.Furthermore, after implementation, patient satisfaction scored significantly lower on the provision of information and opportunity to explain their problems, however, waiting time and the feeling that their problem had been sorted out scored better. No significant differences were found between triaged and non-triaged patients. Although not significant, patients in the lower urgency levels seemed more satisfied than patients in the higher urgency levels.ConclusionsImplementing MTS on its own is not sufficient to improve efficiency and quality of EDs. More complex interventions including process redesigning that targets various groups of ED patients should be evaluated in the future by using rigorous research designs for quality improvement of EDs.
Direct relationship between aging and overcrowding in the ED, and a calculation formula for demand projection: a cross-sectional study
Authors: Kawano Takahisa , Nishiyama Kei , Anan Hideaki , Tujimura Yuka 
Published: January 2013

ObjectiveAlthough it has been suggested that the increase in older population contributes to overcrowding in emergency departments (EDs), there are limited data defining this relationship. This study examines whether patients’ mean age per day affects length of ED stay.MethodsThis cross-sectional analysis evaluated how patient age affects length of ED stay. The study was conducted at an ED attached to Fujisawa City Hospital, Japan, between 1 November 2009 and 31 October 2010. Patients scheduled to visit for childbirth and patients under age 15 were excluded. The primary outcome measure was the relationship between length of ED stay and patient age. The secondary outcome was the relationship between patient age and patient dispositions indicated by column chart and 100% staked column chart.ResultsOver the study period, there were 17 744 patient visits to the ED. The study included 15 840 (89.3%) patients. The mean (SD) age of these patients was 56.9 (21.5) years. In single and multiple linear regression analyses, mean patient age per day was an important factor in length of ED stay for the total number of patients visiting the ED (single linear regression analysis: regression coefficient=1.59 min/year, r2=0.005, p<0.001; multiple linear regression analysis: regression coefficient=0.72 min/year, r2=0.24, p<0.001). The ratio of admitted and transferred patients increased with patient age.ConclusionThe increase in older patients visiting the ED has a direct significant negative effect on overcrowding in the ED.