bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection of Asymptomatic Antigenemia in Pigs Infected by Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) by a Novel Capture Immunoassay with Monoclonal Antibodies against the Nucleocapsid Protein of PRRSV
Authors: Cai Jian-Piao , Wang Ya-Di , Tse Herman , Xiang Hua , Yuen Kwok-Yung , Che Xiao-Yan 
Published: October 2009

ABSTRACTRoutine surveillance for porcine reproductive and respiratory syndrome virus (PRRSV) infections is crucial for the epidemiological control of this disease. Antibody tests are widely used but cannot differentiate between vaccination and reinfection. We developed a PRRSV antigen capture enzyme-linked immunosorbent assay (ELISA) using well-characterized monoclonal antibodies (MAbs) raised against the nucleocapsid (N) protein of North American and European PRRSV. This antigen assay detected purified N protein from both genotypes at levels as low as 0.4 and 0.8 ng, respectively. The specificity and sensitivity of the N antigen assay were evaluated with ground lung tissues from 8 PRRSV-infected and 16 healthy swine, and culture supernatants from six PRRSV isolates as well as other swine viruses were confirmed by reverse transcriptase PCR (RT-PCR). Antigen assays were positive in all eight infected tissues and with six different PRRSV isolates, with no false positives among healthy tissues and other swine viruses (i.e., pseudorabies and foot and mouth disease viruses). A number of sera, field collected from 466 vaccinated and asymptomatic pigs in Guangdong, China, between 2008 and 2009, tested positive by the N antigen assay (12.45%), RT-PCR (15.02%), and a commercial test for antibodies against PRRSV (78.97%). Of the 466 sera, 47 were positive by both antigen and RT-PCR tests, 11 by antigen test only, and 23 by RT-PCR only; the two assays had an overall agreement of 92.7%, indicating a significant percentage of active PRRSV in asymptomatic pigs despite previous immunization. These findings suggest that the antigen assay is a valuable field tool for the epidemiological control of PRRSV that can be used for rapid screening, particularly in asymptomatic animals.
Immune Response and Viral Persistence in Indian Buffaloes (
Bubalus bubalis
) Infected with Foot-and-Mouth Disease Virus Serotype Asia 1
Authors: Maddur Mohan S. , Kishore Subodh , Gopalakrishna S. , Singh Nem , Suryanarayana V. V. , Gajendragad Mukund R. 
Published: October 2009

ABSTRACT

Despite their potential role in the spread of foot-and-mouth disease (FMD), the immune response and viral persistence in FMD virus (FMDV)-infected Indian buffaloes (
Bubalus bubalis
) have been unexplored. We found similar kinetics of neutralizing antibody responses in the sera and secretory fluids of buffaloes following experimental FMDV Asia 1 infection, but the lymphocyte-proliferative response in infected buffaloes was of low magnitude. Despite inducing a significant systemic and secretory immune response, viral persistence seems to be a common outcome in buffaloes following FMDV Asia 1 infection, which is associated with a weak cellular immune response.
Receptor Recognition of and Immune Intracellular Pathways for
Veillonella parvula
Lipopolysaccharide
Authors: Matera Giovanni , Muto Valentina , Vinci Maria , Zicca Emilia , Abdollahi-Roodsaz Shahla , van de Veerdonk Frank L. , Kullberg Bart-Jan , Liberto Maria Carla , van der Meer Jos W. M. , Focà Alfredo , Netea Mihai G. , Joosten Leo A. B. 
Published: October 2009

ABSTRACT

Veillonella parvula
is an anaerobic gram-negative coccus that is part of the normal flora of the animal and human mouth and gastrointestinal and genitourinary tracts. Oral
V. parvula
is involved in the development of early periodontal disease as well as different types of serious infections. Present data on molecular mechanisms responsible for innate immune response against
Veillonella
are very scanty. The aim of this study was to investigate the Toll-like receptor (TLR) pathways responsible for
V. parvula
lipopolysaccharide (LPS) and to identify the intracellular pathways induced by this recognition.
V. parvula
LPS stimulated tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) release in human peripheral blood mononuclear cells (PBMC) in a dose-dependent manner. Pretreatment of cells with a TLR4 antagonist significantly reduced TNF-α and IL-6 production in PBMC stimulated with either
Veillonella
or
Escherichia coli
LPS. However,
V. parvula
LPS was 10- to 100-fold less active than
E. coli
LPS for cytokine induction. TNF-α, IL-1β, IL-6, and IL-10 were released in wild-type and TLR2
−/−
, but not TLR4
−/−
, mouse macrophage cultures.
V. parvula
LPS was able to activate the human PBMC p38 mitogen-activated protein kinase (MAPK). A specific p38 MAPK inhibitor strongly inhibited
V. parvula
LPS-induced TNF-α, IL-1β, IL-6, and IL-10. In conclusion,
V. parvula
LPS is able to induce cytokine production in both human and murine in vitro models, although it is less effective than
Enterobacteriaceae
LPS.
V. parvula
LPS-stimulated cytokine induction, as well as p38 MAPK activation, are TLR4-dependent features.
International External Quality Assurance for Laboratory Diagnosis of Diphtheria
Authors: Neal S. E. , Efstratiou A. 
Published: October 2009

ABSTRACT

The diphtheria surveillance network (DIPNET) encompassing National Diphtheria Reference Centers from 25 European countries is a Dedicated Surveillance Network recognized by the European Commission. A key DIPNET objective is the quality assessment of microbiological procedures for diphtheria across the European Union and beyond. A detailed questionnaire on the level of reference laboratory services and an external quality assessment (EQA) panel comprising six simulated throat specimens were sent to 34 centers. Twenty-three centers are designated National Diphtheria Reference Centers, with the laboratory in the United Kingdom being the only WHO Collaborating Centre. A variety of screening and identification tests were used, including the cysteinase test (20/34 centers), pyrazinamidase test (17/34 centers), and commercial kits (25/34 centers). The classic Elek test for toxigenicity testing is mostly used (28/34 centers), with variations in serum sources and antitoxin concentrations. Many laboratories reported problems obtaining Elek reagents or media. Only six centers produced acceptable results for all six specimens. Overall, 21% of identification and 13% of toxigenicity reports were unacceptable. Many centers could not isolate the target organism, and most found difficulties with the specimens that contained
Corynebacterium striatum
as a commensal contaminant. Nineteen centers generated either false-positive or negative toxigenic results, which may have caused inappropriate medical management. The discrepancies in this diphtheria diagnostics EQA alarmingly reflect the urgent need to improve laboratory performance in diphtheria diagnostics in Europe, standardize feasible and robust microbiological methods, and build awareness among public health authorities. Therefore, DIPNET recommends that regular workshops and EQA distributions for diphtheria diagnostics should be supported and maintained.
Oligonucleotide-Gold Nanoparticle Networks for Detection of
Cryptosporidium parvum
Heat Shock Protein 70 mRNA
Authors: Javier David J. , Castellanos-Gonzalez Alejandro , Weigum Shannon E. , White A. Clinton , Richards-Kortum Rebecca 
Published: October 2009

ABSTRACT

We report on a novel strategy for the detection of mRNA targets derived from
Cryptosporidium parvum
oocysts by the use of oligonucleotide-gold nanoparticles. Gold nanoparticles are functionalized with oligonucleotides which are complementary to unique sequences present on the heat shock protein 70 (HSP70) DNA/RNA target. The results indicate that the presence of HPS70 targets of increasing complexity causes the formation of oligonucleotide-gold nanoparticle networks which can be visually monitored via a simple colorimetric readout measured by a total internal reflection imaging setup. Furthermore, the induced expression of HSP70 mRNA in
Cryptosporidium parvum
oocysts via a simple heat shock process provides nonenzymatic amplification such that the HSP70 mRNA derived from as few as 5 × 10
3
purified
C. parvum
oocysts was successfully detected. Taken together, these results support the use of oligonucleotide-gold nanoparticles for the molecular diagnosis of cryptosporidiosis, offering new opportunities for the further development of point-of-care diagnostic assays with low-cost, robust reagents and simple colorimetric detection.
Heteroresistance to Meropenem in Carbapenem-Susceptible
Acinetobacter baumannii
Authors: Ikonomidis Alexandros , Neou Evangelia , Gogou Vassiliki , Vrioni Georgia , Tsakris Athanassios , Pournaras Spyros 
Published: October 2009

ABSTRACT

The characteristics of carbapenem heteroresistance were studied in 14 apparently carbapenem-susceptible
Acinetobacter baumannii
isolates. The MICs for carbapenems were determined, and the isolates were genotyped by pulsed-field gel electrophoresis (PFGE) and sequence typing (ST). Population analysis, testing of the stability of the heteroresistant subpopulations, and time-killing assays were performed. The agar dilution MICs of both imipenem and meropenem for the native isolates ranged from 0.25 to 4 mg/liter. The isolates belonged to nine PFGE types and exhibited seven ST allelic profiles. Population analysis revealed subpopulations that grew in the presence of imipenem at concentrations of up to 8 mg/liter and meropenem at concentrations of up to 32 mg/liter. The meropenem-heteroresistant subpopulations of 11 isolates exhibited stable resistance with MICs that ranged from 16 to >32 mg/liter; their PFGE profiles were identical to those of the native isolates. Time-kill assays with meropenem revealed less pronounced killing for 10 isolates. These findings indicate that meropenem pressure can produce meropenem-heteroresistant subpopulations that might subsequently select for highly resistant strains.
Molecular Diagnostics of Hemorrhagic Fever with Renal Syndrome during a Dobrava Virus Infection Outbreak in the European Part of Russia
Authors: Dzagurova Tamara K. , Klempa Boris , Tkachenko Evgeniy A. , Slyusareva Galina P. , Morozov Vyacheslav G. , Auste Brita , Kruger Detlev H. 
Published: October 2009

ABSTRACT

A large outbreak of hemorrhagic fever with renal syndrome (HFRS) occurred in the winter of 2006-2007 in a region southeast of Moscow in Central European Russia. Of the 422 patients with HFRS investigated in this study, 58 patients were found to be infected by Puumala virus, whereas as many as 364 were infected by Dobrava-Belgrade virus (DOBV). Early serum samples from 10 DOBV-infected patients were used for nucleic acid amplification, which was successful for 5 patients. Molecular analyses demonstrated that the causative hantavirus belongs to the DOBV-Aa genetic lineage, which is carried by the striped field mouse (
Apodemus agrarius
) as the natural reservoir host. Neutralization assays with convalescent-phase sera from these patients confirmed infection by DOBV-Aa; related viruses, such as the Dobrava-Slovenia virus (DOBV-Af) and the Dobrava-Sochi virus (DOBV-Ap), were neutralized at lower efficiencies. The clinical courses of the 205 patients enrolled in the study were found to be mostly mild to moderate; however, an unexpectedly high fraction (27%) of patients exhibited severe illness. One patient died from kidney failure and showed symptoms of generalized subcutaneous hemorrhage. The results provide molecular, serodiagnostic, and clinical evidence that DOBV-Aa is a common pathogen in East Europe that causes large outbreaks of HFRS.
New Multiplatform Computer Program for Numerical Identification of Microorganisms
Authors: Flores Oscar , Belanche Lluís A. , Blanch Anicet R. 
Published: October 2009

ABSTRACT

The classification of bacteria by using genomic methods or expensive biochemical-based commercial kits is sometimes beyond the reach of many laboratories that need to perform numerous classifications of unknown bacterial strains in a fast, cheap, and reliable way. A new computer program,
Identax
, for the computer-assisted identification of microorganisms by using only results obtained from conventional biochemical tests is presented.
Identax
improves current microbial identification software and provides a multiplatform and user-friendly program. It can be executed from any operating system and can be downloaded without any cost from the
Identax
website (
www.identax.org
).
Clinical Performance of Human Papillomavirus E6 and E7 mRNA Testing for High-Grade Lesions of the Cervix
Authors: Cattani Paola , Zannoni Gian Franco , Ricci Caterina , D'Onghia Sara , Trivellizzi Ilaria Nausica , Di Franco Aldo , Vellone Valerio G. , Durante Maria , Fadda Giovanni , Scambia Giovanni , Capelli Giovanni , De Vincenzo Rosa 
Published: October 2009

ABSTRACT
Infection with high-risk (HR) human papillomavirus (HPV) is the major cause of cervical cancer. However, relatively few infections progress to malignant disease. Progression to malignancy requires the overexpression of the E6 and E7 genes in the integrated HPV genome. It follows that the E6 and E7 transcripts could be useful markers of disease progression. The study presented here tests this possibility, using data from colposcopy and from cytological and histological tests to compare RNA assays for the E6 and E7 genes with DNA testing. A total of 180 women underwent colposcopy, cytology, and biopsy of suspected lesions (143 cases). Cervical brush specimens were analyzed for HPV DNA and for E6 and E7 mRNA. DNA from HR HPV was found in 57.8% of the specimens; E6 and E7 transcripts were found in 45%. The rates of detection of HPV DNA and of E6 and E7 transcripts were 33.3% and 25%, respectively, for specimens with normal findings; 51.4% and 31.9%, respectively, for specimens with cervical intraepithelial neoplasia grade 1 (CIN1); and 61.1% and 44.2% for specimens with CIN2, respectively. All specimens with CIN3 and 95.5% of specimens from patients with squamous cell carcinoma were positive by both assays. Thirty-seven patients with normal colposcopy findings did not undergo biopsy. HPV DNA and mRNA transcripts were found in 32.4% and 18.9% of these cases, respectively. Comparisons with cytological tests produced similar results. Overall, the mRNA tests showed a higher specificity than the DNA tests for high-grade lesions (72.7% and 56.2%, respectively) and a higher positive predictive value (59.3% and 49.0%, respectively). These findings suggest that mRNA assays could be more powerful than DNA testing for predicting the risk of progression and offer a strong potential as a tool for triage and patient follow-up.
Enhanced Viral Etiological Diagnosis of Respiratory System Infection Outbreaks by Use of a Multitarget Nucleic Acid Amplification Assay
Authors: Wong Sallene , Pabbaraju Kanti , Lee Bonita E. , Fox Julie D. 
Published: October 2009

ABSTRACT

A study was undertaken to assess the utility of the xTAG respiratory viral panel (RVP) for enhanced laboratory investigation of respiratory outbreaks. Specimens (
n
= 1,108) from 244 suspected respiratory virus outbreaks in 2006 and 2007 in Alberta, Canada, were included in the study. Testing by direct fluorescent antigen detection (DFA) and various in-house nucleic acid amplification tests (NATs) for common respiratory viruses provided an etiological diagnosis in 177 outbreaks (72.5%), with 524 samples testing positive (47.3%) for a respiratory virus. Two hundred samples from 51 unresolved outbreaks were further tested by RVP retrospectively. Fifty-eight samples from 30 unresolved outbreaks had a respiratory virus detected by RVP (47 picornavirus-positive, 9 coronavirus-positive, and 2 influenza virus A-positive samples). Overall, detection of a viral etiological agent was achieved in 90.8% of outbreaks using a combination of DFA, NATs, and RVP. Use of RVP enhances the laboratory investigation of respiratory virus outbreaks and facilitates appropriate patient and outbreak management.
Novel Multilocus Sequence Typing Scheme Reveals High Genetic Diversity of Human Pathogenic Members of theFusarium incarnatum-F.equisetiandF. chlamydosporumSpecies Complexes within the United States
Authors: O'Donnell Kerry , Sutton Deanna A. , Rinaldi Michael G. , Gueidan Cécile , Crous Pedro W. , Geiser David M. 
Published: October 2009

ABSTRACTSpecies limits within the clinically importantFusarium incarnatum-F.equisetiandF. chlamydosporumspecies complexes (FIESC and FCSC, respectively) were investigated using multilocus DNA sequence data. Maximum-parsimony and maximum-likelihood analyses of aligned DNA sequences from four loci resolved 28 species within the FIESC, within which the species were evenly divided among two clades designated Incarnatum and Equiseti, and four species within the FCSC. Sequence data from a fifth locus, β-tubulin, was excluded from the study due to the presence of highly divergent paralogs or xenologs. The multilocus haplotype nomenclature adopted in a previous study (K. O'Donnell, D. A. Sutton, A. Fothergill, D. McCarthy, M. G. Rinaldi, M. E. Brandt, N. Zhang, and D. M. Geiser, J. Clin. Microbiol. 46:2477-2490, 2008) was expanded to all of the species within the FIESC and FCSC to provide the first DNA sequence-based typing schemes for these fusaria, thereby facilitating future epidemiological investigations. Multilocus DNA typing identified sixty-two sequence types (STs) among 88 FIESC isolates and 20 STs among 26 FCSC isolates. This result corresponds to indices of discrimination of 0.985 and 0.966, respectively, for the FIESC and FCSC four-locus typing scheme using Simpson's index of discrimination. Lastly, four human and two veterinary isolates, received as members of the FIESC or FCSC, were resolved as five phylogenetically distinct species nested outside these species complexes. To our knowledge, these five species heretofore have not been reported to cause mycotic infections (i.e.,F. armeniacum,F. brachygibbosum,F. flocciferum, and two unnamedFusariumspecies within theF. tricinctumspecies complex).
Chronic Wasting Disease (CWD) Susceptibility of Several North American Rodents That Are Sympatric with Cervid CWD Epidemics
Authors: Heisey Dennis M. , Mickelsen Natalie A. , Schneider Jay R. , Johnson Christopher J. , Johnson Chad J. , Langenberg Julia A. , Bochsler Philip N. , Keane Delwyn P. , Barr Daniel J. 
Published: October 2009

ABSTRACT

Chronic wasting disease (CWD) is a highly contagious always fatal neurodegenerative disease that is currently known to naturally infect only species of the deer family,
Cervidae
. CWD epidemics are occurring in free-ranging cervids at several locations in North America, and other wildlife species are certainly being exposed to infectious material. To assess the potential for transmission, we intracerebrally inoculated four species of epidemic-sympatric rodents with CWD. Transmission was efficient in all species; the onset of disease was faster in the two vole species than the two
Peromyscus
spp. The results for inocula prepared from CWD-positive deer with or without CWD-resistant genotypes were similar. Survival times were substantially shortened upon second passage, demonstrating adaptation. Unlike all other known prion protein sequences for cricetid rodents that possess asparagine at position 170, our red-backed voles expressed serine and refute previous suggestions that a serine in this position substantially reduces susceptibility to CWD. Given the scavenging habits of these rodent species, the apparent persistence of CWD prions in the environment, and the inevitable exposure of these rodents to CWD prions, our intracerebral challenge results indicate that further investigation of the possibility of natural transmission is warranted.
Targeting of Murine Leukemia Virus Gag to the Plasma Membrane Is Mediated by PI(4,5)P
2
/PS and a Polybasic Region in the Matrix
Authors: Hamard-Peron E. , Juillard F. , Saad J. S. , Roy C. , Roingeard P. , Summers M. F. , Darlix J.-L. , Picart C. , Muriaux D. 
Published: October 2009

ABSTRACT

Membrane targeting of the human immunodeficiency virus Gag proteins is dependent on phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P
2
] located in the plasma membrane. In order to determine if evolutionarily distant retroviral Gag proteins are targeted by a similar mechanism, we generated mutants of the matrix (MA) domain of murine leukemia virus (MuLV) Gag, examined their binding to membrane models in vitro, and analyzed their phenotypes in cell culture. In vitro, we showed that MA bound all the phosphatidylinositol phosphates with significant affinity but displayed a strong specificity for PI(4,5)P
2
only if enhanced by phosphatidylserine. Mutations in the polybasic region in MA dramatically reduced this affinity. In cells, virus production was strongly impaired by PI(4,5)P
2
depletion under conditions of 5ptaseIV overexpression, and mutations in the MA polybasic region altered Gag localization, membrane binding, and virion production. Our results suggest that the N-terminal polybasic cluster of MA is essential for Gag targeting to the plasma membrane. The binding of the MA domain to PI(4,5)P
2
appears to be a conserved feature among retroviruses despite the fact that the MuLV-MA domain is structurally different from that of human immunodeficiency virus types 1 and 2 and lacks a readily identifiable PI(4,5)P
2
binding cleft.
Enhanced PD-1 Expression by T Cells in Cerebrospinal Fluid Does Not Reflect Functional Exhaustion during Chronic Human Immunodeficiency Virus Type 1 Infection
Authors: Sadagopal Shanmugalakshmi , Lorey Shelly L. , Barnett Louise , Sutherland Deborah , Basham Rebecca , Erdem Husamettin , Kalams Spyros A. , Haas David W. 
Published: October 2009

ABSTRACTDuring chronic viral infections, T cells are exhausted due to constant antigen exposure and are associated with enhanced programmed death 1 (PD-1) expression. Deficiencies in the PD-1/programmed death-ligand 1 (PD-L1) pathway are associated with autoimmune diseases, including those of the central nervous system (CNS). To understand the role of PD-1 expression in regulating T-cell immunity in the CNS during chronic infection, we characterized PD-1 expression in cerebrospinal fluid (CSF) and blood of individuals with chronic human immunodeficiency virus type 1 (HIV-1) infection. PD-1 expression was higher on HIV-specific CD8+T cells than on total CD8+T cells in both CSF and blood. PD-1 expression on CSF T cells correlated positively with CSF HIV-1 RNA and inversely with blood CD4+T-cell counts, suggesting that HIV-1 infection drives higher PD-1 expression on CSF T cells. However, in every HIV-positive individual, PD-1 expression was higher on T cells in CSF than on those in blood, despite HIV-1 RNA levels being lower. Among healthy HIV-negative controls, PD-1 expression was higher in CSF than in blood. Furthermore, frequencies of the senescence marker CD57 were lower on CSF T cells than on blood T cells, consistent with our prior observation of enhanced ex vivo functional capacity of CSF T cells. The higher PD-1 expression level on CSF T cells therefore does not reflect cellular exhaustion but may be a mechanism to downregulate immune-mediated tissue damage in the CNS. As inhibition of the PD-1/PD-L1 pathway is pursued as a therapeutic option for viral infections, potential effects of such a blockade on development of autoimmune responses in the CNS should be considered.