bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the Efficacy of Outer Membrane Protein 31 Vaccine Formulations for Protection against Brucella canis in BALB/c Mice
Authors: Clausse Maria , Díaz Alejandra G. , Ibañez Andrés E. , Cassataro Juliana , Giambartolomei Guillermo H. , Estein Silvia M. 
Published: October 2014

ABSTRACTCanine brucellosis is an infectious disease caused by the Gram-negative bacteriumBrucella canis. Unlike conventional control programs for other species of the genusBrucella, currently there is no vaccine available against canine brucellosis, and preventive measures are simply diagnosis and isolation of infected dogs. New approaches are therefore needed to develop an effective and safe immunization strategy against this zoonotic pathogen. In this study, BALB/c mice were subcutaneously immunized with the following: (i) the recombinantBrucellaOmp31 antigen formulated in different adjuvants (incomplete Freund adjuvant, aluminum hydroxide, Quil A, and Montanide IMS 3012 VGPR), (ii) plasmid pCIOmp31, or (iii) pCIOmp31 plasmid followed by boosting with recombinant Omp31 (rOmp31). The immune response and the protective efficacy againstB. canisinfection were characterized. The different strategies induced a strong immunoglobulin G (IgG) response. Furthermore, spleen cells from rOmp31-immunized mice produced gamma interferon and interleukin-4 (IL-4) afterin vitrostimulation with rOmp31, indicating the induction of a mixed Th1-Th2 response. Recombinant Omp31 administered with different adjuvants as well as the prime-boost strategy conferred protection againstB. canis. In conclusion, our results suggest that Omp31 could be a useful candidate for the development of a subcellular vaccine againstB. canisinfection.
Multicentric Comparative Assessment of the Bio-Evolution Toxoplasma gondii Detection Kit with Eight Laboratory-Developed PCR Assays for Molecular Diagnosis of Congenital Toxoplasmosis
Authors: Filisetti Denis , Sterkers Yvon , Brenier-Pinchart Marie-Pierre , Cassaing Sophie , Dalle Frédéric , Delhaes Laurence , Pelloux Hervé , Touafek Fériel , Varlet-Marie Emmanuelle , Yera Hélène , Candolfi Ermano , Bastien Patrick 
Published: October 2014

ABSTRACT

The detection of
Toxoplasma gondii
in amniotic fluid is an essential tool for the prenatal diagnosis of congenital toxoplasmosis and is currently essentially based on the use of PCR. Although some consensus is emerging, this molecular diagnosis suffers from a lack of standardization and an extreme diversity of laboratory-developed methods. Commercial kits for the detection of
T. gondii
by PCR were recently developed and offer certain advantages; however, they must be assessed in comparison with optimized reference PCR assays. The present multicentric study aimed to compare the performances of the Bio-Evolution
T. gondii
detection kit and laboratory-developed PCR assays set up in eight proficient centers in France. The study compared 157 amniotic fluid samples and found concordances of 99% and 100% using 76
T. gondii
-infected samples and 81 uninfected samples, respectively. Moreover, taking into account the classification of the European Research Network on Congenital Toxoplasmosis, the overall diagnostic sensitivity of all assays was identical and calculated to be 86% (54/63); specificity was 100% for all assays. Finally, the relative quantification results were in good agreement between the kit and the laboratory-developed assays. The good performances of this commercial kit are probably in part linked to the use of a number of good practices: detection in multiplicate, amplification of the repetitive DNA target rep529, and the use of an internal control for the detection of PCR inhibitors. The only drawbacks noted at the time of the study were the absence of uracil-
N
-glycosylase and small defects in the reliability of the production of different reagents.
Genotypic Susceptibility Testing of Mycobacterium tuberculosis Isolates for Amikacin and Kanamycin Resistance by Use of a Rapid Sloppy Molecular Beacon-Based Assay Identifies More Cases of Low-Level Drug Resistance than Phenotypic Lowenstein-Jensen Testing
Authors: Chakravorty Soumitesh , Lee Jong Seok , Cho Eun Jin , Roh Sandy S. , Smith Laura E. , Lee Jiim , Kim Cheon Tae , Via Laura E. , Cho Sang-Nae , Barry Clifton E. , Alland David 
Published: October 2014

ABSTRACT

Resistance to amikacin (AMK) and kanamycin (KAN) in clinical
Mycobacterium tuberculosis
strains is largely determined by specific mutations in the
rrs
gene and
eis
gene promoter. We developed a rapid, multiplexed sloppy molecular beacon (SMB) assay to identify these mutations and then evaluated assay performance on 603 clinical
M. tuberculosis
DNA samples collected in South Korea. Assay performance was compared to gold-standard phenotypic drug susceptibility tests, including Lowenstein-Jensen (LJ) absolute concentration, mycobacterial growth indicator tubes (MGIT), and TREK Sensititre MycoTB MIC plate (MycoTB) methods. Target amplicons were also tested for mutations by Sanger sequencing. The SMB assay correctly detected 115/116 mutant and mixed sequences and 487/487 wild-type sequences (sensitivity and specificity of 99.1 and 100%, respectively). Using the LJ method as the reference, sensitivity and specificity for AMK resistance were 92.2% and 100%, respectively, and sensitivity and specificity for KAN resistance were 87.7% and 95.6%, respectively. Mutations in the
rrs
gene were unequivocally associated with high-level cross-resistance to AMK and KAN in all three conventional drug susceptibility testing methods. However,
eis
promoter mutations were associated with KAN resistance using the MGIT or MycoTB methods but not the LJ method. No testing method associated
eis
promoter mutations with AMK resistance. Among the discordant samples with AMK and/or KAN resistance but wild-type sequence at the target genes, we discovered four new mutations in the
whiB7
5′ untranslated region (UTR) in 6/22 samples. All six samples were resistant only to KAN, suggesting the possible role of these
whiB7
5′ UTR mutations in KAN resistance.
Nontoxigenic Vibrio cholerae Non-O1/O139 Isolate from a Case of Human Gastroenteritis in the U.S. Gulf Coast
Authors: Hasan Nur A. , Rezayat Talayeh , Blatz Peter J. , Choi Seon Young , Griffitt Kimberly J. , Rashed Shah M. , Huq Anwar , Conger Nicholas G. , Colwell Rita R. , Grimes D. Jay 
Published: October 2014

ABSTRACT

An occurrence of
Vibrio cholerae
non-O1/O139 gastroenteritis in the U.S. Gulf Coast is reported here. Genomic analysis revealed that the isolate lacked known virulence factors associated with the clinical outcome of a
V. cholerae
infection but did contain putative genomic islands and other accessory virulence factors. Many of these factors are widespread among environmental strains of
V. cholerae
, suggesting that there might be additional virulence factors in non-O1/O139
V. cholerae
yet to be determined. Phylogenetic analysis revealed that the isolate belonged to a phyletic lineage of environmental
V. cholerae
isolates associated with sporadic cases of gastroenteritis in the Western Hemisphere, suggesting a need to monitor non-O1/O139
V. cholerae
in the interest of public health.
Family Clusters of Avian Influenza A H7N9 Virus Infection in Guangdong Province, China
Authors: Yi Lina , Guan Dawei , Kang Min , Wu Jie , Zeng Xianqiao , Lu Jing , Rutherford Shannon , Zou Lirong , Liang Lijun , Ni Hanzhong , Zhang Xin , Zhong Haojie , He Jianfeng , Lin Jinyan , Ke Changwen 
Published: October 2014

ABSTRACT
Since its first identification, the epizootic avian influenza A H7N9 virus has continued to cause infections in China. Two waves were observed during this outbreak. No cases were reported from Guangdong Province during the first wave, but this province became one of the prime outbreak sites during the second wave. In order to identify the transmission potential of this continuously evolving infectious virus, our research group monitored all clusters of H7N9 infections during the second wave of the epidemic in Guangdong Province. Epidemiological, clinical, and virological data on these patients were collected and analyzed. Three family clusters including six cases of H7N9 infection were recorded. The virus caused severe disease in two adult patients but only mild symptoms for all four pediatric patients. All patients reported direct poultry or poultry market exposure history. Relevant environment samples collected according to their reported exposures tested H7N9 positive. Virus isolates from patients in the same cluster shared high sequence similarities. In conclusion, although continually evolving, the currently circulating H7N9 viruses in Guangdong Province have not yet demonstrated the capacity for efficient and sustained person-to-person transmission.
Semiquantitative Multiplexed Tandem PCR for Detection and Differentiation of Four Theileria orientalis Genotypes in Cattle
Authors: Perera Piyumali K. , Gasser Robin B. , Firestone Simon M. , Smith Lee , Roeber Florian , Jabbar Abdul 
Published: October 2014

ABSTRACT

Oriental theileriosis is an emerging, tick-borne disease of bovines in the Asia-Pacific region and is caused by one or more genotypes of the
Theileria orientalis
complex. This study aimed to establish and validate a multiplexed tandem PCR (MT-PCR) assay using three distinct markers (major piroplasm surface protein, 23-kDa piroplasm membrane protein, and the first internal transcribed spacer of nuclear DNA), for the simultaneous detection and semiquantification of four genotypes (Buffeli, Chitose, Ikeda, and type 5) of the
T. orientalis
complex. Analytical specificity, analytical sensitivity, and repeatability of the established MT-PCR assay were assessed in a series of experiments. Subsequently, the assay was evaluated using 200 genomic DNA samples collected from cattle from farms on which oriental theileriosis outbreaks had occurred, and 110 samples from a region where no outbreaks had been reported. The results showed the MT-PCR assay specifically and reproducibly detected the expected genotypes (i.e., genotypes Buffeli, Chitose, Ikeda, and type 5) of the
T. orientalis
complex, reliably differentiated them, and was able to detect as little as 1 fg of genomic DNA from each genotype. The diagnostic specificity and sensitivity of the MT-PCR were estimated at 94.0% and 98.8%, respectively. The MT-PCR assay established here is a practical and effective diagnostic tool for the four main genotypes of
T. orientalis
complex in Australia and should assist studies of the epidemiology and pathophysiology of oriental theileriosis in the Asia-Pacific region.
A View of the E2-CD81 Interface at the Binding Site of a Neutralizing Antibody against Hepatitis C Virus
Authors: Harman Christine , Zhong Lilin , Ma Li , Liu Peter , Deng Lu , Zhao Zhong , Yan Hailing , Struble Evi , Virata-Theimer Maria Luisa , Zhang Pei 
Published: October 2014

ABSTRACT

Hepatitis C virus (HCV) glycoprotein E2 is considered a major target for generating neutralizing antibodies against HCV, primarily due to its role of engaging host entry factors, such as CD81, a key cell surface protein associated with HCV entry. Based on a series of biochemical analyses in combination with molecular docking, we present a description of a potential binding interface formed between the E2 protein and CD81. The virus side of this interface includes a hydrophobic helix motif comprised of residues W
437
LAGLF
442
, which encompasses the binding site of a neutralizing monoclonal antibody, mAb41. The helical conformation of this motif provides a structural framework for the positioning of residues F442 and Y443, serving as contact points for the interaction with CD81. The cell side of this interface likewise involves a surface-exposed hydrophobic helix, namely, the D-helix of CD81, which coincides with the binding site of 1D6, a monoclonal anti-CD81 antibody known to block HCV entry. Our illustration of this virus-host interface suggests an important role played by the W
437
LAGLF
442
helix of the E2 protein in the hydrophobic interaction with the D-helix of CD81, thereby facilitating our understanding of the mechanism for antibody-mediated neutralization of HCV.

IMPORTANCE
Characterization of the interface established between a virus and host cells can provide important information that may be used for the control of virus infections. The interface that enables hepatitis C virus (HCV) to infect human liver cells has not been well understood because of the number of cell surface proteins, factors, and conditions found to be associated with the infection process. Based on a series of biochemical analyses in combination with molecular docking, we present such an interface, consisting of two hydrophobic helical structures, from the HCV E2 surface glycoprotein and the CD81 protein, a major host cell receptor recognized by all HCV strains. Our study reveals the critical role played by hydrophobic interactions in the formation of this virus-host interface, thereby contributing to our understanding of the mechanism for antibody-mediated neutralization of HCV.
Virulence Determinants in the PB2 Gene of a Mouse-Adapted H9N2 Virus
Authors: Liu Qingtao , Huang Junqing , Chen Yuxin , Chen Hongzhi , Li Qunhui , He Liang , Hao Xiaoli , Liu Jingjing , Gu Min , Hu Jiao , Wang Xiaoquan , Hu Shunlin , Liu Xiaowen , Liu Xiufan 
Published: October 2014

ABSTRACT
The molecular bases of adaptation and pathogenicity of H9N2 influenza virus in mammals are largely unknown. Here, we show that a mouse-adapted PB2 gene with a phenylalanine-to-leucine mutation (F404L) mainly contributes to enhanced polymerase activity, replication, and pathogenicity of H9N2 in mice and also increases the virulence of the H5N1 and 2009 pandemic H1N1 influenza viruses. Therefore, we defined a novel pathogenic determinant, providing further insights into the pathogenesis of influenza viruses in mammals.
Activation of ATP Citrate Lyase by mTOR Signal Induces Disturbed Lipid Metabolism in Hepatitis B Virus Pre-S2 Mutant Tumorigenesis
Authors: Teng Chiao-Fang , Wu Han-Chieh , Hsieh Wen-Chuan , Tsai Hung-Wen , Su Ih-Jen 
Published: October 2014

ABSTRACT

The development of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) has been found to be associated with disturbed lipid metabolism. To elucidate the role of lipid metabolism in HBV tumorigenesis, we investigated the dynamic pattern of lipid metabolism in HBV pre-S2 mutant-induced tumorigenesis. Lipid and gene expression profiles were analyzed in an
in vitro
culture system and in transgenic mouse livers harboring HBV pre-S2 mutant. The pre-S2 mutant transgenic livers showed a biphasic pattern of lipid accumulation, starting from mild fatty change in early (1 month) transgenic livers, which subsided and then, remarkably, increased in HCC tissues. This biphasic pattern was synchronized with ATP citrate lyase (ACLY) activation. Further analyses revealed that the pre-S2 mutant initiated an endoplasmic reticulum (ER) stress-dependent mammalian target of rapamycin (mTOR) signalling cascade. The pre-S2 mutant-induced mTOR signal activated the sterol regulatory element binding transcription factor 1 (SREBF1) to upregulate ACLY, which then activated the fatty acid desaturase 2 (FADS2), mediated through ACLY-dependent histone acetylation. Such an ER stress-dependent mTOR signal cascade also is important for the proliferation of hepatocytes
in vitro
and is further validated in HBV-related HCC tissues.

IMPORTANCE
Aberrations of lipid metabolism frequently occur in chronic HBV infection. Our results provide a potential mechanism of disturbed lipid metabolism in HBV pre-S2 mutant-induced tumorigenesis, which should be valuable for the design of HCC chemoprevention in high-risk HBV carriers.
Comprehensive Molecular Detection of Tick-Borne Phleboviruses Leads to the Retrospective Identification of Taxonomically Unassigned Bunyaviruses and the Discovery of a Novel Member of the Genus Phlebovirus
Authors: Matsuno Keita , Weisend Carla , Kajihara Masahiro , Matysiak Colette , Williamson Brandi N. , Simuunza Martin , Mweene Aaron S. , Takada Ayato , Tesh Robert B. , Ebihara Hideki 
Published: October 2014

ABSTRACT
Until the recent emergence of two human-pathogenic tick-borne phleboviruses (TBPVs) (severe fever with thrombocytopenia syndrome virus [SFTSV] and Heartland virus), TBPVs have been neglected as causative agents of human disease. In particular, no studies have addressed the global distribution of TBPVs, and consequently, our understanding of the mechanism(s) underlying their evolution and emergence remains poor. In order to provide a useful tool for the ecological and epidemiological study of TBPVs, we have established a simple system that can detect all known TBPVs, based on conventional reverse transcription-PCR (RT-PCR) with degenerate primer sets targeting conserved regions of the viral L genome segment. Using this system, we have determined that several viruses that had been isolated from ticks decades ago but had not been taxonomically identified are novel TBPVs. Full-genome sequencing of these viruses revealed a novel fourth TBPV cluster distinct from the three known TBPV clusters (i.e., the SFTS, Bhanja, and Uukuniemi groups) and from the mosquito/sandfly-borne phleboviruses. Furthermore, by using tick samples collected in Zambia, we confirmed that our system had enough sensitivity to detect a new TBPV in a single tick homogenate. This virus, tentatively designated Shibuyunji virus after the region of tick collection, grouped into a novel fourth TBPV cluster. These results indicate that our system can be used as a first-line screening approach for TBPVs and that this kind of work will undoubtedly lead to the discovery of additional novel tick viruses and will expand our knowledge of the evolution and epidemiology of TBPVs.

IMPORTANCE
Tick-borne phleboviruses (TBPVs) have been largely neglected until the recent emergence of two virulent viruses, severe fever with thrombocytopenia syndrome virus and Heartland virus. Little is known about the global distribution of TBPVs or how these viruses evolved and emerged. A major hurdle to study the distribution of TBPVs is the lack of tools to detect these genetically divergent phleboviruses. In order to address this issue, we have developed a simple, rapid, and cheap RT-PCR system that can detect all known TBPVs and which led to the identification of several novel phleboviruses from previously uncharacterized tick-associated virus isolates. Our system can detect virus in a single tick sample and novel TBPVs that are genetically distinct from any of the known TBPVs. These results indicate that our system will be a useful tool for the surveillance of TBPVs and will facilitate understanding of the ecology of TBPVs.
Functions of Antibodies
Authors: Forthal Donald N. 
Published: October 2014

ABSTRACTAntibodies can impact pathogens in the presence or in the absence of effector cells or effector molecules such as complement, and experiments can often sort out with precision the mechanisms by which an antibody inhibits a pathogenin vitro. In addition,in vivomodels, particularly those engineered to knock in or knock out effector cells or effector molecules, are excellent tools for understanding antibody functions. However, it is highly likely that multiple antibody functions occur simultaneously or sequentially in the presence of an infecting organismin vivo. The most critical incentive for measuring antibody functions is to provide a basis for vaccine development and for the development of therapeutic antibodies. In this respect, some functions, such as virus neutralization, serve to inhibit the acquisition of a pathogen or limit its pathogenesis. However, antibodies can also enhance replication or contribute to pathogenesis. This review emphasizes those antibody functions that are potentially beneficial to the host. In addition, this review will focus on the effects of antibodies on organisms themselves, rather than on the toxins the organisms may produce.
Human Metapneumovirus
Authors: Schuster Jennifer E. , Williams John V. 
Published: October 2014

ABSTRACT
Human metapneumovirus (HMPV), a paramyxovirus identified in 2001, is a leading cause of respiratory tract infections in both children and adults. Seroprevalence studies demonstrate that the primary infection occurs before the age of 5 years, and humans are reinfected throughout life. The four subgroups of HMPV occur with year-to-year variability, and infection with one subgroup confers some serologic cross-protection. Experimental vaccines elicit a humoral response in both animal and human models and have been used to identify antigenic determinants. The main target of protective antibodies is the fusion (F) protein, although many of the remaining eight proteins are immunogenic. Monoclonal antibodies (mAbs) targeting the F protein are both protective and therapeutic in animal models. Most recently, the identification of broadly neutralizing antibodies against HMPV and respiratory syncytial virus demonstrates that common epitopes are present between the two viruses. Broadly neutralizing mAbs have significant clinical implications for prophylaxis and treatment of high-risk hosts as well as vaccine development.
Risk Factors for Shiga Toxin-ProducingEscherichia coli-Associated Human Diseases
Authors: Rivas Marta , Chinen Isabel , Miliwebsky Elizabeth , Masana Marcelo 
Published: October 2014

ABSTRACTWe have reviewed the risk factors for the occurrence of Shiga toxin-producingEscherichia coli(STEC)-associated human diseases. The analysis of STEC surveillance data and trends shows differences in frequency and severity of the illnesses across countries, whereas the economic and social costs for the affected families, the community, and the health system are better estimated in developed countries. The occurrence of STEC infections is determined by the interaction of the pathogen, the reservoirs, and the biological, cultural, and behavioral aspects of the host. The main risk factors identified in earlier case-control and population-based studies were dietary behaviors and beef consumption. However, in recent years, other risky exposures have also emerged, like the consumption of raw vegetables and sprouts, working or camping in rural areas, visiting farms, and person-to-person transmission. Epidemiological changes have also been determined by the intensification of cattle production, the increase in centralized food production and distribution, and the growth in the volume of international trade of foods. The main lessons learned from recent large outbreaks are knowledge of virulence determinants of new pathogenic strains, recognition of new vehicles of infection, development of new methodologies for detecting STEC in foods and humans, improvement in food regulations and hygiene guidelines, new therapeutic approaches in the treatment of infected patients, establishment of continuous educational programs for food consumers, and enhanced cooperation and teamwork of regional and international networks.
Enterohemorrhagic
Escherichia coli
Virulence Gene Regulation
Authors: Mellies Jay L. , Lorenzen Emily 
Published: October 2014

ABSTRACT

Coordinated expression of enterohemorrhagic
Escherichia coli
virulence genes enables the bacterium to cause hemorrhagic colitis and the complication known as hemolytic-uremic syndrome. Horizontally acquired genes and those common to
E. coli
contribute to the disease process, and increased virulence gene expression is correlated with more severe disease in humans. Researchers have gained considerable knowledge about how the type III secretion system, secreted effectors, adhesin molecules, and the Shiga toxins are regulated by environmental signals and multiple genetic pathways. Also emergent from the data is an understanding of how enterohemorrhagic
E. coli
regulates response to acid stress, the role of flagellar motility, and how passage through the human host and bovine intestinal tract causes disease and supports carriage in the cattle reservoir, respectively. Particularly exciting areas of discovery include data suggesting how expression of the myriad effectors is coordinately regulated with their cognate type III secretion system and how virulence is correlated with bacterial metabolism and gut physiology.