bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular and Phenotypic Characteristics of Methicillin-Resistant and Vancomycin-Intermediate
Staphylococcus aureus
Isolates from Patients with Septic Arthritis
Authors: Wang Wei-Yao , Lee Shih-Yi , Chiueh Tzong-Shi , Lu Jang-Jih 
Published: September 2009

ABSTRACT

Staphylococcus aureus
is one of the most common pathogens in community- and hospital-associated infections and frequently causes severe and intractable infections in osteoarticular tissues.
S. aureus
isolates that are resistant to methicillin (meticillin) (MRSA isolates) and intermediately resistant to vancomycin (VISA isolates) have emerged. In this report, we described two patients, one female and one male, diagnosed with septic arthritis due to
S. aureus
infections. A total of 13 MRSA isolates were obtained from these two patients. All but one isolate belonged to the VISA group. All seven isolates from the female patient were determined to be community associated, multilocus sequence type (MLST) 59, and staphylococcal cassette chromosome
mecA
(SCC
mec
) type IV; had direct repeat units (DRUs) of nine repeats; were
spa
type t437; and were susceptible to sulfa and quinolone antibiotics. The other six isolates, from the male patient, were determined to be hospital associated, MLST 239, and SCC
mec
type III; had DRUs of 14 repeats; were
spa
type t037; and were resistant to sulfa and quinolone antibiotics. All 13 MRSA isolates were in
agr
group I, were
pvl
negative, and showed no evidence of any association between vancomycin resistance and autolysis.
Antigenemia in Patients with Mediterranean Visceral Leishmaniasis
Authors: Ferrua Bernard , Rol Nicolas , Michel Grégory , Marty Pierre 
Published: September 2009

ABSTRACT

Antigenemia in patients with Mediterranean visceral leishmaniasis (MVL) due to
Leishmania infantum
was retrospectively assessed by sandwich enzyme-linked immunosorbent assay (ELISA). Circulating
Leishmania
antigens, partially in free form, were in evidence in 53% of serum samples from immunocompetent individuals with MVL. Following successful therapy, antigenemia decline as measured by ELISA was more pronounced than antibody decrease.
Foot-and-Mouth Disease Virus Antigen Detection Enzyme-Linked Immunosorbent Assay Using Multiserotype-Reactive Monoclonal Antibodies
Authors: Morioka Kazuki , Fukai Katsuhiko , Yoshida Kazuo , Yamazoe Reiko , Onozato Hiroyuki , Ohashi Seiichi , Tsuda Tomoyuki , Sakamoto Kenichi 
Published: September 2009

ABSTRACT
Monoclonal antibody (MAb)-based sandwich direct enzyme-linked immunosorbent assay (MSD-ELISA) methods that can detect foot-and-mouth disease virus (FMDV) antigens, both multiserotype (MSD-ELISA/MS) (for O, A, C, and Asia 1) and single-serotype (MSD-ELISA/SS) (for O, A, and Asia 1, specifically), were developed. MAb 1H5 was used as an antigen-trapping antibody that reacted with all seven serotypes of FMDV. The MAbs 71F2, 70C4, 16C6, and 7C2 were used as peroxidase-labeled detecting antibodies for multiple serotypes (O, A, C, and Asia 1), type O, type A, and type Asia 1, respectively, in both MSD-ELISA/MS and MSD-ELISA/SS. Our MSD-ELISAs showed high specificity. They produced a very low background of negative samples (buffer, plasma, and saliva) and were able to detect FMDV antigens from clinical samples (plasma and saliva), with results correlating with those of real-time reverse transcription-PCR. In terms of sensitivity, the MSD-ELISAs showed higher optical density values against each diluted serotype antigen than the indirect sandwich ELISA method, which is currently recommended in the manual of the World Organization for Animal Health. The sensitivity and specificity of the MSD-ELISAs seem to be sufficient for the antigenic diagnosis of FMDV.
Two Distinct Clones of Methicillin-Resistant
Staphylococcus aureus
(MRSA) with the Same USA300 Pulsed-Field Gel Electrophoresis Profile: a Potential Pitfall for Identification of USA300 Community-Associated MRSA
Authors: Larsen Anders Rhod , Goering Richard , Stegger Marc , Lindsay Jodi A. , Gould Katherine A. , Hinds Jason , Sørum Marit , Westh Henrik , Boye Kit , Skov Robert 
Published: September 2009

ABSTRACT

Analysis of methicillin-resistant
Staphylococcus aureus
(MRSA) characterized as USA300 by pulsed-field gel electrophoresis identified two distinct clones. One was similar to community-associated USA300 MRSA (ST8-IVa, t008, and Panton-Valentine leukocidin positive). The second (ST8-IVa, t024, and PVL negative) had different molecular characteristics and epidemiology, suggesting independent evolution. We recommend
spa
typing and/or PCR to discriminate between the two clones.
Characterization of
fHbp
,
nhba
(
gna2132
),
nadA
,
porA
, Sequence Type (ST), and Genomic Presence of IS
1301
in Group B Meningococcal ST269 Clonal Complex Isolates from England and Wales
Authors: Lucidarme Jay , Comanducci Maurizio , Findlow Jamie , Gray Stephen J. , Kaczmarski Edward B. , Guiver Malcolm , Kugelberg Elisabeth , Vallely Pamela J. , Oster Philipp , Pizza Mariagrazia , Bambini Stefania , Muzzi Alessandro , Tang Christoph M. , Borrow Ray 
Published: September 2009

ABSTRACT

Highly effective glycoconjugate vaccines exist against four of the five major pathogenic groups of meningococci: A, C, W-135, and Y. An equivalent vaccine against group B meningococci (menB) has remained elusive due to the poorly immunogenic capsular polysaccharide. A promising alternative, the investigational recombinant menB (rMenB)- outer membrane vesicle (OMV) vaccine, contains fHBP, NHBA (previously GNA2132), NadA, and outer membrane vesicles (OMVs) from the New Zealand MeNZB vaccine. MenB currently accounts for 90% of meningococcal disease in England and Wales, where the multilocus sequence type (ST) 269 (ST269) clonal complex (cc269) has recently expanded to account for a third of menB cases. To assess the potential cc269 coverage of the rMenB-OMV vaccine, English and Welsh cc269 isolates from the past decade were genetically characterized with respect to fHBP, NHBA, and NadA. All of the isolates harbored
fHbp
and
nhba
alleles, while 98% of the cc269 isolates were devoid of
nadA
. Subvariant profiling of
fHbp
,
nhba
, and
porA
against STs revealed the presence of two broadly distinct and well-defined clusters of isolates, centered around ST269 and ST275, respectively. An additional molecular marker, insertion sequence IS
1301
, was found to be present in 100% and <2% of isolates of the respective clusters. On the basis of the genetic data, the potential rMenB-OMV coverage of cc269 in England and Wales is high (up to 100%) within both clusters. Expression studies and serum bactericidal antibody assays will serve to enhance predictions of coverage and will augment ongoing studies regarding the significance of IS
1301
within the ST269 cluster.
Non-
spa
-Typeable Clinical
Staphylococcus aureus
Strains Are Naturally Occurring Protein A Mutants
Authors: Baum Cathrin , Haslinger-Löffler Bettina , Westh Henrik , Boye Kit , Peters Georg , Neumann Claudia , Kahl Barbara C. 
Published: September 2009

ABSTRACT

Staphylococcus aureus
is a major human pathogen responsible for increasing the prevalence of community- and hospital-acquired infections. Protein A (SpA) is a key virulence factor of
S. aureus
and is highly conserved. Sequencing of the variable-number tandem-repeat region of SpA (
spa
typing) provides a rapid and reliable method for epidemiological studies. Rarely, non-
spa
-typeable
S. aureus
strains are encountered. The reason for this is not known. In this study, we characterized eight non-
spa
-typeable bacteremia isolates. Sequencing of the entire
spa
locus was successful for five strains and revealed various mutations of
spa
, all of which included a deletion of immunoglobulin G binding domain C, in which the upper primer for
spa
typing is located, while two strains were truly
spa
negative. This is the first report demonstrating that nontypeability of
S. aureus
by
spa
sequencing is due either to mutation or to a true deficiency of
spa
.
Evidence of Pathogenic Subgroups among Atypical Enteropathogenic
Escherichia coli
Strains
Authors: Scaletsky Isabel C. A. , Aranda Katia R. S. , Souza Tamara B. , Silva Neusa P. , Morais Mauro B. 
Published: September 2009

ABSTRACT

We describe the characterization of 126 atypical enteropathogenic
Escherichia coli
(aEPEC) isolates from 1,749 Brazilian children. Classic aEPEC strains were more frequently found in children with diarrhea than in controls (
P
< 0.001), showing their importance as acute diarrhea agents in our country. Only aEPEC strains carrying either the
ehxA
or
paa
gene were significantly associated with diarrhea.
Airway Obstruction Is Increased in
Pneumocystis
-Colonized Human Immunodeficiency Virus-Infected Outpatients
Authors: Morris Alison , Alexander Travis , Radhi Saba , Lucht Lorrie , Sciurba Frank C. , Kolls Jay K. , Srivastava Ruma , Steele Chad , Norris Karen A. 
Published: September 2009

ABSTRACT

We investigated the relationship of
Pneumocystis
colonization, matrix metalloprotease levels in sputum, and airway obstruction in a cohort of human immunodeficiency virus (HIV)-infected outpatients.
Pneumocystis
-colonized subjects had worse obstruction of airways and higher levels of matrix metalloprotease-12 in sputa, suggesting that
Pneumocystis
colonization may be important in HIV-associated chronic obstructive pulmonary disease.
Cleavage Specificity of the UL48 Deubiquitinating Protease Activity of Human Cytomegalovirus and the Growth of an Active-Site Mutant Virus in Cultured Cells
Authors: Kim Eui Tae , Oh Se Eun , Lee Yun-Ok , Gibson Wade , Ahn Jin-Hyun 
Published: September 2009

ABSTRACT

The human cytomegalovirus (HCMV) open reading frame UL48 encodes a 253-kDa tegument protein that is closely associated with the capsid and was recently shown to have ubiquitin-specific protease activity (J. Wang, A. N. Loveland, L. M. Kattenhorn, H. L. Ploegh, and W. Gibson, J. Virol. 80:6003-6012, 2006). Here, we examined the cleavage specificity of this deubiquitinase (DUB) and replication characteristics of an active-site mutant virus. The purified catalytic domain of the UL48 DUB (1 to 359 amino acids), corresponding to the herpes simplex virus UL36
USP
DUB (L. M. Kattenhorn, G. A. Korbel, B. M. Kessler, E. Spooner, and H. L. Ploegh, Mol. Cell 19:547-557, 2005), efficiently released ubiquitin but not ubiquitin-like modifications from a hemagglutinin peptide substrate. Mutating the active-site residues Cys24 or His162 (C24S and H162A, respectively) abolished this activity. The HCMV UL48 and HSV UL36
USP
DUBs cleaved both Lys48- and Lys63-linked ubiquitin dimers and oligomers, showing more activity toward Lys63 linkages. The DUB activity of the full-length UL48 protein immunoprecipitated from virus-infected cells also showed a better cleavage of Lys63-linked ubiquitinated substrates. An HCMV (Towne) mutant virus in which the UL48 DUB activity was destroyed [UL48(C24S)] produced 10-fold less progeny virus and reduced amounts of viral proteins compared to wild-type virus at a low multiplicity of infection. The mutant virus also produced perceptibly less overall deubiquitination than the wild-type virus. Our findings demonstrate that the HCMV UL48 DUB contains both a ubiquitin-specific carboxy-terminal hydrolase activity and an isopeptidase activity that favors ubiquitin Lys63 linkages and that these activities can influence virus replication in cultured cells.
Mutations in the Thumb Allow Human Immunodeficiency Virus Type 1 Reverse Transcriptase To Be Cleaved by Protease in Virions
Authors: Dunn Linda L. , McWilliams Mary Jane , Das Kalyan , Arnold Eddy , Hughes Stephen H. 
Published: September 2009

ABSTRACT
Although human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) has been extensively studied, there are still significant questions about the effects of mutations on the maturation and stability of RT. We show here that a significant fraction (>80%) of the single point mutations we generated in the thumb subdomain of HIV-1 (RT) affect the stability of RT in virions. Fragments of the unstable mutant RTs can be detected in Western blots of virion proteins; however, the degree of degradation varies. The titers of the mutants whose virions contain degraded RTs are reduced. Some, but not all, of the unstable RT thumb subdomain mutants we analyzed have a temperature-sensitive phenotype. A preliminary survey of mutations in other subdomains of RT shows that some of these mutations also destabilize RT. The stability of the RT mutants is enhanced by the addition of a protease inhibitor, suggesting that the viral protease plays an important role in the degradation of the mutant RTs. These results confirm and extend earlier reports of mutations that affect the stability of RT in virions. The data suggest that the stability of a mutant RT in virions could be a major factor in determining the virus titer and, by extension, viral fitness, which could affect whether a mutation in RT is acceptable to the virus.
Cell Cycle Arrest by Transforming Growth Factor β1 Enhances Replication of Respiratory Syncytial Virus in Lung Epithelial Cells
Authors: Gibbs John D. , Ornoff Douglas M. , Igo Heather A. , Zeng Jennifer Y. , Imani Farhad 
Published: September 2009

ABSTRACTRespiratory syncytial virus (RSV) is a common respiratory viral infection in children which is associated with immune dysregulation and subsequent induction and exacerbations of asthma. We recently reported that treatment of primary human epithelial cells (PHBE cells) with transforming growth factor β (TGF-β) enhanced RSV replication. Here, we report that the enhancement of RSV replication is mediated by induction of cell cycle arrest. These data were confirmed by using pharmacologic inhibitors of cell cycle progression, which significantly enhanced RSV replication. Our data also showed that RSV infection alone resulted in cell cycle arrest in A549 and PHBE cells. Interestingly, our data showed that RSV infection induced the expression of TGF-β in epithelial cells. Blocking of TGF-β with anti-TGF-β antibody or use of a specific TGF-β receptor signaling inhibitor resulted in rescue of the RSV-induced cell cycle arrest, suggesting an autocrine mechanism. Collectively, our data demonstrate that RSV regulates the cell cycle through TGF-β in order to enhance its replication. These findings identify a novel pathway for upregulation of virus replication and suggest a plausible mechanism for association of RSV with immune dysregulation and asthma.
Control of Herpes Simplex Virus Replication Is Mediated through an Interferon Regulatory Factor 3-Dependent Pathway
Authors: Menachery Vineet D. , Leib David A. 
Published: September 2009

ABSTRACT

The type I interferon (IFN) cascade is critical in controlling viral replication and pathogenesis. Recognition pathways triggered by viral infection rapidly induce the type I IFN cascade, often in an IFN regulatory factor 3 (IRF-3)-dependent fashion. This dependence predicts that loss of IRF-3 would render early recognition pathways inoperative and thereby impact virus replication, but this has not been observed previously with herpes simplex virus type 1 (HSV-1) in vitro. In this study, HSV-1-infected IRF-3
−/−
bone marrow-derived dendritic cells (BMDCs) and macrophages supported increased HSV replication compared to control cells. In addition, IRF-3-deficient BMDCs exhibited delayed type I IFN synthesis compared to control cells. However, while IFN pretreatment of IRF-3
−/−
BMDCs resulted in reduced virus titers, a far greater reduction was seen after IFN treatment of wild-type cells. This suggests that even in the presence of exogenously supplied IFN, IRF-3
−/−
BMDCs are inherently defective in the control of HSV-1 replication. Together, these results demonstrate a critical role for IRF-3-mediated pathways in controlling HSV-1 replication in cells of the murine immune system.
Adeno-Associated Virus Site-Specific Integration Is Mediated by Proteins of the Nonhomologous End-Joining Pathway
Authors: Daya Shyam , Cortez Nenita , Berns Kenneth I. 
Published: September 2009

ABSTRACT
Adeno-associated virus type 2 (AAV 2) is the only eukaryotic virus capable of site-specific integration; the target site is at chromosome 19q13.4, a site termed AAVS1. The biology of AAV latency has been extensively studied in cell culture, yet the precise mechanism and the required cellular factors are not known. In this study, we assessed the relative frequencies of stable site-specific integration by characterization of cell clones containing integrated AAV vectors. By this assay, two proteins involved in nonhomologous end joining (NHEJ), DNAPKcs and ligase IV, exhibit differential effects on AAV site-specific integration. DNAPKcs is not required; its presence increases the frequency of junction formation indicative of site-specific integration, but seems to reduce the ratio of site-specific integration to random integration (i.e., the latter is even more enhanced). In contrast, site-specific integration is significantly reduced relative to random integration in cells deficient in ligase IV expression. Furthermore, we show that single-stranded AAV vectors are better substrates for site-specific integration than are self-complementary AAV vectors; the absence of DNAPKcs did not affect the targeted integration of these double-stranded AAV vectors. Together, these data suggest that NHEJ proteins participate in site-specific integration, and indicate a role for the single-stranded form of AAV DNA in targeted integration.
Autographa californica
Multiple Nucleopolyhedrovirus Core Gene
ac96
Encodes a Per Os Infectivity Factor (
pif-4
)
Authors: Fang Minggang , Nie Yingchao , Harris Stephanie , Erlandson Martin A. , Theilmann David A. 
Published: September 2009

ABSTRACT

Autographa californica
multiple nucleopolyhedrovirus (AcMNPV)
ac96
is a core gene, but its role in virus replication is still unknown. To determine its role in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an
ac96
-null virus (vAc

96

null
). Our analyses showed that the absence of
ac96
does not affect budded virus (BV) production or viral DNA replication in infected Sf9 cells. Western blotting and confocal immunofluorescence analysis showed that AC96 is expressed in both the cytoplasm and the nucleus throughout infection. In addition, AC96 was detected in the envelope fractions of both BV and occlusion-derived virus. Injection of vAc

96

null
BV into the hemocoel killed
Trichoplusia ni
larvae as efficiently as repaired and control viruses; however, vAc

96

null
was unable to infect the midgut tissue of
Trichoplusia ni
larvae when inoculated per os. Therefore, the results of this study show that
ac96
encodes a new per os infectivity factor (PIF-4).
Loss of Raltegravir Susceptibility by Human Immunodeficiency Virus Type 1 Is Conferred via Multiple Nonoverlapping Genetic Pathways
Authors: Fransen Signe , Gupta Soumi , Danovich Robert , Hazuda Daria , Miller Michael , Witmer Marc , Petropoulos Christos J. , Huang Wei 
Published: September 2009

ABSTRACT
The human immunodeficiency virus type 1 (HIV-1) integrase mutations N155H and Q148R(H)(K) that reduce susceptibility to the integrase inhibitor raltegravir have been identified in patients failing treatment regimens containing raltegravir. Whether these resistance mutations occur individually or in combination within a single virus genome has not been defined, nor do we fully understand the impact of these primary mutations and other secondary mutations on raltegravir susceptibility and viral replication capacity. To address these important questions, we investigated the raltegravir susceptibility and replication capacity of viruses containing mutations at positions 155 and 148 separately or in combination with secondary mutations selected in subjects failing treatment regimens containing raltegravir. Clonal analysis demonstrated that N155H and Q148R(H)(K) occur independently, not in combination. Viruses containing a Q148R(H)(K) mutation generally displayed larger reductions in raltegravir susceptibility than viruses with an N155H mutation. Analysis of site-directed mutants indicated that E92Q in combination with N155H resulted in a higher level of resistance to raltegravir than N155H alone. Viruses containing a Q148R(H) mutation together with a G140S mutation were more resistant to raltegravir than viruses containing a Q148R(H) mutation alone; however, viruses containing G140S and Q148K were more susceptible to raltegravir than viruses containing a Q148K mutation alone. Both N155H and Q148R(H)(K) mutations reduced the replication capacity, while the addition of secondary mutations either improved or reduced the replication capacity depending on the primary mutation. This study demonstrates distinct genetic pathways to resistance in subjects failing raltegravir regimens and defines the effects of primary and secondary resistance mutations on raltegravir susceptibility and replication capacity.
Clade-Specific Evolution Mediated by HLA-B*57/5801 in Human Immunodeficiency Virus Type 1 Clade A1 p24
Authors: McKinnon Lyle R. , Capina Rupert , Peters Harold , Mendoza Mark , Kimani Joshua , Wachihi Charles , Kariri Anthony , Kimani Makobu , Richmond Meika , Kiazyk Sandy Koesters , Fowke Keith R. , Jaoko Walter , Luo Ma , Ball T. Blake , Plummer Francis A. 
Published: September 2009

ABSTRACT

HLA-B*57-mediated selection pressure leads to a typical escape pathway in human immunodeficiency virus type 1 (HIV-1) CD8 epitopes such as TW10. Whether this T242N pathway is shared by all clades remains unknown. We therefore assessed the nature of HLA-B*57 selection in a large, observational Kenyan cohort where clades A1 and D predominate. While T242N was ubiquitous in clade D HLA-B*57
+
subjects, this mutation was rare (15%) in clade A1. Instead, P243T and I247L were selected by clade A1-infected HLA-B*57 subjects but not by HLA-B*5801
+
subjects. Our data suggest that clade A1 consensus proline at Gag residue 243 might represent an inherent block to T242N escape in clade A1. We confirmed immunologically that P243T and I247L likely represent escape mutations. HLA-B*57 evolution also differed between clades in the KF11 and IW9 epitopes. A better understanding of clade-specific evolution is important for the development of HIV vaccines in regions with multiple clades.