bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cydia pomonella granulovirus
Genotypes Overcome Virus Resistance in the Codling Moth and Improve Virus Efficiency by Selection against Resistant Hosts
Authors: Berling Marie , Blachere-Lopez Christine , Soubabere Olivier , Lery Xavier , Bonhomme Antoine , Sauphanor Benoît , Lopez-Ferber Miguel 
Published: December 2008

ABSTRACT

Cydia pomonella granulovirus
(CpGV) has been used for 15 years as a bioinsecticide in codling moth (
Cydia pomonella
) control. In 2004, some insect populations with low susceptibility to the virus were detected for the first time in southeast France. RGV, a laboratory colony of codling moths resistant to the CpGV-M isolate used in the field, was established with collection of resistant insects in the field followed by an introgression of the resistant trait into a susceptible colony (Sv). The resistance level (based on the 50% lethal concentrations [LC
50
s]) of the RGV colony to the CpGV-M isolate, the active ingredient in all commercial virus formulations in Europe, appeared to be over 60,000-fold compared to the Sv colony. The efficiency of CpGV isolates from various other regions was tested on RGV. Among them, two isolates (I12 and NPP-R1) presented an increased pathogenicity on RGV. I12 had already been identified as effective against a resistant
C. pomonella
colony in Germany and was observed to partially overcome the resistance in the RGV colony. The recently identified isolate NPP-R1 showed an even higher pathogenicity on RGV than other isolates, with an LC
50
of 166 occlusion bodies (OBs)/μl, compared to 1.36 × 10
6
OBs/μl for CpGV-M. Genetic characterization showed that NPP-R1 is a mixture of at least two genotypes, one of which is similar to CpGV-M. The 2016-r4 isolate obtained from four successive passages of NPP-R1 in RGV larvae had a sharply reduced proportion of the CpGV-M-like genotype and an increased pathogenicity against insects from the RGV colony.
The Plant Phenolic Compound
p
-Coumaric Acid Represses Gene Expression in the
Dickeya dadantii
Type III Secretion System
Authors: Li Yan , Peng Quan , Selimi Dija , Wang Qi , Charkowski Amy O. , Chen Xin , Yang Ching-Hong 
Published: December 2008

ABSTRACT

The type III secretion system (T3SS) is a major virulence factor in many gram-negative bacterial pathogens. This secretion system translocates effectors directly into the cytosol of eukaryotic host cells, where the effector proteins facilitate bacterial pathogenesis by interfering with host cell signal transduction and other cellular processes. Plants defend themselves against bacterial pathogens by recognizing either the type 3 effectors or their actions and initiating a cascade of defense responses that often results in programmed cell death of the plant cell being attacked. Here we show that a plant phenolic compound,
p
-coumaric acid (PCA), represses the expression of T3SS genes of the plant pathogen
Dickeya dadantii
, suggesting that plants can also defend against bacterial pathogens by manipulating the expression of the T3SS. PCA repressed the expression of T3SS regulatory genes through the HrpX/Y two-component system, a core regulator of the T3SS, rather than through the global regulator GacS/A, which indirectly regulates the T3SS. A further analysis of several PCA analogs suggests that the
para
positioning of the hydroxyl group in the phenyl ring and the double bond of PCA may be important for its biological activity.
Hypovirus-Responsive Transcription Factor Gene
pro1
of the Chestnut Blight Fungus
Cryphonectria parasitica
Is Required for Female Fertility, Asexual Spore Development, and Stable Maintenance of Hypovirus Infection
Authors: Sun Qihong , Choi Gil H. , Nuss Donald L. 
Published: December 2008

ABSTRACT

We report characterization of the gene encoding putative transcription factor PRO1, identified in transcriptional profiling studies as being downregulated in the chestnut blight fungus
Cryphonectria parasitica
in response to infection by virulence-attenuating hypoviruses. Sequence analysis confirmed that
pro1
encodes a Zn(II)
2
Cys
6
binuclear cluster DNA binding protein with significant sequence similarity to the
pro1
gene product that controls fruiting body development in
Sordaria macrospora
. Targeted disruption of the
C. parasitica pro1
gene resulted in two phenotypic changes that also accompany hypovirus infection, a significant reduction in asexual sporulation that could be reversed by exposure to high light intensity, and loss of female fertility. The
pro1
disruption mutant, however, retained full virulence. Although hypovirus CHV1-EP713 infection was established in the
pro1
disruption mutant, infected colonies continually produced virus-free sectors, suggesting that PRO1 is required for stable maintenance of hypovirus infection. These results complement the recent characterization of the hypovirus-responsive homologue of the
Saccharomyces cerevisiae
Ste12 C
2
H
2
zinc finger transcription factor gene,
cpst12
, which was shown to be required for
C. parasitica
female fertility and virulence.
A Strain-Specific Catalase Mutation and Mutation of the Metal-Binding Transporter Gene
mntC
Attenuate
Neisseria gonorrhoeae
In Vivo but Not by Increasing Susceptibility to Oxidative Killing by Phagocytes
Authors: Wu Hong , Soler-García Ángel A. , Jerse Ann E. 
Published: December 2008

ABSTRACT

The hallmark of gonorrhea is an intense inflammatory response that is characterized by polymorphonuclear leukocytes (PMNs) with intracellular gonococci. A redundancy of defenses may protect
Neisseria gonorrhoeae
from phagocyte-derived reactive oxygen species. Here we showed that a gonococcal catalase (
kat
) mutant in strain MS11 was more sensitive to H
2
O
2
than mutants in cytochrome
c
peroxidase (
ccp
), methionine sulfoxide reductase (
msrA
), or the metal-binding protein (
mntC
) of the MntABC transporter.
kat ccp
and
kat ccp mntC
mutants were significantly more sensitive to H
2
O
2
than mutants in any single factor. None of the mutants showed increased susceptibility to murine PMNs. Recovery of the
mntC
and
kat ccp mntC
mutants from the lower genital tract of BALB/c mice, but not the
kat
or
kat ccp
mutants, was significantly reduced relative to wild-type bacteria. Interestingly, unlike the MS11
kat
mutant, a
kat
mutant of strain FA1090 was attenuated during competitive infection with wild-type FA1090 bacteria. The FA1090
kat
mutant and MS11
mntC
mutant were also attenuated in mice that are unable to generate a phagocytic respiratory burst. We conclude that inactivation of three well-characterized antioxidant genes (
kat
,
ccp
, and
mntC
) does not increase gonococcal susceptibility to the phagocytic respiratory burst during infection and that gonococcal catalase and the MntC protein confer an unidentified advantage in vivo. In the case of catalase, this advantage is strain specific. Finally, we also showed that an
msrA
mutant of strain MS11 demonstrated delayed attenuation in BALB/c but not C57BL/6 mice. Therefore, MsrA/B also appears to play a role in infection that is dependent on host genetic background.
Role of Complement in Protection againstCryptococcus gattiiInfection
Authors: Mershon Kileen L. , Vasuthasawat Alex , Lawson Gregory W. , Morrison Sherie L. , Beenhouwer David O. 
Published: December 2008

ABSTRACTPrevious studies have shown that the alternative pathway of complement activation plays an important role in protection against infection withCryptococcus neoformans. Cryptococcus gattiidoes not activate the alternative pathway as well asC. neoformansin vitro. The role of complement inC. gattiiinfection in vivo has not been reported. In this study, we used mice deficient in complement components to investigate the role of complement in protection against aC. gattiiisolate from an ongoing outbreak in northwestern North America. While factor B-deficient mice showed an enhanced rate of death, complement component C3-deficient mice died even more rapidly, indicating that the alternative pathway was not the only complement pathway contributing to protection against disease. Both C3- and factor B-deficient mice had increased fungal burdens in comparison to wild-type mice. Histopathology revealed an overwhelming fungal burden in the lungs of these complement-deficient mice, which undoubtedly prevented efficient gas exchange, causing death. Following the fate of radiolabeled organisms showed that both factor B- and C3-deficient mice were less effective than wild-type mice in clearing organisms. However, opsonization ofC. gattiiwith complement components was not sufficient to prolong life in mice deficient in complement. Killing ofC. gattiiby macrophages in vitro was decreased in the presence of serum from factor B- and C3-deficient versus wild-type mice. In conclusion, we have demonstrated that complement activation is crucial for survival inC. gattiiinfection. Additionally, we have shown that the alternative pathway of complement activation is not the only complement pathway contributing to protection.
Efficacy of a Vaccine Based on Protective Antigen and Killed Spores against Experimental Inhalational Anthrax
Authors: Gauthier Yves P. , Tournier Jean-Nicolas , Paucod Jean-Charles , Corre Jean-Philippe , Mock Michèle , Goossens Pierre L. , Vidal Dominique R. 
Published: December 2008

ABSTRACT

Protective antigen (PA)-based anthrax vaccines acting on toxins are less effective than live attenuated vaccines, suggesting that additional antigens may contribute to protective immunity. Several reports indicate that capsule or spore-associated antigens may enhance the protection afforded by PA. Addition of formaldehyde-inactivated spores (FIS) to PA (PA-FIS) elicits total protection against cutaneous anthrax. Nevertheless, vaccines that are effective against cutaneous anthrax may not be so against inhalational anthrax. The aim of this work was to optimize immunization with PA-FIS and to assess vaccine efficacy against inhalational anthrax. We assessed the immune response to recombinant anthrax PA from
Bacillus anthracis
(rPA)-FIS administered by various immunization protocols and the protection provided to mice and guinea pigs infected through the respiratory route with spores of a virulent strain of
B. anthracis
. Combined subcutaneous plus intranasal immunization of mice yielded a mucosal immunoglobulin G response to rPA that was more than 20 times higher than that in lung mucosal secretions after subcutaneous vaccination. The titers of toxin-neutralizing antibody and antispore antibody were also significantly higher: nine and eight times higher, respectively. The optimized immunization elicited total protection of mice intranasally infected with the virulent
B. anthracis
strain 17JB. Guinea pigs were fully protected, both against an intranasal challenge with 100 50% lethal doses (LD
50
) and against an aerosol with 75 LD
50
of spores of the highly virulent strain 9602. Conversely, immunization with PA alone did not elicit protection. These results demonstrate that the association of PA and spores is very much more effective than PA alone against experimental inhalational anthrax.
Immune Evasion ofLeptospiraSpecies by Acquisition of Human Complement Regulator C4BP
Authors: Barbosa Angela S. , Abreu Patricia A. E. , Vasconcellos Sílvio A. , Morais Zenaide M. , Gonçales Amane P. , Silva Aldacilene S. , Daha Mohamed R. , Isaac Lourdes 
Published: December 2008

ABSTRACTLeptospirosis is a spirochetal zoonotic disease of global distribution with a high incidence in tropical regions. In the last 15 years it has been recognized as an important emerging infectious disease due to the occurrence of large outbreaks in warm-climate countries and, occasionally, in temperate regions. Pathogenic leptospires efficiently colonize target organs after penetrating the host. Their invasiveness is attributed to the ability to multiply in blood, adhere to host cells, and penetrate into tissues. Therefore, they must be able to evade the innate host defense. The main purpose of the present study was to evaluate how severalLeptospirastrains evade the protective function of the complement system. The serum resistance of sixLeptospirastrains was analyzed. We demonstrate that the pathogenic strain isolated from infected hamsters avoids serum bactericidal activity more efficiently than the culture-attenuated or the nonpathogenicLeptospirastrains. Moreover, both the alternative and the classical pathways of complement seem to be responsible for the killing of leptospires. Serum-resistant and serum-intermediate strains are able to bind C4BP, whereas the serum-sensitive strain Patoc I is not. Surface-bound C4BP promotes factor I-mediated cleavage of C4b. Accordingly, we found that pathogenic strains displayed reduced deposition of the late complement components C5 to C9 upon exposure to serum. We conclude that binding of C4BP contributes to leptospiral serum resistance against host complement.
Functional Characterization of the Type III Secretion ATPase HrcN from the Plant Pathogen
Xanthomonas campestris
pv. vesicatoria
Authors: Lorenz Christian , Büttner Daniela 
Published: December 2008

ABSTRACT

Many gram-negative plant and animal pathogenic bacteria employ a type III secretion (T3S) system to inject effector proteins into the cytosol of eukaryotic host cells. The membrane-spanning T3S apparatus is associated with an ATPase that presumably provides the energy for the secretion process. Here, we describe the role of the predicted ATPase HrcN from the plant pathogenic bacterium
Xanthomonas campestris
pathovar vesicatoria. We show that HrcN hydrolyzes ATP in vitro and is essential for T3S and bacterial pathogenicity. Stability of HrcN in
X. campestris
pv. vesicatoria depends on the conserved HrcL protein, which interacts with HrcN in vitro and in vivo. Both HrcN and HrcL bind to the inner membrane protein HrcU and specifically localize to the bacterial membranes under T3S-permissive conditions. Protein-protein interaction studies revealed that HrcN also interacts with the T3S substrate specificity switch protein HpaC and the global T3S chaperone HpaB, which promotes secretion of multiple effector proteins. Using an in vitro chaperone release assay, we demonstrate that HrcN dissociates a complex between HpaB and the effector protein XopF1 in an ATP-dependent manner, suggesting that HrcN is involved in the release of HpaB-bound effectors. Effector release depends on a conserved glycine residue in the HrcN phosphate-binding loop, which is crucial for enzymatic activity and protein function during T3S. There is no experimental evidence that T3S can occur in the absence of the ATPase, in contrast to recent findings reported for animal pathogenic bacteria.
The Cell Wall Regulator σISpecifically Suppresses the Lethal Phenotype ofmblMutants inBacillus subtilis
Authors: Schirner Kathrin , Errington Jeff 
Published: December 2008

ABSTRACTBacterial actin homologues are thought to have a role in cell shape determination by positioning the cell wall synthetic machinery. They are also thought to control other functions, including cell polarity and chromosome segregation in various organisms.Bacillus subtilisand many other gram-positive bacteria have three actin isoforms, MreB, Mbl, and MreBH, which colocalize in helical structures that span the length of the cell, close to the inner surface of the cytoplasmic membrane. Deletion of themblgene has previously been reported to produce viable, although poorly growing, mutant cells. We now show that under normal conditionsΔmblcells are nonviable but suppressors allowing growth readily accumulate. In the presence of high concentrations of Mg2+, viable, nonsuppressed mutants can be obtained. A screen for suppressor mutations revealed that deletion ofrsgIrestores Mg2+-independent growth of themblmutant. Recent work has shown thatrsgIdeletion leads to upregulation of the alternative sigma factor σI. The basis of suppression is not yet clear, but it is independent of the Mg2+effect. We found that the construction of a triple mutant lacking all three actin homologues became possible in thersgIbackground. Triple mutant cells are spherical, but no significant defect in chromosome segregation was detected.
A Regulatory Network Controls Expression of the In Vivo-Expressed HreP Protease of
Yersinia enterocolitica
Authors: Wagner Karin , Schilling Jennifer , Fälker Stefan , Schmidt M. Alexander , Heusipp Gerhard 
Published: December 2008

ABSTRACT

The human enteropathogen
Yersinia enterocolitica
survives and replicates in the lymphoid tissues of its host. Previous in vivo analyses of gene expression revealed that various chromosomal genes are expressed at this stage of infection, but not in vitro. One of these, termed
hreP
, encodes a protease that is necessary for full virulence of
Y. enterocolitica
. Using transposon mutagenesis, we identified three genes,
pypA
,
pypB
, and
pypC
, as positive regulators of
hreP
transcription. PypA is an inner membrane protein with no significant similarity to any known proteins; PypB is a ToxR-like transmembrane transcriptional regulator; and PypC is a cytoplasmic transcriptional regulator with an OmpR-like winged helix-turn-helix DNA binding motif. We show that all Pyp proteins are able to activate
hreP
independently of each other and that PypB and PypC interact directly with the
hreP
promoter region. Furthermore,
pypB
and
pypC
are autoregulated and regulate each other. Additional data indicate that transcription of
hreP
is repressed by the histone-like nucleoid-structuring protein H-NS in a temperature-dependent manner. Our data reveal a new regulatory network that might have implications for the controlled expression of further virulence-associated functions in
Yersinia
.
Relative Contributions of Recombination and Mutation to the Diversification of the
opa
Gene Repertoire of
Neisseria gonorrhoeae
Authors: Bilek Nicole , Ison Catherine A. , Spratt Brian G. 
Published: December 2008

ABSTRACT

To understand the rates and mechanisms of
Neisseria gonorrhoeae opa
gene variation, the 11
opa
genes were amplified independently so that an
opa
allelic profile could be defined for any isolate from the sequences at each locus. The
opa
allelic profiles from 14 unrelated isolates were all different, with no
opa
alleles shared between isolates. Examination of very closely related isolates from sexual contacts and sexual networks showed that these typically shared most
opa
alleles, and the mechanisms by which recent changes occurred at individual
opa
loci could be determined. The great majority of changes were due to recombination among existing alleles that duplicated an
opa
allele present at another locus or resulted in a mosaic of existing
opa
alleles. Single nucleotide changes or insertion/deletion of a single codon also occurred, but few of these events were assigned to mutation, the majority being assigned to localized recombination. Introduction of novel
opa
genes from coinfecting strains was rare, and all but one were observed in the same sexual network. Changes at
opa
loci occurred at a greater rate than those at the porin locus, and the
opa11
locus changed more rapidly than other
opa
loci, almost always differing even between recent sexual contacts. Examination of the neighboring
pilE
gene showed that changes at
opa11
and
pilE
often occurred together, although this linkage may not be a causal one.
Positive Control of Ferric Siderophore Receptor Gene Expression by the Irr Protein inBradyrhizobium japonicum
Authors: Small Sandra K. , Puri Sumant , Sangwan Indu , O'Brian Mark R. 
Published: December 2008

ABSTRACTFerric siderophore receptors are components of high-affinity iron-chelate transport systems in gram-negative bacteria. The genes encoding these receptors are generally regulated by repression. Here, we show that the ferrichrome receptor gene bll4920 and four additional putative ferric siderophore receptor genes inBradyrhizobium japonicumare positively controlled by the regulatory protein Irr, as observed by the low level of mRNA transcripts in anirrmutant in iron-limited cells. Potential Irr binding sites with iron control element (ICE)-like motifs were found upstream and distal to the transcription start sites of the five receptor genes. However, purified recombinant Irr bound only some of those elements. Nevertheless, dissection of the bll4920 promoter region showed that a component in extracts of wild-type cells grown in iron-limited media bound only in the ICE motif region of the promoter. This binding was not observed with extracts of cells from the parent strain grown under high-iron conditions or from anirrmutant strain. Furthermore, gel mobility supershift experiments identified Irr as the binding protein in cell extracts. Chromatin immunoprecipitation experiments demonstrated that Irr occupies the promoters of the five ferric iron transport genes in vivo. We conclude that Irr is a direct positive regulator of ferric iron transport inB. japonicum.
n-RECOGNITION BY PRIME GRAPH OF THE SIMPLE GROUP PSL(2,q)
Authors: KHOSRAVI BEHROOZ 
Published: December 2008

Let G be a finite group. The prime graph Γ(G) of G is defined as follows. The vertices of Γ(G) are the primes dividing the order of G and two distinct vertices p, q are joined by an edge if there is an element in G of order pq. It is proved that if p > 11 and p ≢ 1 (mod 12), then PSL(2,p) is uniquely determined by its prime graph. Also it is proved that if p > 7 is a prime number and Γ(G) = Γ(PSL(2,p2)), then G ≅ PSL(2,p2) or G ≅ PSL(2,p2).2, the non-split extension of PSL(2,p2) by ℤ2. In this paper as the main result we determine finite groups G such that Γ(G) = Γ(PSL(2,q)), where q = pk. As a consequence of our results we prove that if q = pk, k > 1 is odd and p is an odd prime number, then PSL(2,q) is uniquely determined by its prime graph and so these groups are characterizable by their prime graph.
World Christianity: A Training School for Multiculturalism
Authors: Frederiks Martha 
Published: December 2008

AbstractChristianity is plural religious tradition: over the centuries and throughout the world's cultures it has taken on a variety of forms and contents. Yet, Christianity also claims to be one tradition, one community. In this article the dialectic relationship between diversity and unity within World Christianity is explored with the view of investigating whether the debate on multiculturalism in Dutch society can benefit from the expertise within the Christian tradition of balancing between diversity and unity.
The 'Great Move of God' in an African Community: A Retrospect of the 1930s Indigenous Pentecostal Revival in Nigeria and Its Impact on Nigerian Pentecostalism
Authors: Fatokun Samson Adetunji 
Published: December 2008

AbstractThe paper examines the 1930s Pentecostal revival in Nigeria that brought Nigerian Pentecostalism onto the global scene. The study is approached from a socio-historical perspective, drawing data from archival search, oral interview and bibliographical search. Among other things, the research brings to the fore the remote and immediate impact of the revival on the Nigerian Church and State. More importantly, the paper locates the rapid growth of Pentecostalism in Nigeria (particularly the much proliferation of churches in the southwest) in the aftermath effects of the 1930s' indigenous Pentecostal revival. That notwithstanding, the paper denounces the undue emphasis on material prosperity which forms the nucleus of Pentecostal crusades/revival in contemporary time and calls on all stake holders to go back to the 'rock from which they were hewn' and purify Pentecostalism in Nigeria of all questionable characteristics.