bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of CspC and CspE in Regulation of Expression of RpoS and UspA, the Stress Response Proteins in
Escherichia coli
Authors: Phadtare Sangita , Inouye Masayori 
Published: July 2002

ABSTRACT

Nine homologous proteins, CspA to CspI, constitute the CspA family of
Escherichia coli
. Recent studies are aimed at elucidating the individual cellular functions of these proteins. Two members of this family, CspC and CspE, are constitutively produced at 37°C. In the present study, these two proteins were evaluated for their cellular role(s). The expression of three stress proteins, OsmY, Dps, and UspA, is significantly affected by the overexpression and deletion of CspC and CspE. RpoS is a regulatory element for
osmY
and
dps
. Further analysis showed a larger amount and greater stability of the
rpoS
mRNA as well as a higher level of RpoS itself with the overexpression of CspC and CspE. This suggests that CspC and CspE upregulate the expression of OsmY and Dps by regulating the expression of RpoS itself. Indeed, this upregulation is lost in the Δ
rpoS
strain. Other RpoS-controlled proteins such as ProP and KatG, are also upregulated by the overexpression of CspC. The present study suggests that CspC and CspE are the important elements involved in the regulation of the expression of RpoS, a global stress response regulator, and UspA, a protein responding to numerous stresses. In the light of these observations, it seems plausible that CspC and CspE function as regulatory elements for the expression of stress proteins in the complex stress response network of
E. coli
.
Quantitation of the Capacity of the Secretion Apparatus and Requirement for PrsA in Growth and Secretion of α-Amylase in
Bacillus subtilis
Authors: Vitikainen Marika , Pummi Tiina , Airaksinen Ulla , Wahlström Eva , Wu Hongyan , Sarvas Matti , Kontinen Vesa P. 
Published: July 2002

ABSTRACT

Regulated expression of AmyQ α-amylase of
Bacillus amyloliquefaciens
was used to examine the capacity of the protein secretion apparatus of
B. subtilis
. One
B. subtilis
cell was found to secrete maximally 10 fg of AmyQ per h. The signal peptidase SipT limits the rate of processing of the signal peptide. Another limit is set by PrsA lipoprotein. The wild-type level of PrsA was found to be 2 × 10
4
molecules per cell. Decreasing the cellular level of PrsA did not decrease the capacity of the protein translocation or signal peptide processing steps but dramatically affected secretion in a posttranslocational step. There was a linear correlation between the number of cellular PrsA molecules and the number of secreted AmyQ molecules over a wide range of
prsA
and
amyQ
expression levels. Significantly, even when
amyQ
was expressed at low levels, overproduction of PrsA enhanced its secretion. The finding is consistent with a reversible interaction between PrsA and AmyQ. The high cellular level of PrsA suggests a chaperone-like function. PrsA was also found to be essential for the viability of
B. subtilis
. Drastic depletion of PrsA resulted in altered cellular morphology and ultimately in cell death.
EvgA of the Two-Component Signal Transduction System Modulates Production of the YhiUV Multidrug Transporter in
Escherichia coli
Authors: Nishino Kunihiko , Yamaguchi Akihito 
Published: July 2002

ABSTRACT

Overexpression of the EvgA regulator of the two-component signal transduction system was previously found to modulate multidrug resistance of
Escherichia coli
by increasing efflux of drugs (K. Nishino and A. Yamaguchi, J. Bacteriol. 183:1455-1458, 2001). Here we present data showing that EvgA contributes to multidrug resistance through increased expression of the multidrug transporter
yhiUV
gene.
Population Heterogeneity of
Salmonella enterica
Serotype Typhimurium Resulting from Phase Variation of the
lpf
Operon In Vitro and In Vivo
Authors: Kingsley Robert A. , Weening Eric H. , Keestra A. Marijke , Bäumler Andreas J. 
Published: July 2002

ABSTRACT

The
lpf
fimbrial operon oscillates between phase ON and phase OFF expression states, thereby generating heterogeneity within
S. enterica
serotype Typhimurium populations with regard to expression of long polar fimbrial antigens. To determine whether the proportion of
lpf
phase variants changes with growth conditions, the
lpf
phase ON content of cultures was determined after in vitro and in vivo passage. After passage in Luria-Bertani (LB) broth for 120 generations, 96% of cells in a serotype Typhimurium culture carried the
lpf
operon in the phase ON expression state, regardless of the phase ON/OFF ratio in the inoculum. In contrast, a culture passaged on LB agar plates for 500 generations contained approximately 2%
lpf
phase ON cells. Differences in the
lpf
phase ON content of cultures passaged in broth and on plates were not caused by an outgrowth of
lpf
phase ON or
lpf
phase OFF cells, since deletion of
lpf
biosynthesis genes did not alter the phase ON/OFF ratio attained after passage. Instead, growth in LB broth resulted in a eightfold increase in the phase OFF-to-ON transition frequency and a decrease of the
lpf
phase ON-to-OFF transition frequency by a factor of 150 compared to growth on LB agar plates. After infection of naïve CBA/J mice with an
lpf
phase ON culture of serotype Typhimurium, the proportion of
lpf
phase ON cells continuously decreased over time, regardless of whether the strain carried intact fimbrial biosynthesis genes. These data suggest that elaboration of fimbriae does not have a major influence on the population heterogeneity produced by phase variation of the
lpf
operon in naïve mice.
Helicobacter typhlonius
sp. nov., a Novel Murine Urease-Negative
Helicobacter
Species
Authors: Franklin Craig L. , Gorelick Peter L. , Riley Lela K. , Dewhirst Floyd E. , Livingston Robert S. , Ward Jerrold M. , Beckwith Catherine S. , Fox James G. 
Published: July 2002

ABSTRACT

Over the past decade, several
Helicobacter
species have been isolated from rodents. With the advent of PCR for the diagnosis of infectious agents, it has become clear that several previously uncharacterized
Helicobacter
species also colonize rodents. In this report, we describe a novel urease-negative helicobacter,
Helicobacter typhlonius
sp. nov., which was isolated from colonies of laboratory mice independently by two laboratories. Infection of immunodeficient mice by this bacterium resulted in typhlocolitis similar to that observed with other helicobacter infections.
H. typhlonius
is genetically most closely related to
H. hepaticus
. Like
H. hepaticus
, it is a spiral bacterium with bipolar sheathed flagella. However, this novel species contains a large intervening sequence in its 16S rRNA gene and is biochemically distinct from
H. hepaticus
. Notably,
H. typhlonius
does not produce urease or H
2
S nor does it hydrolize indoxyl-acetate. Compared to other
Helicobacter
species that commonly colonize rodents,
H. typhlonius
was found to be less prevalent than
H. hepaticus
and
H. rodentium
but as prevalent as
H. bilis. H. typhlonius
joins a growing list of helicobacters that colonize mice and are capable of inducing enteric disease in various strains of immunodeficient mice.
Cellular Fatty Acid Composition of
Lautropia mirabilis
Authors: Daneshvar Maryam I. , Douglas Michael P. , Weyant Robbin S. 
Published: July 2002

ABSTRACT

Ten strains of
Lautropia mirabilis
(ATCC 51599
T
and nine phenotypically similar clinical isolates) were examined for cellular fatty acid (CFA) composition to evaluate their chemical relatedness to known bacterial species and groups. The CFAs were liberated from whole cells by base hydrolysis, methylated, and analyzed by gas-liquid chromatography. CFA profiles were generated by using a commerical software package (MIDI, Newark, Del.). All strains tested had an identical CFA profile characterized by major amounts of 16:1ω7c (41%) and 16:0 (44%); smaller amounts (1 to 4%) of 3-OH-10:0, 12:0, 14:0, 15:0, and 18:1 ω7c; trace amounts (<1%) of 10:0, 18:2 and 18:0; and no cyclopropane acids. This profile was similar to the CFA profiles of
Acidovorax delafieldii, Comamonas terrigena
, and strains of an unclassified Centers for Disease Control group designated weak oxidizer group 1. CFA analysis, when supplemented by phenotypic characterization, is useful for the identification of
L. mirabilis
isolates.
Antimicrobial Growth Promoter Ban and Resistance to Macrolides and Vancomycin in Enterococci from Pigs
Authors: Boerlin P. , Wissing A. , Aarestrup F. M. , Frey J. , Nicolet J. 
Published: July 2002

ABSTRACT

Ninety-six enterococcus isolates from fecal samples of pigs receiving tylosin as an antimicrobial growth promoter and 59 isolates obtained in the same farms 5 to 6 months after the ban of antimicrobial growth promoters in Switzerland were tested for susceptibility to nine antimicrobial agents. A clear decrease in resistance to macrolides, lincosamides, and tetracycline was visible after the ban. Vancomycin-resistant
Enterococcus faecium
belonged to the same clonal lineage as vancomycin-resistant isolates previously isolated from Danish pigs.
Detection and Identification of Eight
Trichinella
Genotypes by Reverse Line Blot Hybridization
Authors: Rombout Y. B. , Bosch S. , Van Der Giessen J. W. B. 
Published: July 2002

ABSTRACT

A reverse line blot (RLB) assay was developed to identify different
Trichinella
genotypes. The RLB assay accomplishes detection and specific identification of the different
Trichinella
genotypes and relies on hybridization of the amplified 5S ribosomal DNA intergenic spacer regions to specific, membrane-bound oligonucleotide probes. After one single amplification, we were able to detect and genetically identify six sibling species, i.e.,
T. spiralis
,
T. britovi
,
T. nativa
,
T. murrelli
,
T. nelsoni
, and
T. pseudospiralis
, and two additional
Trichinella
genotypes, T6 and T8. Twenty-four
Trichinella
strains of different genotypes were unequivocally identified evaluated using one simple PCR-based assay based on single larvae. This assay allows the specific identification of
Trichinella
species without the need to passage larvae in laboratory animals.
Development of an Immunoassay for Rapid Detection of Ganglioside GM
1
Mimicry in
Campylobacter jejuni
Strains
Authors: Prendergast Martina M. , Kosunen Timo U. , Moran Anthony P. 
Published: July 2002

ABSTRACT

Mimicry of peripheral nerve gangliosides by
Campylobacter jejuni
lipopolysaccharides (LPSs) has been proposed to induce cross-reacting antiganglioside antibodies in Guillain-Barré syndrome (GBS). Because current methods for LPS characterization are labor-intensive and inhibit the screening of large numbers of strains, a rapid GM
1
epitope screening assay was developed. Biomass from two agar plates of confluent growth yielded sufficient LPS using a novel phenol-water and ether extraction procedure. Extracts of LPS were reacted with cholera toxin (GM
1
ligand), peanut agglutinin (Galβ1→3GalNAc ligand), and anti-GM
1
antibodies. After the assay was validated, 12 of 59 (20%)
C. jejuni
serostrains, including four serotypes that have not previously been associated with GBS, reacted with two or more anti-GM
1
ganglioside reagents. Subsequently, LPS extracts from 5 of 7 (71%)
C. jejuni
isolates and 2 of 3 (67%)
C. jejuni
culture collection strains bore GM
1
structures. Overall, the assay system was reliable, efficient, and reproducible and may be adapted for large-scale epidemiological studies.
Diagnosis and Monitoring of Murine Histoplasmosis by a Nested PCR Assay
Authors: Bialek Ralf , Fischer Jörg , Feucht Antje , Najvar Laura K. , Dietz Klaus , Knobloch Jürgen , Graybill John R. 
Published: July 2002

ABSTRACT

A newly developed nested PCR assay was applied to murine models of histoplasmosis. ICR and BALB/c mice were intravenously infected with
Histoplasma capsulatum
and sacrificed up to 29 days later. Samples of blood, spleen, and lung homogenates were cultured and examined by the PCR assay. In the ICR mouse model, 265 of 319 organ samples showed concordant results. With 7 samples, the culture was positive and the PCR assay was negative whereas a positive PCR but a negative culture were obtained with 47 samples (
P
< 0.0001 according to McNemar's test). Organ homogenates and blood samples of either spontaneously cured or treated BALB/c mice were PCR negative. The nested PCR assay performs excellently in the monitoring of spontaneously and treatment-cured murine histoplasmosis. It limits the infection risks of the laboratory staff and might be of diagnostic value for humans.
Disseminated
Mycobacterium lentiflavum
Infection in a Human Immunodeficiency Virus-Infected Patient
Authors: Niobe S. Ngo , Bebear C. M. , Clerc M. , Pellegrin J.-L. , Bebear C. , Maugein J. 
Published: July 2002

ABSTRACT

We report the first case of
Mycobacterium lentiflavum
disseminated infection in a human immunodeficiency virus-infected patient. Conventional identification procedures failed to identify the mycobacterial strain, but sequencing of the 16S rRNA gene led to the species identification. Furthermore, we describe here the analysis of the 16S-23S rRNA internal transcribed spacer sequence of
M. lentiflavum
.
Strategy for Diagnosis of Congenital Toxoplasmosis: Evaluation of Methods Comparing Mothers and Newborns and Standard Methods for Postnatal Detection of Immunoglobulin G, M, and A Antibodies
Authors: Pinon J. M. , Dumon H. , Chemla C. , Franck J. , Petersen E. , Lebech M. , Zufferey J. , Bessieres M.-H. , Marty P. , Holliman R. , Johnson J. , Luyasu V. , Lecolier B. , Guy E. , Joynson D. H. M. , Decoster A. , Enders G. , Pelloux H. , Candolfi E. 
Published: July 2002

ABSTRACT

In a study involving 14 laboratories supported by the European Community Biomed 2 program, we evaluated immunologic methods for the postnatal diagnosis of congenital toxoplasmosis (CT). Among babies born to mothers who seroconverted to positivity for toxoplasmosis during pregnancy, we analyzed 55 babies with CT on the basis of persistent anti-
Toxoplasma
immunoglobulin G (IgG) at 1 year of life and 50 control babies without anti-
Toxoplasma
IgG at 1 year of life in the absence of curative treatment with pyrimethamine-sulfonamides. We tested in-house methods such as the enzyme-linked immunofiltration assay (ELIFA) or Immunoblotting (IB) for the detection of IgG or IgM; these methods allowed comparison of the immunologic profiles of the mothers and the infants. We compared ELIFA and IB with a commercial enzyme immunoassay (EIA) or in-house immunosorbent agglutination assay (ISAGA) for the detection of IgM or IgA. The performances of combinations of methods were also assessed. A cumulative sensitivity of 98% during a 1-year follow-up was obtained with the ELIFA plus ISAGA combination. Only one case of CT was missed by the ELIFA plus ISAGA combination, whereas three cases were missed by the IB plus ISAGA combination, even though 48% of patients with CT were treated with pyrimethamine-sulfonamides, which are known to inhibit antibody neosynthesis. A similar performance was obtained with either ELIFA or IB in combination with EIA. The difference in performance between ELIFA plus ISAGA and IB plus ISAGA was not statistically significant (
P
= 0.31), and we conclude that both combinations of tests can be used for the diagnosis of CT in newborns.
Suitability of a Rapid Immunochromatographic Test for Detection of Antibodies to Human Immunodeficiency Virus in Ghana, West Africa
Authors: Aidoo S. , Ampofo W. K. , Brandful J. A. M. , Nuvor S. V. , Ansah J. K. , Nii-Trebi N. , Barnor J. S. , Apeagyei F. , Sata T. , Ofori-Adjei D. , Ishikawa K. 
Published: July 2002

ABSTRACT
In West African countries such as Ghana, efficient human immunodeficiency virus (HIV) testing is a priority in the fight against AIDS. A new immunochromatographic rapid test, Determine HIV-1/2 (Abbott Diagnostics, North Chicago, Ill.), that detects antibodies against HIV type 1 (HIV-1) and/or HIV-2 was evaluated using Ghanaian blood samples. Two hundred four serum and/or plasma specimens were tested. HIV screening was done by a particle agglutination test and confirmed by a Western blot (WB) test as the “gold standard.” The results revealed 125 HIV-seropositive AIDS patients, 75 HIV-seronegative healthy individuals, and 4 individuals for whom the HIV-1 result was indeterminate. The results obtained by the Determine HIV-1/2 assay and Diagnostic HIV SPOT (Genelabs), which is currently widely used in many districts in Ghana, were compared with those of the WB test, excluding the four HIV-1-indeterminate samples. The sensitivity of the Determine HIV-1/2 assay was 100%, compared with 98.0% for the HIV SPOT assay. The specificity was 100% for both tests. Determine HIV-1/2 is a single-step assay and was found to be rapid and easy to perform without any special equipment. It was highly sensitive and specific. The kit can be applied without electricity and water supplies, making it suitable for the detection of HIV antibodies especially in the rural areas of Ghana, West Africa.
Identification ofEnterococcus, Streptococcus, andStaphylococcusby Multivariate Analysis of Proton Magnetic Resonance Spectroscopic Data from Plate Cultures
Authors: Bourne Roger , Himmelreich Uwe , Sharma Ansuiya , Mountford Carolyn , Sorrell Tania 
Published: July 2002

ABSTRACTA new fingerprinting technique with the potential for rapid identification of bacteria was developed by combining proton magnetic resonance spectroscopy (1H MRS) with multivariate statistical analysis. This resulted in an objective identification strategy for common clinical isolates belonging to the bacterial speciesStaphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, and theStreptococcus millerigroup. Duplicate cultures of 104 different isolates were examined one or more times using1H MRS. A total of 312 cultures were examined. An optimized classifier was developed using a bootstrapping process and a seven-group linear discriminant analysis to provide objective classification of the spectra. Identification of isolates was based on consistent high-probability classification of spectra from duplicate cultures and achieved 92% agreement with conventional methods of identification. Fewer than 1% of isolates were identified incorrectly. Identification of the remaining 7% of isolates was defined as indeterminate.
Cysticercus Antigens in Cerebrospinal Fluid Samples from Patients with Neurocysticercosis
Authors: Pardini Alessandra Xavier , Vaz Adelaide José , Machado Luis Dos Ramos , Livramento José Antônio 
Published: July 2002

ABSTRACT

Antigens were detected in cerebrospinal fluid (CSF) samples from patients with neurocysticercosis (NC) by enzyme-linked immunosorbent assay (ELISA) using polyclonal sera of rabbit anti-
Taenia solium
cysticerci (anti-Tso) and anti-
Taenia crassiceps
cysticerci vesicular fluid (anti-Tcra or anti-Tcra <30 kDa). A group of NC patients (
n
= 174) were studied (NC), including 40 patients in different phases of the disease. ELISAs carried out with the anti-Tso, anti-Tcra, and anti-Tcra <30 kDa showed sensitivities of 81.2, 90, and 95.8% and specificities of 82, 98, and 100%, respectively. The 14- and 18-kDa low-molecular-weight peptides were only detected in CSF samples from patients with NC by immunoblotting with anti-Tso and anti-Tcra sera. Because of the importance of the diagnosis and prognosis of cysticercosis, the detection of antigens may contribute as an additional marker to the study and clarification of the parasite-host relationship.
Native Valve Endocarditis Due to
Bartonella henselae
in a Middle-Aged Human Immunodeficiency Virus-Negative Woman
Authors: De La Rosa Guy R. , Barnett Ben J. , Ericsson Charles D. , Turk Jeffrey B. 
Published: July 2002

ABSTRACT

We report the case of a human immunodeficiency virus-negative woman who developed native valve endocarditis of the aortic valve due to
Bartonell henselae
infection. The diagnosis was established using serology and PCR analysis of excised aortic valve tissue.
rpoB
Gene Sequence-Based Identification of
Staphylococcu
s Species
Authors: Drancourt Michel , Raoult Didier 
Published: July 2002

ABSTRACT

The complete sequence of
rpoB
, the gene encoding the beta subunit of RNA polymerase was determined for
Staphylococcus saccharolyticus
,
Staphylococcus lugdunensis
, S
taphylococcus caprae
, and
Staphylococcus intermedius
and partial sequences were obtained for an additional 27
Staphylococcus
species. The complete
rpoB
sequences varied in length from 3,452 to 3,845 bp and had a 36.8 to 39.2% GC content. The partial sequences had 71.6 to 93.6% interspecies homology and exhibited a 0.08 to 0.8% intraspecific divergence. With a few exceptions, the phylogenetic relationships inferred from the partial
rpoB
sequences were in agreement with those previously derived from DNA-DNA hybridization studies and analyses of 16S ribosomal DNA gene sequences and partial HSP60 gene sequences. The staphylococcal
rpoB
sequence database we established enabled us to develop a molecular method for identifying
Staphylococcus
isolates by PCR followed by direct sequencing of the 751-bp amplicon. In blind tests, this method correctly identified 10
Staphylococcus
isolates, and no positive results were obtained with 10 non-
Staphylococcus
gram-positive and gram-negative bacterial isolates. We propose partial sequencing of the
rpoB
gene as a new tool for the accurate identification of
Staphylococcus
isolates.
Poliovirus Requires a Precise 5′ End for Efficient Positive-Strand RNA Synthesis
Authors: Herold Jens , Andino Raul 
Published: July 2002

ABSTRACT

Poliovirus infectious RNA can be synthesized in vitro using phage DNA-dependent RNA-polymerases. These synthetic transcripts contain several extra nucleotides at the 5′ end, which are deleted during replication to generate authentic viral genomes. We removed those 5′-end extra nucleotides utilizing a hammerhead ribozyme to produce transcripts with accurate 5′ ends. These transcripts replicate substantially more rapidly in cell culture, demonstrating no lag before replication; they also replicate more efficiently in
Xenopus laevis
oocytes and in in vitro translation-replication cell extracts. In both systems, an exact 5′ end is necessary for synthesis of positive-strand RNA but not negative-strand RNA.
Differences in the Ability of Human T-Cell Lymphotropic Virus Type 1 (HTLV-1) and HTLV-2 Tax To Inhibit p53 Function
Authors: Mahieux Renaud , Pise-Masison Cynthia A. , Lambert Paul F. , Nicot Christophe , De Marchis Laura , Gessain Antoine , Green Patrick , Hall William , Brady John N. 
Published: July 2002

ABSTRACT
We have analyzed the functional activity of the p53 tumor suppressor in human T-cell lymphotropic virus type 2 (HTLV-2)-transformed cells. Abundant levels of the p53 protein were detected in both HTLV-2A and -2B virus-infected cell lines. The p53 was functionally inactive, however, both in transient-transfection assays using a p53 reporter plasmid and in induction of p53-responsive genes in response to gamma irradiation. We further investigated HTLV-2A Tax and HTLV-2B Tax effects on p53 activity. Interestingly, although Tax-2A and -2B inactivate p53, the Tax-2A protein appears to inhibit p53 function less efficiently than either Tax-1 or Tax-2B. In transient-cotransfection assays, Tax-1 and Tax-2B inactivated p53 by 80%, while Tax2A reduced p53 activity by 20%. In addition, Tax-2A does not increase the steady-state level of cellular p53 as well as Tax-1 or -2B does in the same assays. Cotransfection assays demonstrated that Tax-2A could efficiently transactivate CREB-responsive promoters to the same level as Tax-1 and Tax-2B, indicating that the protein was functional. This report provides evidence of the first functional difference between the HTLV-2A and -2B subtypes. This comparison of the action of HTLV-1 and HTLV-2 Tax proteins on p53 function will provide important insights into the mechanism of HTLV transformation.