bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of Archaea in a Black Smoker Chimney Structure
Authors: Takai Ken , Komatsu Tetsushi , Inagaki Fumio , Horikoshi Koki 
Published: July 2002

ABSTRACT
Archaeal community structures in microhabitats in a deep-sea hydrothermal vent chimney structure were evaluated through the combined use of culture-independent molecular analyses and enrichment culture methods. A black smoker chimney was obtained from the PACMANUS site in the Manus Basin near Papua New Guinea, and subsamples were obtained from vertical and horizontal sections. The elemental composition of the chimney was analyzed in different subsamples by scanning electron microscopy and energy-dispersive X-ray spectroscopy, indicating that zinc and sulfur were major components while an increased amount of elemental oxygen in exterior materials represented the presence of oxidized materials on the outer surface of the chimney. Terminal restriction fragment length polymorphism analysis revealed that a shift in archaeal ribotype structure occurred in the chimney structure. Through sequencing of ribosomal DNA (rDNA) clones from archaeal rDNA clone libraries, it was demonstrated that the archaeal communities in the chimney structure consisted for the most part of hyperthermophilic members and extreme halophiles and that the distribution of such extremophiles in different microhabitats of the chimney varied. The results of the culture-dependent analysis supported in part the view that changes in archaeal community structures in these microhabitats are associated with the geochemical and physical dynamics in the black smoker chimney.
Occurrence ofCryptosporidiumandGiardiain Wild Ducks along the Rio Grande River Valley in Southern New Mexico
Authors: Kuhn Ryan C. , Rock Channah M. , Oshima Kevin H. 
Published: July 2002

ABSTRACTFecal samples were taken from wild ducks on the lower Rio Grande River around Las Cruces, N. Mex., from September 2000 to January 2001.Giardiacysts andCryptosporidiumoocysts were purified from 69 samples by sucrose enrichment followed by cesium chloride (CsCl) gradient centrifugation and were viewed via fluorescent-antibody (FA) staining. For some samples, recovered cysts and oocysts were further screened via PCR to determine the presence ofGiardia lambliaandCrytosporidium parvum. The results of this study indicate that 49% of the ducks were carriers ofCryptosporidium, and theCryptosporidiumoocyst concentrations ranged from 0 to 2,182 oocysts per g of feces (mean ± standard deviation, 47.53 ± 270.3 oocysts per g); also, 28% of the ducks were positive forGiardia, and theGiardiacyst concentrations ranged from 0 to 29,293 cysts per g of feces (mean ± standard deviation, 436 ± 3,525.4 cysts per g). Of the 69 samples, only 14 had (oo)cyst concentrations that were above the PCR detection limit. Samples did test positive forCryptosporidiumsp. However,C. parvumandG. lambliawere not detected in any of the 14 samples tested by PCR. Ducks on their southern migration through southern New Mexico were positive forCryptosporidiumandGiardiaas determined by FA staining, butC. parvumandG. lambliawere not detected.
Characterization of an Autotrophic Sulfide-Oxidizing Marine
Arcobacter
sp. That Produces Filamentous Sulfur
Authors: Wirsen C. O. , Sievert S. M. , Cavanaugh C. M. , Molyneaux S. J. , Ahmad A. , Taylor L. T. , DeLong E. F. , Taylor C. D. 
Published: July 2002

ABSTRACT

A coastal marine sulfide-oxidizing autotrophic bacterium produces hydrophilic filamentous sulfur as a novel metabolic end product. Phylogenetic analysis placed the organism in the genus
Arcobacter
in the epsilon subdivision of the
Proteobacteria
. This motile vibrioid organism can be considered difficult to grow, preferring to grow under microaerophilic conditions in flowing systems in which a sulfide-oxygen gradient has been established. Purified cell cultures were maintained by using this approach. Essentially all 4′,6-diamidino-2-phenylindole dihydrochloride-stained cells in a flowing reactor system hybridized with
Arcobacter
-specific probes as well as with a probe specific for the sequence obtained from reactor-grown cells. The proposed provisional name for the coastal isolate is “
Candidatus
Arcobacter sulfidicus.” For cells cultured in a flowing reactor system, the sulfide optimum was higher than and the CO
2
fixation activity was as high as or higher than those reported for other sulfur oxidizers, such as
Thiomicrospira
spp. Cells associated with filamentous sulfur material demonstrated nitrogen fixation capability. No ribulose 1,5-bisphosphate carboxylase/oxygenase could be detected on the basis of radioisotopic activity or by Western blotting techniques, suggesting an alternative pathway of CO
2
fixation. The process of microbial filamentous sulfur formation has been documented in a number of marine environments where both sulfide and oxygen are available. Filamentous sulfur formation by “
Candidatus
Arcobacter sulfidicus” or similar strains may be an ecologically important process, contributing significantly to primary production in such environments.
Staphylococcus aureusGrowth Boundaries: Moving towards Mechanistic Predictive Models Based on Solute-Specific Effects
Authors: Stewart Cynthia M. , Cole Martin B. , Legan J. David , Slade Louise , Vandeven Mark H. , Schaffner Donald W. 
Published: July 2002

ABSTRACTThe formulation of shelf-stable intermediate-moisture products is a critical food safety issue. Therefore, knowing the precise boundary for the growth-no-growth interface ofStaphylococcus aureusis necessary for food safety risk assessment. This study was designed to examine the effects of various humectants and to produce growth boundary models as tools for risk assessment. The molecular mobility and the effects of various physical properties of humectants, such as their glass transition temperatures, their membrane permeability, and their ionic and nonionic properties, onS. aureusgrowth were investigated. The effects of relative humidity (RH; 84 to 95%, adjusted by sucrose plus fructose, glycerol, or NaCl), initial pH (4.5 to 7.0, adjusted by HCl), and potassium sorbate concentration (0 or 1,000 ppm) on the growth ofS. aureuswere determined. Growth was monitored by turbidity over a 24-week period. Toxin production was determined by enterotoxin assay. The 1,792 data points generated were analyzed by LIFEREG procedures (SAS Institute, Inc., Cary, N.C.), which showed that all parameters studied significantly affected the growth responses ofS. aureus. Differences were observed in the growth-no-growth boundary when different humectants were used to achieve the desired RH values in both the absence and the presence of potassium sorbate. Sucrose plus fructose was most inhibitory at neutral pH values, while NaCl was most inhibitory at low pH values. The addition of potassium sorbate greatly increased the no-growth regions, particularly when pH was <6.0. Published kinetic growth and survival models were compared with boundary models developed in this work. The effects of solutes and differences in modeling approaches are discussed.
Fasciclin Domain Proteins Are Present in
Nostoc
Symbionts of Lichens
Authors: Paulsrud Per , Lindblad Peter 
Published: July 2002

ABSTRACT

Differences in the soluble protein fraction between the freshly isolated cyanobiont of lichen
Peltigera membranacea
, the corresponding free-living strain, and
Nostoc punctiforme
were analyzed. One protein, which was among the most prominent proteins of the freshly isolated cyanobiont, was expressed at a lower level in the corresponding free-living strain and was not detected at all on the two-dimensional gels of
N. punctiforme
. This protein was partially sequenced, and the corresponding open reading frame (ORF) in the
N. punctiforme
genome was identified. This ORF contains a fasciclin domain typical of a class of surface-associated proteins involved in cell adhesion. Similar fasciclin motif-containing genes have previously been shown to be symbiotically induced in other symbiotic systems.
Tri13
and
Tri7
Determine Deoxynivalenol- and Nivalenol-Producing Chemotypes of
Gibberella zeae
Authors: Lee Theresa , Han You-Kyoung , Kim Kook-Hyung , Yun Sung-Hwan , Lee Yin-Won 
Published: July 2002

ABSTRACT

Gibberella zeae
, a major cause of cereal scab, can be divided into two chemotypes based on production of the 8-ketotrichothecenes deoxynivalenol (DON) and nivalenol (NIV). We cloned and sequenced a
Tri13
homolog from each chemotype. The
Tri13
from a NIV chemotype strain (88-1) is located in the trichothecene gene cluster and carries an open reading frame similar to that of
Fusarium sporotrichioides
, whereas the
Tri13
from a DON chemotype strain (H-11) carries several mutations. To confirm the roles of the
Tri13
and
Tri7
genes in trichothecene production by
G. zeae
, we genetically altered toxin production in 88-1 and H-11. In transgenic strains, the targeted deletion of
Tri13
from the genome of 88-1 caused production of DON rather than NIV. Heterologous expression of the 88-1
Tri13
gene alone or in combination with the 88-1
Tri7
gene conferred on H-11 the ability to synthesize NIV; in the latter case, 4-acetylnivalenol (4-ANIV) also was produced. These results suggest that
Tri13
and
Tri7
are required for oxygenation and acetylation of the oxygen at C-4 during synthesis of NIV and 4-ANIV in
G. zeae
. These functional analyses of the
Tri13
and
Tri7
genes provide the first clear evidence for the genetic basis of the DON and NIV chemotypes in
G. zeae
.
Influence of Different Cultivars on Populations of Ammonia-Oxidizing Bacteria in the Root Environment of Rice
Authors: Briones Aurelio M. , Okabe Satoshi , Umemiya Yoshiaki , Ramsing Niels-Birger , Reichardt Wolfgang , Okuyama Hidetoshi 
Published: July 2002

ABSTRACT

Comparisons of the activities and diversities of ammonia-oxidizing bacteria (AOB) in the root environment of different cultivars of rice (
Oryza sativa
L.) indicated marked differences despite identical environmental conditions during growth. Gross nitrification rates obtained by the
15
N dilution technique were significantly higher in a modern variety, IR63087-1-17, than in two traditional varieties. Phylogenetic analysis based on the ammonium monooxygenase gene (
amoA
) identified strains related to
Nitrosospira multiformis
and
Nitrosomonas europaea
as the predominant AOB in our experimental rice system. A method was developed to determine the abundance of AOB on root biofilm samples using fluorescently tagged oligonucleotide probes targeting 16S rRNA. The levels of abundance detected suggested an enrichment of AOB on rice roots. We identified 40 to 69% of AOB on roots of IR63087-1-17 as
Nitrosomonas
spp., while this subpopulation constituted 7 to 23% of AOB on roots of the other cultivars. These results were generally supported by denaturing gradient gel electrophoresis of the
amoA
gene and analysis of libraries of cloned
amoA
. In hydroponic culture, oxygen concentration profiles around secondary roots differed significantly among the tested rice varieties, of which IR63087-1-17 showed maximum leakage of oxygen. The results suggest that varietal differences in the composition and activity of root-associated AOB populations may result from microscale differences in O
2
availability.
Enterotoxin Production in Natural Isolates of
Bacillaceae
outside the
Bacillus cereus
Group
Authors: Phelps Rebecca J. , McKillip John L. 
Published: July 2002

ABSTRACT

Thirty-nine
Bacillus
strains obtained from a variety of environmental and food sources were screened by PCR for the presence of five gene targets (
hblC
,
hblD
,
hblA
,
nheA
, and
nheB
) in two enterotoxin operons (HBL and NHE) traditionally harbored by
Bacillus cereus
. Seven isolates exhibited a positive signal for at least three of the five possible targets, including
Bacillus amyloliquefaciens
,
B. cereus
,
Bacillus circulans
,
Bacillus lentimorbis
,
Bacillus pasteurii
, and
Bacillus thuringiensis
subsp.
kurstaki
. PCR amplicons were confirmed by restriction enzyme digest patterns compared to a positive control strain. Enterotoxin gene expression of each strain grown in a model food system (skim milk) was monitored by gene-specific reverse transcription-PCR and confirmed with the Oxoid RPLA and Tecra BDE commercial kits. Lecithinase production was noted on egg yolk-polymyxin B agar for all strains except
B. lentimorbis
, whereas discontinuous beta hemolysis was exhibited by all seven isolates grown on 5% sheep blood agar plates. The results of this study confirm the presence of enterotoxin genes in natural isolates of
Bacillus
spp. outside the
B. cereus
group and the ability of these strains to produce toxins in a model food system under aerated conditions at 32°C.
Comparison of Five Commercial Enzyme-Linked Immunosorbent Assays for Detection of Antibodies to
Bordetella pertussis
Authors: Kösters Katrin , Riffelmann Marion , Dohrn Brigitte , von König Carl Heinz Wirsing 
Published: July 2002

ABSTRACT

Measuring antibodies to
Bordetella pertussis
antigens is mostly done by enzyme-linked immunosorbent assays (ELISAs). We compared the performance of five commercially available ELISA kits with the help of 65 serum specimens which were repetitively tested for evaluation of the kits. The specimens contained 20 paired serum samples from patients with clinical pertussis, 15 samples were from children vaccinated with a diphtheria-tetanus-acellular pertussis vaccine, seven specimens were taken from an interlaboratory comparison of ELISAs, and there were three reference preparations from the Food and Drug Administration's (FDA's) Laboratory of Pertussis and from our laboratory. Reference values were obtained from the FDA or from results obtained with an in-house ELISA. Commercial ELISAs were compared with respect to their reproducibility and variability, their ability to detect significant titer rises in paired serum samples, their ability to detect an immune response after vaccination, and the comparability of semiquantitative and quantitative results. Reproducibility was generally good (>89%), intra-assay variation ranged from 2.4 to 28.7%, and indeterminate results were recorded in up to 18.5% of all specimens. Most kits correctly identified the antibody response to an acellular pertussis vaccine. None of the commercial kits identified all cases of pertussis correctly, and the sensitivity ranged between 60 and 95%. All five commercial ELISAs showed great discrepancies when comparing semiquantitative results and contained obviously different antigen preparations. Our data suggest that the five commercial ELISAs tested here need further improvement and standardization.
Peptidoglycan and Lipoteichoic Acid Modify Monocyte Phenotype in Human Whole Blood
Authors: Jørgensen Pål F. , Wang Jacob E. , Almlöf Mia , Thiemermann Christoph , Foster Simon J. , Solberg Rigmor , Aasen Ansgar O. 
Published: July 2002

ABSTRACTWe examined the influence of the gram-positive cell wall products peptidoglycan (PepG) and lipoteichoic acid (LTA), compared to lipopolysaccharide (LPS), on the monocyte expression of receptors involved in antigen presentation (HLA-DR, B7.1, and B7.2), cell adhesion (intercellular adhesion molecule-1 [ICAM-1] and lymphocyte function associated antigen-3 [LFA-3]), phagocytosis (FcγRI), and cell activation (CD14). We also evaluated possible influences of the immunosuppressive drugs cyclosporine A, tacrolimus, and sirolimus on the expression of these receptors. Pretreatment of whole blood for 4 h with the immunosuppressive drugs did not influence the expression of the surface receptors in normal or stimulated blood. Stimulation with both PepG and LTA caused significant up-regulation of the surface expression of ICAM-1 and HLA-DR on whole blood monocytes, similar to that obtained with LPS, whereas B7.1, B7.2, LFA-3, and FcγRI were not modulated. PepG and LTA also caused increased expression of CD14, whereas LPS down-regulated this molecule. In contrast, we did not detect any significant influence of any of the bacterial products on the plasma concentration of soluble CD14. We hypothesized that the increased expression of surface CD14 in blood stimulated with PepG would prime for cellular activation by LPS. Indeed, we show that PepG and the partial PepG structure muramyl dipeptide acted in synergy with LPS to cause the release of tumor necrosis factor-α. The results suggest that PepG and LPS provoke partly different responses on monocyte phenotype and that CD14 may play different roles in the innate response to gram-positive and gram-negative bacteria.
Seroprevalence of Antibodies to Microorganisms Known To Cause Arterial and Myocardial Damage in Patients with or without Coronary Stenosis
Authors: Stöllberger C. , Mölzer G. , Finsterer J. 
Published: July 2002

ABSTRACT

Infections are assumed to play a role in coronary artery disease (CAD) and cardiomyopathies. It is unknown whether the seroprevalence of antibodies to these microorganisms is higher in patients with than without CAD. The seroprevalence of antibodies to
Bartonella henselae, Borrelia burgdorferi, Chlamydia pneumoniae, Coxiella burnetii, Helicobacter pylori
, human granulocytic
Ehrlichia, Leptospira, Rickettsia conorii
, and
Treponema pallidum
was assessed prospectively in patients with exertional dyspnea or anginal chest pain who underwent coronary angiography because of suspected CAD. Patients with normal angiograms (NA) were those in whom no more than 50% stenosis of any coronary artery was found. Patients with CAD were patients who underwent percutaneous transluminal coronary angioplasty. There were 50 patients with CAD (9 female) and 62 with NA (25 female), with a mean age of 62 years. All patients had antibodies to at least one microorganism: to
B. henselae
, 8% of CAD patients and 5% of NA patients; to
B. burgdorferi
IgG, 14% CAD and 6% NA; to
B. burgdorferi
IgM, 6% CAD and 3% NA; to
C. pneumoniae
lipopolysaccharide (LPS) IgA, 76% CAD and 77% NA; to
C. pneumoniae
LPS IgG, 80% CAD and 90% NA; to
C. burnetii
, 0% CAD and 5% NA; to
H. pylori
, 92% CAD and 68% NA; to human granulocytic
Ehrlichia
, 8% CAD and 3% NA; to
Leptospira
IgG, 4% CAD and 2% NA; to
R. conorii
, 10% in both groups; and to
T. pallidum
, 2% CAD and 0% NA. The seroprevalence of antibodies to micro-organisms known to induce arterial and myocardial damage does not differ between patients with CAD and NA.
Inhibition of Ganciclovir-Susceptible and -Resistant Human Cytomegalovirus Clinical Isolates by the Benzimidazole
l
-Riboside 1263W94
Authors: McSharry James J. , McDonough Ann , Olson Betty , Talarico Christine , Davis Michele , Biron Karen K. 
Published: July 2002

ABSTRACT

The average 50% inhibitory concentration (IC
50
) values for AD169 were 0.22 ± 0.09 μM 1263W94 and 5.36 ± 0.12 μM ganciclovir. For 35 human cytomegalovirus (HCMV) clinical isolates the average IC
50
was 0.42 ± 0.09 μM 1263W94, and for 26 ganciclovir-susceptible HCMV clinical isolates the average IC
50
was 3.78 ± 1.62 μM ganciclovir. Nine HCMV clinical isolates that were resistant to ganciclovir were completely susceptible to 1263W94.
Quantitation of Immunoglobulin to Hepatitis E Virus by Enzyme Immunoassay
Authors: Innis Bruce L. , Seriwatana Jitvimol , Robinson Robin A. , Shrestha Mrigendra P. , Yarbough Patrice O. , Longer Charles F. , Scott Robert M. , Vaughn David W. , Myint Khin Saw Aye 
Published: July 2002

ABSTRACT
We developed a quantitative enzyme immunoassay (EIA) for antibody to hepatitis E virus (HEV) by using truncated HEV capsid protein expressed in the baculovirus system to improve seroepidemiology, to contribute to hepatitis E diagnosis, and to enable vaccine evaluations. Five antigen lots were characterized; we used a reference antiserum to standardize antigen potency. We defined Walter Reed antibody units (WR U) with a reference antiserum by using the four-parameter logistic model, established other reference pools as assay standards, and determined the conversion factor: 1 WR U/ml = 0.125 World Health Organization unit (WHO U) per ml. The EIA performed consistently; median intra- and intertest coefficients of variation were 9 and 12%, respectively. The accurate minimum detection limit with serum diluted 1:1,000 was 5.6 WR U/ml; the test could detect reliably a fourfold antibody change. In six people followed from health to onset of hepatitis E, the geometric mean antibody level rose from 7.1 WR U/ml to 1,924.6 WR U/ml. We used the presence of 56- and 180-kDa bands by Western blotting as a confirmatory test and to define true-negative and -positive serum specimens. A receiver-operating characteristics plot identified 30 WR U/ml as an optimum cut-point (sensitivity, 86%; specificity, 89%). The EIA detected antibody more sensitively than a commercially available test. The EIA was transferred to another laboratory, where four operators matched reference laboratory results for a panel of unknowns. Quantitation of antibody to HEV and confirmation of its specificity by Western blotting make HEV serology more meaningful.
Bacterial Immunoglobulin Superantigen Proteins A and L Activate Human Heart Mast Cells by Interacting with Immunoglobulin E
Authors: Genovese Arturo , Bouvet Jean-Pierre , Florio Giovanni , Lamparter-Schummert Bärbel , Björck Lars , Marone Gianni 
Published: July 2002

ABSTRACTHuman heart mast cells (HHMC) have been identified in heart tissue, perivascularly, and in the intima of coronary arteries. In vitro activation of isolated HHMC induces the release of vasoactive and proinflammatory mediators (histamine, tryptase, and cysteinyl leukotriene C4[LTC4]). We investigated the effects of several bacterial proteins on HHMC activation in vitro. HHMC released histamine, tryptase, and LTC4in response toStaphylococcus aureusCowan 1 and the immunoglobulin (Ig)-binding protein A, but not toS. aureusWood 46, which does not synthesize protein A. The effect of protein A was inhibited by preincubation with monoclonal IgM VH3+. Some strains ofPeptostreptococcus magnusexpress an Ig light chain-binding surface protein called protein L. Such bacteria and soluble protein L stimulated the release of preformed and newly synthesized mediators from HHMC. Preincubation of HHMC with either protein A or protein L resulted in complete cross-desensitization to a subsequent challenge with the heterologous stimulus or anti-IgE. Monoclonal IgE (κ chains) blocked protein L-induced release, whereas IgE (λ chains) had no effect. Streptococcal protein G, formyl-containing tripeptide, and pepstatin A did not activate HHMC. Bacterial products protein A and protein L and intact bacteria (S. aureusandP. magnus) activate HHMC by acting as Ig superantigens.
A Region ofPlasmodium falciparumAntigen Pfs25 That Is the Target of Highly Potent Transmission-Blocking Antibodies
Authors: Stowers Anthony W. , Keister David B. , Muratova Olga , Kaslow David C. 
Published: July 2002

ABSTRACTEach of the four epidermal growth factor (EGF)-like domains of thePlasmodium falciparumsexual-stage antigen Pfs25 has been individually expressed as a yeast-secreted recombinant protein (yEGF1 through yEGF4). All four are recognized by the immune sera of animals and humans vaccinated with TBV25H (the corresponding yeast-secreted full-length recombinant form of Pfs25), with antibody titers to yEGF1 and yEGF2 weakly correlating with the ability of the sera to block the transmission of parasites to the mosquito host. All four proteins are poorly immunogenic in mice vaccinated with aluminum hydroxide-absorbed formulations. However, all four successfully primed the mice to mount an effective secondary antibody response after a single boost with TBV25H. Sera from mice vaccinated with yEGF2-TBV25H completely block the development of oocysts in mosquito midguts in membrane-feeding assays. Further, of the four proteins, only the depletion of antibodies to yEGF2 from the sera of rabbits vaccinated with TBV25H consistently abolished the ability of those sera to block oocyst development. Thus, antibodies to the second EGF-like domain of Pfs25 appear to mediate a very potent blocking activity, even at low titers. Vaccination strategies that target antibody response towards this domain may improve the efficacy of future transmission-blocking vaccines.