bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incorporation of [
15
N]Ammonia by the Cellulolytic Ruminal Bacteria
Fibrobacter succinogenes
BL2,
Ruminococcus albus
SY3, and
Ruminococcus flavefaciens
17
Authors: Atasoglu Cengiz , Newbold C. James , Wallace R. John 
Published: July 2002

ABSTRACT

The origin of cell nitrogen and amino acid nitrogen during growth of ruminal cellulolytic bacteria in different growth media was investigated by using
15
NH
3
. At high concentrations of peptides (Trypticase, 10 g/liter) and amino acids (15.5 g/liter), significant amounts of cell nitrogen of
Fibrobacter succinogenes
BL2 (51%),
Ruminococcus flavefaciens
17 (43%), and
Ruminococcus albus
SY3 (46%) were derived from non-NH
3
-N. With peptides at 1 g/liter, a mean of 80% of cell nitrogen was from NH
3
. More cell nitrogen was formed from NH
3
during growth on cellobiose compared with growth on cellulose in all media. Phenylalanine was essential for
F. succinogenes
, and its
15
N enrichment declined more than that of other amino acids in all species when amino acids were added to the medium.
The Mannose-Sensitive Hemagglutinin ofVibrio choleraePromotes Adherence to Zooplankton
Authors: Chiavelli Deborah A. , Marsh Jane W. , Taylor Ronald K. 
Published: July 2002

ABSTRACTThe bacteriumVibrio cholerae, the etiological agent of cholera, is often found attached to plankton, a property that is thought to contribute to its environmental persistence in aquatic habitats. TheV. choleraeO1 El Tor biotype andV. choleraeO139 strains produce a surface pilus termed the mannose-sensitive hemagglutinin (MSHA), whereasV. choleraeO1 classical biotype strains do not. AlthoughV. choleraeO1 classical does not elaborate MSHA, the gene is present and expressed at a level comparable to that of the other strains. SinceV. choleraeO1 El Tor andV. choleraeO139 have displacedV. choleraeO1 classical as the major epidemic strains over the last fifteen years, we investigated the potential role of MSHA in mediating adherence to plankton. We found that mutation ofmshAinV. choleraeO1 El Tor significantly diminished, but did not eliminate, adherence to exoskeletons of the planktonic crustaceanDaphnia pulex. The effect of the mutation was more pronounced forV. choleraeO139, essentially eliminating adherence. Adherence of theV. choleraeO1 classicalmshAmutant was unaffected. The results suggest that MSHA is a factor contributing to the ability ofV. choleraeto adhere to plankton. The results also showed that both biotypes ofV. choleraeO1 utilize factors in addition to MSHA for zooplankton adherence. The expression of MSHA and these additional, yet to be defined, adherence factors differ in a serogroup- and biotype-specific manner.
Distribution, Isolation, Host Specificity, and Diversity of Cyanophages Infecting Marine
Synechococcus
spp. in River Estuaries
Authors: Lu Jingrang , Chen Feng , Hodson Robert E. 
Published: July 2002

ABSTRACT

The abundance of cyanophages infecting marine
Synechococcus
spp. increased with increasing salinity in three Georgia coastal rivers. About 80% of the cyanophage isolates were cyanomyoviruses. High cross-infectivity was found among the cyanophages infecting phycoerythrin-containing
Synechococcus
strains. Cyanophages in the river estuaries were diverse in terms of their morphotypes and genotypes.
Improved Properties of Baker's Yeast Mutants Resistant to 2-Deoxy-
d
-Glucose
Authors: Rincón Ana M. , Codón Antonio C. , Castrejón Francisco , Benı́tez Tahı́a 
Published: July 2002

ABSTRACT

We isolated spontaneous mutants from
Saccharomyces cerevisiae
(baker's yeast V1) that were resistant to 2-deoxy-
d
-glucose and had improved fermentative capacity on sweet doughs. Three mutants could grow at the same rate as the wild type in minimal SD medium (0.17% Difco yeast nitrogen base without amino acids and ammonium sulfate, 0.5% ammonium sulfate, 2% glucose) and had stable elevated levels of maltase and/or invertase under repression conditions but lower levels in maltose-supplemented media. Two of the mutants also had high levels of phosphatase active on 2-deoxy-
d
-glucose-6-phosphate. Dough fermentation (CO
2
liberation) by two of the mutants was faster and/or produced higher final volumes than that by the wild type, both under laboratory and industrial conditions, when the doughs were supplemented with glucose or sucrose. However, the three mutants were slower when fermenting plain doughs. Fermented sweet bakery products obtained with these mutants were of better quality than those produced by the wild type, with regard to their texture and their organoleptic properties.
Novel Alkylsulfatases Required for Biodegradation of the Branched Primary Alkyl Sulfate Surfactant 2-Butyloctyl Sulfate
Authors: Ellis Andrew J. , Hales Stephen G. , Ur-Rehman Naheed G. A. , White Graham F. 
Published: July 2002

ABSTRACT

Recent reports show that contrary to common perception, branched alkyl sulfate surfactants are readily biodegradable in standard biodegradability tests. We report here the isolation of bacteria capable of biodegrading 2-butyloctyl sulfate and the identification of novel enzymes that initiate the process. Enrichment culturing from activated sewage sludge yielded several strains capable of growth on 2-butyloctyl sulfate. Of these, two were selected for further study and identified as members of the genus
Pseudomonas
. Strain AE-A was able to utilize either sodium dodecyl sulfate (SDS) or 2-butyloctyl sulfate as a carbon and energy source for growth, but strain AE-D utilized only the latter. Depending on growth conditions, strain AE-A produced up to three alkylsulfatases, as shown by polyacrylamide gel electrophoresis zymography. Growth on either SDS or 2-butyloctyl sulfate or in nutrient broth produced an apparently constitutive, nonspecific primary alkylsulfatase, AP1, weakly active on SDS and on 2-butyloctyl sulfate. Growth on 2-butyloctyl sulfate produced a second enzyme, AP2, active on 2-butyloctyl sulfate but not on SDS, and growth on SDS produced a third enzyme, AP3, active on SDS but not on 2-butyloctyl sulfate. In contrast, strain AE-D, when grown on 2-butyloctyl sulfate (no growth on SDS), produced a single enzyme, DP1, active on 2-butyloctyl sulfate but not on SDS. DP1 was not produced in broth cultures. DP1 was induced when residual 2-butyloctyl sulfate was present in the growth medium, but the enzyme disappeared when the substrate was exhausted. Gas chromatographic analysis of products of incubating 2-butyloctyl sulfate with DP1 in gels revealed the formation of 2-butyloctanol, showing the enzyme to be a true sulfatase. In contrast,
Pseudomonas
sp. strain C12B, well known for its ability to degrade linear SDS, was unable to grow on 2-butyloctyl sulfate, and its alkylsulfatases responsible for initiating the degradation of SDS by releasing the parent alcohol exhibited no hydrolytic activity on 2-butyloctyl sulfate. DP1 and the analogous AP2 are thus new alkylsulfatase enzymes with novel specificity toward 2-butyloctyl sulfate.
Effects of pH and Magnetic Material on Immunomagnetic Separation of
Cryptosporidium
Oocysts from Concentrated Water Samples
Authors: Kuhn Ryan C. , Rock Channah M. , Oshima Kevin H. 
Published: July 2002

ABSTRACT

In this study, we examined the effect that magnetic materials and pH have on the recoveries of
Cryptosporidium
oocysts by immunomagnetic separation (IMS). We determined that particles that were concentrated on a magnet during bead separation have no influence on oocyst recovery; however, removal of these particles did influence pH values. The optimal pH of the IMS was determined to be 7.0. The numbers of oocysts recovered from deionized water at pH 7.0 were 26.3% higher than those recovered from samples that were not at optimal pH. The results indicate that the buffers in the IMS kit did not adequately maintain an optimum pH in some water samples. By adjusting the pH of concentrated environmental water samples to 7.0, recoveries of oocysts increased by 26.4% compared to recoveries from samples where the pH was not adjusted.
Rapid PCR-Based Method Which Can Determine Both Phenotype and Genotype of
Lactococcus lactis
Subspecies
Authors: Nomura Masaru , Kobayashi Miho , Okamoto Takashi 
Published: July 2002

ABSTRACT

A highly efficient, rapid, and reliable PCR-based method for distinguishing
Lactococcus lactis
subspecies (
L. lactis
subsp.
lactis
and
L. lactis
subsp.
cremoris
) is described. Primers complementary to positions in the glutamate decarboxylase gene have been constructed. PCR analysis with extracted DNA or with cells of different
L. lactis
strains resulted in specific fragments. The length polymorphism of the PCR fragments allowed a clear distinction of the
L. lactis
subspecies. The amplified fragment length polymorphism with the primers and the restriction fragment length polymorphism of the amplified products agreed perfectly with the identification based on genotypic and phenotypic analyses, respectively. Isolates from cheese starters were investigated by this method, and amplified fragments of genetic variants were found to be approximately 40 bp shorter than the typical
L. lactis
subsp.
cremoris
fragments.
Biotransformation of 2,7-Dichloro- and 1,2,3,4-Tetrachlorodibenzo-
p
-Dioxin by
Sphingomonas wittichii
RW1
Authors: Hong Hyo-Bong , Chang Yoon-Seok , Nam In-Hyun , Fortnagel Peter , Schmidt Stefan 
Published: July 2002

ABSTRACT

Aerobic biotransformation of the diaryl ethers 2,7-dichlorodibenzo-
p
-dioxin and 1,2,3,4-tetrachlorodibenzo-
p
-dioxin by the dibenzo-
p
-dioxin-utilizing strain
Sphingomonas wittichii
RW1, producing corresponding metabolites, was demonstrated for the first time. Our strain transformed 2,7-dichlorodibenzo-
p
-dioxin, yielding 4-chlorocatechol, and 1,2,3,4-tetrachlorodibenzo-
p
-dioxin, producing 3,4,5,6-tetrachlorocatechol and 2-methoxy-3,4,5,6-tetrachlorophenol; all of these compounds were unequivocally identified by mass spectrometry both before and after
N
,
O
-bis(trimethylsilyl)-trifluoroacetamide derivatization by comparison with authentic standards. Additional experiments showed that strain RW1 formed a second metabolite, 2-methoxy-3,4,5,6-tetrachlorophenol, from the original degradation product, 3,4,5,6-tetrachlorocatechol, by methylation of one of the two hydroxy substituents.
Development of a Procedure for Discriminating among
Escherichia coli
Isolates from Animal and Human Sources
Authors: Guan Shukui , Xu Renlin , Chen Shu , Odumeru Joseph , Gyles Carlton 
Published: July 2002

ABSTRACT

Counts of
Escherichia coli
cells in water indicate the potential presence of pathogenic microbes of intestinal origin but give no indication of the sources of the microbial pollution. The objective of this research was to evaluate methods for differentiating
E. coli
isolates of livestock, wildlife, or human origin that might be used to predict the sources of fecal pollution of water. A collection of 319
E. coli
isolates from the feces of cattle, poultry, swine, deer, goose, and moose, as well as from human sewage, and clinical samples was used to evaluate three methods. One method was the multiple-antibiotic-resistance (MAR) profile using 14 antibiotics. Discriminant analysis revealed that 46% of the livestock isolates, 95% of the wildlife isolates, and 55% of the human isolates were assigned to the correct source groups by the MAR method. Amplified fragment length polymorphism (AFLP) analysis, the second test, was applied to 105 of the
E. coli
isolates. The AFLP results showed that 94% of the livestock isolates, 97% of the wildlife isolates, and 97% of the human isolates were correctly classified. The third method was analysis of the sequences of the16S rRNA genes of the
E. coli
isolates. Discriminant analysis of 105
E. coli
isolates indicated that 78% of the livestock isolates, 74% of the wildlife isolates, and 80% of the human isolates could be correctly classified into their host groups by this method. The results indicate that AFLP analysis was the most effective of the three methods that were evaluated.
Crescent Bodies of
Parachlamydia acanthamoeba
and Its Life Cycle within
Acanthamoeba polyphaga
: an Electron Micrograph Study
Authors: Greub Gilbert , Raoult Didier 
Published: July 2002

ABSTRACT

Parachlamydiaceae
are endosymbionts of free-living amoeba first identified in 1997. Two developmental stages, elementary and reticulate bodies, were observed; however, their localization and proportions according to culture condition and duration remain unknown. The life cycle of
Parachlamydia acanthamoeba
within
Acanthamoeba polyphaga
was studied by transmission electron microscopy of 8-, 36-, and 144-h coculture. Morphometry and quantification were performed using SAMBA software. The elementary body, the predominant stage within the amoebae, was located mainly within their vacuoles. The multiplication of
Parachlamydia
bacteria by binary fission of reticulate bodies was independently associated with culture in PYG broth (odds ratio [OR] = 4.4; 95% confidence interval [CI], 1.55 to 12.46) and with the presence of reticulate bodies within the amoebae (OR = 2.10; 95% CI, 1.53 to 2.89). A third developmental stage was observed, the crescent body. Its presence outside and inside the amoebae was associated mainly with prolonged incubation time (OR = 3.98; 95% CI, 1.49 to 10.68, and OR = 5.98; 95% CI, 1.75 to 20.4, respectively). Elementary and crescent bodies were released into the extracellular medium within vesicles or after amoebal lysis. For both, phagocytosis was their mode of entry. This electron micrograph study revealed another infective developmental stage, the crescent body, and provided quantitative analysis of the life cycle of
P. acanthamoeba
within
A. polyphaga
.
Sequential Use of Paraformaldehyde and Methanol as Optimal Conditions for the Direct Quantification of ZEBRA and Rta Antigens by Flow Cytometry
Authors: Imbert-Marcille Berthe-Marie , Coste-Burel Marianne , Robillard Nelly , Foucaud-Gamen Jacqueline , Billaudel Sylviane , Drouet Emmanuel 
Published: July 2002

ABSTRACT
A technique was developed with flow cytometry to quantify the two immediate-early proteins ZEBRA and Rta, which are involved in the activation of Epstein-Barr virus replication. We evaluated four monoclonal antibodies on four cell lines (B95-8, RAJI, Namalwa, and P3HR1) with varying levels of expression of these replication-phase antigens. The Namalwa lymphoma cell line was used as a negative control. Four fixation-permeabilization procedures were compared. The preparation of cells with paraformaldehyde and methanol in sequence, and antigen detection with AZ125 and AR 5A9 monoclonal antibodies, were found to be the optimal conditions in these cell lines. Our procedure allowed ZEBRA antigen to be detected in 4.85% of peripheral blood mononuclear cells from a transplant recipient with a lymphoproliferative disease.
Use of Monoclonal Antibodies for Rapid Diagnosis of Respiratory Viruses in a Community Hospital
Authors: Irmen Kenneth E. , Kelleher James J. 
Published: July 2002

ABSTRACT
An indirect fluorescence antibody (IFA) procedure was used for the rapid detection of respiratory viruses in direct clinical specimens and for determining the epidemiology of viruses in a community hospital setting. Viral respiratory diseases were monitored for 10 consecutive respiratory seasons. The Bartels Viral Respiratory Screening and Identification Kit is an IFA method that contains pooled and individual monoclonal antibodies for seven common respiratory viruses. Compared with 8,670 conventional tube cell cultures, IFA staining of direct patient specimens had an overall sensitivity of 84.2% and a specificity of 87.7%. Yearly epidemics of respiratory syncytial virus were seen with alternating short and long intervals between successive periods when virus was isolated. Epidemics following short intervals were more severe. Influenza A virus epidemics occurred yearly, and influenza B virus activity was seen generally every other year. When influenza A and influenza B viruses were cocirculating in a given season, the months of peak activity of one virus were always within 1 month of the peak activity of the other virus. Parainfluenza virus type 1 was detected in the autumn of odd-numbered years, and parainfluenza type 2 virus was seen usually in the autumn of even-numbered years. Parainfluenza type 3 virus and adenovirus were the most ubiquitous agents, with peak incidence occurring in the late winter to spring.
A Latex Bead-Based Flow Cytometric Immunoassay Capable of Simultaneous Typing of Multiple Pneumococcal Serotypes (Multibead Assay)
Authors: Park M. K. , Briles D. E. , Nahm M. H. 
Published: July 2002

ABSTRACT

A simple and rapid method of simultaneously determining 15
Streptococcus pneumoniae
serotypes was developed. Fifteen latex beads of different sizes and different red fluorescence levels were coated with 1 of 15 serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9N, 9V, 14, 18C, 19A, 19F, 22F, and 23F) of pneumococcal capsular polysaccharide (PS). The bead mixture was incubated with individual pneumococcal lysate, a pool of rabbit antisera capable of binding the 15 serotypes, and fluorescein (green fluorescence)-conjugated anti-rabbit antibody. Bead size, red fluorescence, and green fluorescence were measured in a single flow cytometer run. The green fluorescence of the beads was inhibited only when there was a serotypic match between PS on the bead and PS in the pneumococcal lysate. This method distinguished cross-reactive serotypes and correctly identified the serotypes in 100% of 86 pneumococcal isolates tested.
Antigenic Properties and Diagnostic Potential of Baculovirus-Expressed Infectious Bursal Disease Virus Proteins VPX and VP3
Authors: Martínez-Torrecuadrada Jorge L. , Lázaro Beatriz , Rodriguez José F. , Casal J. Ignacio 
Published: July 2002

ABSTRACT
The routine technique for detecting antibodies specific to infectious bursal disease virus (IBDV) is a serological evaluation by enzyme-linked immunosorbent assay (ELISA) with preparations of whole virions as the antigens. To avoid using complete virus in the standard technique, we have developed two new antigens through the expression of the VPX and VP3 genes in insect cells. VPX and especially VP3 were expressed at high levels in insect cells and simple to purify. The immunogenicity of both proteins was similar to that of the native virus. VPX was able to elicit neutralizing antibodies but VP3 was not. Purified VPX and VP3 were tested in an indirect ELISA with more than 300 chicken sera. There was an excellent correlation between the results of the ELISA using VPX and those of the two commercial kits. VP3 did not perform as well as VPX, and the linear correlation was significantly lower. A comparison with the standard reference technique, seroneutralization, showed that the indirect ELISA was more sensitive. Therefore, VPX-based ELISA is a good alternative to conventional ELISAs that use whole virions.
Comparison of Two Recombinant Major Outer Membrane Proteins of the Human Granulocytic Ehrlichiosis Agent for Use in an Enzyme-Linked Immunosorbent Assay
Authors: Tajima Tomoko , Zhi Ning , Lin Quan , Rikihisa Yasuko , Horowitz Harold W. , Ralfalli John , Wormser Gary P. , Hechemy Karim E. 
Published: July 2002

ABSTRACT

Enzyme-linked immunosorbent assay (ELISA) for human granulocytic ehrlichiosis (HGE) using two different recombinant P44 proteins (rP44 and rP44-2hv) of the HGE agent as antigens was evaluated. Sera from a total of 72 healthy humans both from regions where HGE is nonendemic and regions where HGE is endemic were used as negative controls to determine the cutoff value for ELISA. Sera from a total of 14 patients (nine from whom the HGE agent was isolated and five who were HGE-PCR positive) were used as positive controls. One hundred nine sera from 72 patients in an area where HGE is endemic who were suspected of having HGE were examined by ELISA and indirect immunofluorescence assay (IFA). All IFA-negative sera were negative by both ELISAs. Of 39 sera that were IFA positive, 35 and 27 were positive by ELISA using rP44 and rP44-2hv, respectively, indicating that the use of rP44 is more sensitive. Western blot analysis of the four rP44-ELISA-negative IFA-positive sera using whole HGE agent as antigen suggests that these four sera were false IFA positive. There was no difference in results with or without the preabsorption of sera with
Escherichia coli
or with or without the cleavage of the fused protein derived from the vector. There was a significant positive correlation between IFA titers and optical densities of ELISAs. Four
Ehrlichia chaffeensis
-positive and 10
Borrelia burgdorferi
-positive sera were negative by ELISA. However, two
Babesia microti
-positive sera showed strong cross-reactivity to the fused vector protein, which was eliminated after cleavage of the protein. Thus, ELISA using rP44 nonfusion protein would provide a simple, specific, and objective HGE serologic test which can be easily automated.
An IS
711
Element Downstream of the
bp26
Gene Is a Specific Marker of
Brucella
spp. Isolated from Marine Mammals
Authors: Cloeckaert Axel , Grayon Maggy , Grepinet Olivier 
Published: July 2002

ABSTRACT

DNA polymorphism of the
bp26
gene, coding for a diagnostic protein antigen for brucellosis, was assessed by PCR and restriction fragment length polymorphism analysis using primers to amplify the
bp26
gene with its flanking regions. Surprisingly, whereas PCR performed on DNA of the reference strains of the six recognized
Brucella
species produced a product of the expected size (1,029 bp), PCR performed on DNA of three representative strains from marine mammals (from a seal, a dolphin, and a porpoise) produced a larger product, of about 1,900 bp. Nucleotide sequencing of the 1,900-bp PCR products revealed the presence of an insertion sequence, IS
711
, downstream of the
bp26
gene and adjacent to a Bru-RS1 element previously described as being a hot spot for IS
711
insertion. PCR performed on a large number of field strains from different geographic origins and from marine mammal isolates indicated that the occurrence of an IS
711
element downstream of the
bp26
gene was a feature specific to the marine mammal
Brucella
strains. Thus, this PCR assay is able to differentiate
Brucella
terrestrial isolates from marine mammal isolates and could be applied for diagnostic purposes.
Hyper-Immunoglobulin A in the Hyperimmunoglobulinemia D Syndrome
Authors: Klasen Ina S. , Göertz Joop H. C. , van de Wiel Gertrude A. S. , Weemaes Corry M. R. , van der Meer Jos W. M. , Drenth Joost P. H. 
Published: July 2002

ABSTRACTThe hyperimmunoglobulinemia D syndrome (HIDS) is an autosomal recessive disorder characterized by recurrent febrile attacks with abdominal, articular, and skin manifestations. Apart from elevated immunoglobulin D (IgD) levels (>100 IU/ml), there are high IgA levels in the majority of cases. Mutations in the gene encoding mevalonate kinase constitute the molecular defect in HIDS. The cause of elevated IgA concentrations in HIDS patients remains to be elucidated. We studied the hyper-IgA response in serum of a group of HIDS patients. Elevated IgA concentrations result from increased IgA1 concentrations. IgA and IgA1 concentrations correlated significantly with IgD concentrations, and levels of IgA polymers were significantly higher than the levels in healthy donors. These results indicate a continuous, presumably systemic, stimulation of IgA in HIDS patients.