bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagnostic Potential of Parechovirus Capsid Proteins
Authors: Alho Annu , Marttila Jane , Ilonen Jorma , Hyypiä Timo 
Published: June 2003

ABSTRACT

To study humoral and cellular immunity against human parechovirus type 1 (HPEV1), the viral capsid proteins VP0, VP1, and VP3 were expressed and purified as glutathione
S
-transferase (GST)-tagged recombinant proteins. The fusion proteins were used to raise antisera in rabbits. VP0 and VP1 antisera specifically detected HPEV1-infected cells in culture by immunoperoxidase staining and immunofluorescence. Furthermore, antisera against the VP0 and VP1 proteins had neutralizing effects against HPEV1 infection. When the HPEV1 antibody titers of 20 adults and 55 children were determined by a microneutralization test, the prevalence of HPEV1 antibodies in the adult population was 96%, while 50% of children were seropositive. Selected sera were used to evaluate HPEV1 fusion proteins as antigens in an enzyme immunoassay. The VP3 capsid protein appeared to be suitable for the purpose, with specificity of 100% and sensitivity of 96% compared to the neutralization test. Furthermore, T-cell responses to the purified HPEV1 and HPEV1 capsid fusion proteins were studied in 20 adults. Sixty percent of the subjects had T-cell proliferation responses to purified HPEV1, and 90% of the subjects also had positive T-cell responses to at least one of the GST capsid proteins.
Studies of Epidemiology and Seroprevalence of Bovine Noroviruses in Germany
Authors: Deng Y. , Batten C. A. , Liu B. L. , Lambden P. R. , Elschner M. , Günther H. , Otto P. , Schnürch P. , Eichhorn W. , Herbst W. , Clarke I. N. 
Published: June 2003

ABSTRACT

Jena virus (JV) is a bovine enteric calicivirus that causes diarrhea in calves. The virus is approximately 30 nm in diameter and has a surface morphology similar to the human Norwalk virus. The genome sequence of JV was recently described, and the virus has been assigned to the genus
Norovirus
of the family
Caliciviridae
. In the present study, the JV capsid gene encoded by open reading frame 2 was cloned into the baculovirus transfer vector pFastBac 1, and this was used to transform
Escherichia coli
to generate a recombinant bacmid. Transfection of insect cells with the recombinant baculovirus DNA resulted in expression of the JV capsid protein. The recombinant JV capsid protein undergoes self-assembly into virus-like particles (VLPs) similar to JV virions in size and appearance. JV VLPs were released into the cell culture supernatant, concentrated, and then purified by CsCl equilibrium gradient centrifugation. Purified JV VLPs were used to hyperimmunize laboratory animals. An antigen capture enzyme-linked immunosorbent assay (ELISA) was developed and characterized initially with clinical specimens containing defined human noroviruses and bovine diarrheal samples from calves experimentally infected with JV; the ELISA was specific only for JV. The ELISA was used to screen 381 diarrheal samples collected from dairy herds in Thuringia, Hesse, and Bavaria, Germany, from 1999 to 2002; 34 of these samples (8.9%) were positive for JV infection. The unexpectedly high prevalence of JV was confirmed in a seroepidemiological study using 824 serum or plasma samples screened using an anti-JV ELISA, which showed that 99.1% of cattle from Thuringia have antibodies to JV.
Molecular Epidemiology of
Vibrio cholerae
O139 in China: Polymorphism of Ribotypes and CTX Elements
Authors: Qu Mei , Xu Jing , Ding Yanpeng , Wang Ruibai , Liu Peng , Kan Biao , Qi Guoming , Liu Yanqing , Gao Shouyi 
Published: June 2003

ABSTRACT

Vibrio cholerae
O139, the second etiological serogroup of cholera, triggered the first outbreak of O139 cholera in China in 1993. To analyze the clone polymorphism of O139 isolates in China, 117 strains of
V. cholerae
O139, isolated from different areas in China between 1993 and 1999, were selected to characterize the phylogenetic relationships by molecular techniques. Analysis of restriction fragment length polymorphism in the conserved 16S rRNA gene revealed seven different ribotypes within the 117 strains. Among these strains, there were eight that lacked the cholera toxin gene (
ctxAB
),
zot
, and the repetitive sequence (RS); these eight strains belonged to three individual ribotypes. Our results suggested that
V. cholerae
O139 strains in China had clone diversity in phylogeny. The results of our hybridization patterns for CTX genetic elements (
ctxAB
,
zot
, and RS) showed that CTXΦ genomes in most
V. cholerae
O139 strains had two or more copies and had extensive restriction patterns even for the strains which belong to the same ribotype. For 22 (20.1%) strains, the copies of
ctxAB
were different from those of
zot
, suggesting that a
ctxAB
-negative CTXΦ genome may exist in O139 strains. This
ctxAB
-negative CTXΦ genome may coexist with the intact CTXΦ genome in a strain. In addition, the dendrogram for I-
Ceu
I-generated pulsed-field gel electrophoresis patterns showed that
V. cholerae
serogroup O139 has a closer relationship with one strain of serogroup O22 than with the strains of serogroup O1. The results of this study showed the clonal diversity and the distribution of O139 strains in China, suggesting multiple origins of the O139 cholera epidemic or sporadic events.
Genetic Variability among Group A and B Respiratory Syncytial Virus Isolates from a Large Referral Hospital in New Delhi, India
Authors: Rajala Maitreyi S. , Sullender Wayne M. , Prasad A. K. , Dar Lalit , Broor Shobha 
Published: June 2003

ABSTRACT
Respiratory syncytial virus (RSV) is an important childhood pathogen of acute lower respiratory infections in developed and developing countries. The molecular epidemiology of RSV in India is largely unknown. The present study was undertaken to standardize and evaluate reverse transcription-PCR (RT-PCR) for the rapid and simultaneous detection of RSV groups A and B in clinical samples and to study intragroup genetic variability. RT-PCR was evaluated by comparing the results of seminested RT-PCR with centrifugation-enhanced cultures on 200 nasopharyngeal aspirates from children with acute lower respiratory infections. RSV was isolated in 34 nasopharyngeal aspirates by centrifugation-enhanced cultures and identified in 45 samples by RT-PCR. In 15 samples RSV was identified by seminested RT-PCR alone and in four by centrifugation-enhanced cultures alone. Of the 45 samples positive for RSV by nested PCR, 15 belonged to group A, 29 to group B, and one sample suggested a mixed infection. Group B RSV predominated in both years of the 2-year study. Genetic variability within RSV groups was studied by restriction fragment analysis of 35 PCR products. Among both group A and group B RSV, two different composite patterns were observed. Thus, RSV was found to be a major pathogen of acute lower respiratory tract infections in India, as it was detected in 24.5% of children by RT-PCR. RT-PCR provides a sensitive method for detection and typing of RSV group A and B viruses in clinical samples as well as a means to study intragroup variations. However, a higher sensitivity of detection of RSV in clinical samples can be obtained by its combination with additional techniques, such as virus cultivation.
Changing Patterns of Rotavirus Genotypes in Ghana: Emergence of Human Rotavirus G9 as a Major Cause of Diarrhea in Children
Authors: Armah George E. , Steele Andrew Duncan , Binka Fred N. , Esona Mathew D. , Asmah Richard Harry , Anto Francis , Brown David , Green Jon , Cutts Felicity , Hall Andy 
Published: June 2003

ABSTRACT
Genotyping of human rotaviruses was performed on 312 rotavirus-positive samples collected from 2,205 young children with diarrhea in the Upper East District of Ghana, a rural community. Of the 271 (86.9%) rotavirus strains that could be VP7 (G) or VP4 (P) characterized, 73 (26.9%) were of G9 specificity. The predominant G9 genotype was G9P[8], which constituted 79.5% of all G9 strains detected, followed by G9P[6] (12.3%), G9P[10] (2.7%), and G9P[4] (1.3%). G9 strains with mixed P types constituted 2.7% of all G9 strains found in the study. All the G9P[8] strains had a long RNA electrophoretic pattern with VP6 subgroup II specificity. Four G9 isolates, GH1319, GH1416, GH3550, and GH3574, which were selected based on the abundance of stool material and were representative of the three electropherotypes observed, were cloned and sequenced. The Ghanaian isolates shared more than 98% sequence nucleotide homology with other G9 strains from the United States (US1205), Malawi (MW69), Brazil (R160), Japan (95H115), and Nigeria (Bulumkutu). However, they showed only 95% nucleotide homology with the Thai G9 strain Mc345. Phylogenetic analysis of the nucleic acid sequence revealed the existence of at least three clusters, with Ghanaian strains forming one cluster, Nigerian and Brazilian strains forming a second cluster, and U.S., Malawian, and Japanese strains forming a third.
Rapid Diagnosis of Extrapulmonary Tuberculosis by PCR: Impact of Sample Preparation and DNA Extraction
Authors: Honoré-Bouakline S. , Vincensini J. P. , Giacuzzo V. , Lagrange P. H. , Herrmann J. L. 
Published: June 2003

ABSTRACT

In cases of suspected extrapulmonary tuberculosis, rapid and accurate laboratory diagnosis is of prime importance, since traditional techniques of detecting acid-fast bacilli have limitations. The major difficulty with mycobacteria is achieving optimal cell lysis. Buffers used in commercial kits do not allow this complete lysis in a number of clinical specimens. A comparison of two sample preparation methods, pretreatment with proteinase K (PK-Roche) and complete DNA purification (cetyltrimethylammonium bromide [CTAB]-Roche), was conducted on 144 extrapulmonary specimens collected from 120 patients to evaluate the impact on the Cobas-Amplicor method. Thirty patients were diagnosed with tuberculosis, with 15 patients culture positive for
Mycobacterium tuberculosis
. Amplification and detection of the amplicons were impaired by a high number of inhibitory specimens (39 to 52%). CTAB-Roche allowed the detection of more culture-positive specimens by PCR than PK-Roche. Comparison with the final diagnoses of tuberculosis confirmed that CTAB-Roche produced the best sensitivity (53.8%) compared to culture (43.3%), PK-Roche (16%), and smear (13%). However, the specificity of the PCR assay with CTAB-Roche-extracted material was always lower (78.8%) than those with culture (100%) and PK-Roche (96.5%). False-positive specimens were lung biopsy material, lymph node biopsy material and aspirate, or bone marrow aspirate, mainly from immunocompromised patients. Despite the efficiency of complete DNA extraction for the rapid diagnosis by PCR of extrapulmonary tuberculosis, the false-positive results challenge our understanding of PCR results.
Molecular Characterization of Ampicillin-Resistant
Enterococcus faecium
Isolates from Hospitalized Patients in Norway
Authors: Jureen Roland , Top Janetta , Mohn Stein Christian , Harthug Stig , Langeland Nina , Willems Rob J. L. 
Published: June 2003

ABSTRACT

The genetic relationship of 81 ampicillin-resistant and 21 ampicillin-susceptible
Enterococcus faecium
isolates from clinical infections and rectal screening in hospitalized patients in Norway was studied by pulsed-field gel electrophoresis (PFGE) and amplified fragment length polymorphism (AFLP). PFGE showed 55 different banding patterns, and 65 of the isolates could be grouped into one large group. With AFLP, 46 patterns were discerned, and 74 isolates clustered in one group. In general, the isolates had a higher degree of similarity than with PFGE. The
purK
gene, which is one of the targets of the
E. faecium
multilocus sequence typing scheme, was sequenced. Eleven different
purK
alleles could be discerned, with the majority of isolates (
n
= 80) harboring allele 1. With only two exceptions, all strains carrying
purK-1
clustered in the same PFGE and AFLP groups, indicating a good correlation between PFGE type, AFLP type, and
purK
allele. Genetic polymorphism of a 571-bp PCR fragment of the C-terminal domain of the penicillin-binding protein 5 gene (
pbp5
) was determined, and sequence differences were associated with the level of ampicillin resistance. This study indicates that the majority of ampicillin-resistant
E. faecium
strains in Norway belong to a distinct genetic lineage of closely related genotypes. Rectal and clinical isolates were generally indistinguishable, and differences in clonal distribution and allele polymorphism were found mainly between ampicillin-resistant and -susceptible isolates.
Emergence of Rifampin-Resistant
Rhodococcus equi
with Several Types of Mutations in the
rpoB
Gene among AIDS Patients in Northern Thailand
Authors: Asoh Norichika , Watanabe Hiroshi , Fines-Guyon Marguerite , Watanabe Kiwao , Oishi Kazunori , Kositsakulchai Weerayut , Sanchai Tippaya , Kunsuikmengrai Khemrassamee , Kahintapong Sumpun , Khantawa Banyong , Tharavichitkul Prasit , Sirisanthana Thira , Nagatake Tsuyoshi 
Published: June 2003

ABSTRACT

The antimicrobial susceptibilities of 30
Rhodococcus equi
isolates obtained from 30 patients between 1993 and 2001 in northern Thailand were investigated. The MICs showed a tendency toward resistance to various antibiotics but sensitivity to imipenem, minocycline, vancomycin, and teicoplanin (MICs, ≤0.5 μg/ml) and relative sensitivity to meropenem, clarithromycin, and ciprofloxacin (MICs, ≤2 μg/ml). Of the 30 isolates, 26 were susceptible (MICs, ≤1 μg/ml), 1 showed low-level resistance (MIC, 8 μg/ml), and 3 showed high-level resistance (MICs, ≥64 μg/ml) to rifampin. PCR amplification and DNA sequencing of the
rpoB
gene and molecular typing by pulsed-field gel electrophoresis (PFGE) were performed for eight
R. equi
isolates from eight AIDS patients with pneumonia or lung abscess caused by
R. equi
between 1998 and 2001, including one low- and three high-level rifampin-resistant isolates. As a result, two high-level rifampin-resistant strains with PFGE pattern A had a Ser531Trp (
Escherichia coli
numbering) mutation, and one high-level rifampin-resistant strain with PFGE pattern B had a His526Tyr mutation, whereas one low-level rifampin-resistant strain with PFGE pattern C had a Ser509Pro mutation. Four rifampin-susceptible strains with PFGE patterns D and E showed an absence of mutation in the
rpoB
region. Our results indicate the presence of several types of rifampin-resistant
R. equi
strains among AIDS patients in northern Thailand.
Distribution of the Secondary Type III Secretion System Locus Found in Enterohemorrhagic
Escherichia coli
O157:H7 Isolates among Shiga Toxin-Producing
E. coli
Strains
Authors: Makino Sou-Ichi , Tobe Toru , Asakura Hiroshi , Watarai Masahisa , Ikeda Testuya , Takeshi Koichi , Sasakawa Chihiro 
Published: June 2003

ABSTRACT

The ability of the complete genome sequence of enterohemorrhagic
Escherichia coli
O157 led to the identification of a 17-kb chromosomal region which contained a type III secretion system gene cluster at min 64.5. This locus contains open reading frames whose amino acid sequences show high degrees of similarity with those of proteins that make up the type III secretion apparatus, which is encoded by the
inv-spa-prg
locus on a
Salmonella
SPI-1 pathogenicity island. This locus was designated ETT2 (
E. coli
type III secretion 2) and consisted of the
epr
,
epa
, and
eiv
genes. ETT2 was found in enteropathogenic
E. coli
strains and also in some non-O157 Shiga toxin-producing
E. coli
(STEC) strains, but most of them contained a truncated portion of ETT2. Most O157 isolates had a complete collection of toxin-encoding genes
eae
and
hlyA
and the ETT2 locus, while most O26 strains had toxin-encoding genes
eae
and
hlyA
genes but an incomplete ETT2 locus. Thus, an intact copy of ETT2 might mark a pathogenic distinction for particular STEC strains. Therefore, the presence of the ETT2 locus can be used for identification of truly pathogenic STEC strains and for molecular fingerprinting of the epidemic strains in humans and animals.
The Genus
Aeromonas
: Biochemical Characteristics, Atypical Reactions, and Phenotypic Identification Schemes
Authors: Abbott Sharon L. , Cheung Wendy K. W. , Janda J. Michael 
Published: June 2003

ABSTRACT

A total of 193 strains representing 14 different
Aeromonas
genomospecies were evaluated for 63 phenotypic properties to create useful tables for the reference identification of mesophilic aeromonads. Only 9 of 62 biochemical tests (14%) yielded uniform results, and the fermentation of certain carbohydrates was found to be linked to specific species. A number of unusual or aberrant properties for the genus
Aeromonas
were also detected in the collection of 428 strains (193 in the phenotypic study, 235 in a retrospective review). These tests included susceptibility to the vibriostatic agent, fermentation of
m-
inositol and
d
-xylose, hydrolysis of urea, and the lack of cytochrome oxidase activity. Fermentation of melibiose was linked to raffinose fermentation in all
Aeromonas
species except
A. jandaei
. Keys are provided for clinical laboratories choosing to identify aeromonads to species level based upon initial Møeller decarboxylase and dihydrolase reactions. In addition, several new tests were identified that help to separate members of the
A. caviae
complex (
A. caviae, A. media,
and
A. eucreonophila
).
Devices for Rapid Diagnosis of Malaria: Evaluation of Prototype Assays That Detect
Plasmodium falciparum
Histidine-Rich Protein 2 and a
Plasmodium vivax
-Specific Antigen
Authors: Forney J. Russ , Wongsrichanalai Chansuda , Magill Alan J. , Craig Leslie G. , Sirichaisinthop Jeeraphat , Bautista Christian T. , Miller R. Scott , Ockenhouse Christian F. , Kester Kent E. , Aronson Naomi E. , Andersen Ellen M. , Quino-Ascurra Higinio A. , Vidal Carlos , Moran Kimberly A. , Murray Clinton K. , DeWitt Caroline Cady , Heppner D. Gray , Kain Kevin C. , Ballou W. Ripley , Gasser Robert A. 
Published: June 2003

ABSTRACT

The
Para
Sight F test was developed as a pioneer industry effort in the large-scale, process-controlled production of a device for the rapid diagnosis of malaria. This device performed well in field settings but was limited to the detection of a single malaria species,
Plasmodium falciparum.
The
Para
Sight F+V assay advanced upon the
Para
Sight F test format by incorporating a monoclonal antibody directed against a proprietary
Plasmodium vivax
-specific antigen, in addition to the antibody directed against
P. falciparum
histidine-rich protein 2, which was used in the
Para
Sight F assay. The modified assay was developed to add the capability to detect
P. falciparum
and
P. vivax
in a single-test-strip format. The present study evaluated three distinct
Para
Sight F+V prototypes with samples from symptomatic patients in regions of Thailand and Peru where malaria is endemic. Over a 2-year enrollment period (1998 and 1999), a total of 4,894 patients consented to participation in the study. Compared with the results for duplicate microscopic examinations of Giemsa-stained blood smears as the reference diagnostic standard, each successive prototype showed substantial improvement in performance. The final
Para
Sight F+V prototype, evaluated in 1999, had an overall sensitivity for detection of asexual
P. falciparum
parasites of 98%. The sensitivity of the device was 100% for
P. falciparum
densities of >500 parasites/μl, with a sensitivity of 83% for parasite densities of ≤500/μl. The specificity for the exclusion of
P. falciparum
was 93%. For
P. vivax
, the overall sensitivity was 87% for the final 1999 prototype. The sensitivities calculated for different levels of
P. vivax
parasitemia were 99% for parasite densities of >5,000/μl, 92% for parasite densities of 1,001 to 5,000/μl, 94% for parasite densities of 501 to 1,000/μl, and 55% for parasite densities of 1 to 500/μl. The specificity for the exclusion of
P. vivax
was 87%. The areas under the receiver operating characteristic curves for the diagnostic performance of the assay for the detection of
P. falciparum
and
P. vivax
were 0.8907 and 0.8522, respectively. These findings indicate that assays for rapid diagnosis have the potential to enhance diagnostic capabilities in those instances in which skilled microscopy is not readily available.
Precise Characterization of Norovirus (Norwalk-Like Virus)-Specific Monoclonal Antibodies with Broad Reactivity
Authors: Yoda Tomoko , Suzuki Yasuhiko , Terano Yoshitake , Yamazaki Kenji , Sakon Naomi , Kuzuguchi Tsuyoshi , Oda Hajime , Tsukamoto Teizo 
Published: June 2003

ABSTRACT
We have been characterizing monoclonal antibodies against Norovirus (Norwalk-like virus). In the course of our study, two monoclonal antibodies generated against Norovirus genogroup II capsid protein were found to react not only to genogroup II but also to genogroup I recombinant capsid proteins. In addition, we showed that these two monoclonal antibodies reacted to a 40-amino-acid-fragment located close to the N-terminal region of genogroup II Norovirus. Similar reactivity was observed with the equivalent region of genogroup I Norovirus. In this study, we confirmed that the epitopes of the two monoclonal antibodies existed within an 11-amino-acid peptide. To obtain an idea of the reactive ranges of the two monoclonal antibodies toward different strains of Norovirus, their reactivities were investigated using 16 types of peptide constructed according to the data in GenBank and 8 recombinant capsid proteins (7 whole capsid proteins and 1 short [80-amino-acid] protein fragment). A characteristic broad reactivity of the two monoclonal antibodies is clearly shown by the results of this study. Thus, these monoclonal antibodies could be useful tools for detecting a broad range of Norovirus strains.
The World Health Organization's External Quality Assurance System Proficiency Testing Program Has Improved the Accuracy of Antimicrobial Susceptibility Testing and Reporting among Participating Laboratories Using NCCLS Methods
Authors: Chaitram Jasmine M. , Jevitt Laura A. , Lary Sara , Tenover Fred C. 
Published: June 2003

ABSTRACT

A total of 150 laboratories in 33 countries that followed the NCCLS testing procedures participated in the World Health Organization's External Quality Assurance System for Antimicrobial Susceptibility Testing (EQAS-AST) from January 1998 through March 2001. Laboratories tested seven bacterial isolates for antimicrobial resistance and reported the results to the Centers for Disease Control and Prevention (CDC) in Atlanta, Ga. The results were compared to the results generated at the CDC with the NCCLS broth microdilution and disk diffusion reference methods. Although there were few testing errors with
Salmonella enterica
subsp.
enterica
serovar Enteritidis, drugs that are not appropriate for therapy of
Salmonella
infections were tested and reported by 136 (91%) of 150 laboratories. In addition, 29 (20%) of 150 laboratories used the
Staphylococcus aureus
breakpoints to report oxacillin results for
Staphylococcus saprophyticus
. For a
vanB
-containing
Enterococcus faecalis
strain, 124 (83%) of 150 laboratories correctly reported vancomycin results that were ±1 doubling dilution from the reference MIC or ±3 mm from the reference disk diffusion result. Of the laboratories that tested
Streptococcus agalactiae
by disk diffusion, 17% reported nonsusceptible results for penicillin in error. While 110 laboratories (73%) tested the
S
.
pneumoniae
challenge isolate against a fluoroquinolone, 83% tested it against ciprofloxacin, for which there are no NCCLS interpretive criteria. Ten of 12 laboratories testing levofloxacin and 4 of 4 laboratories testing ofloxacin by an MIC method correctly reported resistant results for the isolate. Feedback letters sent to participating laboratories highlighted areas of susceptibility testing in individual laboratories that needed improvement. The positive impact of the feedback letters and the overall effectiveness of the EQAS program were documented in repeat testing challenges with pneumococci and staphylococci. The 31 and 19% increases in the numbers of laboratories using appropriate testing methods for pneumococci and staphylococci, respectively, in 2000 versus 1998 indicate that laboratory performance is improving.