bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pyrazinamide-Monoresistant
Mycobacterium tuberculosis
in the United States
Authors: Hannan Margaret M. , Desmond Edward P. , Morlock Glenn P. , Mazurek Gerald H. , Crawford Jack T. 
Published: July 2002

ABSTRACT

Mycobacterium bovis
is naturally resistant to the antituberculosis drug pyrazinamide (PZA). To determine whether all
Mycobacterium tuberculosis
complex isolates demonstrating PZA monoresistance were truly
M. bovis
, we examined the phenotype and genotype of isolates reported as PZA monoresistant in five counties in California from January 1996 through June 1999. Isolates reported by local laboratories to be PZA monoresistant were sent to the state reference laboratory for repeat susceptibility testing using the BACTEC radiometric method and to the Centers for Disease Control and Prevention for
pncA
sequencing and PCR-restriction fragment length polymorphism (RFLP) analysis of the
oxyR
gene. Of 1,916 isolates, 14 were reported as PZA monoresistant and 11 were available for retesting. On repeat testing, 6 of the 11 isolates were identified as PZA-susceptible
M. tuberculosis
, 1 was identified as PZA-monoresistant
M. bovis
, and 1 was identified as
M. bovis
BCG. The three remaining isolates were identified as PZA-monoresistant
M. tuberculosis
. Sequencing of the
pncA
and
oxyR
genes genotypically confirmed the two
M. bovis
and the six susceptible
M. tuberculosis
species. Each of the three PZA-monoresistant
M. tuberculosis
isolates had different, previously unreported,
pncA
gene mutations: a 24-bp deletion in frame after codon 88, a base substitution at codon 104 (Ser
104
Cys), and a base substitution at codon 90 (Ile
90
Ser). This study demonstrates that PZA monoresistance is not an absolute marker of
M. bovis
species but may also occur in
M. tuberculosis
, associated with a number of different mutational events in the
pncA
gene. It is the first report of PZA-monoresistant
M. tuberculosis
in the United States.
Rotavirus Strain Diversity in Blantyre, Malawi, from 1997 to 1999
Authors: Cunliffe N. A. , Gondwe J. S. , Graham S. M. , Thindwa B. D. M. , Dove W. , Broadhead R. L. , Molyneux M. E. , Hart C. A. 
Published: July 2002

ABSTRACT

In a 2-year study of viral gastroenteritis in children in Blantyre, Malawi, the diversity of rotavirus strains was investigated by using electropherotyping, reverse transcription-PCR amplification of the VP7 and VP4 genes (G and P genotyping), and nucleotide sequencing. Of 414 rotavirus strains characterized, the following strain types were identified: P[8], G1 (
n
= 111; 26.8%); P[6], G8 (
n
= 110; 26.6%); P[8], G3 (
n
= 93; 22.5%); P[4], G8 (
n
= 31; 7.5%); P[8], G4 (
n
= 21; 5.1%); P[6], G3 (
n
= 12; 2.9%); P[6], G1 (
n
= 7; 1.7%); P[6], G9 (
n
= 3; 0.7%); P[6], G4 (
n
= 3; 0.7%); P[4], G3 (
n
= 1; 0.2%); and mixed (
n
= 15; 3.6%). While all strains could be assigned a G type, seven strains (1.7%) remained P nontypeable. The majority of serotype G8 strains and all serotype G9 strains had short electropherotype profiles. All remaining typeable strains had long electropherotypes. Divergent serotype G1 rotaviruses, which contained multiple base substitutions in the 9T-1 primer binding site, were commonly identified in the second year of surveillance. Serotype G2 was not identified. Overall, G8 was the most frequently identified VP7 serotype (
n
= 144; 34.8%) and P[8] was the most frequently detected VP4 genotype (
n
= 227; 54.8%). Partial sequence analysis of the VP4 gene of genotype P[8] rotaviruses identified three distinct clusters, which predominantly (but not exclusively) comprised strains belonging to a distinct VP7 serotype (G1, G3, or G4). As a result of mutations in the 1T-1 primer binding site, strains belonging to each cluster required a separate primer for efficient typing. One cluster, represented by P[8], G4 strain OP354, was highly divergent from the established Wa and F45 VP4 P[8] lineages. As is the case for some other countries, the diversity of rotaviruses in Malawi implies that rotavirus vaccines in development will need to protect against a wider panel of serotypes than originally envisioned.
Comparison of the E-test with the NCCLS M38-P Method for Antifungal Susceptibility Testing of Common and Emerging Pathogenic Filamentous Fungi
Authors: Espinel-Ingroff Ana 
Published: July 2002

ABSTRACT

The National Committee for Clinical Laboratory Standards (NCCLS) M38-P method describes standard parameters for testing the fungistatic antifungal activities (MICs) of established agents against filamentous fungi (molds). The present study evaluated the in vitro fungistatic activities of itraconazole and amphotericin B by the E-test and the NCCLS M38-P microdilution method against 186 common and emerging pathogenic molds (123 isolates of
Aspergillus
spp. [five species], 16 isolates of
Fusarium
spp. [two species], 4
Paecilomyces lilacinus
isolates, 5
Rhizopus arrhizus
isolates, 15
Scedosporium
spp., 18 dematiaceous fungi, and 5
Trichoderma longibrachiatum
isolates). The agreement between the methods for amphotericin B MICs ranged from 70% for
Fusarium solani
to ≥90% for most of the other species after the first reading; agreement was dependent on both the incubation time and the species being evaluated. Major discrepancies between the amphotericin B MICs determined by the E-test and the NCCLS M38-P method were demonstrated for three of the five species of
Aspergillus
tested and the two species of
Fusarium
tested. This discrepancy was more marked after 48 h of incubation; the geometric mean MICs determined by the E-test increased between 24 and 48 h from between 1.39 and 3.3 μg/ml to between 5.2 and >8 μg/ml for
Aspergillus flavus, Aspergillus fumigatus
, and
Aspergillus nidulans
. The agreement between the itraconazole MICs determined by the E-test and the NCCLS M38-P method ranged from 83.3% for
A. nidulans
to ≥90% for all the other species tested; the overall agreement was higher (92.7%) than that for amphotericin B (87.9%). The agreement was less dependent on the incubation time. Clinical trials need to be conducted to establish the role of the results of either the E-test or the NCCLS M38-P method in vitro for molds with the two agents as predictors of clinical outcome.
Detection of
Aspergillus
Species DNA by PCR in Bronchoalveolar Lavage Fluid
Authors: Hayette Marie-Pierre , Vaira Dolores , Susin Fabrice , Boland Pascal , Christiaens Geneviève , Melin Pierrette , De Mol Patrick 
Published: July 2002

ABSTRACT

The usefulness of a nested PCR assay for detection of
Aspergillus
sp. DNA was evaluated in 177 bronchoalveolar lavage (BAL) fluid specimens. This test was accurate both to diagnose culture-negative BAL fluid specimens from patients with invasive pulmonary aspergillosis and to confirm culture-positive samples. However, it did not differentiate between infection and colonization.
Potential Impact of the VITEK 2 System and the Advanced Expert System on the Clinical Laboratory of a University-Based Hospital
Authors: Sanders Christine C. , Peyret Michel , Moland Ellen Smith , Cavalieri Stephen J. , Shubert Carole , Thomson Kenneth S. , Boeufgras Jean-Marc , Sanders W. Eugene 
Published: July 2002

ABSTRACT

A study was designed to assess the impact of the VITEK 2 automated system and the Advanced Expert System (AES) on the clinical laboratory of a typical university-based hospital. A total of 259 consecutive, nonduplicate isolates of
Enterobacteriaceae
members,
Pseudomonas aeruginosa
, and
Staphylococcus aureus
were collected and tested by the VITEK 2 system for identification and antimicrobial susceptibility testing, and the results were analyzed by the AES. The results were also analyzed by a human expert and compared to the AES analyses. Among the 259 isolates included in this study, 245 (94.6%) were definitively identified by VITEK 2, requiring little input from laboratory staff. For 194 (74.9%) isolates, no inconsistencies between the identification of the strain and the antimicrobial susceptibility determined by VITEK 2 were detected by the AES. Thus, no input from laboratory staff was required for these strains. The AES suggested one or more corrections to results obtained with 65 strains to remove inconsistencies. The human expert thought that most of these corrections were appropriate and that some resulted from a failure of the VITEK 2 system to detect certain forms of resistance. Antimicrobial phenotypes assigned to the strains by the AES for β-lactams, aminoglycosides, quinolones, macrolides, tetracyclines, and glycopeptides were similar to those assigned by the human expert for 95.7 to 100% of strains. These results indicate that the VITEK 2 system and AES can provide accurate information in tests for most of the clinical isolates examined and remove the need for human analysis of results for many. Certain problems were identified in the study that should be remediable with further work on the software supporting the AES.
Prevalence of the Pandemic Genotype of
Vibrio parahaemolyticus
in Dhaka, Bangladesh, and Significance of Its Distribution across Different Serotypes
Authors: Bhuiyan N. A. , Ansaruzzaman M. , Kamruzzaman M. , Alam Khorshed , Chowdhury N. R. , Nishibuchi M. , Faruque Shah M. , Sack David A. , Takeda Yoshifumi , Nair G. Balakrish 
Published: July 2002

ABSTRACT

Sixty-six strains of
Vibrio parahaemolyticus
belonging to 14 serotypes were isolated from hospitalized patients in Dhaka, Bangladesh, from January 1998 to December 2000. Among these, 48 strains belonging to four serotypes had the pandemic genotype and possessed the
tdh
gene. A marker (open reading frame ORF8) for a filamentous phage previously thought to correspond to the pandemic genotype was found to have a poor correlation with the pandemic genotype.
Primary Meningoencephalitis by
Naegleria fowleri
: First Reported Case from Mangalore, South India
Authors: Shenoy Shalini , Wilson Godwin , Prashanth H. V. , Vidyalakshmi K. , Dhanashree B. , Bharath R. 
Published: July 2002

ABSTRACT

A fatal case of primary amebic meningoencephalitis (PAM) in a 5-month-old infant is described. The disease may have been contracted during bathing. The source of water was from an artificial well. The clinical presentation, the isolation of the ameba from the cerebrospinal fluid, the poor response to amphotericin B, and the ultimate fatal outcome are all consistent with the diagnosis of PAM. On the basis of its ability to grow at temperatures above 30°C, the morphology of the trophozoite, and the presence of flagellate forms, the ameba was identified as
Naegleria fowleri
. Pathogenic
N. fowleri
amebae were recovered from samples of water from the well. To our knowledge this case represents the second case of PAM in an infant in the absence of the history of swimming.
rpoB
Genotypes of
Mycobacterium tuberculosis
Beijing Family Isolates from East Asian Countries
Authors: Qian Lishi , Abe Chiyoji , Lin Tao-Ping , Yu Ming-Chih , Cho Sang-Nae , Wang Sumin , Douglas James T. 
Published: July 2002

ABSTRACT

The 81-bp region of the
rpoB
gene in 66 Rif
r
Mycobacterium tuberculosis
isolates from China, Japan, Korea, and Taiwan was analyzed. Twelve single-nucleotide substitutions in the
rpoB
gene were detected. The most prevalent mutations were at Ser-531 (52%), Asp-516 (17%), and His-526 (11%). Mutations were not found in seven (11%) of the isolates. Higher mutation rates in 50 Beijing family isolates were found than in other isolates for mutations at Asp-516 (18 and 12.5%, respectively) and His-526 (12 and 6.3%, respectively). The different rates of mutation may reflect the choice of rifamycin analogs.
Incidence of and Risk Factors for Symptomatic Visceral Leishmaniasis among Human Immunodeficiency Virus Type 1-Infected Patients from Spain in the Era of Highly Active Antiretroviral Therapy
Authors: de la Rosa Rafael , Pineda Juan A , Delgado Juan , Macías Juan , Morillas Francisco , Mira José A. , Sánchez-Quijano Armando , Leal Manuel , Lissen Eduardo 
Published: July 2002

ABSTRACTThe way in which the extensive use of highly active antiretroviral therapy (HAART) has influenced the incidence of visceral leishmaniasis (VL) among human immunodeficiency type 1 (HIV-1)-infected patients is not yet understood. The present study assessed whether the incidence of symptomatic VL in HIV-infected patients has decreased since the introduction of HAART. Likewise, the role of other potential risk factors for VL was also analyzed. Therefore, 479 HIV-1-infected patients receiving antiretroviral treatment, according to the available drugs at each moment, were prospectively followed from April 1989 to June 2000 in two university hospitals in southern Spain. A bone marrow aspiration was performed when patients showed symptoms suggestive of kala-azar. A diagnosis of VL was made whenLeishmaniaamastigotes were seen in Giemsa-stained samples or promastigotes were cultured in specific media. The median follow-up time was 1,380 [8 to 4,536] days. Twenty-one patients were diagnosed with symptomatic VL. The density of incidence of VL has decreased 64.8% as of January 1997, when HAART began to be used extensively in our area. The use of HAART was the main independent factor associated with VL; this therapy was a protective factor (adjusted hazard ratio [HR], 0.05; 95% confidence interval [CI], 0.02 to 0.15). CDC clinical category C at entry in the cohort (HR, 4.08; 95% CI, 1.46 to 11.35) and CD4+cell counts below 300 cells/mm3during the follow-up (HR, 3.96; 95% CI, 1.56 to 10.01) were also independently associated with kala-azar. A VL diagnosis prior to follow-up and low compliance with antiretroviral therapy were not independently associated with symptomatic VL, although statistical significance was almost reached (P= 0.1 andP= 0.08, respectively). In summary, the use of HAART has led to a fall in the incidence of symptomatic VL in HIV-infected patients. The main risk factor associated with kala-azar emergence in patients infected with HIV is deep immunosuppression.
Cloning of a Truncated
Babesia equi
Gene Encoding an 82-Kilodalton Protein and Its Potential Use in an Enzyme-Linked Immunosorbent Assay
Authors: Hirata Haruyuki , Ikadai Hiromi , Yokoyama Naoaki , Xuan Xuenan , Fujisaki Kozo , Suzuki Naoyoshi , Mikami Takeshi , Igarashi Ikuo 
Published: July 2002

ABSTRACT

To isolate
Babesia equi
genes encoding immunodominant proteins, a cDNA expression library prepared from
B. equi
mRNA was immunoscreened with
B. equi
-infected horse serum. Eighteen positive cDNA clones were obtained, and the clone that showed the strongest immunoreactivity, designated Be82, was further characterized. The Be82 gene consisted of 1,953 bp and contained a partial open reading frame lacking the 5′-terminal sequence. As shown by Western blot analyses, immune sera from mice intraperitoneally injected with the Be82 gene product recognized the 82- and 52-kDa proteins of
B. equi
but not those of
Babesia caballi
. The glutathione
S
-transferase fusion protein expressed in
Escherichia coli
that was purified and used as the antigen in the enzyme-linked immunosorbent assay reacted specifically with
B. equi
-infected horse sera. These results suggest that the Be82 gene product is a potential diagnostic antigen candidate in the detection of
B. equi
infection in horses that will be useful both in the performance of epidemiological studies and in the granting of quarantine passes.
Shiga Toxin-Producing
Escherichia coli
Infection and Antibodies against Stx2 and Stx1 in Household Contacts of Children with Enteropathic Hemolytic-Uremic Syndrome
Authors: Ludwig Kerstin , Sarkim Volkan , Bitzan Martin , Karmali Mohamed A. , Bobrowski Christoph , Ruder Hans , Laufs Rainer , Sobottka Ingo , Petric Martin , Karch Helge , Müller-Wiefel Dirk E. 
Published: July 2002

ABSTRACT

Ninety-five household contacts (aged 2 months to 73 years) of patients with enteropathic hemolytic-uremic syndrome (HUS) were investigated for the presence of immunoglobulin (Ig) G antibodies to Shiga toxins Stx2 and Stx1 by Western blot assay. Thirty-one percent of the household contacts and 19% of 327 controls had anti-Stx2 IgG (heavy and light chain [H + L]), 5 and 8%, respectively, had anti-Stx1 IgG (H + L), and 3 and 2%, respectively, had both anti-Stx2 and anti-Stx1 IgG (H + L). The incidence of infections with Stx-producing
Escherichia coli
(STEC) was determined based on the following diagnostic criteria: STEC isolation, detection of
stx
gene sequences, free fecal Stx in stool filtrates, and serum IgM antibodies against
E. coli
O157 lipopolysaccharide. Evidence of STEC infection was observed in 25 household contacts, of whom 18 (72%) were asymptomatic and represented a potential source of infection. Six of 13 (46%) household contacts with Stx2-producing
E. coli
O157:H7 in stool culture developed anti-Stx2 IgG (H + L), compared to 71% of Stx2-associated HUS cases. In individuals showing anti-Stx2 IgG (H + L), the antibody response was directed against the B subunit in 69% of household contacts and 71% of controls, in contrast to 28% of HUS patients. In this investigation controls had a significant increase of the median of IgM antibodies to O157 lipopolysaccharide (LPS) with age, up to the fifth decade. The lack of disease in household contacts with B subunit-specific antibodies, as well as the significantly higher median of anti-O157 LPS IgM antibodies in controls beyond 4.9 years of age, suggests a protective role for anti-Stx and anti-O157 LPS antibodies.
Correlation between the Elastase Activity Index and Invasiveness of Clinical Isolates ofAspergillus fumigatus
Authors: Blanco Jose L. , Hontecillas Raquel , Bouza Emilio , Blanco Isabel , Pelaez Teresa , Muñoz Patricia , Perez Molina Jose , Garcia Marta E. 
Published: July 2002

ABSTRACTWe calculated an elastase activity index (EAI) by dividing the diameter of the elastin lysis halo by the fungal growth diameter. After 10 days' incubation at 37°C, all strains but one obtained from invasive aspergillosis showed an EAI ≥ 1. Of the 18 strains obtained from colonized patients, only 4 (22.2%) had an EAI ≥ 1, whereas neither of the strains isolated from patients with fungus ball reached this value. Overall, 44 out of the 142 strains obtained from the environment had an EAI ≥ 1 (30.9%).
Evidence that the 5′-End Cap Structure Is Essential for Encapsidation of Hepatitis B Virus Pregenomic RNA
Authors: Jeong Jong-Keun , Yoon Gye-Soon , Ryu Wang-Shick 
Published: July 2002

ABSTRACT

Hepatitis B virus (HBV) replicates by reverse transcription of an RNA intermediate, the pregenomic RNA. The first step of HBV genome replication is the encapsidation of the pregenomic RNA encoding the encapsidation signal, termed ɛ, into the core particles, which is preceded by recognition and binding of HBV DNA polymerase to ɛ. The pregenomic RNA contains two identical ɛ elements due to its terminal redundancy: one near the 5′ end and another near the 3′ end. Despite the fact that both ɛ elements have an identical sequence, only the 5′ ɛ, but not the 3′ ɛ, is functional for encapsidation. To understand the molecular nature of this position effect, we made a series of
lacZ
RNA expression plasmids which contain the ɛ element at various positions from the 5′ end of the transcripts. Following transfection, the
lacZ
RNAs in cytoplasmic core particles were measured by RNase protection assay for encapsidation. The results indicated that the
lacZ
RNAs with ɛ positioned up to 65 nucleotides from the 5′ end were encapsidated, whereas the
lacZ
RNAs with ɛ positioned further downstream were not. Interestingly, the cap-free
lacZ
RNA transcribed by T7 RNA polymerase was not encapsidated, implying that the 5′ cap structure is required for encapsidation of the pregenomic RNA. We hypothesized that HBV DNA polymerase must somehow recognize the cap structure and/or its associated factors, as well as the 5′ ɛ, for encapsidation to occur.
Restricting Expression Prolongs Expression of Foreign Genes Introduced into Animals by Retroviruses
Authors: Pinto Valerian B. , Prasad Shiv , Yewdell Jonathan , Bennink Jack , Hughes Stephen H. 
Published: July 2002

ABSTRACTIf foreign genes are ubiquitously expressed in mice using a viral vector, expression is abrogated by CD8+cells in 2 to 4 weeks. However, if the expression of the genes is confined to skeletal muscle cells, the CD8+T-cell response is much weaker and expression is maintained for more than 6 weeks. These data show that restricting the expression of foreign genes to skeletal muscle cells and presumably to other cells that are inefficient at antigen presentation can prolong the expression of a foreign gene product.
HLA Class I-Restricted Cytotoxic T-Cell Epitopes of the Respiratory Syncytial Virus Fusion Protein
Authors: Brandenburg A. H. , de Waal L. , Timmerman H. H. , Hoogerhout P. , de Swart R. L. , Osterhaus A. D. M. E. 
Published: July 2002

ABSTRACTVirus-specific cytotoxic T lymphocytes (CTL) play a major role in the clearance of respiratory syncytial virus (RSV) infection. We have generated cytotoxic T-cell clones (TCC) from two infants who had just recovered from severe RSV infection. These TCC were functionally characterized and used to identify HLA class I (B57 and C12)-restricted CTL epitopes of RSV.
Epstein-Barr Virus That Lacks Glycoprotein gN Is Impaired in Assembly and Infection
Authors: Lake Cathleen M. , Hutt-Fletcher Lindsey M. 
Published: July 2002

ABSTRACT
The Epstein-Barr virus (EBV) glycoproteins N and M (gN and gM) are encoded by the BLRF1 and BBRF3 genes. To examine the function of the EBV gN-gM complex, recombinant virus was constructed in which the BLRF1 gene was interrupted with a neomycin resistance cassette. Recombinant virus lacked not only gN but also detectable gM. A significant proportion of the recombinant virus capsids remained associated with condensed chromatin in the nucleus of virus-producing cells, and cytoplasmic vesicles containing enveloped virus were scarce. Virus egress was impaired, and sedimentation analysis revealed that the majority of the virus that was released lacked a complete envelope. The small amount of virus that could bind to cells was also impaired in infectivity at a step following fusion. These data are consistent with the hypothesis that the predicted 78-amino-acid cytoplasmic tail of gM, which is highly charged and rich in prolines, interacts with the virion tegument. It is proposed that this interaction is important both for association of capsids with cell membrane to assemble and release enveloped particles and for dissociation of the capsid from the membrane of the newly infected cell on its way to the cell nucleus. The phenotype of EBV lacking the gN-gM complex is more striking than that of most alphaherpesviruses lacking the same complex but resembles in many respects the phenotype of pseudorabies virus lacking glycoproteins gM, gE, and gI. Since EBV does not encode homologs for gE and gI, this suggests that functions that may have some redundancy in alphaherpesviruses have been concentrated in fewer proteins in EBV.