bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Neuraminidase Enzyme Assays Using Different Substrates To Measure Susceptibility of Influenza Virus Clinical Isolates to Neuraminidase Inhibitors: Report of the Neuraminidase Inhibitor Susceptibility Network
Authors: Wetherall N. T. , Trivedi T. , Zeller J. , Hodges-Savola C. , McKimm-Breschkin J. L. , Zambon M. , Hayden F. G. 
Published: February 2003

ABSTRACT

The increasing use of influenza virus neuraminidase (NA) inhibitors (NIs) necessitates the development of reliable methods for assessing the NI susceptibility of clinical isolates. We evaluated three NA inhibition assays against a panel of five clinical isolates each of influenza virus A/H1N1, A/H3N2, and B strains and four viruses with a defined resistance genotype (R292K, H274Y, R152K, and E119V). For fluorometric enzyme assay (FA) 1 (FA-1), 2′-(4-methylumbelliferyl)-α-
d
-
N
-acetylneuraminic acid (MUNANA) at 100 μM was used as the substrate, with pretitration of the virus input. For FA-2, MUNANA at 200 μM was used as the substrate, with a fixed 1:10 dilution of input virus. For the chemiluminescence (CL) assay, the 1,2-dioxetane derivative of sialic acid at 100 μM was used as the substrate, with pretitration of the virus. Four different operators repeated the assays several times in a blinded fashion with both zanamivir and oseltamivir carboxylate (GS4071) to determine intra- and interassay variations. Mean 50% inhibitory concentration (IC
50
) values were lower and generally less variable with the CL assay. FA-1 displayed greater variation than the CL assay or FA-2 and the highest IC
50
values with zanamivir; FA-2 showed the highest values with oseltamivir, particularly for influenza virus B, and was more variable with zanamivir than was the CL assay. All three assays detected 40-fold or greater changes in IC
50
values for the resistant viruses with at least one drug. Mixing experiments, whereby increasing fractions (0, 20, 40, 60, 80, and 100%) of NA from a known NI-resistant virus were mixed with the corresponding NI-sensitive parental NA, indicated that the resolution of IC
50
values was clearer with the CL assay than with FA-2 for two of the resistant variants (R152K and E119V). The FA and CL methods were reliable for the detection of NI resistance, but all assays have certain limitations. Based on reproducibility, ease of automation, time required for the assay, and greater sensitivity, the CL assay was selected for future susceptibility testing of influenza virus isolates circulating globally.
Molecular Fingerprinting of Fish-Pathogenic
Lactococcus garvieae
Strains by Random Amplified Polymorphic DNA Analysis
Authors: Ravelo Carmen , Magariños Beatriz , López-Romalde Sonia , Toranzo Alicia E. , Romalde Jesús L. 
Published: February 2003

ABSTRACT

In this work, we used the random amplified polymorphic DNA (RAPD) technique to evaluate the genetic diversity in
Lactococcus garvieae
, an important pathogen for fish. Fifty-seven strains with different hosts and geographical origins, including Japan and several countries of the Mediterranean area such as Spain, Portugal, France, Italy, England, and Turkey, were analyzed. Two primers, oligonucleotides 5 and 6 (Pharmacia Biotech) were utilized; primer 5 was the most discriminative, since allowed us to differentiate 10 RAPD -types related to the origin of the strains. Regardless of the oligonucleotide primer employed, the 57 isolates of
L. garvieae
studied were separated into three genetic groups, composed of the Spanish, Portuguese, English, and Turkish strains (group A), the Italian and French strains (group B), and the Japanese strains (group C). The similarity of isolates within each group, estimated on the basis of the Dice coefficient, ranged from 75 to 100%. Our findings also indicate that RAPD profiling constitutes a useful tool for epidemiological studies of this fish pathogen.
Occurrence of Extended-Spectrum and AmpC Beta-Lactamases in Bloodstream Isolates of
Klebsiella pneumoniae:
Isolates Harbor Plasmid-Mediated FOX-5 and ACT-1 AmpC Beta-Lactamases
Authors: Coudron Philip E. , Hanson Nancy D. , Climo Michael W. 
Published: February 2003

ABSTRACT

We tested 190
Klebsiella pneumoniae
bloodstream isolates recovered from 189 patients in 30 U.S. hospitals in 23 states to determine the occurrence of extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase producers. Based on growth inhibition by clavulanic acid by disk and MIC test methods, 18 (9.5%) of the isolates produced ESBLs. Although the disk diffusion method with standard breakpoints identified 28 cefoxitin-nonsusceptible isolates, only 5 (18%) of these were confirmed as AmpC producers. Of two AmpC confirmatory tests, the three-dimensional extract test was easier to perform than was the double-disk approximation test using a novel inhibitor, Syn2190. Three of the five AmpC producers carried the
bla
FOX-5
gene, while the other two isolates harbored the
bla
ACT-1
gene. All AmpC genes were transferable. In vitro susceptibility testing with standard inocula showed that all five AmpC-producing strains were susceptible to cefepime, imipenem, and ertapenem but that with a high inoculum, more of these strains were susceptible to the carbapenems than to cefepime. All but 1 of 14 screen-positive AmpC nonproducers (and ESBL nonproducers) were susceptible to ceftriaxone and cefepime at the standard inoculum as were 6 of 6 isolates that were randomly selected and tested with a high inoculum. These results indicate that (i) a significant number of
K. pneumoniae
bloodstream isolates harbor ESBL or AmpC β-lactamases, (ii) confirmatory tests are necessary to identify true AmpC producers, and (iii) in vitro, carbapenems are active against AmpC-producing strains of
K. pneumoniae
.
Apophysomyces elegans
: an Emerging Zygomycete in India
Authors: Chakrabarti A. , Ghosh A. , Prasad G. S. , David J. K. , Gupta S. , Das A. , Sakhuja V. , Panda N. K. , Singh S. K. , Das S. , Chakrabarti T. 
Published: February 2003

ABSTRACT

Apophysomyces elegans
was considered a rare but medically important zygomycete. We analyzed the clinical records of eight patients from a single center in whom zygomycosis due to
A. elegans
was diagnosed over a span of 25 months. We also attempted a DNA-based method for rapid identification of the fungi and looked for interstrain polymorphism using microsattelite primers. Three patients had cutaneous and subcutaneous infections, three had isolated renal involvement, one had rhino-orbital tissue infection, and the final patient had a disseminated infection involving the spleen and kidney. Underlying illnesses were found in two patients, one with diabetes mellitus and the other with chronic alcoholism. A history of traumatic implantation was available for three patients. All except two of the patients responded to surgical and/or medical therapy; the diagnosis for the two exceptions was made at the terminal stage of infection. Restriction enzyme (
Mbo
I,
Msp
I,
Hin
fI) digestion of the PCR-amplified internal transcribed spacer region helped with the rapid and specific identification of
A. elegans
. The strains could be divided into two groups according to their patterns, with clustering into one pattern obtained by using microsatellite [(GTG)
5
and (GAC)
5
] PCR fingerprinting. The study highlights the epidemiology, clinical spectrum, and diagnosis of emerging
A. elegans
infections.
Use of Multienzyme Multiplex PCR Amplified Fragment Length Polymorphism Typing in Analysis of Outbreaks of Multiresistant
Klebsiella pneumoniae
in an Intensive Care Unit
Authors: van der Zee Anneke , Steer Niels , Thijssen Eveline , Nelson Jolande , van't Veen Annemarie , Buiting Anton 
Published: February 2003

ABSTRACT

We developed and optimized a new modified amplified fragment length polymorphism (AFLP) typing method to obtain a multibanding fingerprint that can be separated by agarose gel electrophoresis. Both to maximize the discriminatory power and to facilitate the computer-assisted analysis, bacterial DNA was digested with four different restriction enzymes. After ligation of adaptors to the DNA fragments, PCR testing of various single primers was performed. Two single primers that gave optimal results with regard to band resolution and discriminatory power were selected and combined. The computer-assisted analysis of fingerprint patterns was performed with Pearson's product-moment correlation values of densitometric curves, without assigning bands to peaks. Thus, the analysis is not subject to human interpretation errors. With this method, we investigated two outbreaks of multiresistant
Klebsiella pneumoniae
in an intensive care unit and various sporadic isolates of
K. pneumoniae
and
Klebsiella oxytoca.
Cluster analysis of isolates analyzed in different experiments and on different gels showed that fingerprint patterns clustered correctly according to subspecies or to the outbreaks. Multienzyme multiplex PCR AFLP revealed that the first outbreak was caused by two different types of strains. Outbreak two was caused by yet another strain of
K. pneumoniae
. In conclusion, the typing method used here is easy to perform and highly reproducible, and due to generation of complex banding patterns, it has a higher discriminatory power. Furthermore, the multienzyme multiplex PCR fingerprints are easy to analyze, and a reliable database can be stored in the computer to facilitate comparison of future isolates of
Klebsiella
spp. The method can be performed in every clinical microbiology laboratory.
Rapid Detection of Adenovirus in Throat Swab Specimens by PCR during Respiratory Disease Outbreaks among Military Recruits
Authors: Echavarria Marcela , Sanchez Jose L. , Kolavic-Gray Shellie A. , Polyak Christina S. , Mitchell-Raymundo Felicia , Innis Bruce L. , Vaughn David , Reynolds Richard , Binn Leonard N. 
Published: February 2003

ABSTRACT

We evaluated the performance of a generic PCR test to detect adenoviruses (AdV) in throat swab specimens collected from asymptomatic and ill military recruits with acute respiratory disease. Samples (
n
= 210) were collected at entry to basic training and at the time of large outbreaks of AdV-associated acute respiratory disease among military recruits at Fort Jackson, South Carolina, from 1997 to 1998. Compared to cell culture, a sensitivity of 99% and a specificity of 98% were noted for the PCR method to detect AdV in throat swabs. Similar results were obtained with or without DNA extraction, suggesting the absence of significant inhibitors for the PCR method in throat swab samples. No AdV was detected by culture or PCR in throat swabs from healthy recruits, suggesting the absence of latency or asymptomatic shedding. Throat swab specimens proved to be adequate, noninvasive samples to rapidly diagnose respiratory disease in young adults. This generic direct PCR proved to be a useful test for the rapid diagnosis of AdV-associated respiratory disease, detecting all serotypes tested to date and furnishing results within 6 h of specimen arrival. The use of this direct, rapid, sensitive, and specific assay would assist health care providers and public health practitioners in the early diagnosis, management, and control of AdV-associated respiratory disease.
Detection of
Helicobacter pylori
in Paraffin-Embedded and in Shock-Frozen Gastric Biopsy Samples by Fluorescent In Situ Hybridization
Authors: Rüssmann Holger , Feydt-Schmidt Anne , Adler Kristin , Aust Daniela , Fischer Almuth , Koletzko Sibylle 
Published: February 2003

ABSTRACT

We report on the successful application of fluorescent in situ hybridization for detection of
Helicobacter pylori
and determination of its clarithromycin susceptibility in formalin-fixed and paraffin-embedded gastric biopsy specimens that had been prepared for pathological examination. This method is useful when results from conventional culturing with antibiotic susceptibility testing are not available.
Detection of
Candida albicans
mRNA from Formalin-Fixed, Paraffin-Embedded Mouse Tissues by Nested Reverse Transcription-PCR
Authors: Schofield David A. , Westwater Caroline , Paulling Emily E. , Nicholas Peter J. , Balish Edward 
Published: February 2003

ABSTRACT

Histopathology archives represent a vast source of infectious disease specimens that can be used to elucidate important disease processes. In this report, we describe a method to detect
Candida albicans
gene expression from infected, formalin-fixed, paraffin-embedded mouse tissue. By use of glass beads to break open the fungal cells and proteinase K treatment, RNA was extracted routinely from tissue sections that had been fixed for up to 72 h. Upon reverse transcription of the RNA and nested PCR, the procedure detected
C. albicans
“housekeeping” and putative virulence genes.
Clinical Utility of Urinary Antigen Detection for Diagnosis of Community-Acquired, Travel-Associated, and Nosocomial Legionnaires' Disease
Authors: Helbig Jürgen H. , Uldum Søren A. , Bernander Sverker , Lück Paul Christian , Wewalka Günther , Abraham Bill , Gaia Valeria , Harrison Timothy G. 
Published: February 2003

ABSTRACT

The clinical utility of
Legionella
urinary antigen assays for the diagnosis of Legionnaires' disease was assessed by using samples from 317 culture-proven cases. The sensitivities of the Binax enzyme immunoassay (EIA) and Biotest EIA were found to be 93.7 and 94.4% for travel-associated infection and 86.5 and 76.0% for community-acquired infection but only 44.2 and 45.7% for nosocomially acquired infection, respectively.
Phylogeny of the Genus
Nocardia
Based on Reassessed 16S rRNA Gene Sequences Reveals Underspeciation and Division of Strains Classified as
Nocardia asteroides
into Three Established Species and Two Unnamed Taxons
Authors: Roth Andreas , Andrees Sebastian , Kroppenstedt Reiner M. , Harmsen Dag , Mauch Harald 
Published: February 2003

ABSTRACT

Conventional identification of
Nocardia
in the routine laboratory remains problematic due to a paucity of reliable phenotypic tests and due to the yet-unresolved taxonomy of strains classified as belonging to the species
Nocardia asteroides
, which comprises the type strain and isolates with drug pattern types II and VI. The 16S rRNA gene of 74 representative strains of the genus
Nocardia
, encompassing 25 established species, was sequenced in order to provide a molecular basis for accurate species identification and with the aim of reassessing the phylogeny of taxons assigned to the species
N. asteroides
. The result of this phylogenetic analysis confirms that the interspecies heterogeneity of closely related nocardial species can be considerably low (a sequence divergence of only 0.5% was found between
N. paucivorans
and
N. brevicatena
). We observed a sequence microheterogeneity (sequence divergence of fewer than five bases) in 8 of 11 species of which more than one strain in the species was studied. At least 10 taxons were found that merit description as new species. Strains previously classified as
N. asteroides
fell into five distinct phylogenetic groups: the type strain cluster (
N. asteroides
sensu strictu),
N. abscessus
,
N. cyriacigeorgica
, and two clusters closely related to
N. carnea
or
N. flavorosea
. The strains within the latter two groups probably represent new species, pending further genetic and phenotypic evaluation. Restricted phenotypic data revealed that
N. abscessus
,
N. cyriacigeorgica
, and the two
Nocardia
species taxons are equivalent to drug patterns I, VI, and II, respectively. In the future, these data will help in finding species-specific markers after adoption of a more precise nomenclature for isolates closely related to
N. asteroides
and unravel confusing phenotypic data obtained in the past for unresolved groups of strains that definitely belong to separate taxons from a phylogenetic point of view.
Novel Observation of Hot-Cold-Hot Hemolysis Exhibited by Group B Streptococci
Authors: Okazaki Norio , Osawa Ro , Suzuki Rieko , Nikkawa Takayasu , Whiley Robert A. 
Published: February 2003

ABSTRACT
Six human isolates of group B streptococci (GBS) were cultured on blood agar anaerobically at 37°C for 18 h and then at 4°C for 6 h and reincubated anaerobically at 37°C for 6 h. Three of the strains showed a marked enlargement of the hemolysis zone compared with that obtained after hot-only (37°C for 18 h) or hot-cold (37°C for 18 h and then 4°C for 6 h) treatment. Subsequent broth culture experiments revealed that enhanced hemolytic activity due to hot-cold-hot treatment was observed in all 6 GBS strains when cultured in the presence of starch.
Value of Indirect Hemagglutination and Coagglutination Tests for SerotypingHaemophilus parasuis
Authors: Del Río M. L. , Gutiérrez C.B. , Rodríguez Ferri E. F. 
Published: February 2003

ABSTRACTAn indirect hemagglutination test (IHA) and a coagglutination test (CA) were evaluated using saline, boiled, and autoclaved extracts for serotypingHaemophilus parasuis. CA showed several cross-reactions, whereas IHA gave rise to specific reactions, with minor exceptions. IHA was further compared with the immunodiffusion test (the “gold standard”) for the serotyping of 67 field isolates. As a conclusion, IHA is recommended as a useful method for sensitive and specific serotyping ofH. parasuis.
Molecular Typing of
Clostridium perfringens
from a Food-Borne Disease Outbreak in a Nursing Home: Ribotyping versus Pulsed-Field Gel Electrophoresis
Authors: Schalch Barbara , Bader Lutz , Schau Hans-Peter , Bergmann Rolf , Rometsch Andrea , Maydl Gertraud , Keßler Silvia 
Published: February 2003

ABSTRACT

In 1998, 21 inhabitants of a German nursing home fell ill with acute gastroenteritis after consumption of minced beef heart (P. Graf and L. Bader, Epidemiol. Bull. 41:327-329, 2000). Two residents died during hospital treatment. Seventeen
Clostridium perfringens
strains were collected from two different dishes and from patients' stool samples and autopsy materials. A majority of these isolates was not typeable by restriction fragment length polymorphism-pulsed-field gel electrophoresis (PFGE). Subsequent ribotyping of
C. perfringens
distinguished four different groups. The same ribopattern was detected in a minced beef heart dish, in autopsy material from the two deceased patients, and additionally in stool samples from six further residents who had fallen ill with diarrhea. Three further ribopatterns from food and autopsy materials could be differentiated. As chromosomal macrorestriction with subsequent PFGE is generally regarded more useful than ribotyping for molecular strain analysis, four selected isolates were lysed in parallel with a standard protocol and two nucleases inhibiting modifications. Neither of these methods could differentiate all of the isolates. These results suggest that PFGE with the current standard protocols is not able to characterize all
C. perfringens
isolates from food-borne disease investigations and that ribotyping is still a helpful method for molecular identification of clonal relationships.
Identification and Quantification of Ovine Gammaherpesvirus 2 DNA in Fresh and Stored Tissues of Pigs with Symptoms of Porcine Malignant Catarrhal Fever
Authors: Albini Sarah , Zimmermann Werner , Neff Felix , Ehlers Bernhard , Häni Hansjürg , Li Hong , Hüssy Daniela , Engels Monika , Ackermann Mathias 
Published: February 2003

ABSTRACT
Cases of porcine malignant catarrhal fever were analyzed by a combination of identification and quantitation of ovine gammaherpesvirus 2 DNA in a variety of paraffin-embedded tissues from diseased pigs, serology, and exclusion of primary porcine gammaherpesviruses. In spite of reduced signal due to fixation and paraffin embedding, ovine gammaherpesvirus 2 DNA in pig brains exceeded the amounts found in sheep brains by orders of magnitude.
Nocardia africana
Isolated from a Feline Mycetoma
Authors: Hattori Yousuke , Kano Rui , Kunitani Yasuko , Yanai Tokuma , Hasegawa Atsuhiko 
Published: February 2003

ABSTRACT

Nocardia africana
was isolated from a subcutaneous nodule of a cat. The isolate developed orange, wrinkled colonies. The bacteria were rod shaped to coccoid (1 by 5 μm) and gram positive. Analysis of the 16S ribosomal DNAs of the isolate and a reference strain of
N. africana
showed 100% homology.
Costs and Caregiver Consequences of Early Supported Discharge for Stroke Patients
Authors: Teng Josephine , Mayo Nancy E. , Latimer Eric , Hanley Jim , Wood-Dauphinee Sharon , Côté Robert , Scott Susan 
Published: February 2003

Background and Purpose—Early supported discharge (ESD) for stroke has been shown to yield outcomes similar to or better than those of conventional care, but there is less information on the impact on costs and on the caregiver. The purpose of this study is to estimate the costs associated with an ESD program compared with those of usual care.Methods—We conducted a randomized controlled trial of stroke patients who required rehabilitation services and who had a caregiver at home.Results—Acute-care costs incurred before randomization when patients were medically ready for discharge averaged $3251 per person. The costs for the balance of the acute-care stay, from randomization to discharge, were $1383 for the home group and $2220 for the usual care group. The average cost of providing the 4-week home intervention service was $943 per person. The total cost generated by persons assigned to the home group averaged $7784 per person, significantly lower than the $11 065 per person for those assigned to usual care. A large proportion of the cost differential between the 2 groups arose from readmissions, for which the usual care group generated costs more than quadruple those of the home intervention group.Conclusions—Providing care at home was no more (or less) expensive for those with greater functional limitation than for those with less. Caregivers in the ESD group scored consistently lower on the Burden Index than caregivers with usual care, even caregivers of persons with major functional limitations. For persons recovering from stroke and their families, ESD provides a cost-effective alternative to usual care.
Safety of Dexamphetamine in Acute Ischemic Stroke
Authors: Martinsson Louise , Wahlgren Nils Gunnar 
Published: February 2003

Background and Purpose—Amphetamine is reported to enhance recovery after experimental stroke, but results from the first few trials in humans are inconclusive. Limited information is available on treatment safety. This study intended to investigate the safety and tolerability of dexamphetamine in patients with acute cerebral ischemia.Methods—Forty-five patients with cerebral ischemia were enrolled within 72 hours after onset of symptoms. Patients were randomized to 1 of 3 dose levels (2.5, 5, or 10 mg orally twice daily) or placebo for 5 consecutive days. Adverse events, blood pressure, heart rate, body temperature, consciousness level, and functional outcome measures were followed up daily during treatment. Follow-ups were made at day 7 and 1 and 3 months after stroke.Results—Mean systolic and diastolic blood pressures and heart rate increased 14 mm Hg, 8 mm Hg, and 9 bpm, respectively, with dexamphetamine treatment compared with placebo (P≤0.01). There was no difference between dexamphetamine and placebo regarding adverse events, body temperature, or consciousness level. During treatment, there was a benefit of dexamphetamine in neurological and functional outcome (P<0.05), but differences were not maintained at follow-up.Conclusions—Overall, dexamphetamine was safe and well tolerated by patients with acute cerebral ischemia, but blood pressure and heart rate increased during treatment in comparison to placebo. These observations may be important in the future planning of amphetamine trials because changes in these variables have been observed to interfere with clinical outcome. The suggestions of improvement in outcome must be confirmed in further studies.