bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of a Novel Hepatitis C Virus (HCV) Major-Epitope Chimeric Polypeptide for Diagnosis of HCV Infection
Authors: Chien David Y. , Arcangel Phillip , Medina-Selby Angelica , Coit Doris , Baumeister Mark , Nguyen Steve , George-Nascimento Carlos , Gyenes Alexander , Kuo George , Valenzuela Pablo 
Published: December 2019

ABSTRACT
The genome of hepatitis C virus (HCV) consists of seven functional regions: the core, E1, E2/NS1, NS2, NS3, NS4, and NS5 regions. The U.S. Food and Drug Administration-licensed 2.0G immunoassay for the detection of anti-HCV uses proteins from the core, NS3, and NS4 regions (McHutchinson et al., Hepatology 15:19–25, 1992). The 3.0G enzyme-linked immunosorbent assay includes the protein from the NS5 region (Uyttendaele et al., Vox Sang. 66:122–129, 1994). The necessity of detecting antibodies to viral envelope proteins (E1 and E2) and to different genotype samples has been demonstrated previously (Chien et al., Lancet 342:933, 1993; Lok et al., Hepatology 18:497–502, 1993). In this study we have attempted to improve the sensitivity of the anti-HCV assay by developing a single multiple-epitope fusion antigen (MEFA; MEFA-6) which incorporates all of the major immunodominant epitopes from the seven functional regions of the HCV genome. A nucleic acid sequence consisting of proteins from the viral core, E1, E2, NS3, NS4, and NS5 regions and different subtype-specific regions of the NS4 region was constructed, cloned, and expressed in yeast. The epitopes present on this antigen can be detected by epitope-specific monoclonal and polyclonal antibodies. In a competition assay, the MEFA-6 protein competed with 83 to 96% of genotype-specific antibodies from HCV genotype-specific peptides. This recombinant antigen was subsequently used to design an anti-HCV chemiluminescent immunoassay. We designed our assay using a monoclonal anti-human immunoglobulin G antibody bound to the solid phase. Because MEFA-6 is fused with human superoxide dismutase (h-SOD), we used an anti-human superoxide dismutase, dimethyl acridinium ester-labeled monoclonal antibody for detection. Our results indicate that MEFA-6 exposes all of the major immunogenic epitopes. Its excellent sensitivity and specificity for the detection of clinical seroconversion are demonstrated by this assay.
Postsurgical
Candida albicans
Infections Associated with an Extrinsically Contaminated Intravenous Anesthetic Agent
Authors: McNeil Michael M. , Lasker Brent A. , Lott Timothy J. , Jarvis William R. 
Published: December 2019

ABSTRACT

From 16 to 30 April 1990, four of 364 (1%) postsurgical patients at one hospital developed
Candida albicans
fungemia or endophthalmitis. The case patients’ surgeries were clustered on two days. To identify risk factors for
C. albicans
infections, we conducted a cohort study comparing these 4 patients with 67 control patients who had surgeries on the same days but did not acquire
C. albicans
infections. The participation of anesthesiologist 9 (relative risk [RR], undefined;
P < 0.001)
and receipt of intravenous propofol, an anesthetic agent without preservative, which was administered by an infusion pump (RR, 8.8;
P = 0.048)
were identified as risk factors for
C. albicans
infections. The anesthetic had been recently introduced in the hospital. Hand cultures of 8 of 14 (57%) anesthesiologists were positive for
Candida
species; one yielded
C. albicans
. Anesthesiologist 9 was the only one to use stored syringes of propofol in the infusion pump and to reuse propofol syringes. DNA fingerprinting with a digoxigenin-labeled
C. albicans
repetitive element 2 probe and electrophoretic karyotyping showed two distinct banding patterns among patient isolates. We hypothesize that extrinsic contamination of propofol by anesthesiologist 9 likely resulted in
C. albicans
infections. These data suggest that strict aseptic techniques must be used when preparing and administering propofol.
Multicenter Quality Assessment of PCR Methods for Detection of Enteroviruses
Authors: Muir Peter , Ras Albert , Klapper Paul E. , Cleator Graham M. , Korn Klaus , Aepinus Christian , Fomsgaard Anders , Palmer Pierre , Samuelsson Agneta , Tenorio Antonio , Weissbrich Benedikt , van Loon A. M. 
Published: December 2019

ABSTRACT

We conducted a multicenter evaluation of commercial and in-house PCR methods for the detection of enteroviruses. Three coded panels of test and control RNA samples, artificial clinical specimens, and representative enterovirus serotypes were used to assess amplification methods, RNA extraction methods, and reactivities with different enterovirus serotypes. Despite several differences between PCR methods, there was good agreement, although some variation in sensitivity was observed. Most PCR methods were able to detect enterovirus RNA derived from 0.01 50% tissue culture infective dose (TCID
50
) and were able to detect at least 1 TCID
50
of enterovirus in cerebrospinal fluid, stool, or throat swab specimens. Most were also able to detect a wide range of enterovirus serotypes, although serotypic identification was not possible. Some laboratories experienced false-positive results due to PCR contamination, which appeared to result mainly from cross-contamination of specimens during RNA extraction. Provided that this problem is overcome, these PCR methods will prove to be a sensitive and rapid alternative to cell culture for the diagnosis of enterovirus infection.
Clinical and Financial Benefits of Rapid Bacterial Identification and Antimicrobial Susceptibility Testing
Authors: Barenfanger Joan , Drake Cheryl , Kacich Gail 
Published: December 2019

ABSTRACT

To assess the expected clinical and financial benefits of rapid reporting of microbiology results, we compared patients whose cultured samples were processed in the normal manner to patients whose samples were processed more rapidly due to a minor change in work flow. For the samples tested in the rapid-reporting time period, the vast majority of bacterial identification and antimicrobial susceptibility testing (AST) results were verified with the Vitek system on the same day that they were available. This time period was called rapid AST (RAST). For RAST, a technologist on the evening shift verified the data that became available during that shift. For the control time period, cultures were processed in the normal manner (normal AST [NAST]), which did not include evening-shift verification. For NAST, the results for approximately half of the cultures were verified on the first day that the result was available. The average turnaround time for the reporting of AST results was 39.2 h for RAST and 44.4 h for NAST (5.2 h faster for RAST [
P
= 0.001]). Subsequently, physicians were able to initiate appropriate antimicrobial therapy sooner for patients whose samples were tested as part of RAST (
P
= 0.006). The mortality rates were 7.9 and 9.6% for patients whose samples were tested as part of RAST and NAST, respectively (
P
= 0.45). The average length of stay was 10.7 days per patient for RAST and 12.6 days for NAST, a difference of 2.0 days less for RAST (
P
= 0.006). The average variable cost was $4,927 per patient for RAST and $6,677 for NAST, a difference of $1,750 less per patient for RAST (
P
= 0.001). This results in over $4 million in savings in variable costs per year in our hospital.
Clinical Evaluation of the Enhanced Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test for Rapid Diagnosis of Tuberculosis in Prison Inmates
Authors: Bergmann John S. , Yuoh Gbo , Fish Geoffrey , Woods Gail L. 
Published: December 2019

ABSTRACT

The reliability of the enhanced Amplified Mycobacterium Tuberculosis Direct Test (E-MTD; Gen-Probe, Inc., San Diego, Calif.) for rapid diagnosis of pulmonary tuberculosis (TB) was evaluated by testing 1,004 respiratory specimens from 489 Texas prison inmates. Results were compared to those of mycobacterial culture (BACTEC TB 460 and Middlebrook 7H11 biplates), smear for acid-fast bacilli (AFB; auramine O), and clinical course. After chart review, three patients (nine specimens) who were on antituberculosis therapy before the study began were excluded from final analysis. Of the remaining 995 specimens, 21 were AFB smear positive: 13 grew
Mycobacterium tuberculosis
complex (MTBC), 6 grew nontuberculous mycobacteria, and 2 (from two patients diagnosed with TB and started on therapy after the study began) were culture negative. Twenty-eight specimens (20 patients) were positive for MTBC by culture and E-MTD. Seven specimens (seven patients) were positive by culture alone; three were from patients who had other E-MTD-positive specimens, two were false-positive cultures, and two were false-negative E-MTD results. Eight specimens were positive by E-MTD only; four specimens (four patients) were false-positive E-MTD results, and four specimens were from two patients with earlier E-MTD-positive specimens that grew MTBC. Thus, there were 22 patients with TB (10 smear positive and 12 smear negative). The sensitivity and specificity of the AFB smear for diagnosis of TB, by patient, were 45.5 and 98.9%, respectively. After resolving discrepancies, these same values for E-MTD were 90.9 and 99.1% overall, 100 and 100% for the smear-positive patients, and 83.3 and 99.1% for the smear-negative patients. Excluding the one smear-negative patient whose E-MTD-negative, MTBC culture-positive specimen contained inhibitory substances, the sensitivity of E-MTD was 95.2% overall and 90.9% in smear-negative patients. The specificity and positive predictive value of E-MTD can be improved, without altering other performance characteristics, by modifying the equivocal zone recommended by the manufacturer. These data suggest that E-MTD is a reliable method for rapid diagnosis of pulmonary TB, irrespective of the AFB smear result. Guidelines for the most appropriate use of E-MTD with smear-negative patients are needed.
Coaggregation of
Candida dubliniensis
with
Fusobacterium nucleatum
Authors: Jabra-Rizk Mary Ann , Falkler William A. , Merz William G. , Kelley Jacqueline I. , Baqui A. A. M. A. , Meiller Timothy F. 
Published: December 2019

ABSTRACT

The binding of microorganisms to each other and oral surfaces contributes to the progression of microbial infections in the oral cavity.
Candida dubliniensis
, a newly characterized species, has been identified in human immunodeficiency virus-seropositive patients and other immunocompromised individuals.
C. dubliniensis
phenotypically resembles
Candida albicans
in many respects yet can be identified and differentiated as a unique
Candida
species by phenotypic and genetic profiles. The purpose of this study was to determine oral coaggregation (CoAg) partners of
C. dubliniensis
and to compare these findings with CoAg of
C. albicans
under the same environmental conditions. Fifteen isolates of
C. dubliniensis
and 40 isolates of
C. albicans
were tested for their ability to coaggregate with strains of
Fusobacterium nucleatum
,
Peptostreptococcus micros
,
Peptostreptococcus magnus
,
Peptostreptococcus anaerobius
,
Porphyromonas gingivalis
, and
Prevotella intermedia
. When
C. dubliniensis
and
C. albicans
strains were grown at 37°C on Sabouraud dextrose agar, only
C. dubliniensis
strains coaggregated with
F. nucleatum
ATCC 49256 and no
C. albicans
strains showed CoAg. However, when the
C. dubliniensis
and
C. albicans
strains were grown at 25 or 45°C, both
C. dubliniensis
and
C. albicans
strains demonstrated CoAg with
F. nucleatum
. Heating the
C. albicans
strains (grown at 37°C) at 85°C for 30 min or treating them with dithiothreitol allowed the
C. albicans
strains grown at 37°C to coaggregate with
F. nucleatum
. CoAg at all growth temperatures was inhibited by mannose and α-methyl mannoside but not by EDTA or arginine. The CoAg reaction between
F. nucleatum
and the
Candida
species involved a heat-labile component on
F. nucleatum
and a mannan-containing heat-stable receptor on the
Candida
species. The CoAg reactions between
F. nucleatum
and the
Candida
species may be important in the colonization of the yeast in the oral cavity, and the CoAg of
C. dubliniensis
by
F. nucleatum
when grown at 37°C provides a rapid, specific, and inexpensive means to differentiate
C. dubliniensis
from
C. albicans
isolates in the clinical laboratory.
Detection of Unculturable Bacteria in Periodontal Health and Disease by PCR
Authors: Harper-Owen R. , Dymock D. , Booth V. , Weightman A. J. , Wade W. G. 
Published: December 2019

ABSTRACT

Recently developed molecular methods have made it possible to characterize mixed microflora in their entirety, including the substantial numbers of bacteria which do not grow on artificial culture media. In a previous study, molecular analysis of the microflora associated with acute oral infections resulted in the identification of three phylotypes, PUS3.42, PUS9.170, and PUS9.180, representing as-yet-uncultured organisms. The aim of this study was to design and validate specific PCR primers for these phylotypes and to determine their incidences in samples collected from healthy and diseased periodontal tissues. Two specific reverse primers were devised for each phylotype, and these were used in duplex PCRs with universal forward and reverse primers. All three phylotypes were detected in periodontal sites; PUS9.170, related to oral asaccharolytic
Eubacterium
spp., was significantly associated with disease. This study demonstrates the possibility of using unculturable, and therefore uncharacterized, organisms as markers of disease.
Western Immunoblot Analysis of the Antigens ofHaemobartonella feliswith Sera from Experimentally Infected Cats
Authors: Alleman A. Rick , Pate Melanie G. , Harvey John W. , Gaskin Jack M. , Barbet Anthony F. 
Published: December 2019

ABSTRACTCats were experimentally infected with a Florida isolate ofHaemobartonella felisin order to collect organisms and evaluate the immune response toH. felis. Cryopreserved organisms were thawed and injected intravenously into nonsplenectomized and splenectomized cats. Splenectomized animals were given 10 mg of methylprednisolone per ml at the time of inoculation. Blood films were evaluated daily for 1 week prior to infection and for up to 60 days postinfection (p.i.). Blood forH. felispurification was repeatedly collected from splenectomized animals at periods of peak parasitemias. Organisms were purified from infected blood by differential centrifugation, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and transferred to nitrocellulose membranes for immunoblot analysis. Serum was collected from nonsplenectomized animals prior to and for up to 60 days p.i. and was used on immunoblots to identify antigens. The combination of splenectomy and corticosteroid treatment resulted in marked, cyclic parasitemias without concurrent severe anemia, providing an opportunity to harvest organisms in a manner that was not lethal to the animals. Several antigens (150, 52, 47, 45, and 14 kDa) were identified. An antigen with a molecular mass of approximately 14 kDa appeared to be one of the most immunodominant and was consistently recognized by immune sera collected at various times during the course of infection. These data suggest that one or more of these antigens might be useful for the serologic diagnosis ofH. felisinfections in cats.
Membrane Filtration Test for Rapid Presumptive Differentiation of Four
Candida
Species
Authors: Bauters T. G. , Peleman R. , Moerman M. , Vermeersch H. , de Looze D. , Noens L. , Nelis H. J. 
Published: December 2019

ABSTRACT

A rapid enzymatic two-step test for the presumptive differentiation of four
Candida
species commonly occurring in various clinical samples is described. The technique involves membrane filtration of a liquid sample, followed by preincubation of the membrane filter on Sabouraud glucose agar supplemented with ticarcillin-clavulanic acid to yield microcolonies. In a separate assay step, parts of the filter are placed on absorbent pads impregnated with fluorogenic 4-methylumbelliferyl (4-MU) enzyme substrates (4-MU-
N
-acetyl-β-
d
-galactosaminide, 4-MU-phosphate, 4-MU-pyrophosphate, and 4-MU-β-
d
-galactoside) in combination with 0.1% digitonin acting as a membrane permeabilizer. The membrane filter in contact with the assay medium is incubated to allow cleavage of the enzyme substrate, resulting in fluorescent microcolonies under long-wavelength UV light. This approach, tested on 301 clinical samples, is able to presumptively differentiate
C. albicans
,
C. glabrata
,
C. krusei
, and
C. tropicalis
and to distinguish them from other
Candida
spp. in about 9 to 11 h. Overall agreement with the conventional methods of 94.4% (one
Candida
species present in the sample) to 83.8% (multiple
Candida
spp. present) was obtained. The false-negative rates with reference to identification by traditional methods were 1.3% (single species) and 3.8% (multiple species).
Evaluation of Recombinant Antigens for Serodiagnosis of Chagas’ Disease in South and Central America
Authors: Umezawa Eufrosina S. , Bastos Sueli F. , Camargo Mario E. , Yamauchi Luci M. , Santos Márcia R. , Gonzalez Antonio , Zingales Bianca , Levin Mariano J. , Sousa Octavio , Rangel-Aldao Rafael , da Silveira José Franco 
Published: December 2019

ABSTRACT

The commercially available diagnostic tests for Chagas’ disease employ whole extracts or semipurified fractions of
Trypanosoma cruzi
epimastigotes. Considerable variation in the reproducibility and reliability of these tests has been reported by different research laboratories, mainly due to cross-reactivity with other pathogens and standardization of the reagents. The use of recombinant antigens for the serodiagnosis of Chagas’ disease is recommended to increase the sensitivity and specificity of serological tests. Expressed in
Escherichia coli
, as fusion products with glutathione
S
-transferase, six
T. cruzi
recombinant antigens (H49, JL7, A13, B13, JL8, and 1F8) were evaluated in an enzyme-linked immunosorbent assay for Chagas’ disease. The study was carried out with a panel of 541 serum samples of chagasic and nonchagasic patients from nine countries of Latin America (Argentina, Bolivia, Brazil, Chile, Colombia, El Salvador, Guatemala, Honduras, and Venezuela). The optimal concentration of each recombinant antigen for coating of plates was determined with the help of
125
I-labelled recombinant proteins. While the specificity of the epimastigote antigen was 84% because of false positives from leishmaniasis cases, for the recombinant antigens it varied from 96.2 to 99.6%. Recombinant antigens reacted with 79 to 100% of serum samples from chronic chagasic patients. In this way, it is proposed that a mixture of a few
T. cruzi
recombinant antigens should be employed in a diagnostic kit to minimize individual variation and promote high sensitivity in the diagnosis of Chagas’ disease.
Visualization of Hydatid Elements: Comparison of Several Techniques
Authors: Clavel A. , Varea M. , Doiz O. , López L. , Quílez J. , Castillo F. J. , Rubio C. , Gómez-Lus R. 
Published: December 2019

ABSTRACT

Some techniques available at our laboratory were tested for their ability to aid in the morphological diagnosis of hydatid elements (
Echinococcus granulosus
[“
Taenia echinococcus
”]) isolated from cysts in humans and sheep. Unstained, methanol-fixed hooklets were fluorescent, most starkly so under violet light (excitation filter wavelength, 405 nm; long-pass filter wavelength, 495 nm). Auramine-rhodamine and Gram procedures failed to stain hooklets. Ziehl-Neelsen stain yielded indifferent results when organisms were viewed under transmitted light but resulted in a surprisingly intense red fluorescence when organisms were viewed under green light (excitation, 546 nm; long pass, 590 nm). Wheatley trichrome stain gave better and more uniform results than fuchsin. Ryan trichrome blue stain was the best under transmitted light; hooklets stained uniformly and intensely and were easily distinguishable from the background. Very satisfactory results were also obtained with a much simpler procedure (modified Baxby technique: no fixation, steaming hot 1% safranin for 2 min, and malachite green for 30 s). Therefore, Ryan and modified Baxby stains are recommended for the examination of
E. granulosus
under transmitted light. For fluorescence microscopy, Ziehl-Neelsen stain under green excitation light, or violet light with no staining, is also very useful. Epifluorescence microscopy is especially convenient for examining samples concentrated by filtration, as it renders the filter pores inconspicuous.
Virulence Factors and Phenotypical Traits of Verotoxin-Producing
Escherichia coli
Strains Isolated from Asymptomatic Human Carriers
Authors: Stephan R. , Untermann F. 
Published: December 2019

ABSTRACT

Fourteen verotoxin-producing
Escherichia coli
strains isolated from stool samples of 14 different asymptomatic human carriers were further characterized. A variety of serotypes was found, but none of the strains belonged to serogroup O157. Only one isolate carried most of the virulence genes that are associated with increased pathogenicity.
Microbiological Characteristics of Yeasts Isolated from Urinary Tracts of Intensive Care Unit Patients Undergoing Urinary Catheterization
Authors: Febré N. , Silva V. , Medeiros E. A. S. , Wey S. B. , Colombo A. L. , Fischman O. 
Published: December 2019

ABSTRACTWe studied 70 intensive care unit patients to determine the incidence of nosocomial candiduria associated with indwelling urinary catheters and to assess microbiological characteristics of the yeasts. The yeasts were isolated, 13 of 17 in urine cultures and 4 of 17 in blood cultures, and colonization had occurred 3 days after the insertion of indwelling urinary catheters. For four strains the MICs of the antifungal drugs were high.
Comparison of Human Immunodeficiency Virus Type 1 (HIV-1) Protease Mutations in HIV-1 Genomes Detected in Plasma and in Peripheral Blood Mononuclear Cells from Patients Receiving Combination Drug Therapy
Authors: Koch Nathalie , Yahi Nouara , Ariasi Franck , Fantini Jacques , Tamalet Catherine 
Published: December 2019

ABSTRACT
Detections of mutations in the protease gene of human immunodeficiency virus type 1 in plasma and peripheral blood mononuclear cells (PBMC) were sought in two matched populations of 23 individuals receiving combination drug therapy with or without protease inhibitors. In the control group (23 patients not receiving protease inhibitors), no primary resistance mutations were found. In contrast, primary resistance mutations (especially at codons M46, V82, and L90) were found in 16 of 23 patients (70%) treated with protease inhibitors. In 30% of the cases, these mutations were detected in plasma but not in PBMC.
Detection of Caprine Herpesvirus 1 in Sacral Ganglia of Latently Infected Goats by PCR
Authors: Tempesta Maria , Pratelli Annamaria , Greco Grazia , Martella Vito , Buonavoglia Canio 
Published: December 2019

ABSTRACTA study of the latency of caprine herpesvirus 1 (CpHV.1) was carried out with four latently infected goats. Three goats were treated with dexamethasone and euthanized after 4 and 6 days. PCR and virus isolation allowed us to detect CpHV.1 only in the third and fourth sacral ganglia of the two animals euthanized 6 days after the start of treatment.
Evaluation of the MRL Diagnostics Dengue Fever Virus IgM Capture ELISA and the PanBio Rapid Immunochromatographic Test for Diagnosis of Dengue Fever in Jamaica
Authors: Palmer Carol J. , King S. Dorothy , Cuadrado Raul R. , Perez Eddy , Baum Mariana , Ager Arba L. 
Published: December 2019

ABSTRACT
We evaluated two new commercial dengue diagnostic tests, the MRL Diagnostics Dengue Fever Virus IgM Capture ELISA and the PanBio Rapid Immunochromatographic Test, on serum samples collected during a dengue epidemic in Jamaica. The MRL ELISA method correctly identified 98% (78 of 80) of the samples as dengue positive, while the PanBio test identified 100% (80 of 80). Both tests were 100% (20 samples of 20) specific.