bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluconazole Susceptibilities of Bloodstream
Candida
sp. Isolates as Determined by National Committee for Clinical Laboratory Standards Method M27-A and Two Other Methods
Authors: Cantón Emilia , Pemán Javier , Carrillo-Muñoz Alfonso , Orero Ana , Ubeda Pedro , Viudes Angel , Gobernado Miguel 
Published: December 2019

ABSTRACT

The in vitro activity of fluconazole against 143
Candida
spp. obtained from the bloodstreams of 143 hospitalized patients from 1995 to 1997 was studied. Susceptibility tests were carried out by two macrodilution methods, the M27-A and a modified M27-A method (0.165 M, pH 7/morpholinepropanesulfonic acid-buffered RPMI 1640 medium supplemented with 20 g of
d
-dextrose per liter), and by the agar diffusion method (with 15-μg fluconazole [Neo-Sensitab] tablets). With 2 μg of fluconazole per ml, 96.92% of 65
C. albicans
isolates, 86.2% of 58
C. parapsilosis
isolates 7 of 8
C. tropicalis
isolates, and 1 of 6
C. glabrata
isolates were inhibited. Only one strain of
C. albicans
and one strain of
C. tropicalis
were resistant. The agreement between the two macrodilution methods was greater than 90% within ±2 log
2
dilutions for all strains except
C. glabrata
(83.3%) and
C. tropicalis
(87.5%). Generally, MICs were 1 log
2
dilution lower in glucose-supplemented RPMI 1640 medium. No correlation between zone sizes and MICs was found. All strains susceptible by the diffusion test were susceptible by the dilution method, but the converse was not necessarily true. Interestingly, inhibition zones were smaller for
C. albicans
, for which the geometric mean MIC was 0.29 μg/ml and the mean inhibition zone diameter was 25.7 mm, while for
C. parapsilosis
the geometric mean MIC was 0.96 μg/ml and the mean inhibition zone diameter was 31.52 mm. In conclusion, the two macrodilution methods give similar results. The modified M27-A method with 2% dextrose has the advantage of shortening the incubation time and simplifying the endpoint determination.
Validity of Interpretation Criteria for Standardized Western Blots (Immunoblots) for Serodiagnosis of Lyme Borreliosis Based on Sera Collected throughout Europe
Authors: Hauser Ulrike , Lehnert Gisela , Wilske Bettina 
Published: December 2019

ABSTRACTWestern blotting (WB; immunoblotting) is a widely used tool for the serodiagnosis of Lyme borreliosis (LB), but so far, no generally accepted criteria for performance and interpretation have been established in Europe. The current study was preceeded by a detailed analysis of WB with whole-cell lysates of three species ofBorrelia burgdorferisensu lato (U. Hauser, G. Lehnert, R. Lobentanzer, and B. Wilske, J. Clin. Microbiol. 35:1433–1444, 1997). In that study, interpretation criteria for a positive WB result were developed with the data for 330 serum samples (from patients with LB in different stages [n= 189] and from a control group [n= 141]) originating mostly from southern Germany. In the present work, the interpretation criteria for strains PKo (Borrelia afzelii) and PBi (Borrelia garinii) developed in the previous study were reevaluated with 224 serum samples (from patients with LB in different stages [n= 97] and from a control group [n= 127]) originating from throughout Europe that were provided by the European Union Concerted Action on Lyme Borreliosis (EUCALB). De novo criteria were developed on the basis of the reactivities of the EUCALB sera and were evaluated with the data for the samples from southern Germany. Comparison of all results led to the following recommendations: For WB for immunoglobulin G (IgG), at least two bands among p83/100, p58, p43, p39, p30, OspC, p21, p17, and p14 for PKo and at least one band among p83/100, p39, p30, OspC, p21, and p17b for PBi; for WB for IgM, at least one band among p39, OspC, and p17 or a strong p41 band for PKo and at least one band among p39 and OspC or a strong p41 band for PBi. WB with PKo was the most sensitive, and this strain is recommended for use in WB for the serodiagnosis of LB throughout Europe.
Delayed versus Immediate Bedside Inoculation of Culture Media for Diagnosis of Vaginal Trichomonosis
Authors: Schwebke Jane R. , Venglarik Moira F. , Morgan Shellie C. 
Published: December 2019

ABSTRACT
A comparison of delayed versus immediate inoculation of culture medium for the diagnosis of trichomonosis was conducted. The sensitivities of the two methods were 100 and 97.4%, respectively. Delayed inoculation of culture medium for women without evidence of trichomonosis on direct microscopic examination is a valid diagnostic procedure.
Cleavase Fragment Length Polymorphism Analysis of
Neisseria meningitidis
Basic Metabolic Genes
Authors: Tondella Maria Lucia C. , Reeves Mike W. , Popovic Tanja , Rosenstein Nancy , Holloway Brian P. , Mayer Leonard W. 
Published: December 2019

ABSTRACT

Cleavase fragment length polymorphism (CFLP) is a subtyping system based on the property of the enzyme cleavase to recognize junctions between single- and double-stranded regions of DNA formed after denaturation and cooling. To assess the capacity of CFLP for discriminating
Neisseria meningitidis
serogroup B strains belonging to the electrophoretic type (ET) 5 (ET-5) complex from other serogroup B strains, 30 serogroup B
N. meningitidis
isolates were subtyped by CFLP with internal fragments of five housekeeping genes,
adk
,
aspC
,
carA
,
dhp
, and
glnA
. Two genes (
glnA
and
carA
) which demonstrated a high degree of diversity for the serogroup B isolates were then used to further evaluate the suitability of CFLP for screening 50 serogroup C
N. meningitidis
outbreak-associated and sporadic-case isolates with a single metabolic gene. The results were compared to those from multilocus enzyme electrophoresis (MEE), the current standard subtyping method. CFLP was able to distinguish the ET-5 complex isolates from other serogroup B isolates as efficiently as MEE. Furthermore, CFLP analysis of a single gene was sufficient to identify and cluster the serogroup C isolates belonging to the ET-37 complex from other, unrelated serogroup C isolates but was not capable of differentiating between the isolates of the major individual ETs of this complex (ET-17 and ET-24) causing most serogroup C meningococcal disease outbreaks in the United States. CFLP based on a single gene with a high degree of diversity but not under selective pressure can be applied to the rapid screening of a large number of isolates related to the recognized epidemic complex ET-5 or ET-37. Additionally, CFLP can be used as an initial screening tool to survey the amount of diversity in genes that might be used to develop a DNA sequence-based subtyping system.
Utility of Multiple-Stool-Specimen Ova and Parasite Examinations in a High-Prevalence Setting
Authors: Cartwright Charles P. 
Published: December 2019

ABSTRACT
A retrospective analysis of the results of 2,704 ova and parasite (O & P) examinations performed on stool specimens collected from 1,374 patients between October 1996 and September 1997 was performed to evaluate the utility of performing O & P examinations on multiple, independently collected stool specimens in a high-prevalence setting. A total of 995 specimens (36.8%) examined during the study contained parasites; 546 (20.2%) contained pathogenic organisms. The positivity rate (54.5%) for the patients from whom three specimens were examined was significantly higher than for the patients from whom either two specimens (33.3%) or a single specimen (19.8%) was submitted for examination. For the group of patients from whom at least 3 specimens were submitted for O & P examination, 373 independent opportunities for diagnosing infection with intestinal parasites could be analyzed. The first stool specimen collected proved to be adequate in only 75.9% (283 of 373) of evaluated cases; however, examination of two specimens increased the sensitivity of O & P detection to 92% (343 of 373). The third specimen collected provided additional information on only 30 of 373 occasions (8%). These data indicate that in populations with a high prevalence of intestinal parasitic infections, two independently collected stool specimens should be subjected to O & P examination to ensure adequate diagnostic sensitivity.
Molecular Typing of Multiple-Antibiotic-Resistant
Salmonella enterica
Serovar Typhi from Vietnam: Application to Acute and Relapse Cases of Typhoid Fever
Authors: Wain John , Hien Tran T. , Connerton Phillippa , Ali Tahir , M. Parry Christopher , Chinh Nguyen T. T. , Vinh Ha , Phuong Cao X. T. , Ho Vo A. , Diep To S. , Farrar Jeremy J. , White Nicholas J. , Dougan Gordon 
Published: December 2019

ABSTRACT

The rate of multiple-antibiotic resistance is increasing among
Salmonella enterica
serovar Typhi strains in Southeast Asia. Pulsed-field gel electrophoresis (PFGE) and other typing methods were used to analyze drug-resistant and -susceptible organisms isolated from patients with typhoid fever in several districts in southern Vietnam. Multiple PFGE and phage typing patterns were detected, although individual patients were infected with strains of a single type. The PFGE patterns were stable when the
S. enterica
serovar Typhi strains were passaged many times in vitro on laboratory medium. Paired
S. enterica
serovar Typhi isolates recovered from the blood and bone marrow of individual patients exhibited similar PFGE patterns. Typing of
S. enterica
serovar Typhi isolates from patients with relapses of typhoid indicated that the majority of relapses were caused by the same
S. enterica
serovar Typhi strain that was isolated during the initial infection. However, some individuals were infected with distinct and presumably newly acquired
S. enterica
serovar Typhi isolates.
Detection of Bovine Herpesvirus Type 1 in Blood from Naturally Infected Cattle by Using a Sensitive PCR That Discriminates between Wild-Type Virus and Virus Lacking Glycoprotein E
Authors: Fuchs Monika , Hübert Peter , Detterer Jan , Rziha Hanns-Joachim 
Published: December 2019

ABSTRACTIn the present study, we report for the first time on the detection of bovine herpesvirus type 1 (BHV-1) in whole-blood samples derived from naturally infected cattle. Sensitive PCR assays specific for glycoprotein B (gB), gC, and gE of BHV-1 allow the detection of one BHV-1 DNA copy in 105to 107peripheral blood leukocytes (PBLs). The incidence of BHV-1-positive PBLs in naturally infected cattle appears to be quite high (92.2% positive PBLs among all samples tested), although in most cases only between 10−5and 10−7positive leukocytes were present. The results demonstrate that the viral DNA is detectable not only in the peripheral blood of acutely infected animals but, more importantly, also in the peripheral blood of subclinically infected cattle. The gE-specific PCR described in the report allows discrimination between wild-type (WT) virus-infected and vaccinated animals, which is of importance for control programs that use the recently introduced vaccination strategy with a gE-negative virus. The results further show that doubtful serological results can be verified or falsified and that individual animals can be monitored for the presence or absence of WT BHV-1 or gE-negative virus in cattle herds. The PCR protocols allow the detection of BHV-1 prior to seroconversion or in BHV-1-seronegative cattle. Finally, the results indicate the simultaneous presence of WT and gE-negative vaccine virus in the PBLs of several cattle. Therefore, investigations of viremia in naturally and experimentally infected cattle and on the identification of infected cell types of bovine PBLs can be now performed.
Genotype Dependence of Hepatitis C Virus Load Measurement in Commercially Available Quantitative Assays
Authors: Mellor Janet , Hawkins Anna , Simmonds Peter 
Published: December 2019

ABSTRACT

Standardization and genotype independence of methods used to quantify hepatitis C virus (HCV) RNA in clinical specimens are necessary for accurate assessment of the role of HCV quantitation as a prognostic marker for HCV infection and monitoring of the response to antiviral treatment. Commercially available methods used to measure HCV loads include PCR-based (Roche Monitor) and hybridization-based (Quantiplex bDNA-2) methods. Recently, a new version of the Roche Monitor assay (version 2.0) has become available; it has been modified to achieve more equal quantitation of different HCV genotypes. Consistent with previous reports, Roche Monitor version 1.0 substantially underestimated concentrations of RNA transcripts of types 2b, 3a, 4a, 5a, and 6a and virus loads in individuals infected with genotypes 2 to 6 relative to reference tests. However, version 2.0 achieved equivalent quantitation of each genotype over a narrow quantitative range (10
3
to 5 × 10
5
copies of RNA/ml) but significantly underestimated RNA concentrations above this range. The assay showed an equivalent inability to quantify high levels of HCV RNA in plasma samples, and this was responsible for the falsely narrow range of virus loads detected in HCV-infected individuals. In contrast, the Chiron bDNA-2 assay could only measure RNA concentrations in the upper quantitative range (2 × 10
5
to 5 × 10
7
copies of RNA/ml) but showed equivalent sensitivity for genotypes 1 to 5; however, concentrations of type 6a RNA transcripts and virus loads in clinical specimens from individuals infected with type 6a were underestimated by a factor of 2 to 4. Differences were observed between PCR- and hybridization-based assays in their relative quantitation of HCV RNA transcripts and HCV genomic RNA, which may cause problems with the use of transcripts for interassay calibration.
Inhibition Enzyme-Linked Immunosorbent Assay for Serotyping of Group B Streptococcal Isolates
Authors: Arakere Gayathri , Flores Aurea E. , Ferrieri Patricia , Frasch Carl E. 
Published: December 2019

ABSTRACTGroup B Streptococcus (GBS) is one of the most common organisms causing neonatal sepsis as well as serious infections in adults. Serotyping the organism is important in studying the epidemiology of the disease as well as deciding a course of treatment. There are several methods available for serotyping. Most of them need high-titered sera and are not quantitative. We are reporting a new inhibition enzyme-linked immunosorbent assay (ELISA) for serotyping which is sensitive and specific compared to the conventional methods but does not need high-titered serotype-specific antisera, as the specificity is controlled by the polysaccharide coating on the ELISA plates. The method can also be quantitative, and we have measured polysaccharide elaborated by different serotype V strains. Thus, the inhibition ELISA method will be useful in serotyping for epidemiological studies, assessing virulence, and performing strain selection for vaccine production.
Fluorescent Oligonucleotide Probes for Clinical and Environmental Detection of
Acanthamoeba
and the T4 18S rRNA Gene Sequence Type
Authors: Stothard Diane R. , Hay John , Schroeder-Diedrich Jill M. , Seal David V. , Byers Thomas J. 
Published: December 2019

ABSTRACT

The first genus- and subgenus-specific fluorescent oligonucleotide probes for in situ staining of
Acanthamoeba
are described. Sequences of these phylogeny-based probes complement the 18S rRNA and the gene encoding it (18S rDNA). The genus-specific probe (GSP) is a fluorescein-labeled 22-mer specific for
Acanthamoeba
as shown here by its hybridization to growing trophozoites of all 12 known
Acanthamoeba
18S rDNA sequence types and by its failure to hybridize with amoebae of two other genera (
Hartmannella vermiformis
and
Balamuthia mandrillaris
), two human cell lines, and two bacteria (
Pseudomonas aeruginosa
and
Escherichia coli
). The sequence type T4-specific probe (ST4P) is a rhodamine-labeled 30-mer specific for
Acanthamoeba
18S rDNA sequence type T4, as shown here in hybridization tests with trophozoites of all 12 sequence types. T4 is the subgenus group associated most closely with
Acanthamoeba
keratitis (AK). GSP also was tested with corneal scrapings from 17 patients with a high index of clinical suspicion of AK plus 5 patient controls. GSP stained both trophozoites and cysts, although nonspecific cyst wall autofluorescence also was observed. Results could be obtained with GSP in 1 to 2 days, and based on results from cell culture tests, the probe correctly detected the presence or absence of
Acanthamoeba
in 21 of 24 specimens from the 22 patients. The use of GSP with cultured trophozoites and cysts from corneal scrapings has illustrated the suitability of using fluorescent oligonucleotide probes for identification of the genus
Acanthamoeba
in both environmental and clinical samples. In addition, the use of ST4P with cultured amoebae has indicated the potential of oligonucleotide probes for use in subgenus classification.
Comparative Performance of the RapID Yeast Plus System and the API 20C AUX Clinical Yeast System
Authors: Smith Michael B. , Dunklee Daisy , Vu Hangna , Woods Gail L. 
Published: December 2019

ABSTRACT

The performance of the RapID Yeast Plus System (Innovative Diagnostic Systems, Norcross, Ga.), a 4-h micropanel using single-substrate enzymatic test reactions, was compared with that of the API 20C AUX Clinical Yeast System (bioMerieux Vitek, Hazelwood, Mo.), a 48- to 72-h carbohydrate assimilation panel. Two hundred twenty-five yeasts, yeast-like fungi, and algae, comprising 28 species and including 30 isolates of
Cryptococcus neoformans
, an important pathogen not tested in appreciable numbers in other comparisons, were tested by both methods. On initial testing, 196 (87.1%) and 215 (95.6%) isolates were correctly identified by the RapID and API systems, respectively. Upon repeat testing, the number of correctly identified isolates increased to 220 (97.8%) for the RapID system and 223 (99.1%) for the API system. Reducing the turbidity of the test inoculum to that of a no. 3 McFarland turbidity standard, which is below that recommended by the manufacturer, resulted in the correct identification of most of the isolates initially misidentified by the RapID system, including 10 of 30
C. neoformans
isolates. Concordance between the RapID and API results after repeat testing was 97.3%.
Molecular Detection and Identification of Intimin Alleles in Pathogenic
Escherichia coli
by Multiplex PCR
Authors: Reid Sean D. , Betting David J. , Whittam Thomas S. 
Published: December 2019

ABSTRACT

A multiplex PCR was designed to detect the
eae
gene and simultaneously identify specific alleles in pathogenic
Escherichia coli
. The method was tested on 87 strains representing the diarrheagenic
E. coli
clones. The results show that the PCR assay accurately detects
eae
and resolves alleles encoding the α, β, and γ intimin variants.
Optimizing Voriconazole Susceptibility Testing of
Candida
: Effects of Incubation Time, Endpoint Rule, Species of
Candida
, and Level of Fluconazole Susceptibility
Authors: Lozano-Chiu M. , Arikan S. , Paetznick V. L. , Anaissie E. J. , Rex J. H. 
Published: December 2019

ABSTRACT

Voriconazole is a new triazole antifungal agent that has potent activity against many isolates of
Candida
, including
Candida krusei
and
Candida glabrata
. In this work, we studied the impact of glucose supplementation, incubation time, agitation of the plates prior to reading, endpoint determination rule, visual versus spectrophotometric reading,
Candida
species, and fluconazole MIC on the MIC of voriconazole for
Candida
isolates tested by using the microdilution format assay of the National Committee for Clinical Laboratory Standards (NCCLS) M27-A antifungal susceptibility testing methodology. For both voriconazole and fluconazole, a spectrophotometric endpoint of 50% reduction in turbidity relative to the growth control correlated most closely with the NCCLS-defined visual endpoint of “prominent decrease in turbidity.” Correlation was generally better after 24 h of incubation than after 48 h. Supplementation of the medium to contain 20 g of glucose/liter did not alter the MIC significantly but did enhance growth and simplify visual readings. All
Candida
species appeared potentially susceptible to voriconazole, including isolates of
C. krusei
. For some isolates for which fluconazole MICs were markedly elevated voriconazole MICs were also elevated, but the clinical significance of these observations remains to be determined.
Automated Quantitative Analysis of Hepatitis B Virus DNA by Using the Cobas Amplicor HBV Monitor Test
Authors: Noborg Ulrika , Gusdal Annkatrin , Pisa Eva K. , Hedrum Anders , Lindh Magnus 
Published: December 2019

ABSTRACT

A highly sensitive method of quantitative analysis of hepatitis B virus (HBV) DNA in serum, the Cobas Amplicor HBV Monitor (Cobas-AM) test, was evaluated. Following a manual extraction of viral DNA, amplification, colorimetric detection, and quantitative determination are all automatically performed in the Cobas analyzer. Serially diluted samples with known HBV DNA concentrations were analyzed blindly. All samples with a virus concentration of 400 copies/ml and 83% of samples with a virus concentration of 100 copies/ml could be detected. A linear correlation between input HBV DNA and measured HBV DNA was seen in the range from 100 to 10
5
copies/ml. The mean coefficient of variation was 29.6% for all input levels and 18.9% for HBV DNA concentrations above 400 copies/ml. Samples with an HBV DNA level above 10
9
copies/ml could be reproducibly measured after predilution to 10
−4
or 10
−6
in negative serum; however, the level was underestimated if target DNA after dilution was still above the linear range of the assay. Quantitative results of the Cobas-AM test were interchangeable with measurements by the manual microwell plate version of Amplicor HBV Monitor (MWP-AM); the mean ratio for log Cobas-AM results/log MWP-AM results was 0.97 (standard error of the mean, 0.007) when serum samples from 153 chronic carriers were analyzed. The test should be of value for clinical assessment of chronic carriers and for monitoring the response to antiviral treatment. A limitation is the relatively narrow linear range of the assay, requiring predilution of high-titer (mainly hepatitis B e-antigen-positive) samples.
Use of Molecular Assays in Diagnosis and Monitoring of Cytomegalovirus Disease following Renal Transplantation
Authors: Aitken Celia , Barrett-Muir Winsome , Millar Colin , Templeton Kate , Thomas Janice , Sheridan Fran , Jeffries Donald , Yaqoob Magdi , Breuer Judith 
Published: December 2019

ABSTRACT

We compared two commercial molecular assays (the Murex Hybrid Capture CMV DNA assay [HCA], version 2, and the Roche Amplicor plasma PCR assay) with a standard shell vial assay in detecting and predicting cytomegalovirus (CMV) disease in a group of renal transplant patients and assessed the role of viral load measurements (using the HCA) in their management. The sensitivity of the HCA and Amplicor assay in terms of disease detection was 100%, compared to 71% for the shell vial assay. Both the HCA and the PCR assay detected all cases of disease, at medians of 11 and 12.5 days before the onset of symptoms, respectively. Significantly higher viral loads were detected in those patients with symptoms (7.9 × 10
5
copies/ml) than in patients without symptoms (7.9 × 10
4
copies/ml;
P
< 0.0001). There was also a trend towards higher viral loads in those patients with primary infections (7.8 × 10
5
copies/ml) than in those patients with reactivations of CMV disease or reinfections. Successful treatment with ganciclovir was associated with a >90% reduction in viral load. Both of these new assays are sensitive and easy to use. A comparison of accurate quantitation is also useful in monitoring responses to antiviral therapy.