bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Three Commercial Enzyme-Linked Immunosorbent Assays for Diagnosis of Chagas’ Disease
Authors: Oelemann Walter M. R. , Teixeira Maria Da Glória M. , Veríssimo Da Costa Giovani C. , Borges-Pereira José , De Castro José Adail F. , Coura José Rodrigues , Peralta José Mauro 
Published: December 2019

ABSTRACT

Chagas’ disease is a common cause of morbidity in Latin American countries. In Brazil, naturally occurring transmission of its etiologic agent,
Trypanosoma cruzi
, has been almost completely abolished through effective control programs aimed at the triatomid insect vector. Thus, transfusion of blood from infected donors has become the major route for contracting Chagas’ disease due to the socioeconomically motivated migration of residents from areas where the disease is endemic to the larger urban centers. Therefore, the employment of screening tests is mandatory for all blood banks throughout the country. We compared the diagnostic performances of three commercially available screening assays used in routine testing in Brazilian blood banks: the Abbott Chagas antibody enzyme immunoassay (Abbott Laboratórios do Brasil, São Paulo), the BIOELISACRUZI kit (Biolab-Mérieux, Rio de Janeiro, Brazil), and the BIOZIMA Chagas kit (Polychaco S.A.I.C., Buenos Aires, Argentina). The evaluation was performed with sera obtained from chagasic patients and healthy residents of four different areas in Brazil where Chagas’ disease is either endemic or emergent and where clinical manifestations of the disease and circulating parasite strains vary. The results obtained with each kit were compared to matched in-house enzyme-linked immunosorbent assay and immunofluorescence assay data obtained for each sample. Depending on the area under investigation, the three commercial kits produced specificity values between 93.3 and 100.0%, sensitivity values between 97.7 and 100%, and accuracies ranging from 93.6 to 100.0%.
Use of an Amplified-Fragment Length Polymorphism Technique To Fingerprint and Differentiate Isolates of
Helicobacter pylori
Authors: Gibson J. R. , Slater E. , Xerry J. , Tompkins D. S. , Owen R. J. 
Published: December 2019

ABSTRACT

Amplified-fragment length polymorphism (AFLP) analysis is the name given to a genotypic technique in which adapter oligonucleotides are ligated to restriction enzyme fragments and then used as target sites for primers in a PCR amplification process. The amplified fragments are electrophoretically separated to give strain-specific band profiles. We have developed a single-enzyme approach that did not require costly equipment or reagents for the fingerprinting of strains of
Helicobacter pylori
. The method was assessed with 46 isolates of
H. pylori
from 28 patients, and the results were compared with those from other genotypic tests. The AFLP profiles derived from
Hin
dIII fragments differentiated strains of
H. pylori
from unrelated individuals and confirmed the common origin of strains in some family members. AFLP analysis was also applied to investigate persistent infection following antibiotic therapy. Overall, the modified technique was relatively rapid and technically simple yet gave reproducible and discriminatory results. AFLP analysis samples variation throughout the genome and is a valuable addition to the existing genotypic fingerprinting methods for
H. pylori
.
Intercontinental Spread of a Multidrug-Resistant MethicillinResistantStaphylococcus aureusClone
Authors: de Sousa M. Aires , Sanches I. Santos , Ferro M. L. , Vaz M. J. , Saraiva Z. , Tendeiro T. , Serra J. , de Lencastre H. 
Published: December 2019

ABSTRACTTwo hundred ten methicillin-resistantStaphylococcus aureus(MRSA) isolates recovered between 1990 and 1997 from three Portuguese hospitals located in Lisbon and Oporto were analyzed by molecular fingerprinting techniques. The hybridization ofClaI restriction digests with themecA- and Tn554-specific DNA probes combined with pulsed-field gel electrophoresis documented the abrupt appearance and extensive intrahospital spread of the Brazilian epidemic MRSA clone in the 1995 samples of each one of the three hospitals analyzed—suggesting the intercontinental transfer of this strain from Brazil to Portugal. The appearance of this clone may challenge the dominance of another highly epidemic imported clone—the Iberian MRSA, currently the most widely spread MRSA clone in Portuguese hospitals.
Comparative Evaluation of Colorimetric Microtiter Plate Systems for Detection of Herpes Simplex Virus in Cerebrospinal Fluid
Authors: Tang Yi-Wei , Rys Paul N. , Rutledge Barbara J. , Mitchell P. Shawn , Smith Thomas F. , Persing David H. 
Published: December 2019

ABSTRACT
In the past few years, application of the PCR to the detection of herpes simplex virus (HSV) DNA in the cerebrospinal fluid (CSF) from patients with encephalitis and meningitis has become standard laboratory practice. However, from an operational perspective, the true diagnostic value of PCR in this setting is yet to be realized because most laboratories subject the amplification products to lengthy probe hybridization procedures by Southern blotting. As alternatives to Southern blotting, we evaluated colorimetric microtiter plate (MTP) systems from ViroMed Laboratories, Inc. (PrimeCapture), CPG, Inc. (Quanti-PATH), and Incstar Corp. (GEN-ETI-K), in addition to a system developed at the Mayo Clinic with the PCR ELISA system (Boehringer Mannheim Corp.). We tested PCR products from 86 clinical CSF specimens submitted to our Molecular Microbiology Laboratory. The CSF specimens used had to have sufficient volume for comparative analysis. By conventional Southern blotting methods, 54 were positive and 32 were negative for HSV DNA. Compared with Southern blotting, the sensitivity and specificity were 63.0 and 100.0%, respectively, for the PrimeCapture system, 98.2 and 96.9%, respectively, for the Quanti-PATH system, 98.2 and 100.0%, respectively, for the GEN-ETI-K system, and 100.0 and 96.9%, respectively, for the Mayo system. All four MTP systems had turnaround times 12 to 24 h less than that for Southern blotting. There were no significant differences in costs or technologist time between the Mayo system and Southern blotting. Other features of the Mayo system include type-specific genotypic identification of HSV and the potential for determination of drug resistance by DNA sequencing. Overall, we found that colorimetric MTP systems were likely to improve test turnaround times and patient care at no additional cost.
Genotypic Characterization of Clarithromycin-Resistant and -Susceptible
Helicobacter pylori
Strains from the Same Patient Demonstrates Existence of Two Unrelated Isolates
Authors: Wang Ge , Jiang Qin , Taylor Diane E. 
Published: December 2019

ABSTRACT

Clarithromycin-susceptible and clarithromycin-resistant
Helicobacter pylori
isolates from the same patient were investigated for the mode of development and mechanism of clarithromycin resistance. The clarithromycin-resistant strain UA1182 harbors homozygous A-to-G mutations at position 2143 in both copies of the 23S rRNA gene and has a phenotype of resistance to clarithromycin and clindamycin but no significant resistance to streptogramin B. Pulsed-field gel electrophoresis patterns of
Nru
I- and
Not
I-digested genomic DNA from the Cla
s
and Cla
r
isolates demonstrated that they are genetically distinct, suggesting that the development of clarithromycin resistance is not from the mutation of the existing Cla
s
strain but from a completely new strain.
Modification of Results of Drug Susceptibility Tests by Coexistence of
Mycobacterium avium
Complex with
Mycobacterium tuberculosis
in a Sputum Sample: Case Report and Experimental Considerations
Authors: Suzuki Katsuhiro , Kimoto Terumi , Tsuyuguchi Kazunari , Matsumoto Hisako , Niimi Akio , Tanaka Eisaku , Murayama Takako , Amitani Ryoichi 
Published: December 2019

ABSTRACT

We report on a patient whose sputum contained both
Mycobacterium tuberculosis
and
Mycobacterium avium
complex (MAC). The MAC failed to be detected by the PCR-based AMPLICOR test. The unrecognized coexistence of MAC in the sample modified the results of drug susceptibility tests. Experiments revealed that the presence of both
M. tuberculosis
and MAC was not detected by the AMPLICOR test under certain conditions.
Novel Method for Rapid Measurement of Growth of Mycobacteria in Detergent-Free Media
Authors: Meyers Paul R. , Bourn William R. , Steyn Lafras M. , van Helden Paul D. , Beyers Albert D. , Brown Gordon D. 
Published: December 2019

ABSTRACT

We describe a novel, rapid, and inexpensive method for the measurement of growth of
Mycobacterium tuberculosis
,
Mycobacterium bovis
, and
Mycobacterium smegmatis
in the presence or absence of detergent. The method, which employs hot NaOH treatment of mycobacterial cells to release total cellular protein, compares favorably with other methods for monitoring mycobacterial growth but is particularly useful for heavily clumped cultures grown in defined minimal medium.
Molecular Epidemiology of Extended-Spectrum β-Lactamase-Producing
Klebsiella pneumoniae
Isolates in a District Hospital in Taiwan
Authors: Liu Peter Yuk-Fong , Tung Jai-Chin , Ke Se-Chin , Chen Shun-Liang 
Published: December 2019

ABSTRACT

Thirty-one of 104 clinical isolates of
Klebsiella pneumoniae
collected over a period of 8 months were found to be putative extended-spectrum β-lactamase (ESBL) producers. Isoelectric focusing and an iodine overlay agar method were used for preliminary identification of the ESBLs. They were further identified by DNA sequencing. Seventy-one percent of the isolates were found to produce SHV-5. The variation in the ESBL patterns of these isolates was slight, with only five patterns being identified. The strains were typed by pulsed-field gel electrophoresis (PFGE), and 16 different genotypes were identified. When the PFGE patterns were analyzed by the algorithmic clustering method called the unweighted-pair group method using arithmetic averages, five clusters were found. However, significant genetic variations were found among 11 isolates and between each cluster. A plasmid of 36 kb was found in all clinical isolates and in the transconjugants. Our results indicate that the increase in the number of ESBL-producing
K. pneumoniae
isolates in this hospital is due mainly to the dissemination of a resistance plasmid rather than to the clonal spread of a few epidemic strains.
Clinical Evaluation of the BDProbeTec Strand Displacement Amplification Assay for Rapid Diagnosis of Tuberculosis
Authors: Bergmann John S. , Woods Gail L. 
Published: December 2019

ABSTRACT

The reliability of the BDProbeTec MTB Test (Becton Dickinson, Sparks, Md.) for direct detection of
Mycobacterium tuberculosis
in respiratory specimens was evaluated by comparing results to those of conventional mycobacterial culture, with the BACTEC TB 460 and Middlebrook 7H11 biplates. Patients known to have tuberculosis were excluded from analysis. Of 523 specimens from 277 patients, 53 grew a mycobacterium: 24 specimens of
M. tuberculosis
and 29 specimens of nontuberculous mycobacteria. After initial testing, 42 specimens were positive by the BDProbeTec, for overall sensitivity, specificity, and positive and negative predictive values of 95.8, 96.2, 54.8, and 99.8%, respectively. After resolution of discrepancies, 28 specimens were positive by the BDProbeTec, for overall sensitivity, specificity, and positive and negative predictive values of 100, 99.2, 85.7, and 100%, respectively. These same values were 100, 80.8, 93.4, and 100%, respectively, for smear-positive samples and 100, 99.4, 75.0, and 100%, respectively, for smear-negative specimens.
Isolation of
Francisella tularensis
by Centrifugation of Shell Vial Cell Culture from an Inoculation Eschar
Authors: Fournier Pierre-Edouard , Bernabeu Lionel , Schubert Bernard , Mutillod Maryse , Roux Veronique , Raoult Didier 
Published: December 2019

ABSTRACT

A 52-year-old man was admitted to the hospital following the development of an inoculation eschar and fever six days after being bitten by a tick. He was clinically diagnosed as suffering from rickettsiosis. Eschar biopsy cultures on standard bacteriological media remained sterile. However, inoculation of cells with the homogenized specimen by the centrifugation-shell vial technique (M. Marrero and D. Raoult, Am. J. Trop. Med. Hyg. 40:197–199, 1989) resulted in the recovery of a bacterium. Determination of the sequence of the 16S rRNA gene amplified from the organism and comparison of the sequence to other sequences identified it as a strain of
Francisella tularensis
, whereas the specific serology was still negative. Our findings demonstrate that the centrifugation-cell culture, which is a tool for investigation of tick-transmitted diseases, may have the potential to serve as a method for the cultural isolation of
F. tularensis
.
Antimicrobial Susceptibility of
Helicobacter pylori
Determined by the E Test Using Tetrazolium Egg Yolk Agar
Authors: Valdez Yanet , Velapatiño Billie , Gilman Robert H. , Gutierrez Vilma , León Carlos 
Published: December 2019

ABSTRACT

Metronidazole and tetracycline E tests were compared to an agar dilution method for the antimicrobial susceptibility testing of
Helicobacter pylori
. Sixteen strains were tested by using tetrazolium egg yolk (TEY) agar. The characteristic E test inhibition ellipse was clearer on TEY agar than on standard blood agar and gave results comparable to those of the agar dilution test. The use of TEY medium is preferable to that of blood agar medium in E test MIC determinations for
H. pylori.
Rapid Identification of
Candida glabrata
by Using a Dipstick To Detect Trehalase-Generated Glucose
Authors: Peltroche-Llacsahuanga Heidrun , Schnitzler Norbert , Lütticken Rudolf , Haase Gerhard 
Published: December 2019

ABSTRACT

Candida glabrata
is a yeast frequently isolated from human specimens. Based upon its well-known ability to rapidly hydrolyze trehalose, we have developed a novel and cost-effective test incubating one yeast colony emulsified in 50 μl of citrate buffer (0.1 M [pH 5.0]) containing 4% (wt/vol) trehalose for 3 h at 37°C. Trehalase-generated glucose is detected with a commercially available dipstick (range, 1.0 to 50 g/liter). For evaluation, consecutive clinical isolates and several reference strains of
C. glabrata
(
n
= 160),
C. albicans
(
n
= 120), and other yeast species with potential ability for utilization of trehalose (
C. dubliniensis
,
n
= 11;
C. famata
,
n
= 15;
C. guilliermondii
,
n
= 5;
C. lusitaniae
,
n
= 16;
C. parapsilosis
,
n
= 20;
C. tropicalis
,
n
= 34;
C. viswanathii
,
n
= 5;
Pichia angusta
,
n
= 2;
C. zeylanoides
,
n
= 2;
Saccharomyces cerevisiae
,
n
= 16;
C. neoformans
,
n
= 7) were tested. Identification of
C. glabrata
is achieved within 3 h, with a specificity of 99.1% and a sensitivity of 98.8% when grown on Sabouraud dextrose agar supplemented with 4% glucose.
Evaluation of the Abbott LCx
Mycobacterium tuberculosis
Assay for Direct Detection of
Mycobacterium tuberculosis
Complex in Human Samples
Authors: Garrino Maria Grazia , Glupczynski Youri , Degraux Josiane , Nizet Henri , Delmée Michel 
Published: December 2019

ABSTRACT

Seven hundred thirty-seven clinical samples from 460 patients were processed for direct detection of
Mycobacterium tuberculosis
complex by a semiautomated ligase chain reaction commercial assay, the LCx
Mycobacterium tuberculosis
Assay (LCx assay) from Abbott Laboratories. Results were compared to those of direct microscopy and standard microbiological culture. Of 26 patients (5.7%) with a culture positive for
M. tuberculosis
, 22 (84.6%) were found positive by the LCx assay. The sensitivity of the LCx assay was 98% for smear-positive samples and 27% for smear-negative samples. With an overall culture positivity rate for
M. tuberculosis
of 8.3% (61 of 737 samples) and after resolution of discrepant results according to clinical data, the sensitivity, specificity, and positive and negative predictive values of the LCx assay were 78, 100, 95, and 98%, respectively, compared to 85, 100, 100, and 98%, respectively, for culture and 67, 99, 87, and 97%, respectively, for acid-fast staining. In conclusion, the LCx assay proved satisfactory and appears to be an easy-to-use 1-day test which must be used with standard culture methods but can considerably reduce diagnosis time versus culture. However, its clinical interest appears to be limited in our population with low mycobacterial prevalence because of its cost considering the small gain in sensitivity versus direct microscopy.
Analysis of
Legionella pneumophila
Serogroup 1 Isolates by Pulsed-Field Gel Electrophoresis
Authors: Marrie Thomas J. , Tyler Shaun , Bezanson Gregory , Dendy Charles , Johnson Wendy 
Published: December 2019

ABSTRACT

At a hospital in Halifax, Nova Scotia, Canada, three strains of
Legionella pneumophila
were detectable based on plasmid content, while the isolates collected at another hospital in Halifax had no plasmids. Genomic DNA was digested with
Bss
HII,
Sal
I, and
Spe
I and subjected to pulsed-field gel electrophoresis (PFGE). We found no relationship between plasmid profile and PFGE pattern.
Case of Onychomycosis Caused by
Microsporum racemosum
Authors: García-Martos Pedro , Gené Josepa , Solé María , Mira José , Ruíz-Henestrosa Ricardo , Guarro Josep 
Published: December 2019

ABSTRACT

We report the case of a Spanish 60-year-old female who presented in 1997 with onychomycosis of the left thumbnail following an injury caused by a fresh fish bone.
Microsporum racemosum
was repeatedly cultured from nail scrapings, and its identity was confirmed by sequencing the isolate’s ITS1/ITS2 and 5.8S rRNA regions. The patient was successfully treated with itraconazole, which was administered for 12 weeks. This represents the first case of onychomycosis due to
M. racemosum
and the first time that this species has been isolated from a human in Europe.
Development of a
Plasmodium
PCR for Monitoring Efficacy of Antimalarial Treatment
Authors: Ciceron Liliane , Jaureguiberry Ginette , Gay Frederick , Danis Martin 
Published: December 2019

ABSTRACT

We report in this work a highly sensitive and nonradioactive PCR method for the detection of the four species of parasite causing human malaria.
Plasmodium
-specific primers corresponding to the small-subunit rRNA genes of the malaria parasite were used, and a 291-bp fragment was amplified. Our results showed a high specificity for the four human
Plasmodium
species, and we were able to detect one parasite in 50 μl of whole blood. The responses of 12 patients infected with
Plasmodium falciparum
to antimalarial therapy were monitored by PCR diagnosis and examination of thick blood film for at least 20 min by an experienced microscopist. For one patient this study allowed early diagnosis of therapeutic failure, confirmed 7 days later by examination of the thick blood film. A total of 134 samples were examined; 94 were positive by PCR, and among these 68 were positive by thick blood film examination. The sensitivity of the thick blood film was 72.3% compared to PCR and 60.7% compared to dot blot hybridization.
Multicenter Evaluation of the Mycobacteria Growth Indicator Tube for Testing Susceptibility of
Mycobacterium tuberculosis
to First-Line Drugs
Authors: Rüsch-Gerdes Sabine , Domehl Cornelia , Nardi Giampietro , Gismondo Maria Rita , Welscher Hans-Martin , Pfyffer Gaby E. 
Published: December 2019

ABSTRACT

In a multicenter study involving three reference centers for mycobacteria, the reliability of the Mycobacteria Growth Indicator Tube (MGIT) for rapid antimicrobial susceptibility testing (AST) of
Mycobacterium tuberculosis
was evaluated and compared to the radiometric method (BACTEC 460TB). Test cultures for which the results of the MGIT and BACTEC 460TB tests were discordant were checked by the conventional proportion method on solid medium. Four hundred forty-one isolates have been tested for susceptibility to isoniazid (INH), rifampin (RMP), ethambutol (EMB), and streptomycin (SM). Discrepant results were obtained for three isolates (0.7%) with INH (susceptible by MGIT, resistant by BACTEC 460TB), for four isolates (0.9%) with RMP (susceptible by MGIT, resistant by BACTEC 460TB), for six isolates (1.9%) with EMB (four susceptible by MGIT, resistant by BACTEC 460TB; two resistant by MGIT, susceptible by BACTEC 460TB), and for four isolates (0.9%) with SM (two susceptible by MGIT, resistant by BACTEC 460TB; two resistant by MGIT, susceptible by BACTEC 460TB). When cultures with discordant results were tested by the conventional proportion method, about half of the cultures yielded results similar to the BACTEC 460TB results, while the other half yielded results similar to the MGIT results. Turnaround times were 3 to 14 days (median, 8.8 days) for MGIT and 3 to 15 days (median, 7.8 days) for BACTEC 460TB. There was no statistically significant difference between the susceptibility testing results of the two methods (
P
> 0.05). These data demonstrate that the MGIT system is an accurate, nonradiometric alternative to the BACTEC 460TB method for rapid susceptibility testing of
M. tuberculosis
.
Evaluation of a Novel Dry Latex Preparation for Demonstration of Infectious Mononucleosis Heterophile Antibody in Comparison with Three Established Tests
Authors: Rogers Richard , Windust Alison , Gregory Josie 
Published: December 2019

ABSTRACT
A new, dried antigen-coated latex preparation for the demonstration of infectious mononucleosis (IM) heterophile antibody (Dryspot IM kit; Oxoid, Ltd., Basingstoke, Hampshire, United Kingdom) was compared with the IM kit (a liquid latex reagent from the same source), an immunoassay (ImmunoCard Mono; Meridian Diagnostics), and an absorption test (Monospot; Meridian Diagnostics). The latter was used as a standard for initial statistical comparisons. Discrepancies were resolved by using Epstein-Barr virus serology. Of the 328 routine samples tested, 77 were positive and 222 were negative by all IM heterophile antibody-based kits. Twenty-nine samples gave discrepant results. Following resolution of discrepant results, the sensitivity and specificity values for the IM Dryspot kit were 87.0 and 98.7%, those for the Oxoid liquid latex IM kit were 83.0 and 99.6%, and those for the ImmunoCard Mono immunoassay were 85.0 and 100.0%, respectively. The evaluation shows that the Dryspot kit, which is uniquely straightforward to use and may be stored at room temperature, is comparable in performance to other rapid heterophile tests for the confirmation of IM.