bluuebunny/crossref_metadata_2025_split huggingface dataset:
Macroscopic Agglutination Test for Rapid Diagnosis of Human Leptospirosis
Authors: Brandão Angela P. , Camargo Eide D. , da Silva Emilson D. , Silva Marcos V. , Abrão Rui V. 
Published: December 2019

ABSTRACT
A commercially available slide agglutination test (SAT) for the diagnosis of human leptospirosis was evaluated by comparing it to an immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) and to the microscopic agglutination test (MAT). For all 108 patients, leptospirosis was diagnosed on the basis of a fourfold or greater increase in titer by MAT (seroconversion), and all but 1 of 245 controls were MAT negative (titers, <1:100). Both SAT and the IgM ELISA failed to detect one case of infection (sensitivity, 99%). Only 3 of 145 blood donors and none of the 100 patients with other illnesses were SAT positive (specificity, 99%). The overall results were similar for the three tests; however, SAT and ELISA were statistically more sensitive as initial screening tests. For 22% of the patients, the diagnosis of leptospirosis was made earlier by SAT than by MAT. SAT detected 27 (44%) of 62 MAT-negative patients with the first serum sample. ELISA and SAT had very similar results. Follow-up of patients for 1 year after the onset of symptoms showed a decreasing rate of positivity by SAT from the third month on. The rate of positivity by ELISA decreased more slowly, to about 67% by the end of the study. By MAT all patients were persistently reactive. SAT and ELISA seem to be convenient methods for the rapid and early screening for leptospirosis and could replace the less sensitive MAT. ELISA gives less subjective results than SAT and provides information on IgM kinetics, but it can be performed only by the more sophisticated laboratories. SAT is inexpensive, can be performed more quickly and more easily than ELISA, and could be used by the less well equipped laboratories.
Molecular Analysis of Glycopeptide-Resistant
Enterococcus faecium
Isolates Collected from Michigan Hospitals over a 6-Year Period
Authors: Thal LeeAnn , Donabedian Susan , Robinson-Dunn Barbara , Chow Joseph W. , Dembry Louise , Clewell Don B. , Alshab Drew , Zervos Marcus J. 
Published: December 2019

ABSTRACT

The purpose of this study was to evaluate the molecular relatedness of clinical isolates of glycopeptide-resistant
Enterococcus faecium
isolates collected from hospitals in Michigan. A total of 379 isolates used in this study were all vancomycin-resistant
E. faecium
isolates collected from 28 hospitals and three extended-care facilities over a 6-year period from 1991 to 1996. For the 379 isolates, there were 73 pulsed-field gel electrophoresis (PFGE) strain types. Within strain types, there were as many as six restriction fragment differences. Most isolates (70%) belonged to six strain types, which were designated M1 (36%), M2 (3%), M3 (18%), M4 (6%), M10 (4%), and M11 (3%). PFGE strain M1 was cultured from 135 patients in 13 hospitals during the period 1993 to 1996. Strain type M2 was cultured from 11 patients in two hospitals during the period 1991 to 1992 and was not observed after 1992. Strain type M3 was cultured from 70 patients in 10 hospitals during the period of 1994 to 1996. Both M4 and M10 were cultured from 23 patients in three hospitals and from 15 patients in two hospitals, respectively, during 1995 to 1996. M11 was cultured from 13 patients in four hospitals during 1996. A total of 23 of 28 hospitals had evidence of clonal dissemination of some isolates. Plasmid content and hybridization analysis done on 103 isolates from one hospital and two affiliated extended-care facilities indicated that the strains contained from one to eight plasmids. Mating experiments indicated transfer of vancomycin resistance from 94 of these isolates into plasmid-free
E. faecium
GE-1 at transfer frequencies of <10
−9
to 10
−4
. Gentamicin resistance and erythromycin resistance were cotransferred at various frequencies. A probe for the
vanA
gene hybridized to the plasmids of 23 isolates and to the chromosomes of 72 isolates. A probe for the
vanB
gene hybridized to the chromosomes of 8 isolates. The results of this study suggest inter- and intrahospital dissemination of vancomycin-resistant
E. faecium
strains over a 6-year period in southeastern Michigan. The majority of isolates studied belonged to the same few PFGE strains, indicating that clonal dissemination was responsible for most of the spread of resistance that occurred.
Characterization of La Crosse Virus RNA in Autopsied Central Nervous System Tissues
Authors: Chandler Laura J. , Borucki Monica K. , Dobie Dawn K. , Wasieloski Leonard P. , Thompson Wayne H. , Gundersen Cameron B. , Case Kay , Beaty Barry J. 
Published: December 2019

ABSTRACT
A reverse transcription-PCR (RT-PCR) technique was used to detect La Crosse (LAC) virus RNA in the central nervous system (CNS) tissues of two patients who died of LAC encephalitis in 1960 and 1978. Viral RNA was readily detected by RT-PCR although the tissues had been stored frozen for up to 37 years. LAC virus was detected in the cerebral cortex but not in other CNS tissues. RT-PCR allowed detection of replicative forms of the virus, indicating that the virus was actively replicating in the specific CNS tissues. The small (S) RNA segments of the viruses from the CNS samples were demonstrated to be genetically similar by single-strand conformation polymorphism analyses. These S RNA segments were then sequenced; only two base changes were demonstrated between the 1960 and the 1978 samples, suggesting that LAC virus is genetically stable in areas of endemicity. The RT-PCR analyses of analyte directly from CNS tissues allows study of the virus without passage in cell culture.
Genetic Heterogeneity ofBorrelia burgdorferiSensu Lato inIxodes ricinusTicks Collected in Belgium
Authors: Misonne Marie-Christine , Van Impe Georges , Hoet Philippe P. 
Published: December 2019

ABSTRACTBorrelia burgdorferisensu lato (s.l.), the etiological agent of Lyme disease, is transmitted by the bite ofIxodes ricinus. Four hundred eighty-nine ticks, collected in four locations of a region of southern Belgium where Lyme disease is endemic, were examined for the presence of the spirochete. In a PCR test with primers that recognize a chromosomal gene of all strains, 23% of the ticks were found to be infected. The speciesB. burgdorferis.l. comprises at least three pathogenic genomospecies,B. burgdorferisensu stricto (s.s.),Borrelia garinii, andBorrelia afzelii, which could be distinguished in PCR tests with species-specific primers that correspond to distinct plasmid sequences.B. gariniiwas most prevalent (53% of infected ticks), followed byB. burgdorferis.s. (38%) andB. afzelii(9%). Of the infected ticks, 40% were infected with a single species, 40% were infected with two species, and 5% were infected with all three species. For 15% of the ticks, the infecting species could not be identified. No difference in rates of prevalence was observed among the four locations, which had similar ground covers, even though they belonged to distinct biogeographic regions. A greater heterogeneity of spirochetal DNA in ticks than in cultured reference DNA was suggested by a comparison of the results of PCRs with two different sets of species-specific primer sequences.
Development and Evaluation of an Epstein-Barr Virus (EBV) Immunoglobulin M Enzyme-Linked Immunosorbent Assay Based on the 18-Kilodalton Matrix Protein for Diagnosis of Primary EBV Infection
Authors: Chan K. H. , Luo R. X. , Chen H. L. , Ng M. H. , Seto W. H. , Peiris J. S. M. 
Published: December 2019

ABSTRACT
A new immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) based on the recombinant Epstein-Barr virus (EBV) matrix protein was developed. Compared to indirect immunofluorescence for the detection of IgM antibody to the EBV capsid antigen on clinical specimens, the sensitivity and specificity of the new IgM ELISA were 96 and 96%, respectively.
Comparison of Costs of Strategies for Measuring Levels of Human Immunodeficiency Virus Type 1 RNA in Plasma by Using Amplicor and Ultra Direct Assays
Authors: Raboud J. M. , Seminari E. , Rae S. L. , Harrigan P. R. , Hogg R. S. , Conway B. , Sherlock C. , Schechter M. T. , O’Shaughnessy M. V. , Montaner J. S. G. 
Published: December 2019

ABSTRACT
The costs of four algorithms for monitoring plasma human immunodeficiency virus type 1 RNA were compared. For patients with strong virologic responses, the use of Ultra Direct exclusively was the cheapest strategy. For patients with weak virologic responses, small savings could be obtained by using Amplicor and retesting only samples with values below 500 copies/ml with Ultra Direct.
Evaluation of the Nuclisens HIV-1 QT Assay for Quantitation of Human Immunodeficiency Virus Type 1 RNA Levels in Plasma
Authors: Segondy Michel , Ly Thoai-Duong , Lapeyre Martine , Montes Brigitte 
Published: December 2019

ABSTRACT
Nuclisens HIV-1 QT is a new version of the NASBA HIV-1 QT assay for quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in plasma. The specificity of this assay was 100% in one laboratory and 99%—with nonrepeatability of the initial false positive—in another. The test was linear between 2.0 and 6.0 log RNA copies per ml. According to the input HIV-1 RNA concentration, accuracy varied from −0.11 to +0.10 log RNA copy per ml and precision varied from 0.66 to 0.14 log RNA copy per ml. Reproducibility decreased when the HIV-1 RNA level was near the lower limit of quantitation of the test. HIV-1 RNA could be quantitated by Nuclisens HIV-1 QT in 36% (laboratory 1) and 24% (laboratory 2) of clinical samples with HIV-1 RNA levels lower than the lower limit of quantitation by NASBA HIV-1 QT. Nuclisens HIV-1 QT was not suitable for measurement of RNA from clade G and group O HIV-1 strains.
Seroprevalence of
Ehrlichia canis
and of Canine Granulocytic Ehrlichia Infection in Dogs in Switzerland
Authors: Pusterla Nicola , Pusterla Jeannine Berger , Deplazes Peter , Wolfensberger Celestine , Müller Werner , Hörauf Angelika , Reusch Claudia , Lutz Hans 
Published: December 2019

ABSTRACT

Serum samples from 996 dogs in Switzerland were examined for antibodies to
Ehrlichia canis
and to the agent causing canine granulocytic ehrlichiosis (CGE). Ehrlichiosis, borreliosis, and systemic illness not associated with ticks were suspected in 75, 122, and 157 of these dogs, respectively. The remainder of the serum samples were obtained from clinically healthy dogs which resided north (
n
= 235) or south (
n
= 407) of the Alps. The serum samples were tested by an indirect immunofluorescence technique for antibodies to the two agents incriminated,
E. canis
and
Ehrlichia phagocytophila
, a surrogate marker of the agent of CGE. Twenty-two of 996 (2.2%) serum samples had antibodies to
E. canis
and were distributed as follows: 20 of 75 (26.7%) samples from dogs suspected of having ehrlichiosis, 1 of 122 (0.8%) from dogs suspected of having borreliosis, and 1 of 407 (0.2%) from healthy dogs which resided south of the Alps. Of the 75 (7.5%) serum samples that had antibodies to
E. phagocytophila
, significantly more samples were from ill dogs than from healthy dogs. Among the sera from healthy dogs, antibodies to
E. phagocytophila
were significantly more prevalent in the north. Because seropositive dogs had a history of travel outside Switzerland and because
Rhipicephalus sanguineus
is found exclusively south of the Alps, it was presumed that, in contrast to the agent of CGE,
E. canis
is not indigenous to Switzerland.
Comparative Evaluation of Chlamydiazyme, PACE 2, and AMP-CT Assays for Detection of
Chlamydia trachomatis
in Endocervical Specimens
Authors: Wylie John L. , Moses Stephen , Babcock Ryan , Jolly Ann , Giercke Sandra , Hammond Greg 
Published: December 2019

ABSTRACT

We conducted a comparative evaluation of the Chlamydiazyme (Abbott Laboratories), PACE 2 (Gen-Probe), and AMP-CT (Gen-Probe) assays for the detection of
Chlamydia trachomatis
in endocervical samples. Specimens from 787 females were included in the study. The sensitivities of the PACE 2 and Chlamydiazyme assays in comparison to the results of the AMP-CT assay were 79.3 and 63.4%, respectively. The specificities of the Chlamydiazyme and PACE 2 assays were 100%. All of the positive specimens detected in this study were positive by the AMP-CT assay. On the basis of the final results of the comparison, the prevalence of
C. trachomatis
in the population was 10.4%. Retesting of specimens whose results were in the intermediate zone by the PACE 2 assay by a probe competition assay identified some additional true-positive specimens. Amplification assay testing of such specimens did not significantly increase the yield. The majority of specimens which tested positive by the AMP-CT assay only were not in the intermediate zone by the PACE 2 assay. We were unable to identify demographic or clinical factors which could predict those individuals who tested positive by amplified tests but not by nonamplified tests. The Gen-Probe PACE 2 assay proved to be superior to the Chlamydiazyme assay for the screening and diagnosis of
C. trachomatis
infections in female endocervical specimens.
Tick-Borne Relapsing Fever in British Columbia, Canada: First Isolation of
Borrelia hermsii
Authors: Banerjee Satyendra N. , Banerjee Maya , Fernando Keerthi , Burgdorfer Willy , Schwan Tom G. 
Published: December 2019

ABSTRACT

The spirochete that causes tick-borne relapsing fever,
Borrelia hermsii
, was isolated in pure culture during 1995 and 1996 from three acutely ill human patients infected in southern British Columbia, Canada. The geographic area of exposure is a known focus of this disease dating back to 1930 when the first case was recognized in a human. Analyses of plasmid DNA, protein profiles, and reactivity with a species-specific monoclonal antibody identified the new isolates of spirochetes as
B. hermsii
, all of which were most similar to an isolate of this spirochete from northern California described previously. These are the first reported isolates of
B. hermsii
from Canada.
Identification of Three Major Clones of Multiply Antibiotic-Resistant
Streptococcus pneumoniae
in Taiwanese Hospitals by Multilocus Sequence Typing
Authors: Shi Zhi-Yuan , Enright Mark C. , Wilkinson Paul , Griffiths David , Spratt Brian G. 
Published: December 2019

ABSTRACT

In this paper we demonstrate the advantages of a new molecular typing procedure, multilocus sequence typing, for the unambiguous characterization of penicillin-resistant pneumococci. The sequences of ∼450-bp fragments of seven housekeeping genes were determined for 74 penicillin-resistant Taiwanese isolates of
Streptococcus pneumoniae
(MIC of penicillin > 0.5 μg/ml). The combination of alleles at the seven loci defined an allelic profile for each strain, and a dendrogram, based on the pairwise mismatches in allelic profiles, grouped 86% of the isolates into one of three penicillin-resistant clones for which the MICs of penicillin were 1 to 2 μg/ml. Isolates within each clone had identical alleles at all seven loci or differed at only a single locus, and the fingerprints of their
pbp1A
,
pbp2B
, and
pbp2X
genes were uniform. Isolates of the Taiwan-19F clone and the Taiwan-23F clone were resistant to penicillin, tetracycline, and erythromycin but were susceptible to chloramphenicol. A second serotype 23F clone and serotype 19F variants of this clone were resistant to penicillin, tetracycline, chloramphenicol, and, in some cases, erythromycin. Comparisons of the allelic profiles of the three major clones with those of reference isolates of the known penicillin-resistant clones showed that the Taiwan-19F and Taiwan-23F clones were previously undescribed, whereas the second serotype 23F clone was indistinguishable from the Spanish multidrug-resistant serotype 23F clone. Single isolates of the Spanish penicillin-resistant serotype 9V clone and the Spanish multidrug-resistant serotype 6B clone were also identified in the collection.
Prenatal Diagnosis of Congenital Cytomegalovirus Infection
Authors: Lazzarotto T. , Guerra B. , Spezzacatena P. , Varani S. , Gabrielli L. , Pradelli P. , Rumpianesi F. , Banzi C. , Bovicelli L. , Landini M. P. 
Published: December 2019

ABSTRACT
We report here the results of a study on the prenatal diagnosis of congenital cytomegalovirus (CMV) infection. The study was carried out by both PCR and virus isolation from amniotic fluid (AF) for 82 pregnant women at risk of transmitting CMV for the detection of (i) seroconversion to CMV immunoglobulin G (IgG) positivity during the first trimester of pregnancy, (ii) symptomatic CMV infection in the mother during the first trimester of pregnancy or intrauterine growth retardation detected by ultrasound or abnormal ultrasonographic findings suggestive of fetal infections, and (iii) seropositivity for CMV-specific IgM. For 50 women, fetal blood (FB) was also obtained and tests for antigenemia and PCR were performed. The results indicate that AF is better than FB for the prenatal diagnosis of CMV infection. PCR with AF has a sensitivity (SNS) of 100%, a specificity (SPE) of 83.3%, a positive predictive value (PPV) of 40%, and a negative predictive value (NPV) of 100%; rapid virus isolation with the same material has an SNS of 50%, an SPE of 100%, a PPV of 100%, and an NPV of 94.7%. Fewer than 10% of the women positive for IgM by enzyme immunoassay (EIA) had a congenitally infected fetus or newborn infant. When EIA IgM positivity was confirmed by Western blotting (WB) and the WB profile was considered, the percent transmission detected among women with an “at-risk” profile was higher than that observed among IgM-positive women and was the same as that among women who seroconverted during the first trimester of pregnancy (transmission rates of 29 and 25%, respectively).
Shiga Toxin-Producing
Escherichia coli
in Finland from 1990 through 1997: Prevalence and Characteristics of Isolates
Authors: Keskimäki Markku , Saari Marjut , Heiskanen Tarja , Siitonen Anja 
Published: December 2019

ABSTRACT

During the past 10 years Shiga toxin-producing
Escherichia coli
(STEC) has emerged as one of the most important causes of food-borne infections in industrialized countries. In Finland, with a population of 5.1 million, however, only four STEC O157:H7 infections were identified from 1990 through 1995; the occurrence of non-O157 STEC infections was unknown. In 1996, we established a national prospective study to determine the prevalence of STEC serotypes in feces of Finns with bloody diarrhea. During this enhanced 1-year study period eight sporadic cases of STEC infection were found; of them, only two were indigenously acquired O157:H7 infections. In 1997, O157 infections increased dramatically, with O157 strains causing 51 of all 61 STEC infections. Altogether 14 non-O157:H7 STEC strains were found in Finland in the 1990s: O26:H11 (four strains), O26:HNM (HNM indicates nonmotile), O2:H29, O91:H21, O91:H40, O101:HNM, O107:H27, O157:HNM, O165:H25, OX3:H21, and Rough:H49. All O157:H7 and O26:H11 isolates produced enterohemolysin, but seven of the other STEC strains did not. Most (
n
= 63) of the 71 STEC strains isolated carried the
stx
2
gene only, five carried the
stx
1
gene only, and three carried both genes. The
eaeA
gene was detected in all other isolates except five non-O157 strains. There were seven distinct pulsed-field gel electrophoresis (PFGE) genotypes among 57 O157 strains and three distinct PFGE types among four O26:H11 strains. The main PFGE type was found among 65% of all O157 isolates.
Phenotypic and Genotypic Characterization of Nosocomial
Staphylococcus aureus
Isolates from Trauma Patients
Authors: Na’was T. , Hawwari A. , Hendrix E. , Hebden J. , Edelman R. , Martin M. , Campbell W. , Naso R. , Schwalbe R. , Fattom A. I. 
Published: December 2019

ABSTRACT

Staphylococcus aureus
is a major cause of nosocomial infections. During the period from March 1992 to March 1994, the patients admitted to the intensive care unit of the University of Maryland Shock Trauma Center were monitored for the development of
S. aureus
infections. Among the 776 patients eligible for the study, 60 (7.7%) patients developed 65 incidents of nosocomial
S. aureus
infections. Of the clinical isolates, 43.1% possessed a polysaccharide type 5 capsule, 44.6% possessed a type 8 capsule, and the remaining 12.3% had capsules that were not typed by the type 5 or type 8 antibodies. Six antibiogram types were noted among the infection-related isolates, with the majority of the types being resistant only to penicillin and ampicillin. It was noted that the majority of cases of pneumonia were caused by relatively susceptible strains, while resistant strains were isolated from patients with bacteremia and other infections. Only 16 (6.3%) of the isolates were found to be methicillin-resistant
S. aureus
(MRSA). DNA fingerprinting by pulsed-field gel electrophoresis showed 36 different patterns, with characteristic patterns being found for MRSA strains and the strains with different capsular types. Clonal relationships were established, and the origins of the infection-related isolates in each patient were determined. We conclude that (i) nosocomial infection-related isolates from the shock trauma patients did not belong to a single clone, although the predominance of a methicillin-resistant genotype was noted, (ii) most infection-related
S. aureus
isolates were relatively susceptible to antibiotics, but a MRSA strain was endemic, and (iii) for practical purposes, the combination of the results of capsular and antibiogram typing can be used as a useful epidemiological marker.
Evaluation of PCR Primers for Early Diagnosis of Cytomegalovirus Infection following Liver Transplantation
Authors: Mendez Julio C. , Espy Mark J. , Smith Thomas F. , Wilson Jennie A. , Paya Carlos V. 
Published: December 2019

ABSTRACT

The availability of microbiologic methods that detect early replication of cytomegalovirus (CMV) posttransplantation will enhance the process of initiating preemptive antiviral therapy prior to the appearance of CMV disease. Using PCR techniques we sought to determine which region of the CMV genome present in peripheral blood leukocytes (PBLs) or serum provides the highest sensitivity for the detection of CMV posttransplantation. Blood samples were prospectively collected weekly for at least 8 weeks from a cohort of 21 consecutive liver transplant recipients not receiving anti-CMV prophylaxis. Results of PCR assays were correlated with recovery of CMV in cell cultures and histopathological findings from biopsy specimens of infected organs to assess clinical symptomatic infection. Of 148 specimens, primer pairs directed to the
Hin
dIII-X fragment region of CMV detected target DNA with a 94% sensitivity, compared to an 87% sensitivity with primer pairs directed to
Eco
RI fragment D, 32% sensitivity with primer pairs directed to the immediate-early antigen 1 gene (IEA1 gene), and 20% sensitivity with primer pairs directed to the major immediate-early (MIE) gene. The performance characteristics in terms of the sensitivity of primers for amplifying CMV DNA associated with symptomatic infection ranged from 100% (
Hin
dIII-X) to 20% (MIE gene); however, specificity was inversely related (
Hin
dIII-X, 45%; MIE gene, 91%) to primers directed to these gene targets. When
Hin
dIII-X and
Eco
RI-D primer sets were used, CMV DNA from PBLs was a more sensitive target than CMV DNA from serum for the early detection of symptomatic CMV infection (17 versus 12 days). Importantly, CMV DNA was not detected in five patients with no evidence of this viral infection. In conclusion, primers directed to the
Hin
dIII-X fragment region were the most optimal for the early detection of CMV DNA in PBLs and sera from symptomatic liver transplant recipients.