bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of
Bartonella
Species Directly in Clinical Specimens by PCR-Restriction Fragment Length Polymorphism Analysis of a 16S rRNA Gene Fragment
Authors: Matar Ghassan M. , Koehler Jane E. , Malcolm Georgia , Lambert-Fair Mary Ann , Tappero Jordan , Hunter Suzan B. , Swaminathan Bala 
Published: December 2019

ABSTRACT

It is now established that two species of
Bartonella
, namely,
Bartonella henselae
and
B. quintana
, cause bacillary angiomatosis in human immunodeficiency virus-infected patients. In addition,
B. henselae
causes cat scratch disease and
B. quintana
,
B. henselae
, and
B. elizabethae
can cause bacteremia and endocarditis in immunocompetent persons. We have developed a PCR-restriction fragment length polymorphism-based assay for direct detection and identification to species level of
Bartonella
in clinical specimens. This is accomplished by PCR amplification of
Bartonella
DNA using primers derived from conserved regions of the gene carrying the 16S ribosomal DNA, followed by restriction analysis using
Dde
I and
Mse
I restriction endonucleases. We amplified a
Bartonella
genus-specific 296-bp fragment from 25 clinical samples obtained from 25 different individuals. Restriction analysis of amplicons showed that identical patterns were seen from digestion of
B. henselae
and
B. quintana
amplicons with
Dde
I, whereas a different unique pattern was seen by using the same enzyme with
B. vinsonii
and
B. elizabethae
. With
Mse
I digestion,
B. henselae
and
B. vinsonii
gave nearly identical patterns while
B. quintana
and
B. elizabethae
gave a different pattern. By combining the restriction analysis data generated with
Mse
I and
Dde
I, unique “signature” restriction patterns characteristic for each species were obtained. These patterns were useful in identifying the
Bartonella
species associated with each tissue specimen.
Methods for Improved Detection of Oxacillin Resistance in Coagulase-Negative Staphylococci: Results of a Multicenter Study
Authors: Tenover Fred C. , Jones Ronald N. , Swenson Jana M. , Zimmer Barbara , McAllister Sigrid , Jorgensen James H. 
Published: December 2019

ABSTRACT

A multilaboratory study was undertaken to determine the accuracy of the current National Committee for Clinical Laboratory Standards (NCCLS) oxacillin breakpoints for broth microdilution and disk diffusion testing of coagulase-negative staphylococci (CoNS) by using a PCR assay for
mecA
as the reference method. Fifty well-characterized strains of CoNS were tested for oxacillin susceptibility by the NCCLS broth microdilution and disk diffusion procedures in 11 laboratories. In addition, organisms were inoculated onto a pair of commercially prepared oxacillin agar screen plates containing 6 μg of oxacillin per ml and 4% NaCl. The results of this study and of several other published reports suggest that, in order to reliably detect the presence of resistance mediated by
mecA
, the oxacillin MIC breakpoint for defining resistance in CoNS should be lowered from ≥4 to ≥0.5 μg/ml and the breakpoint for susceptibility should be lowered from ≤2 to ≤0.25 μg/ml. In addition, a single disk diffusion breakpoint of ≤17 mm for resistance and ≥18 mm for susceptibility is suggested. Due to the poor sensitivity of the oxacillin agar screen plate for predicting resistance in this study, this test can no longer be recommended for use with CoNS. The proposed interpretive criteria for testing CoNS have been adopted by the NCCLS.
Leuconostoc pseudomesenteroides
as a Cause of Nosocomial Urinary Tract Infections
Authors: Cappelli Elisabete A. , Barros Rosana R. , Camello Thereza Cristina F. , Teixeira Lúcia M. , Merquior Vânia Lúcia C. 
Published: December 2019

ABSTRACT

The phenotypic and genotypic characterization of five clinical isolates of
Leuconostoc pseudomesenteroides
associated with nosocomially acquired urinary tract infections is described. All the strains were susceptible to chloramphenicol, clindamycin, erythromycin, gentamicin, and tetracycline; all were resistant to nalidixic acid, norfloxacin, and vancomycin; and all were intermediately affected by ampicillin and penicillin. Analysis of chromosomal DNA by pulsed-field gel electrophoresis after treatment with
Sma
I indicated a clonal relationship of the isolates. The results provide evidence for the possibility of nosocomial transmission of this unusual opportunistic, vancomycin-resistant pathogen.
Seroepidemiology of Human Group C Rotavirus in South Africa
Authors: Steele A. D. , James V. L. A. 
Published: December 2019

ABSTRACT
Sera from three separate healthy population cohorts were used to determine the incidence of group C rotavirus infections in 1,356 South Africans. Using an enzyme-linked immunosorbent assay based on a recombinant group C rotavirus VP6 protein, the total percent positivity was found to be 34.4% (range, 33 to 38%), with almost half of the population infected after the age of 20 years.
Analysis of GB Virus C Markers in Families Over Three Generations
Authors: Chen Margaret , Fischler Björn , Hultgren Catharina , Halasz Robert , Nemeth Antal , Sällberg Matti 
Published: December 2019

ABSTRACT
GB virus C (GBV-C) markers were analyzed in two to three generations in three families with documented vertical transmission of GBV-C. None of the maternal grandparents had GBV-C markers, whereas the male spouses had GBV-C envelope 2 antibodies. Evidence was found for intrafamilial transmission but not for GBV-C transmission over three generations.
Cord Formation in MB/BacT Medium Is a Reliable Criterion for Presumptive Identification of
Mycobacterium tuberculosis
Complex in Laboratories with High Prevalence of
M. tuberculosis
Authors: Badak F. Zuhre , Goksel Servet , Sertoz Ruchan , Guzelant Asuman , Kizirgil Ahmet , Bilgic Altinay 
Published: December 2019

ABSTRACT

We evaluated cord formation in MB/BacT broth as a rapid method for presumptive identification of the
Mycobacterium tuberculosis
complex. Kinyoun acid-fast-stained smears from 370 positive MB/BacT bottles were examined for the presence of serpentine cording. The smears were examined independently by two observers. Observer 1 (the supervisor of the mycobacteriology laboratory) examined all of the smears while observer 2 (a clinical microbiologist not familiar with acid-fast bacillus [AFB] microscopy) examined 148 randomly chosen smears that were read by observer 1 without knowledge of which smear was which. The sensitivity, specificity, and positive and negative predictive values of cording for the presumptive identification of
M. tuberculosis
read by observer 1 were 88.2, 97.4, 99.2, and 69.7%, respectively. These values were reported at 90.6, 52.3, 82.8, and 69.7%, respectively, by observer 2. Our laboratory prevalence of
M. tuberculosis
among positive cultures was 78% during the time this study was conducted. At the time of positive signal of the MB/BacT bottles, the broth of the bottles had sufficient cell mass to allow for observation of the presence or absence of serpentine cording. The presence of cords in MB/BacT broth is a reliable criterion for rapid, predictive identification of the
M. tuberculosis
complex for laboratories with a high proportion of the
M. tuberculosis
complex when the smears are examined by a microbiologist who has experience with AFB staining.
Identification of
Candida dubliniensis
in a Prospective Study of Patients in the United States
Authors: Jabra-Rizk Mary Ann , Baqui A. A. M. A. , Kelley Jacqueline I. , Falkler William A. , Merz William G. , Meiller Timothy F. 
Published: December 2019

ABSTRACT

Although
Candida albicans
remains the fungal species most frequently isolated as an opportunistic oral pathogen, other yeast species are often identified in human immunodeficiency virus (HIV)-seropositive patients.
Candida dubliniensis
phenotypically resembles
C. albicans
in many respects, yet it can be identified and differentiated as a unique
Candida
species by its phenotypic and genetic profiles. The purpose of the present study was to prospectively test for the presence of
C. dubliniensis
among clinical isolates and to determine the clinical and demographic characteristics of patients harboring
C. dubliniensis
. Over a 90-day period, isolates from 724 patients that were presumptively identified as
C. albicans
were screened for
C. dubliniensis
by use of tests for germ tube and chlamydospore production, by detection of an inability to grow at 45°C, by colony color on CHROMagar Candida medium, and by the results of a sugar assimilation test with the API 20C AUX yeast identification system. Among 699 isolates retrieved from those specimens evaluated, 5 from 25 HIV-seropositive patients and 1 isolate from a patient whose HIV status was unknown were shown to be consistent by phenotyping and by electrophoretic karyotyping with the European reference strain of
C. dubliniensis
. One of the
C. dubliniensis
isolates had dose-dependent susceptibility to fluconazole (MIC, 16 μg/ml). These results confirm the presence of this interesting species in the United States and support the need for further investigations into the prevalence and pathogenesis of
C. dubliniensis.
Limits in Reliability of Glycoprotein G-Based Type-Specific Serologic Assays for Herpes Simplex Virus Types 1 and 2
Authors: Schmid D. Scott , Brown Denise R. , Nisenbaum Rosane , Burke Rae Lyn , Alexander D’Anna , Ashley Rhoda , Pellett Philip E. , Reeves William C. 
Published: December 2019

ABSTRACT
Type-specific serologic assays for herpes simplex virus (HSV) types 1 and 2 based on glycoprotein G-1 (gG-1) (HSV-1) and gG-2 (HSV-2) discriminate between antibodies against HSV-1 and HSV-2. We previously developed a Western blot assay using gG-1 and gG-2 expressed in baculovirus, performed extensive validation studies, and determined that it was both sensitive and specific for type-specific detection of HSV antibody. Here we report that, among a cohort of Thai military recruits, the serostatus of some individuals changed from positive to negative over time (6.6% among those ever positive for HSV-1, and 14.9% among those ever positive for HSV-2). We tested a subset of these specimens in three other gG-based assays: an enzyme-linked immunosorbent assay, an immunoblot strip assay, and a Western blot assay. Positive-to-negative shifts occurred in every assay; the frequency of the shifts ranged from 6.1% to 21.2% of the specimen sets tested. There was only limited agreement among the assays concerning which individuals lost reactivity. This inaccuracy, exhibited by all of the assay protocols, was not predicted by validation studies employing specimens from cross-sectional studies and was most pronounced in HSV-2 testing. This argues for the inclusion of serial blood specimens in serologic assay validation procedures.
Rickettsia helvetica
in
Ixodes ricinus
Ticks in Sweden
Authors: Nilsson Kenneth , Lindquist Olle , Liu Ai Jie , Jaenson Thomas G. T. , Friman Göran , Påhlson Carl 
Published: December 2019

ABSTRACT

In the present study further characterization of the amplified sequence of the citrate synthase gene of the spotted fever group
Rickettsia
isolated from
Ixodes ricinus
ticks in Sweden showed that it has 100% homology with the deposited sequence of the citrate synthase gene of
Rickettsia helvetica
. The restriction fragment length polymorphism (RFLP) pattern of an amplified 382-bp product of the citrate synthase sequence, defined by primers RpCS877 and RpCS1258, yielded fragments for our isolate that could be visualized as a double band that migrated at approximately 44 bp, another double band at 85 bp, and a single band at nearly 120 bp after digestion with the restriction enzyme
Alu
I. When calculating a theoretical PCR-RFLP pattern of the sequence of the citrate synthase gene of
R. helvetica
from the known positions where the
Alu
I enzyme cuts, we arrived at the same pattern that was obtained for our isolate, a pattern distinctly different from the previously published PCR-RFLP pattern for
R. helvetica
. Investigation of 125 living
I. ricinus
ticks showed a higher prevalence of rickettsial DNA in these ticks than we had found in an earlier study. Rickettsial DNA was detected by amplification of the 16S rRNA gene, for which a seminested primer system consisting of two oligonucleotide primer pairs was used. Of the 125 ticks, some were pooled, giving a total of 82 tick samples, of which 20 were found to be positive for the rickettsial DNA gene investigated. When considering the fact that some of the positive samples were pooled, the minimum possible prevalence in these ticks was 20 of 125 (16%) and the maximum possible prevalence was 46 of 125 (36.8%). These prevalence estimates conform to those of other studies of spotted fever group rickettsiae in hard ticks in Europe.
Stability of Insertion Sequence IS
1245
, a Marker for Differentiation of
Mycobacterium avium
Strains
Authors: Bauer Jeanett , Andersen Åse Bengård 
Published: December 2019

ABSTRACT

Recently a novel insertion element, IS
1245
, has been described and suggested for use as a probe in restriction fragment length polymorphism studies of
Mycobacterium avium
strains. An important issue in this context is the stability of the insertion element. We analyzed single colonies of
M. avium
cultures and found frequent small one- to two-band changes. However, following repeated in vitro passages over 1 year, similar one- to two-band changes were observed in the IS
1245
patterns of only six
M. avium
strains investigated.
Hemolysin as a Virulence Factor for Systemic Infection with Isolates of
Mycobacterium avium
Complex
Authors: Maslow Joel N. , Dawson David , Carlin Elizabeth A. , Holland Steven M. 
Published: December 2019

ABSTRACT

Isolates of the
Mycobacterium avium
complex were examined for hemolysin expression. Only invasive isolates of
M. avium
were observed to be hemolytic (
P
< 0.001), with activity the greatest for isolates of serovars 4 and 8. Thus,
M. avium
hemolysin appears to represent a virulence factor necessary for invasive disease.
Detection of Viable
Mycobacterium tuberculosis
by Reverse Transcriptase-Strand Displacement Amplification of mRNA
Authors: Hellyer T. J. , DesJardin L. E. , Teixeira L. , Perkins M. D. , Cave M. D. , Eisenach K. D. 
Published: December 2019

ABSTRACT

Numerous assays have been described for the detection of DNA and rRNA sequences that are specific for the
Mycobacterium tuberculosis
complex. Although beneficial to initial diagnosis, such assays have proven unsuitable for monitoring therapeutic efficacy owing to the persistence of these nucleic acid targets long after conversion of smears and cultures to negative. However, prokaryotic mRNA has a typical half-life of only a few minutes and we have previously shown that the presence of mRNA is a good indicator of bacterial viability. The purpose of the present study was to develop a novel reverse transcriptase-strand displacement amplification system for the detection of
M. tuberculosis
α-antigen (85B protein) mRNA and to demonstrate the use of this assay in assessing chemotherapeutic efficacy in patients with pulmonary tuberculosis. The assay was applied to sequential, noninduced sputum specimens collected from four patients: 10 of 11 samples (91%) collected prior to the start of therapy were positive for alpha-antigen mRNA, compared with 1 of 8 (13%), 2 of 8 (25%), 2 of 8 (25%), and 0 of 8 collected on days 2, 4, 7, and 14 of treatment, respectively. In contrast, 39 of 44 samples (89%) collected on or before day 14 were positive for α-antigen DNA. The loss of detectable mRNA corresponded to a rapid drop over the first 4 days of treatment in the number of viable organisms present in each sputum sample, equivalent to a mean fall of 0.43 log
10
CFU/ml/day. Analysis of mRNA is a potentially useful method for monitoring therapeutic efficacy and for rapid in vitro determination of drug susceptibility.
Serologic Testing for Human Granulocytic Ehrlichiosis at a National Referral Center
Authors: Comer James A. , Nicholson William L. , Olson James G. , Childs James E. 
Published: December 2019

ABSTRACTAn indirect immunofluorescence assay (IFA) was used to identify patients with antibodies reactive to the human granulocytic ehrlichiosis (HGE) agent. Serum samples collected from clinically ill individuals were submitted to the Centers for Disease Control and Prevention by physicians via state health departments from throughout the United States and tested against a panel of ehrlichial and rickettsial pathogens. Antibodies reactive to the HGE agent were detected in 142 (8.9%) of 1,602 individuals tested. There were 19 confirmed and 59 probable (n= 78) cases of HGE as defined by seroconversion or a fourfold or higher titer to the HGE agent than to theEhrlichia chaffeensisantigens. The average age of patients with HGE was 57 years, and males accounted for 53 (68%) of the patients. Cases of HGE occurred in 21 states; 47 (60%) of the cases occurred in Connecticut (n= 14), New York (n= 18), and Wisconsin (n= 15). Onset of HGE was identified from April through December, with cases peaking in June and July. The earliest confirmed cases of HGE occurred in 1987 in Wisconsin and 1988 in Florida. No fatalities were reported among the 78 patients with confirmed or probable HGE. Reactivity to the HGE agent and to eitherCoxiella burnetii,Rickettsia rickettsii, orRickettsia typhiwas infrequent; however, 74 (52%) of the 142 individuals who were positive for HGE had at least one serum sample that also reacted to theE. chaffeensisantigen. Thirty-four persons with confirmed or probable human monocytic ehrlichiosis due toE. chaffeensisalso had antibodies to the HGE agent in at least one serum sample. The specific etiologic agent for 30 patients was not ascribed because of similarity of titers to both ehrlichial antigens. The use of both antigens may be required to correctly diagnose most cases of human ehrlichiosis, especially in geographic regions where both the HGE agent andE. chaffeensisoccur.
Laboratory Diagnosis of Toscana Virus Infection by Enzyme Immunoassay with Recombinant Viral Nucleoprotein
Authors: Soldateschi Dario , Dal Maso Grazia Maria , Valassina Marcello , Santini Laura , Bianchi Silvia , Cusi Maria Grazia 
Published: December 2019

ABSTRACT

A recombinant enzyme immunoassay (rEIA) to detect serum immunoglobulin M (IgM) and IgG to Toscana virus (TOSV) was developed with the aim of establishing a simple and easily available assay for diagnosing acute and/or previous infections. The rEIA, based on the recombinant nucleoprotein of TOSV expressed in
Escherichia coli
, was evaluated with 97 serum samples collected in an area where TOSV is endemic and compared to an analogous assay based on cell-derived TOSV. Discordant results were resolved by immunoblotting (IB). Twenty-two of these samples, obtained from subjects hospitalized during the summer season with meningitis of suspected TOSV etiology, were further characterized by indirect immunofluorescence and IB, and detection of specific TOSV RNA sequences in the cerebrospinal fluid of these patients was attempted by nested PCR. The results indicated that rEIA was able to diagnose acute TOSV infection by detection of specific serum IgM in all of the subjects with TOSV meningitis confirmed by nested PCR or serology. The overall sensitivity and specificity of rEIA were both 100% for IgM detection and 100 and 96.6%, respectively, for IgG detection. Thus, rEIA appears to be a simple and reliable laboratory test for the diagnosis of acute TOSV infection and for the assessment of immune status.
Case Report and Molecular Analysis of Subacute Sclerosing Panencephalitis in a South African Child
Authors: Vardas Eftyhia , Leary P. M. , Yeats Jane , Badrodien Waseila , Kreis Stephanie 
Published: December 2019

ABSTRACT
This is the first case of subacute sclerosing panencephalitis from South Africa in which the molecular characteristics of the causative measles virus were examined. The virus found is classified as genotype D3, which has not previously been found in Africa and was last circulating in the United States before 1992.
Evaluation of the Ultrasensitive Roche Amplicor HIV-1 Monitor Assay for Quantitation of Human Immunodeficiency Virus Type 1 RNA
Authors: Erali Maria , Hillyard David R. 
Published: December 2019

ABSTRACT
The ultrasensitive Amplicor HIV-1 Monitor test (Roche Diagnostic Systems) was evaluated for precision, linearity, and sensitivity and was compared to the standard Amplicor assay. The ultrasensitive assay reliably quantified samples in the range from 50 to 50,000 human immunodeficiency virus type 1 RNA copies/ml with acceptable correlation with the standard Amplicor test.
Reproducibility and Performance of the Second-Generation Branched-DNA Assay in Routine Quantification of Human Immunodeficiency Virus Type 1 RNA in Plasma
Authors: Murphy Donald G. , Gonin Patrick , Fauvel Micheline 
Published: December 2019

ABSTRACT

We examined the reproducibility of a second-generation branched-DNA (bDNA) assay (Quantiplex HIV RNA 2.0) for quantification of human immunodeficiency virus type 1 (HIV-1) RNA in plasma by retesting 325 specimens on separate runs and on different lots. The performance of the bDNA test was also assessed by data analysis obtained during routine testing of 15,365 specimens. Upon retesting, 96 and 86% of specimens displaying RNA levels above 5,000 and between 500 and 5,000 copies/ml, respectively, showed less than a 0.3 log
10
(twofold) difference with their initial values. Assay variability was found to increase as viral load decreased. Overall, the bDNA version 2.0 assay was found to be a reproducible and efficient test for routine quantification of HIV-1 RNA in plasma.
Helicobacter pylori
Can Be Induced To Assume the Morphology of
Helicobacter heilmannii
Authors: Fawcett Paul T. , Gibney Kathleen M. , Vinette Kathleen M. B. 
Published: December 2019

ABSTRACT

Cultures of
Helicobacter pylori
obtained from the American Type Culture Collection (strain 43504) were grown as isolated colonies or lawns on blood agar plates and in broth culture with constant shaking. Examination of bacterial growth with Gram-stained fixed preparation and differential interference contrast microscopy on wet preparations revealed that bacteria grown on blood agar plates had a morphology consistent with that normally reported for
H. pylori
whereas bacteria from broth cultures had the morphologic appearance of
Helicobacter heilmannii
. Bacteria harvested from blood agar plates assumed an
H. heilmannii
-like morphology when transferred to broth cultures, and bacteria from broth cultures grew with morphology typical of
H. pylori
when grown on blood agar plates. Analysis by PCR of bacteria isolated from blood agar plates and broth cultures indicated that a single strain of bacteria (
H. pylori
) was responsible for both morphologies.
Immunohistochemical Detection of JC Virus in Nontumorous Renal Tissue of a Patient with Renal Cancer but without Progressive Multifocal Leukoencephalopathy
Authors: Aoki Naoto , Kitamura Tadaichi , Tominaga Takashi , Fukumori Nobutaka , Sakamoto Yosimitsu , Kato Kenzo , Mori Mayumi 
Published: December 2019

ABSTRACT
We performed immunohistochemical staining on the nontumorous renal tissue of 45 patients with renal cancer but without progressive multifocal encephalopathy using JCV-specific antibody. For one patient we found positive staining of the nuclei of the renal collecting ducts. Immunoelectron microscopic examination of the positive cell nuclei revealed electron-dense polyomavirus-like particles.