bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow Cytometry Compared with Indirect Immunofluorescence for Rapid Detection of Dengue Virus Type 1 after Amplification in Tissue Culture
Authors: Kao Chuan-Liang , Wu Meng-Chan , Chiu Yen-Hui , Lin Jing-Lin , Wu Yin-Chang , Yueh Yi-Yung , Chen Li-Kuang , Shaio Men-Fang , King Chwan-Chuen 
Published: July 2002

ABSTRACTDengue virus (DV) was detected early in infected mosquito C6/36 cells by using indirect immunofluorescence (IF) in conjunction with flow cytometry. Three fixation-permeabilization methods and three DV serotype 1 (DEN-1)-specific monoclonal antibodies, 8-8 (anti-E), 16-4 (anti-NS1), and 15F3-1 (anti-NS1), were evaluated for the detection of DEN-1 in infected C6/36 cells. We found that these three monoclonal antibodies were capable of detecting DV in C6/36 cells as early as 24 h postinoculation by using a conventional indirect IF stain. Both 8-8 and 16-4 detected DV earlier and showed a greater number of DV-positive cells than 15F3-1. In flow cytometry, 3% paraformaldehyde plus 0.1% Triton X-100 with 16-4, the best fixation-permeabilization method for testing DV, showed higher sensitivity (up to 1 PFU) than indirect IF stain. The higher sensitivity of 16-4 in detecting DEN-1 was found with both IF and flow cytometry. Flow cytometry, which had a sensitivity similar to that of nested reverse transcription-PCR, was more sensitive in detecting DV in the infected mosquito cells 10 h earlier than the conventional IF stain. When clinical specimens were amplified in mosquito C6/36 cells and then assayed for DV using flow cytometry and conventional virus isolation at day 7 postinfection, both methods had 97.22% (35 out of 36) agreement. Moreover, among 12 positive samples which were detected by conventional culture method, the flow cytometry assay could detect DV in 58.33% (7 out of 12) of samples even at day 3 postinfection. In conclusion, both monoclonal antibodies 8-8 and 16-4 can be used for the early detection of DEN-1-infected C6/36 cells, with 16-4 (anti-NS1) being the best choice for the rapid diagnosis of DV by both the IF staining and flow cytometry methods.
Evaluation of BACTEC MGIT 960 and BACTEC 460TB Systems for Recovery of Mycobacteria from Clinical Specimens of a University Hospital with Low Incidence of Tuberculosis
Authors: Leitritz Lorenz , Schubert Sören , Bücherl Bettina , Masch Adelheid , Heesemann Jürgen , Roggenkamp Andreas 
Published: July 2002

ABSTRACT

Clinical samples obtained over a period of 8 months (
n
= 2,624) were processed in parallel with the BACTEC 460TB system, with the MGIT 960 system, and in Löwenstein-Jensen (LJ) medium, resulting in the recovery of 127 mycobacteria. Recovery rates in combinations of the BACTEC 460TB or MGIT 960 system with LJ were, respectively, 94.7 and 94.7% for
Mycobacterium tuberculosis
complex (
n
= 57) and 91.4 and 70.0% for nontuberculous mycobacteria (
n
= 70). Contamination rates, elevated in the MGIT 960 system, were associated with patients (cystic fibrosis) and type of material but not with transport time. Detection time was reduced in the MGIT 960 system.
Heterogeneity and Compartmentalization of
Pneumocystis carinii
f. sp.
hominis
Genotypes in Autopsy Lungs
Authors: Helweg-Larsen Jannik , Lundgren Bettina , Lundgren Jens D. 
Published: July 2002

ABSTRACT

The extent and importance of genotype heterogeneity of
Pneumocystis carinii
f. sp.
hominis
within lungs have not previously been investigated. Two hundred forty PCR clones obtained from respiratory specimens and lung segments from three patients with fatal
P. carinii
pneumonia were investigated to detect genetic diversity in the internal transcribed spacer (ITS) region of the nuclear rRNA operon, the mitochondrial large-subunit (mtLSU) rRNA gene, and the dihydropteroate synthase-encoding gene. For two of the three examined patients, a mixture of different mtLSU rRNA and ITS genotypes was observed. Not all genotypes present in the lungs at autopsy were detected in the diagnostic respiratory samples. Compartmentalization of specific ITS and mtLSU rRNA sequence types was observed in different lung segments. In conclusion, the interpretation of genotype data and in particular ITS sequence types in the assessment of epidemiological questions should be cautious since genotyping done on respiratory samples cannot a priori be assumed to represent all genotypes present within the lung.
Standardization of Broth Microdilution and Disk Diffusion Susceptibility Tests for
Actinobacillus pleuropneumoniae
and
Haemophilus somnus
: Quality Control Standards for Ceftiofur, Enrofloxacin, Florfenicol, Gentamicin, Penicillin, Tetracycline, Tilmicosin, and Trimethoprim-Sulfamethoxazole
Authors: McDermott P. F. , Barry A. L. , Jones R. N. , Stein G. E. , Thornsberry C. , Wu C. C. , Walker R. D. 
Published: July 2002

ABSTRACT

Quality control (QC) standards for the in vitro antimicrobial susceptibility testing of two fastidious veterinary pathogens,
Actinobacillus pleuropneumoniae
and
Haemophilus somnus
, were developed in a multilaboratory study according to procedures established by the National Committee for Clinical Laboratory Standards for broth microdilution and disk diffusion testing. The medium recommended for the broth microdilution testing is cation-adjusted Mueller-Hinton broth supplemented with 2% lysed horse blood, 2% yeast extract, and 2% supplement C. This medium has been designated veterinary fastidious medium. The medium recommended for the disk diffusion testing is chocolate Mueller-Hinton agar. The recommended QC organisms are
A. pleuropneumoniae
ATCC 27090 and
H. somnus
ATCC 700025. The QC MICs of ceftiofur, enrofloxacin, florfenicol, gentamicin, penicillin, tetracycline, tilmicosin, and trimethoprim-sulfamethoxazole were determined for each isolate, as were the zone size ranges. Of the results from the participating laboratories, 94.0% of the zone diameter results and 97.0% of the MIC results fell within the suggested QC ranges for all compounds. These QC guidelines should allow greater accuracy in interpreting results when testing these antimicrobial agents against fastidious pathogens.
Staphylococcus aureus
Isolated in Cases of Impetigo Produces Both Epidermolysin A or B and LukE-LukD in 78% of 131 Retrospective and Prospective Cases
Authors: Gravet A. , Couppié P. , Meunier O. , Clyti E. , Moreau B. , Pradinaud R. , Monteil H. , Prévost G. 
Published: July 2002

ABSTRACT

Clinical symptoms of impetigo and staphylococcal scalded skin syndrome may not only be expressed as the splitting of cell layers within the epidermis but are often accompanied by some localized inflammation. Toxin patterns of
Staphylococcus aureus
isolates originating from patients with impetigo and also from those with other primary and secondary skin infections in a retrospective isolate collection in France and a prospective isolate collection in French Guiana revealed a significant association (75% of the cases studied) of impetigo with production of at least one of the epidermolysins A and B and the bicomponent leucotoxin LukE-LukD (
P
< 0.001). However, most of the isolates were able to produce one of the nonubiquitous enterotoxins. Pulsed-field gel electrophoresis (PFGE) of genomic DNA hydrolyzed with
Sma
I showed a polymorphism of the two groups of isolates despite the fact that endemic clones were suspected in French Guiana and France. The combination of toxin patterns with PFGE fingerprinting may provide further discrimination among isolates defined in a given cluster or a given pulsotype and account for a specific virulence. The new association of toxins with a clinical syndrome may reveal principles of the pathological process.
Sterilization of
Mycobacterium tuberculosis
Erdman Samples by Antimicrobial Fixation in a Biosafety Level 3 Laboratory
Authors: Schwebach J. Reid , Jacobs William R. , Casadevall Arturo 
Published: July 2002

ABSTRACT

Incomplete sterilization of
Mycobacterium tuberculosis
Erdman cultures followed 1 h of incubation in low concentrations of glutaraldehyde (0.5 and 1.0%) or azide. In contrast, 2.5% glutaraldehyde, paraformaldehyde (2 or 4%), Vesphine IIse or 5% formalin sterilized these samples after 1 h. These results suggest caution in removing fixed
M. tuberculosis
samples from biosafety level 3.
Use of Immunoglobulin G Antibody Avidity for Differentiation of Primary Human Herpesvirus 6 and 7 Infections
Authors: Ward K. N. , Turner D. J. , Parada X. Couto , Thiruchelvam A. D. 
Published: July 2002

ABSTRACTA human herpesvirus 7 (HHV-7) indirect immunofluorescence antibody avidity test was developed and used with an existing human herpesvirus 6 (HHV-6) antibody avidity test to detect and distinguish low-avidity antibodies to HHV-6 and HHV-7 and hence the respective primary infections. With sera from 269 British children aged 0 to 179 weeks, the tests showed that most (10 of 98 serum samples [13%]) HHV-6 low-avidity antibody was found in the first year of life, whereas for HHV-7, most (18 of 101 serum samples [20%]) HHV-7 low-avidity antibody was found in the second year of life. Five children had low-avidity antibodies to both viruses. Of nine Japanese children with previously serologically proven primary HHV-6 or HHV-7 infections, eight had low-avidity antibody only to the relevant virus, but one child had low-avidity antibodies to HHV-6 and HHV-7. The avidity tests were applied to five British children and further proof of viral infection was sought by the detection of specific DNA in serum or plasma, and saliva or cerebrospinal fluid. In two children who had low-avidity antibody to HHV-7 but who were seronegative for HHV-6, only HHV-7 was found. Both viruses were detected in one child with low-avidity HHV-7 antibody and high-avidity HHV-6 antibody. In two children with low-avidity antibodies to both viruses, HHV-6 and HHV-7 DNAs were found, confirming dual primary infections and excluding antibody cross-reactivity.
Outbreak of
Pichia anomala
Infection in the Pediatric Service of a Tertiary-Care Center in Northern India
Authors: Chakrabarti A. , Singh K. , Narang A. , Singhi S. , Batra R. , Rao K. L. N. , Ray P. , Gopalan S. , Das S. , Gupta V. , Gupta A. K. , Bose S. M. , McNeil M. M. 
Published: July 2002

ABSTRACT

An outbreak of nosocomial fungemia due to the unusual yeast,
Pichia anomala
occurred in the pediatric wards of our hospital over a period of 23 months (April 1996 to February 1998). A total of 379 neonates and children (4.2% admissions) were infected. The probable index case was admitted to the pediatric emergency ward, with subsequent transmission to the premature nursery, pediatric intensive care units, and other children wards. Carriage on the hands of health care personnel was likely to be responsible for dissemination of the fungus. The outbreak could only be controlled after a health education campaign to improve hand-washing practices was instituted and after nystatin-fluconazole prophylaxis to all premature neonates and high-risk infants was introduced. In a case-control study, we identified a lower gestational age, a very low birth weight (<1,500 g), and a longer duration of hospital stay as significant risk factors associated with
P. anomala
fungemia in premature neonates. We conducted a culture prevalence survey of 50 consecutive premature neonates and found that 28% were colonized with
P. anomala
at a skin or mucosal site on the date of delivery and that 20% of these neonates subsequently developed
P. anomala
fungemia. We performed multilocus enzyme electrophoresis on 40
P. anomala
outbreak isolates (including patient and health care workers' hand isolates), and the results suggested that these isolates were identical. Our study highlights the importance of
P. anomala
as an emerging nosocomial fungal pathogen.
Helicobacter
sp. Flexispira Bacteremia in an Immunocompetent Young Adult
Authors: Iten Anne , Graf Susanne , Egger Martin , Täuber Martin , Graf Joerg 
Published: July 2002

ABSTRACT

A young immunocompetent patient was admitted for a febrile illness with malaise, arthralgias, painful leg swelling, and polyserositis. Shortly prior to becoming ill, the patient had traveled to the Northern African desert. The symptoms disappeared during treatment with antibiotics (doxycycline and ceftriaxone) but recurred twice after stopping therapy. A motile gram-negative fusiform rod was isolated from a blood culture taken on the first admission. Analysis of the 16S rRNA gene of the blood culture isolate revealed close similarity with
Helicobacter
sp. flexispira taxon 8 (99.9% identity), a species that was previously reported as “
Flexispira rappini
.” This is the first reported case of a recurrent
Helicobacter
sp. flexispira bacteremia in an adult, immunocompetent patient.
Genotyping
Neisseria gonorrhoeae
Using Fluorescent Amplified Fragment Length Polymorphism Analysis
Authors: Palmer Helen M. , Arnold Catherine 
Published: July 2002

ABSTRACT

An evaluation of fluorescent amplified fragment length polymorphism (FAFLP) for typing
Neisseria gonorrhoeae
using 52 isolates revealed that its discriminatory power approached that of Opa-typing in identifying epidemiologically linked isolates. Automated, accurate sizing of FAFLP amplified fragments permits objective data analysis and storage, making it an attractive method for large surveillance projects.
Characterization of IS
6110
Restriction Fragment Length Polymorphism Patterns and Mechanisms of Antimicrobial Resistance for Multidrug-Resistant Isolates of
Mycobacterium tuberculosis
from a Major Reference Hospital in Assiut, Egypt
Authors: Abbadi Said , Rashed Heba G. , Morlock Glenn P. , Woodley Charles L. , El Shanawy O. , Cooksey Robert C. 
Published: July 2002

ABSTRACT

We evaluated 25
Mycobacterium tuberculosis
isolates from patients at a major Egyptian reference hospital in Assiut, Egypt, who had been treated for at least 1 year for tuberculosis. Typing patterns (IS
6110
) were diverse, and multidrug resistance was found among 11 (44%) of the isolates. Mutations associated with antimicrobial drug resistance were found in
rpoB,
katG, rpsL,
and
embB
in the resistant isolates.
Comparison of Restriction Fragment Length Polymorphism, Microsatellite Length Polymorphism, and Random Amplification of Polymorphic DNA Analyses for Fingerprinting
Aspergillus fumigatus
Isolates
Authors: Bart-Delabesse Emmanuelle , Sarfati Jacqueline , Debeaupuis Jean-Paul , van Leeuwen Willem , van Belkum Alex , Bretagne Stephane , Latge Jean-Paul 
Published: July 2002

ABSTRACT

Aspergillus fumigatus
fingerprints generated by random amplification of polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP) upon hybridization with repeated DNA sequences, and PCR detection of microsatellite length polymorphism (MLP) were compared among 67 isolates. In contrast to RAPD, RFLP and MLP gave discriminating and significantly concordant genotyping results.
Evaluation of the VITEK 2 System for the Identification and Susceptibility Testing of Three Species of Nonfermenting Gram-Negative Rods Frequently Isolated from Clinical Samples
Authors: Joyanes Providencia , del Carmen Conejo Marı́a , Martı́nez-Martı́nez Luis , Perea Evelio J. 
Published: July 2002

ABSTRACT

VITEK 2 is a new automatic system for the identification and susceptibility testing of the most clinically important bacteria. In the present study 198 clinical isolates, including
Pseudomonas aeruginosa
(
n
= 146),
Acinetobacter baumannii
(
n
= 25), and
Stenotrophomonas maltophilia
(
n
= 27) were evaluated. Reference susceptibility testing of cefepime, cefotaxime, ceftazidime, ciprofloxacin, gentamicin, imipenem, meropenem, piperacillin, tobramycin, levofloxacin (only for
P. aeruginosa
), co-trimoxazole (only for
S. maltophilia
), and ampicillin-sulbactam and tetracycline (only for
A. baumannii
) was performed by microdilution (NCCLS guidelines). The VITEK 2 system correctly identified 91.6, 100, and 76% of
P. aeruginosa
,
S. maltophilia
, and
A. baumannii
isolates, respectively, within 3 h. The respective percentages of essential agreement (to within 1 twofold dilution) for
P. aeruginosa
and
A. baumannii
were 89.0 and 88.0% (cefepime), 91.1 and 100% (cefotaxime), 95.2 and 96.0% (ceftazidime), 98.6 and 100% (ciprofloxacin), 88.4 and 100% (gentamicin), 87.0 and 92.0% (imipenem), 85.0 and 88.0% (meropenem), 84.2 and 96.0% (piperacillin), and 97.3 and 80% (tobramycin). The essential agreement for levofloxacin against
P. aeruginosa
was 86.3%. The percentages of essential agreement for ampicillin-sulbactam and tetracycline against
A. baumannii
were 88.0 and 100%, respectively. Very major errors for
P. aeruginosa
(resistant by the reference method, susceptible with the VITEK 2 system [resistant to susceptible]) were noted for cefepime (0.7%), cefotaxime (0.7%), gentamicin (0.7%), imipenem (1.4%), levofloxacin (2.7%), and piperacillin (2.7%) and, for one strain of
A. baumannii,
for imipenem. Major errors (susceptible to resistant) were noted only for
P. aeruginosa
and cefepime (2.0%), ceftazidime (0.7%), and piperacillin (3.4%). Minor errors ranged from 0.0% for piperacillin to 22.6% for cefotaxime against
P. aeruginosa
and from 0.0% for piperacillin and ciprofloxacin to 20.0% for cefepime against
A. baumannii
. The VITEK 2 system provided co-trimoxazole MICs only for
S. maltophilia
; no very major or major errors were obtained for co-trimoxazole against this species. It is concluded that the VITEK 2 system allows the rapid identification of
S. maltophilia
and most
P. aeruginosa
and
A. baumannii
isolates. The VITEK 2 system can perform reliable susceptibility testing of many of the antimicrobial agents used against
P. aeruginosa
and
A. baumannii
. It would be desirable if new versions of the VITEK 2 software were able to determine MICs and the corresponding clinical categories of agents active against
S. maltophilia
.
Evaluation of PCR-Restriction Profile Analysis and IS
2404
Restriction Fragment Length Polymorphism and Amplified Fragment Length Polymorphism Fingerprinting for Identification and Typing of
Mycobacterium ulcerans
and
M. marinum
Authors: Chemlal K. , Huys G. , Fonteyne P.-A. , Vincent V. , Lopez A. G. , Rigouts L. , Swings J. , Meyers W. M. , Portaels F. 
Published: July 2002

ABSTRACT

Mycobacterium ulcerans
and
M. marinum
are emerging necrotizing mycobacterial pathogens that reside in common reservoirs of infection and exhibit striking pathophysiological similarities. Furthermore, the interspecific taxonomic relationship between the two species is not clear as a result of the very high phylogenetic relatedness (i.e., >99.8% 16S rRNA sequence similarity), in contrast to only 25 to 47% DNA relatedness. To help understand the genotypic affiliation between these two closely related species, we performed a comparative analysis including PCR restriction profile analysis (PRPA), IS
2404
restriction fragment length polymorphism (RFLP), and amplified fragment length polymorphism (AFLP) on a set of
M. ulcerans
(
n
= 29) and
M. marinum
(
n
= 28) strains recovered from different geographic origins. PRPA was based on a triple restriction of the 3′ end region of 16S rRNA, which differentiated
M. ulcerans
into three types; however, the technique could not distinguish
M. marinum
from
M. ulcerans
isolates originating from South America and Southeast Asia. RFLP based on IS
2404
produced six
M. ulcerans
types related to six geographic regions and did not produce any band with
M. marinum
, confirming the previous findings of Chemlal et al. (K. Chemlal, K. DeRidder, P. A. Fonteyne, W. M. Meyers, J. Swings, and F. Portaels, Am. J. Trop. Med. Hyg. 64:270–273, 2001). AFLP analysis resulted in profiles which grouped
M. ulcerans
and
M. marinum
into two separate clusters. The numerical analysis also revealed subgroups among the
M. marinum
and
M. ulcerans
isolates. In conclusion, PRPA appears to provide a rapid method for differentiating the African
M. ulcerans
type from other geographical types but is unsuitable for interspecific differentiation of
M. marinum
and
M. ulcerans
. In comparison, whole- genome techniques such as IS
2404
-RFLP and AFLP appear to be far more useful in discriminating between
M. marinum
and
M. ulcerans
, and may thus be promising molecular tools for the differential diagnosis of infections caused by these two species.
Selective Amplification of
tyv
(rfbE),
prt
(rfbS),
viaB
, and
fliC
Genes by Multiplex PCR for Identification of
Salmonella enterica
Serovars Typhi and Paratyphi A
Authors: Hirose Kenji , Itoh Ken-Ichiro , Nakajima Hiroshi , Kurazono Takayuki , Yamaguchi Masanori , Moriya Kazuo , Ezaki Takayuki , Kawamura Yoshiaki , Tamura Kazumichi , Watanabe Haruo 
Published: July 2002

ABSTRACT

The PCR primers for O, H, and Vi antigen genes,
tyv
(rfbE),
prt
(
rfbS
),
fliC-d, fliC-a
, and
viaB
, were designed and used for the rapid identification of
Salmonella enterica
serovars Typhi and Paratyphi A with multiplex PCR. The results showed that all the clinical isolates examined of
Salmonella
serovars Typhi and Paratyphi A were accurately identified by this assay.
Rapidly Increasing Prevalence of Penicillin-Resistant
Streptococcus
pneumoniae
in Middle Tennessee: a 10-Year Clinical and Molecular Analysis
Authors: Tang Yi-Wei , Li Haijing , Griffin Jane P. , Haas David W. , D'Agata Erika M. C. 
Published: July 2002

ABSTRACT

The clinical and molecular epidemiology of penicillin-resistant
Streptococcus
pneumoniae
and the diagnostic accuracy of a six-primer PCR assay in identifying penicillin resistance were analyzed by using clinical isolates recovered over a 10-year period in middle Tennessee. The prevalence of non-penicillin-susceptible
S. pneumoniae
isolates (MIC, ≥0.1 μg/ml) increased from 10% in 1990 to 70% in 1999 (
P
< 0.001). Among
S. pneumoniae
isolates for which the penicillin MIC was ≥2 μg/ml (highly penicillin-resistant
S. pneumoniae
[PRSP]), 23 and 5% were resistant to at least three and at least five other antimicrobial classes, respectively. Pulsed-field gel electrophoresis identified 13 unique strain types, with type B accounting for 33% of PRSP isolates. The sensitivity, specificity, and negative and positive predictive values of the PCR assay in detecting PRSP were 99, 100, 99, and 100%, respectively. Penicillin resistance is rapidly increasing among
S. pneumoniae
isolates in Tennessee. The simultaneous detection of
S. pneumoniae
and high-level penicillin resistance can be accurately performed with the six-primer PCR assay.