bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biofilm-Forming Ability ofCandida albicansIs Unlikely To Contribute to High Levels of Oral Yeast Carriage in Cases of Human Immunodeficiency Virus Infection
Authors: Jin Y. , Yip H. K. , Samaranayake Y. H. , Yau J. Y. , Samaranayake L. P. 
Published: July 2003

ABSTRACTAn increased prevalence of candidal carriage and oral candidiasis is common in cases of human immunodeficiency virus (HIV) infection, and the reasons for this may include the enhanced ability of colonizing yeasts to produce biofilms on mucosal surfaces. The aim of the present study was therefore to examine the differences, if any, in the biofilm-forming abilities of 26Candida albicansyeast isolates from HIV-infected individuals and 20 isolates from HIV-free individuals, as this attribute of yeast isolates from patients with HIV disease has not been examined before. Biofilm formation in microtiter plate wells was quantitatively determined by both the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) reduction method and the crystal violet method. Although candidal biofilm formation could be quantitatively evaluated by either technique, the better reproducibility (P< 0.05) of the XTT reduction assay compared with that of the crystal violet method led us to conclude that the former is more reliable. There were no significant quantitative differences in biofilm formation betweenC. albicansisolates from HIV-infected patients and isolates from HIV-free individuals during in vitro incubation in a multiwell culture system over a period of 66 h. Three of eight host factors in the HIV-infected group were found to be associated with candidal biofilm formation. Thus, yeasts isolated from older individuals and those with higher CD4-cell counts exhibited decreased biofilm formation, while the findings for yeasts from individuals receiving zidovudine showed the reverse (P< 0.05 for all comparison). Our data indicate that attributes other than biofilm formation may contribute to the increased oral yeast carriage rates in cases of HIV infection.
Continued Low Rates of Transmission of
Mycobacterium tuberculosis
in Norway
Authors: Dahle Ulf R. , Sandven Per , Heldal Einar , Caugant Dominique A. 
Published: July 2003

ABSTRACT

In this study, we determined the genetic diversity of
Mycobacterium tuberculosis
isolated in Norway from 1999 to 2001. The results were compared to those for strains isolated from 1994 to 1998. A total of 818 patients were diagnosed with tuberculosis (TB) during the last 3-year period. Of these cases, 576 (70%) were verified by culturing, and strains from 551 patients (96%) were analyzed by the IS
6110
restriction fragment length polymorphism (RFLP) method. We excluded 13 strains (2.4%) from the analyses, since they were found to represent false-positive samples. A total of 67 strains (12%) that carried fewer than five copies of IS
6110
were analyzed by spoligotyping. The strains were from 157 patients (29%) of Norwegian origin and 381 patients (71%) of foreign origin. The rate of diversity among all of the strains was 90%, while in 1994 to 1998 it was 87%. Clusters were assumed to have arisen from recent transmission; the degree of such transmission was 10% in 1999 to 2001, while for the whole 8-year period (1994 to 2001), it was 11%. Of the 109 patients diagnosed as being part of a cluster in 1999 to 2001, 89 were infected with a strain that carried more than four copies of IS
6110
. Among these 89 patients, 52 (58%) were infected with a strain that had already been identified in 1994 to 1998. The results indicated that most cases of TB in Norway were due to the import of new strains rather than to transmission within the country. This finding demonstrates that screening of immigrants for TB upon arrival in Norway needs to be improved. Outbreaks, however, were caused mainly by strains that have been circulating in Norway for many years.
Characterization of a Lipoprotein Common to
Legionella
Species as a Urinary Broad-Spectrum Antigen for Diagnosis of Legionnaires' Disease
Authors: Kim Min Ja , Sohn Jang Wook , Park Dae Won , Park Seung Chul , Chun Byung Chul 
Published: July 2003

ABSTRACT

We have previously identified the
Legionella
19-kDa peptidoglycan-associated lipoprotein (PAL) as a species-common immunodominant antigen. We describe here for the first time the excretion and detection of the PAL antigen in infected urine specimens, which is useful for the diagnosis of Legionnaires' disease. Rabbit anti-PAL immunoglobulin G (IgG) antibody was produced by immunization with the purified, recombinant PAL of
Legionella pneumophila
serogroup 1 and used in the PAL antigen capture enzyme-linked immunosorbent assay (ELISA) to detect urinary PAL antigen. A soluble-antigen capture ELISA using rabbit IgG antibodies against
Legionella
soluble antigens was prepared independently and used as a broad-spectrum standard test to detect soluble antigens of several
Legionella
species. Urine samples were obtained from guinea pigs experimentally infected with each of
L. pneumophila
serogroups 1, 3, and 6, and other
Legionella
species. The absorbance values of the PAL antigen ELISA highly correlated with those of the soluble-antigen ELISA in infected urine samples, with a correlation coefficient of 0.84 (
P
< 0.01). When applied to 17 infected urine samples and 67 negative controls from guinea pigs, the sensitivity and specificity of the PAL antigen capture ELISA were 88.2 and 95.5%, respectively. Compared to the commercial Biotest enzyme immunoassay, the PAL antigen ELISA was more efficient for detecting pneumophila non-serogroup 1 and nonpneumophila species. None of the 161 control human urine specimens obtained from healthy adults and patients with either non-
Legionella
pneumonia or urinary tract infections tested positive in the PAL antigen ELISA. The present study shows that the
Legionella
PAL is a very useful broad-spectrum antigen for urinary diagnostic testing. Moreover, since recombinant PAL antigen can be produced more efficiently than the soluble antigens, the development of a broad-spectrum diagnostic immunoassay based on the detection of the PAL antigen appears to be warranted.
Evaluation of Culture Methods and a DNA Probe-Based PCR Assay for Detection of
Campylobacter
Species in Clinical Specimens of Feces
Authors: Maher Majella , Finnegan Cathriona , Collins Evelyn , Ward Brid , Carroll Cyril , Cormican Martin 
Published: July 2003

ABSTRACT

Campylobacter
species are the leading agents of bacterial gastroenteritis in developed countries. In this study 320 specimens of feces from patients with symptoms of acute gastroenteritis were cultured for
Campylobacter
species by direct plating on modified charcoal cefoperazone deoxycholate agar and by enrichment in modified Preston broth, with or without blood added, for 48 h at 37°C prior to plating. A 16S/23S PCR/DNA probe membrane-based colorimetric detection assay was evaluated on a subset of the feces (
n
= 127), including 18 culture-positive and 109 culture-negative specimens. DNA was extracted directly from the fecal specimens by using the QIAamp DNA stool Minikit for the DNA probe-based PCR assay (PCR/DNA probe assay). A second PCR/DNA probe assay based on the 16S rRNA gene in C
ampylobacter
spp. was applied to all specimens that were culture negative, PCR/DNA positive on initial analysis.
Campylobacter
species were cultured in 20 of the 320 specimens. The 16S/23S PCR/DNA probe assay detected campylobacter DNA in 17 of 18 (94% sensitivity) culture-positive specimens and in 41 (38%) culture-negative specimens. The presence of campylobacter DNA in 35 of 41 culture-negative specimens was confirmed by the 16S PCR/DNA probe assay. DNA sequence analysis of seven 16S/23S PCR products and five 16S PCR products amplified from a selection of these specimens confirmed the presence of campylobacter DNA and more specifically
Campylobacter jejuni
,
C. concisus
,
C. curvus
, and
C. gracilis
DNA in these specimens. The molecular assays described in this study are rapid methods for the detection and identification of
Campylobacter
species in fecal specimens. The finding of
Campylobacter
spp. DNA in a large number of specimens of feces from patients with no other identified cause of diarrhea may suggest that
Campylobacter
spp. other than
C. jejuni
and
C. coli
may account for a proportion of cases of acute gastroenteritis in which no etiological agent is currently identified.
Human Metapneumovirus Associated with Respiratory Tract Infections in a 3-Year Study of Nasal Swabs from Infants in Italy
Authors: Maggi Fabrizio , Pifferi Massimo , Vatteroni Marialinda , Fornai Claudia , Tempestini Elena , Anzilotti Silvia , Lanini Letizia , Andreoli Elisabetta , Ragazzo Vincenzo , Pistello Mauro , Specter Steven , Bendinelli Mauro 
Published: July 2003

ABSTRACT
The newly described human metapneumovirus (hMPV) is reported here to be more commonly associated with lower respiratory tract disease. The present study examined nasal swab specimens from 90 infants with acute respiratory tract infections in Pisa, Italy, over a period of three respiratory virus seasons. The incidence of infection varied in each of the 3 years, with the rates of positivity for hMPV being 7% in 2001 but 37 and 43% in 2000 and 2002, respectively. hMPV was noted to occur seasonally in a pattern typical of the frequency of occurrence of respiratory syncytial virus. More than one-half (14 of 23) of the infants infected with hMPV had bronchopneumonia. One-third (9 of 23) of the hMPV-infected patients were also infected with another respiratory virus, a relationship that has not previously been reported. Mixed infections did not account for a higher percentage of cases of bronchopneumonia than hMPV infection alone did. Furthermore, 7 of 17 infants whose plasma was also tested for hMPV RNA were demonstrated to have virus in both nasal swab and blood specimens. The study indicates that hMPV is seen as commonly as other respiratory viruses, may be associated with severe respiratory disease in infants, can establish mixed infections with other respiratory viruses, and has a seasonal occurrence.
Determination of Amoebicidal Activities of Multipurpose Contact Lens Solutions by Using a Most Probable Number Enumeration Technique
Authors: Beattie Tara K. , Seal David V. , Tomlinson Alan , McFadyen Angus K. , Grimason Anthony M. 
Published: July 2003

ABSTRACT

Six multipurpose contact lens solutions [All-in-One, All-in-One (Light), ReNu MultiPlus, Optifree Express, Complete, and Solo-care soft] were tested for their efficacies against
Acanthamoeba castellanii
trophozoites and cysts by using a most probable number (MPN) technique for amoebic enumeration. Against trophozoites, All-in-One, ReNu Multiplus, and Optifree Express achieved total kill (log reduction of >3) after the manufacturer's minimum recommended disinfection time (MMRDT), with the remaining solutions failing to reach a log reduction of 1. After 24 h of exposure, all solutions proved trophozoiticidal, achieving, with the exception of Complete (log reduction of 3.13), total kill. Against cysts, All-in-One gave a log reduction of >3 within the MMRDT, with all other solutions failing to achieve a log reduction of 1. After 24 h of exposure, All-in-One achieved total kill of cysts (log reduction of 3.74), ReNu MultiPlus gave a log reduction of 3.15, and the remaining solutions reached log reductions of between 1.09 and 2.27. The MPN technique provides a simple, reliable, and reproducible method of amoebic enumeration that depends on simply establishing the presence or absence of growth on culture plates inoculated with a series of dilutions and determining the MPN of amoebae present from statistical tables. By use of this technique, two of the multipurpose solutions tested, ReNu MultiPlus and Optifree Express, demonstrated effective trophozoiticidal activities within the recommended disinfection times; however, only All-in-One proved effective against both trophozoites and cysts over the same time period. This MPN technique, which uses axenically produced trophozoites and mature, double-walled cysts, has the potential to form the basis of a national standard for amoebicidal efficacy testing of multipurpose contact lens disinfecting solutions.
Molecular Epidemiology of Methicillin-ResistantStaphylococcus aureusStrains Causing Neonatal Toxic Shock Syndrome-Like Exanthematous Disease in Neonatal and Perinatal Wards
Authors: Kikuchi Ken , Takahashi Naoto , Piao Chuncheng , Totsuka Kyoichi , Nishida Hiroshi , Uchiyama Takehiko 
Published: July 2003

ABSTRACTNeonatal toxic shock syndrome-like exanthematous disease (NTED) is a new neonatal disease caused by toxic shock syndrome toxin 1 (TSST-1). We conducted a prospective surveillance study and characterized the methicillin-resistantStaphylococcus aureus(MRSA) strains isolated from patients with NTED and compared them with the strains from patients with other MRSA infections and asymptomatic carriers. The study was performed in the neonatal intensive care unit and a general neonatal and maternal ward in the Tokyo Women's Medical University Hospital (TWMUH) from September to December 1998. Among 103 patients eligible for the study, MRSA was detected in 62 (60.2%) newborns; of these 62 newborns, 8 (12.9%) developed NTED, 1 (1.6%) had another MRSA infection, and 53 (85.5%) were asymptomatic MRSA carriers. Sixty-nine MRSA strains were obtained from the 62 newborns. DNA fingerprinting by pulsed-field gel electrophoresis showed two clusters: clone A with 8 subtypes and clone B. Sixty-seven of the 69 MRSA strains (97.1%) belonged to clone A, and type A1 was the most predominant (42 of 69 strains; 60.9%) in every neonatal and perinatal ward. All but one of the clone A strains had the TSST-1 and staphylococcal enterotoxin C genes. We also analyzed eight MRSA strains from eight NTED patients in five hospitals in Japan other than TWMUH. All the MRSA strains from NTED patients also belonged to clone A. These results suggest that a single clone that predominated in the neonatal wards of six hospitals might have caused NTED. However, the occurrence of NTED might not be dependent on the presence of an NTED-specific strain.
High Prevalence of M184 Mutation among Patients with Viroimmunologic Discordant Responses to Highly Active Antiretroviral Therapy and Outcomes after Change of Therapy Guided by Genotypic Analysis
Authors: Nicastri Emanuele , Sarmati Loredana , d'Ettorre Gabriella , Parisi Saverio G. , Palmisano Lucia , Galluzzo Clementina , Montano Marco , Uccella Ilaria , Amici Roberta , Gatti Francesca , Vullo Vincenzo , Concia Ercole , Vella Stefano , Andreoni Massimo 
Published: July 2003

ABSTRACT

Whether highly active antiretroviral therapy (HAART) should be modified in patients with persistent increases in CD4
+
T cells despite detectable viral loads is an unresolved question. Forty-three heavily pretreated human immunodeficiency virus (HIV)-infected patients with virologic failure during HAART were studied before a change of therapy guided by genotypic analysis and during follow-up. Patients with an increase in CD4
+
cell count (>100 cells/ml) over pre-HAART values were considered to be discordant patients (20 individuals), whereas patients with a lower increase or no increase in CD4
+
cell count were considered failing patients (23 individuals). Based on univariate analysis, a high CD4
+
cell count before antiretroviral treatment, homosexual behavior as a risk factor for HIV infection, reduced drug exposure to nonnucleoside reverse transcriptase inhibitors, low replicative capacity of HIV isolates, and more frequent detection of HIV isolates with a non-B subtype, an R5 biological phenotype, and M184V and T215Y/F mutations were factors associated with a discordant response to HAART. Based on multivariate analysis, only the M184V mutation remained significantly associated with a viroimmunologic discordant response (odds ratio, 25.48; 95% confidence interval, 1.43 to 453.93). No difference in lamivudine exposure was found between discordant (95%) and failing (91%) patients. Twelve months after the genotypic analysis-guided change of therapy, 3 discordant (15%) and 6 failing patients (26%) achieved undetectable viral loads (<50 copies/ml), whereas in patients with HIV RNA loads of >500 copies/ml, discordant responses were observed in 5 out of 15 discordant patients and in 4 out of 16 failing patients. A relationship between the M184V mutation and a viroimmunologic discordant response to HAART was found. After the genotypic analysis-driven change of therapy, similar rates of virologic suppression were detected in the two groups.
Reliability of Nucleic Acid Amplification Methods for Detection of
Chlamydia trachomatis
in Urine: Results of the First International Collaborative Quality Control Study among 96 Laboratories
Authors: Verkooyen Roel P. , Noordhoek Gerda T. , Klapper Paul E. , Reid Jim , Schirm Jurjen , Cleator Graham M. , Ieven Margareta , Hoddevik Gunnar 
Published: July 2003

ABSTRACT

The first European Quality Control Concerted Action study was organized to assess the ability of laboratories to detect
Chlamydia trachomatis
in a panel of urine samples by nucleic acid amplification tests (NATs). The panel consisted of lyophilized urine samples, including three negative, two strongly positive, and five weakly positive samples. Ninety-six laboratories in 22 countries participated with a total of 102 data sets. Of 204 strongly positive samples 199 (97.5%) were correctly reported, and of 506 weakly positive samples 466 (92.1%) were correctly reported. In 74 (72.5%) data sets correct results were reported on all samples, and 17 data sets (16.7%) showed either one false-negative or one false-positive result. In another 11 data sets, two or more incorrect results were reported, and two data sets reported a false-positive result on one negative sample. The Roche COBAS Amplicor test was performed in 44 (43%) data sets, the Abbott LCx assay was performed in 31 (30%) data sets, the Roche Amplicor manual assay was performed in 9 (9%) data sets, an in-house PCR was performed in 9 (9%) data sets, the Becton Dickinson ProbeTec ET assay was performed in 5 (4.9%) data sets, and the GenProbe TMA assay was performed in 4 (3.9%) data sets. The results of the Roche Amplicor manual (95.6% correct), COBAS Amplicor (97.0%), and Abbott LCx (94.8%) tests were comparable (
P
= 0.48). The results with the in-house PCR, BD ProbeTec ET, and GenProbe TMA tests were reported correctly in 88.6, 98, and 92.5% of the tests, respectively. Freeze-drying of clinical urine specimens proved to be a successful method for generating standardized, stable, and easy-to-transport samples for the detection of
C. trachomatis
by using NATs. Although the results, especially the specificity, for this proficiency panel were better than most quality control studies, sensitivity problems occurred frequently, underlining the need for good laboratory practice and reference reagents to monitor the performance of these assays.
Severity of Nonbullous
Staphylococcus aureus
Impetigo in Children Is Associated with Strains Harboring Genetic Markers for Exfoliative Toxin B, Panton-Valentine Leukocidin, and the Multidrug Resistance Plasmid pSK41
Authors: Koning Sander , van Belkum Alex , Snijders Susan , van Leeuwen Willem , Verbrugh Henri , Nouwen Jan , Op ′t Veld Mariet , van Suijlekom-Smit Lisette W. A. , van der Wouden Johannes C. , Verduin Cees 
Published: July 2003

ABSTRACT

Nonbullous impetigo is a common skin infection in children and is frequently caused by
Staphylococcus aureus
. Staphylococcal toxins and especially exfoliative toxin A are known mediators of bullous impetigo in children. It is not known whether this is also true for nonbullous impetigo. We set out to analyze clonality among clinical isolates of
S. aureus
from children with nonbullous impetigo living in a restricted geographical area in The Netherlands. We investigated whether staphylococcal nasal carriage and the nature of the staphylococcal strains were associated with the severity and course of impetigo. Bacterial isolates were obtained from the noses and wounds of children suffering from impetigo. Strains were genetically characterized by pulsed-field gel electrophoresis-mediated typing and binary typing, which was also used to assess toxin gene content. In addition, a detailed clinical questionnaire was filled in by each of the participating patients. Staphylococcal nasal carriage seems to predispose the patients to the development of impetigo, and 34% of infections diagnosed in the Rotterdam area are caused by one clonal type of
S. aureus
. The
S. aureus
strains harbor the exfoliative toxin B (ETB) gene as a specific virulence factor. In particular, the numbers (
P
= 0.002) and sizes (
P
< 0.001) of the lesions were increased in patients infected with an ETB-positive strain. Additional predictors of disease severity and development could be identified. The presence of a staphylococcal plasmid encoding multiple antibiotic resistance traits, as detected by binary typing, was associated with a reduction in the cure rate. Our results recognize that a combination of staphylococcal virulence and resistance genes rather than a single gene determines the development and course of nonbullous impetigo. The identification of these microbial genetic markers, which are predictive of the severity and the course of the disease, will facilitate guided individualized antimicrobial therapy in the future.
Sequence Diversity of the Intergenic Spacer Region of the rRNA Gene of
Malassezia globosa
Colonizing the Skin of Patients with Atopic Dermatitis and Healthy Individuals
Authors: Sugita Takashi , Kodama Minako , Saito Masuyoshi , Ito Tomonobu , Kato Yukihiko , Tsuboi Ryoji , Nishikawa Akemi 
Published: July 2003

ABSTRACT

The lipophilic yeast
Malassezia globosa
is one of the major constituents of the mycoflora of the skin of patients with atopic dermatitis (AD). We compared the genotypes of
M. globosa
colonizing the skin surface of 32 AD patients and 20 healthy individuals for polymorphism of the intergenic spacer (IGS) 1 region of the rRNA gene. Sequence analysis demonstrated that
M. globosa
was divided into four major groups, which corresponded to the sources of the samples, on the phylogenetic tree. Of the four groups, two were from AD patients and one was from healthy subjects. The remaining group included samples from both AD patients and healthy subjects. In addition, the IGS 1 region of
M. globosa
contained short sequence repeats: (CT)
n
, and (GT)
n
. The number of sequence repeats also differed between the IGS 1 of
M. globosa
from AD patients and that from healthy subjects. These findings suggest that a specific genotype of
M. globosa
may play a significant role in AD, although
M. globosa
commonly colonizes both AD patients and healthy subjects.