bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent Emergence of an Epidemic Clindamycin-Resistant Clone of
Clostridium difficile
among Polish Patients with
C. difficile
-Associated Diarrhea
Authors: Pituch Hanna , van Belkum Alex , van den Braak Nicole , Obuch-Woszczatynski Piotr , Verbrugh Henri , Meisel-Mikołajczyk Felicja , Łuczak Mirosław 
Published: September 2003

ABSTRACT

Analysis of both the antibiotic resistance and the virulence characteristics of anaerobic human microbial pathogens is important in order to improve our understanding of a number of clinically significant infectious diseases, including
Clostridium difficile
-associated diarrhea (CDAD). We determined the presence of the clindamycin resistance-associated gene
ermB
and the ribotype of 33
C. difficile
strains isolated from Polish patients suffering from CDAD. While all strains produced cytotoxin B (TcdB), enterotoxin A (TcdA) was produced by a subset of 15 strains only. The results showed that a single
ermB
-positive, TcdA
−
B
+
C. difficile
strain with ribotype A has disseminated widely in the two Warsaw hospitals under investigation. Although different strains with the same phenotype were detected, the genotype A strain appeared to be the only one with a clear epidemic character. Apparently, enhanced local spread of CDAD-causing
C. difficile
may be restricted to a limited number of bacterial genotypes only.
Detection and Analysis of Iron Uptake Components Expressed by
Acinetobacter baumannii
Clinical Isolates
Authors: Dorsey Caleb W. , Beglin Melanie S. , Actis Luis A. 
Published: September 2003

ABSTRACT

The
Acinetobacter baumannii
19606 prototype strain produces a 78-kDa iron-regulated outer membrane protein immunologically related to FatA, which is required for iron acquisition by the fish pathogen
Vibrio anguillarum
via the anguibactin-mediated system. This
A. baumannii
strain also secretes histamine, a biosynthetic precursor of the siderophore anguibactin. In contrast, the
A. baumannii
8399 clinical strain isolated in Oregon produces a siderophore and a putative 73-kDa iron-regulated outer membrane (OM73) receptor that are different from those produced by
V. anguillarum
and
A. baumannii
19606. These observations suggest that different
A. baumannii
clinical isolates express unrelated iron uptake systems. This hypothesis is supported by differences in outer membrane protein profiles among
A. baumannii
isolates obtained from Oregon and Europe. The 19606 isolate and some European isolates expressed a FatA-like protein, while neither 19606 nor any of the European isolates expressed proteins related to OM73. Some European isolates failed to express FatA- and OM73-like proteins. All but one of the Oregon isolates expressed OM73-like proteins, while none of them contained a FatA-like protein. The presence of these proteins always correlated with the presence of the
om73
- and
fatA
-like genes in the cognate strains. While 19606 and a few European isolates produced histamine, none of the Oregon isolates had this capability. Interestingly, one strain each from the Oregon and European isolates did not express any of these products involved in iron acquisition, indicating that they could acquire iron through siderophore-mediated transport systems different from those expressed by the 19606 and 8399 clinical isolates.
Clonal Distribution of Invasive Pneumococcal Isolatesfrom Children and Selected Adults in the United States Prior to7-Valent Conjugate VaccineIntroduction
Authors: Gertz Robert E. , McEllistrem M. Catherine , Boxrud David J. , Li Zhongya , Sakota Varja , Thompson Terry A. , Facklam Richard R. , Besser John M. , Harrison Lee H. , Whitney Cynthia G. , Beall Bernard 
Published: September 2003

ABSTRACT
Theseven-valent pneumococcal conjugated polysaccharide vaccine PC7V was
licensed for use among children in 2000. Since 90 serotypes of
pneumococci exist, an increase in nonvaccine serotypes could occur
through immune selection for capsular type switching. Eleven hundred
sixty-eight invasive isolates (24 serotypes), recovered primarily from
pediatric patients (855 isolates = 73%) and 22 reference
strains of known multilocus sequence types (STs) were subjected to
macrorestriction profiling (pulsed-field gel electrophoresis
[PFGE]). The correlation of 187 ST results (including 49
newly discovered STs) with the PFGE data assigned 1,042 (89.2%)
study isolates to 46 defined clonal complexes or genetic lineages based
on related multilocus STs (BURST). Seventeen clonal complexes were
represented by 2 to 10 related allelic profiles (STs), while 33
lineages (including reference strains) consisted of single STs with 4
or fewer allelic identities to other STs found in the study. Expansion
of the BURST analysis to a global analysis of all known pneumococcal
STs (as of 27 November 2002) reduced the number of single ST lineages
from 33 to 8, and the number of multi-ST clonal complexes was reduced
from 17 to 13. In this work, we established the basic genetic structure
within individual serotypes prior to PC7V use. The resultant database
will be useful for detecting potential selective effects of this
vaccine in postvaccine
surveillance.
Immunoassay Targeting Nonstructural Protein 5 To Differentiate West Nile Virus Infection from Dengue and St. Louis Encephalitis Virus Infections and from Flavivirus Vaccination
Authors: Wong Susan J. , Boyle Rebekah H. , Demarest Valerie L. , Woodmansee Anh N. , Kramer Laura D. , Li Hongmin , Drebot Michael , Koski Raymond A. , Fikrig Erol , Martin Denise A. , Shi Pei-Yong 
Published: September 2003

ABSTRACTWest Nile virus (WNV) is an emerging flavivirus that has caused frequent epidemics since 1996. Besides natural transmission by mosquitoes, WNV can also be transmitted through blood transfusion and organ transplantation, thus heightening the urgency of development of a specific and rapid serologic assay of WNV infection. The current immunoassays lack specificity because they are based on detection of antibodies against WNV structural proteins and immune responses to structural proteins among flaviviruses cross-react to each other. Here, we describe microsphere immunoassays that detect antibodies to nonstructural proteins 3 and 5 (NS3 and NS5). In contrast to immunoassays based on viral envelope and NS3 proteins, the NS5-based assay (i) reliably discriminates between WNV infections and dengue virus or St. Louis encephalitis virus infections, (ii) differentiates between flavivirus vaccination and natural WNV infection, and (iii) indicates recent infections. These unique features of the NS5-based immunoassay will be very useful for both clinical and veterinary diagnosis of WNV infection.
Molecular Typing ofMycobacterium tuberculosisby Using Nine Novel Variable-Number Tandem Repeats across the Beijing Family and Low-Copy-Number IS6110Isolates
Authors: Spurgiesz R. Scott , Quitugua Teresa N. , Smith Kimothy L. , Schupp James , Palmer Eldon G. , Cox Rebecca A. , Keim Paul 
Published: September 2003

ABSTRACTMolecular epidemiological tools for genotyping clinical isolates ofMycobacterium tuberculosishave been developed and used to help track and contain transmission of tuberculosis. We identified 87 short sequence repeat loci within the genome of theM. tuberculosisH37Rv strain. Nine tandem repeats were found to be variable (variable-number tandem repeats [VNTRs]) in a set of 91 isolates. Fifty-seven of the isolates had only four IS6110bands. The other 34 isolates were members of the Beijing strain family. The number of alleles of each these nine VNTRs was determined by examining each isolate. Six of the loci (Mtb-v1, -v4, -v10, -v15, -v18, and -v20) were able to differentiate the Beijing spoligotype identical isolates into seven distinct genotypes. Five of the loci (Mtb-v3, -v5, -v6, -v10, and -v15) were informative in discriminating the four-band IS6110restriction fragment length polymorphism isolates from each other. The Nei's diversity values of each marker ranged from 0.02 to 0.59, with the number of alleles ranging from two to eight across the entire strain set. These nine loci provide a useful, discriminatory extension of VNTR typing methods for application to molecular epidemiologic studies ofM. tuberculosis.
Development and Application of Real-Time PCR Assay for Quantification of
Mycobacterium ulcerans
DNA
Authors: Rondini S. , Mensah-Quainoo E. , Troll H. , Bodmer T. , Pluschke G. 
Published: September 2003

ABSTRACT

Buruli
ulcer, an infection caused by
Mycobacterium ulcerans
, is,
after tuberculosis and leprosy, the third most common mycobacterial
disease. The mode of transmission of
M. ulcerans
is not
exactly known, but since Buruli ulcer often occurs in focalized swampy
areas, it is assumed that there is a reservoir of the pathogen in
stagnant water. Buruli ulcer usually starts as a painless nodule and
can lead to massive destruction of skin, subcutaneous tissue, and
eventually muscle and bone. Currently the only recommended treatment is
wide surgical excision. In this report we describe the development of a
real-time PCR method for the quantification of
M. ulcerans
DNA
(IS2404 TaqMan). The highly specific assay is based on the detection of
the
M. ulcerans
specific insertion sequence IS
2404
.
The IS2404 TaqMan assay turned out to be about 10 times more sensitive
than the available conventional PCR-based diagnostic test. It is
demonstrated that the IS2404 TaqMan assay is suitable for the
quantitative assessment of the dissemination of the mycobacteria in
Buruli ulcer lesions. Prototype results obtained with excised tissue
from a patient with a late preulcerative Buruli ulcer lesion
reconfirmed earlier histopathological findings indicating that tissue
damage occurs far beyond the regions in which large numbers of
mycobacteria are detectable. The IS2404 TaqMan assay should be a useful
tool for both diagnosis and research into the pathology and mode of
transmission of this still inadequately investigated mycobacterial
disease.
Cohort Study of Guinean Children: Incidence, Pathogenicity, Conferred Protection, and Attributable Risk for Enteropathogens during the First 2 Years of Life
Authors: Valentiner-Branth Palle , Steinsland Hans , Fischer Thea K. , Perch Michael , Scheutz Flemming , Dias Francisco , Aaby Peter , Mølbak Kåre , Sommerfelt Halvor 
Published: September 2003

ABSTRACTWe recruited 200 children shortly after birth and collected stool specimens weekly, irrespective of whether the children had diarrhea, until up to 2 years of age. All children were recruited during the first year of the study and were monitored for a median of 18.4 months. To measure pathogenicity, the odds ratio for diarrhea, adjusted for age, sex, and coinfections with other enteropathogens, was determined by logistic regression. Standard estimation of the population attributable risk indicated that rotavirus, enterotoxigenicEscherichia colithat produced only the heat-stable toxin ST,Isosporaspp.,Cryptosporidium parvum, Shiga toxin (Stx)-producingE. coli(STEC), andShigellaspp. or enteroinvasiveE. coliwere the most important contributors to diarrhea in this population. Stx2- but not Stx1-producing STEC strains were pathogenic. EnteroaggregativeE. coli, diffusely adherentE. coli, and attaching-and-effacingE. colistrains, which were the most commonly isolated microorganisms, were not associated with diarrhea. For most of the microorganisms, primary infections did not confer protection against reinfection with the same organism, but some conferred protection against diarrhea from reinfection.
Presence of
Pseudomonas putida
Strains Harboring Plasmids Bearing the Metallo-β-Lactamase Gene
bla
IMP
in a Hospital in Japan
Authors: Yomoda Sachie , Okubo Toyoji , Takahashi Ayako , Murakami Masami , Iyobe Shizuko 
Published: September 2003

ABSTRACT

To determine the persistence and spread of antibiotic-resistant strains in Gunma University Hospital, 83
Pseudomonas putida
strains (each from a different patient) were isolated from January 1997 through December 2001. Of the 83 strains isolated, 27 were resistant to carbapenems. All 27 produced metallo-β-lactamase and were found to be PCR positive for the
bla
IMP
gene. Most (22 strains) were primarily isolated from the wards (W7 [9 strains] and W4 [8 strains]). Another five
bla
IMP
-positive
P. putida
strains from wards W7 and W4 were obtained by swabbing around the water pipes. A total of 32
bla
IMP
-positive
P. putida
strains were assessed by pulsed-field gel electrophoresis (PFGE) and testing of drug susceptibility to 10 chemotherapeutic agents. Both PFGE and MIC patterns revealed that there were long-term resident strains among inpatients and hospital environments. The
bla
IMP
genes of 22 of 32 strains were all transferable to a recipient strain of
Pseudomonas aeruginosa
by conjugation or transformation and conferred resistance to carbapenems and cephems. The
bla
IMP
plasmids were conjugally transmissible among
P. aeruginosa
strains and mediated resistance to amikacin as well as β-lactams. Ten of the 22 plasmids mediated additional resistance to gentamicin and tobramycin. Plasmids with identical DNA and drug resistance patterns were found in
P. putida
strains with identical PFGE patterns and with different PFGE patterns. We presumed that
P. putida
was one of the resident species in inpatients and especially in hospital environments, spreading drug resistance genes via plasmids among
P. putida
strains and supplying them to more pathogenically important species, such as
P. aeruginosa
.
Modification of Rapid Susceptibility Assay for Antifungal Susceptibility Testing of
Aspergillus fumigatus
Authors: Wetter Tracy J. , Hazen Kevin C. , Cutler Jim E. 
Published: September 2003

ABSTRACT

To improve objectivity and speed of current antifungal mold susceptibility testing, the yeast Rapid Susceptibility Assay (RSA) was adapted for
Aspergillus
species. The RSA is based on glucose utilization in the presence of an antifungal drug.
Aspergillus fumigatus
conidia were incubated in 0.2% glucose RPMI 1640 containing 0.03 to 16 μg of amphotericin B or itraconazole/ml. Drug-related inhibition of glucose utilization correlated with suppression of conidial germination. Following incubation of conidia with various concentrations of antifungal drug, the percentage of residual glucose in the growth medium was determined colorimetrically and plotted against drug concentration to determine the MIC (MIC
RSA
). National Committee for Clinical Laboratory Standards (NCCLS) M38-P testing was also performed to obtain NCCLS MICs (MIC
NCCLS
) for direct comparison with MIC
RSA
s. Conidial inocula of an optical density at 530 nm (OD
530
) of 0.11 facilitated determination of amphotericin B and itraconazole MIC
RSA
s at 16 h equal to or within a single twofold dilution of MIC
NCCLS
s obtained at 48 h. Preliminary testing with a 0.11-OD
530
conidial inoculum of the slower-growing
Aspergillus terreus
resulted in itraconazole and amphotericin B MIC
RSA
s at 16 h equal to or within a single twofold dilution of MIC
NCCLS
s obtained at 48 h. These data indicate that the mold RSA provides a more objective and rapid method for
Aspergillus
spp. susceptibility testing than the NCCLS M38-P assay.
Use of the VITEK 2 System for Rapid Identification of Clinical Isolates of Staphylococci from Bloodstream Infections
Authors: Spanu Teresa , Sanguinetti Maurizio , Ciccaglione Daniela , D'Inzeo Tiziana , Romano Lucio , Leone Fiammetta , Fadda Giovanni 
Published: September 2003

ABSTRACT

Staphylococci are an increasing cause of bloodstream infections. Rapid reliable identification of these organisms is essential for accurate diagnosis and prompt effective treatment. We evaluated the ability of the VITEK 2 system (bioMérieux, Inc, Hazelwood, Mo.) to identify these organisms rapidly and accurately. A total of 405 clinically relevant nonduplicate staphylococcal isolates (
Staphylococcus aureus
,
n
= 130; coagulase-negative staphylococci,
n
= 275) collected from blood cultures were tested. VITEK 2 results were considered correct when they were identical to those furnished by the comparison method based on the ID 32 STAPH system (bioMérieux, Marcy l'Etoile, France) plus supplementary manual testing. When discrepancies occurred, isolate identity was verified by molecular typing. The VITEK 2 correctly identified 387 (95.6%) isolates at the species level: 379 (including all but one [99.2%] of 130
S. aureus
isolates and 249 of 275 [90.5%] coagulase-negative isolates) were identified by the automated reading; for the other eight, supplemental tests suggested by the manufacturer had to be used. Only one strain (0.2%) was misidentified (
Staphylococcus hominis
as
Staphylococcus epidermidis
), and four (1%), all
S. epidermidis
, were not identified. For the remaining 13 strains (including 10
S. hominis
), the VITEK 2 system was unable to discriminate among two species, and no supplemental tests were suggested for conclusive identification. Over 90% of results were obtained within 4 h. These results suggest that the VITEK 2 system can provide rapid, accurate, and reliable species-level identification of staphylococci responsible for bloodstream infections, although there is room for improvement in the identification of certain coagulase-negative species, especially
S. hominis
.
Multiple CTX-M-Type Extended-Spectrum β-Lactamases in Nosocomial Isolates of
Enterobacteriaceae
from a Hospital in Northern Italy
Authors: Pagani Laura , Dell'Amico Emanuela , Migliavacca Roberta , D'Andrea Marco Maria , Giacobone Ernesto , Amicosante Gianfranco , Romero Egidio , Rossolini Gian Maria 
Published: September 2003

ABSTRACT

Twelve isolates of
Enterobacteriaceae
(1 of
Klebsiella pneumoniae
, 8 of
Escherichia coli
, 1 of
Proteus mirabilis
, and 2 of
Proteus vulgaris
) classified as extended-spectrum β-lactamase (ESBL) producers according to the ESBL screen flow application of the BD-Phoenix automatic system and for which the cefotaxime MICs were higher than those of ceftazidime were collected between January 2001 and July 2002 at the Laboratory of Clinical Microbiology of the San Matteo University Hospital of Pavia (northern Italy). By PCR and sequencing, a CTX-M-type determinant was detected in six isolates, including three of
E. coli
(carrying
bla
CTX-M-1
), two of
P. vulgaris
(carrying
bla
CTX-M-2
), and one of
K. pneumoniae
(carrying
bla
CTX-M-15
). The three CTX-M-1-producing
E. coli
isolates were from different wards, and genotyping by pulsed-field gel electrophoresis (PFGE) revealed that they were clonally unrelated to each other. The two CTX-M-2-producing
P. vulgaris
isolates were from the same ward (although isolated several months apart), and PFGE analysis revealed probable clonal relatedness. The
bla
CTX-M-1
and
bla
CTX-M-2
determinants were transferable to
E. coli
by conjugation, while conjugative transfer of the
bla
CTX-M-15
determinant from
K. pneumoniae
was not detectable. Present findings indicate that CTX-M enzymes of various types are present also in Italy and underscore that different CTX-M determinants can be found in a single hospital and can show different dissemination patterns. This is also the first report of CTX-M-2 in
P. vulgaris
.
Molecular Properties of
Salmonella enterica
Serotype Paratyphi B Distinguish between Its Systemic and Its Enteric Pathovars
Authors: Prager Rita , Rabsch Wolfgang , Streckel Wiebke , Voigt Wolfgang , Tietze Erhardt , Tschäpe Helmut 
Published: September 2003

ABSTRACT

Salmonella enterica
serotype O1,4,5,12:Hb:1,2, designated according to the current Kauffmann-White scheme as
S. enterica
serotype Paratyphi B, is a very diverse serotype with respect to its clinical and microbiological properties. PCR and blot techniques, which identify the presence, polymorphism, and expression of various effector protein genes, help to distinguish between strains with systemic and enteric outcomes of disease. All serotype Paratyphi B strains from systemic infections have been found to be somewhat genetically related with respect to the pattern of their virulence genes
sopB
,
sopD
,
sopE1
,
avrA
, and
sptP
as well as other molecular properties (multilocus enzyme electrophoresis type, pulsed-field gel electrophoresis [PFGE] type, ribotype, and IS
200
type). They have been classified as members of the systemic pathovar (SPV). All these SPV strains possess a new
sopE1
-carrying bacteriophage (designated ΦSopE309) with high SopE1 protein expression but lack the commonly occurring
avrA
determinant. They exhibit normal SopB protein expression but lack SopD protein production. In contrast, strains from enteric infections classified as belonging to the enteric pathovar possess various combinations of the respective virulence genes, PFGE pattern, and ribotypes. We propose that the PCR technique for testing for the presence of the virulence genes
sopE1
and
avrA
be used as a diagnostic tool for identifying both pathovars of
S. enterica
serotype Paratyphi B. This will be of great public health importance, since strains of serotype Paratyphi B have recently reemerged worldwide.
Phage-Based Typing Scheme for
Salmonella enterica
Serovar Heidelberg, a Causative Agent of Food Poisonings in Canada
Authors: Demczuk Walter , Soule Geoff , Clark Clifford , Ackermann Hans-W. , Easy Russell , Khakhria Rasik , Rodgers Frank , Ahmed Rafiq 
Published: September 2003

ABSTRACT

Salmonella enterica
serovar Heidelberg is perhaps the second most frequent
Salmonella
serovar isolated from humans and the most common isolated from animals in Canada. This pathogen has shown increasing resistance to antimicrobial agents and mimics the multidrug resistance observed in
S. enterica
serovar Typhimurium strain DT 104. However, unlike for serovar Typhimurium, a rapid and inexpensive subtyping method has not been available for large-scale surveillance efforts. We developed a phage typing scheme and subtyped 2,523 strains of serovar Heidelberg from outbreaks, sporadic infections, and environmental sources in Canada between January 1991 and December 2000. All strains were sensitive to one or more phages and could be subdivided into 49 phage types. A total of 196 isolates from 13 major outbreaks could be subtyped into six phage types, while 86 strains from family outbreaks were assigned to seven phage types. All strains were typeable, and epidemiologically related strains isolated from patients and implicated foods had identical phage types, antibiograms, and pulsed-field gel electrophoresis (PFGE) patterns. Combining PFGE with phage typing increased the discriminatory power of the analysis beyond that of either method alone. We concluded that this phage typing scheme, in conjunction with PFGE, enhances subtyping of serovar Heidelberg strains. Furthermore, this phage typing scheme is a rapid, economical, stable, and reliable epidemiologic tool for tracing the origin of food-borne disease and for the surveillance of sporadic infections.