bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pasteurella
multocida
subsp.
multocida
and
P. multocida
subsp.
septica
Differentiation by PCR Fingerprinting and α-Glucosidase Activity
Authors: Hunt Gerardo Sharon , Citron Diane M. , Claros Marina C. , Fernandez Helen T. , Goldstein Ellie J. C. 
Published: July 2002

ABSTRACT

Pasteurella multocida
is composed of three subspecies that are often differentiated by fermentation of sorbitol and dulcitol. We studied 35 dulcitol-negative
P. multocida
isolates from infected dog and cat bite wounds, 16 of which yielded weak and/or conflicting fermentation reactions in Andrades sorbitol, thus making it difficult to distinguish between the two dulcitol-negative subspecies of
P. multocida
, i.e.,
P. multocida
subsp.
multocida
and
P. multocida
subsp.
septica
. All isolates and two control strains were further analyzed using a PCR fingerprinting technique with a single primer (M13 core) and assessed for α-glucosidase (α-Glu) activity. Although the PCR fingerprint patterns and α-Glu activity did not correlate well with the sorbitol fermentation reactions, they did correlate well with each other. All strains identified as
P. multocida
subsp.
septica
were positive for α-Glu activity and exhibited the group I PCR fingerprint profile. All strains categorized as
P. multocida
subsp.
multocida
displayed either the group II or group III PCR fingerprint profile; 9 of 11 of these isolates were α-Glu negative. These data suggest that both PCR fingerprinting and α-Glu activity provide reliable means for differentiating
P. multocida
subsp.
multocida
from
P. multocida
subsp.
septica
, particularly in strains that produce weak and/or discrepant sorbitol fermentation reactions.
Detection of RTX Toxin Gene in
Vibrio cholerae
by PCR
Authors: Chow K. H. , Ng T. K. , Yuen K. Y. , Yam W. C. 
Published: July 2002

ABSTRACT

A PCR that amplifies a recently discovered
Vibrio cholerae
RTX (repeat in toxin) toxin gene was developed. Among 166 clinical and environmental isolates of
V. cholerae
causing epidemics and sporadic cases of cholera in various parts of the world, all were found to be toxigenic by both PCR and HEp-2 cell cytotoxicity assay. Standard strains of the classical biotype containing a deletion within the gene cluster exhibited negative results by both assays. This is the first rapid genotyping method for differentiation of
V. cholerae
O1 classical biotype strains from El Tor biotype strains as well as strains of other non-O1 serogroups including serogroup O139. The PCR assay that was developed also specifically detects RTX toxin genes in
V. cholerae
, as clinical isolates of
Vibrio parahaemolyticus
, diarrheagenic
Escherichia coli,
Aeromonas
species, and
Plesiomonas
species were all negative by the RTX toxin-specific PCR as well as the HEp-2 cytotoxicity assay. These findings highlight the characteristics of the RTX toxins in
V. cholerae
. Their role in the pathogenicity of the bacterium requires further investigation.
Novel Fluorescent Broth Microdilution Method for Fluconazole Susceptibility Testing of
Candida albicans
Authors: Liao Robert S. , Rennie Robert P. , Talbot James A. 
Published: July 2002

ABSTRACT

A comparative evaluation of the reference National Committee for Clinical Laboratory Standards (NCCLS) broth microdilution method with a novel fluorescent carboxyfluorescein diacetate (CFDA)-modified microdilution method for the susceptibility testing of fluconazole was conducted with 68
Candida
strains, including 53
Candida albicans
, 5
Candida tropicalis
, 5
Candida glabrata
, and 5
Candida parapsilosis
strains. We found trailing endpoints and discordant fluconazole MICs of <8 μg/ml at 24 h and of ≥64 μg/ml at 48 h for 12 of the
C. albicans
strains. These strains satisfy the definition of the low-high MIC phenotype. All 12 low-high phenotype strains were correctly shown to be susceptible at 48 h with the CFDA-modified microdilution method. For the 41 non-low-high phenotype
C. albicans
strains, the CFDA-modified microdilution method yielded 97.6% (40 of 41 strains) agreement within ±1 dilution at 24 h compared with the reference method and 92.7% (38 of 41 strains) agreement within ±1 dilution at 48 h compared with the reference method. The five strains each from
C. tropicalis
,
C. glabrata,
and
C. parapsilosis
that were tested showed 100% agreement within ±2 dilutions for the two methods being evaluated.
Molecular and Antigenic Comparison of
Ehrlichia canis
Isolates from Dogs, Ticks, and a Human in Venezuela
Authors: Unver Ahmet , Perez Miriam , Orellana Nelson , Huang Haibin , Rikihisa Yasuko 
Published: July 2002

ABSTRACT

We previously culture isolated a strain of
Ehrlichia canis
, the causative agent of canine ehrlichiosis, from a human in Venezuela. In the present study, we examined whether dogs and ticks are infected with
E. canis
in Venezuela and, if so, whether this is the same strain as the human isolate. PCR analysis using
E. canis
-specific primers revealed that 17 of the 55 dog blood samples (31%) and all three pools of four
Rhipicephalus sanguineus
ticks each were positive. An ehrlichial agent (Venezuelan dog
Ehrlichia
[VDE]) was isolated and propagated in cell culture from one dog sample and was further analyzed to determine its molecular and antigenic characteristics. The 16S rRNA 1,408-bp sequence of the new VDE isolate was identical to that of the previously reported Venezuelan human
Ehrlichia
isolate (VHE) and was closely related (99.9%) to that of
E. canis
Oklahoma. The 5′ (333-bp) and 3′ (653-bp) sequences of the variable regions of the 16S rRNA genes from six additional
E. canis
-positive dog blood specimens and from three pooled-tick specimens were also identical to those of VHE. Western blot analysis of serum samples from three dogs infected with VDE by using several ehrlichial antigens revealed that the antigenic profile of the VDE was similar to the profiles of VHE and
E. canis
Oklahoma. Identical 16S rRNA gene sequences among ehrlichial organisms from dogs, ticks, and a human in the same geographic region in Venezuela and similar antigenic profiles between the dog and human isolates suggest that dogs serve as a reservoir of human
E. canis
infection and that
R. sanguineus
, which occasionally bites humans residing or traveling in this region, serves as a vector. This is the first report of culture isolation and antigenic characterization of an ehrlichial agent from a dog in South America, as well as the first molecular characterization of
E. canis
directly from naturally infected ticks.
Quantitation of Varicella-Zoster Virus DNA in Patients with Ramsay Hunt Syndrome and Zoster Sine Herpete
Authors: Furuta Yasushi , Ohtani Fumio , Sawa Hirofumi , Fukuda Satoshi , Inuyama Yukio 
Published: July 2002

ABSTRACT
Varicella-zoster virus (VZV) reactivation causes facial nerve palsy in Ramsay Hunt syndrome (RHS) and zoster sine herpete (ZSH) with and without zoster rash, respectively. In the present study, we analyzed the VZV DNA copy number in saliva samples from 25 patients with RHS and 31 patients with ZSH using a TaqMan PCR assay to determine differences in the viral load between the two diseases. VZV copy number in saliva peaked near the day of the appearance of zoster in patients with RHS. Consequently, VZV DNA was less frequently detected in patients with RHS who exhibited facial palsy several days after the appearance of zoster. These findings suggest that the VZV load in saliva samples reflects the kinetics of viral reactivation in patients with RHS. In addition, VZV DNA was equally detected in saliva from patients with RHS and ZSH, and there was no significant difference in the highest viral copy number between patients with RHS and those with ZSH. The VZV load does not appear to reflect a major difference between RHS and ZSH.
Characterization of Clinical Isolates ofKlebsiella pneumoniaefrom 19 Laboratories Using the National Committee for Clinical Laboratory Standards Extended-Spectrum β-Lactamase Detection Methods
Authors: Steward Christine D. , Rasheed J. Kamile , Hubert Susannah K. , Biddle James W. , Raney Patti M. , Anderson Gregory J. , Williams Portia P. , Brittain Kelley L. , Oliver Antonio , McGowan John E. , Tenover Fred C. 
Published: July 2002

ABSTRACTExtended-spectrum β-lactamases (ESBLs) are enzymes found in gram-negative bacilli that mediate resistance to extended-spectrum cephalosporins and aztreonam. In 1999, the National Committee for Clinical Laboratory Standards (NCCLS) published methods for screening and confirming the presence of ESBLs inKlebsiella pneumoniae, Klebsiella oxytoca, andEscherichia coli. To evaluate the confirmation protocol, we tested 139 isolates ofK. pneumoniaethat were sent to Project ICARE (Intensive Care Antimicrobial Resistance Epidemiology) from 19 hospitals in 11 U.S. states. Each isolate met the NCCLS screening criteria for potential ESBL producers (ceftazidime [CAZ] or cefotaxime [CTX] MICs were ≥2 μg/ml for all isolates). Initially, 117 (84%) isolates demonstrated a clavulanic acid (CA) effect by disk diffusion (i.e., an increase in CAZ or CTX zone diameters of ≥5 mm in the presence of CA), and 114 (82%) demonstrated a CA effect by broth microdilution (reduction of CAZ or CTX MICs by ≥3 dilutions). For five isolates, a CA effect could not be determined initially by broth microdilution because of off-scale CAZ results. However, a CA effect was observed in two of these isolates by testing cefepime and cefepime plus CA. The cefoxitin MICs for 23 isolates that failed to show a CA effect by broth microdilution were ≥32 μg/ml, suggesting either the presence of an AmpC-type β-lactamase or porin changes that could mask a CA effect. By isoelectric focusing (IEF), 7 of the 23 isolates contained a β-lactamase with a pI of ≥8.3 suggestive of an AmpC-type β-lactamase; 6 of the 7 isolates were shown by PCR to contain bothampC-type andblaOXAgenes. The IEF profiles of the remaining 16 isolates showed a variety of β-lactamase bands, all of which had pIs of ≤7.5. All 16 isolates were negative by PCR with multiple primer sets forampC-type,blaOXA, andblaCTX-Mgenes. In summary, 83.5% of theK. pneumoniaeisolates that were identified initially as presumptive ESBL producers were positive for a CA effect, while 5.0% contained β-lactamases that likely masked the CA effect. The remaining 11.5% of the isolates studied contained β-lactamases that did not demonstrate a CA effect. An algorithm based on phenotypic analyses is suggested for evaluation of such isolates.
Detection of Cervical Infections in Colposcopy Clinic Patients
Authors: Lanham Stuart , Herbert Amanda , Basarab Adriana , Watt Peter 
Published: July 2002

ABSTRACT

The purpose of this study was to determine if
Neisseria gonorrhoeae; Chlamydia trachomatis
; herpes simplex virus; cytomegalovirus; Epstein-Barr virus; human herpesviruses 6, 7, and 8; or adeno-associated virus influenced the production of cervical intraepithelial neoplasia. Two hundred thirty-one cervical smear samples were tested for the presence of the organisms by PCR. In addition, human papillomavirus types in the samples were determined by PCR and classified into cancer risk types of high, moderate, and low. There was no link with cervical intraepithelial neoplasia status and detection of herpes simplex virus, cytomegalovirus, Epstein-Barr virus, human herpesviruses 6 and 8, gonorrhea, or chlamydia. However, high-grade cervical intraepithelial neoplasia was found more frequently with mixed infection by moderate-risk human papillomavirus types and human herpesvirus 7 than with these papillomavirus types alone. The presence of human herpesvirus 7 may increase the oncogenic potential of moderate-risk human papillomavirus types.
Automated Ribotyping Using Different Enzymes To Improve Discrimination ofListeria monocytogenesIsolates, with a Particular Focus on Serotype 4b Strains
Authors: De Cesare Alessandra , Bruce James L. , Dambaugh Timothy R. , Guerzoni Maria E. , Wiedmann Martin 
Published: July 2002

ABSTRACTTo develop improved automated subtyping approaches forListeria monocytogenes, we characterized the discriminatory power of different restriction enzymes for ribotyping. When 15 different restriction enzymes were used for automated ribotyping of 16 selectedL. monocytogenesisolates, the restriction enzymesEcoRI,PvuII, andXhoI showed high discriminatory ability (Simpson's index of discrimination > 0.900) and produced complete and reproducible restriction cut patterns. These three enzymes were thus evaluated for their ability to differentiate among isolates representing the two major serotype 4b epidemic clones, those having ribotype reference pattern DUP-1038 (51 isolates) and those having pattern DUP-1042 (20 isolates). Among these isolates,PvuII provided the highest discrimination for a single enzyme (nine different subtypes; index of discrimination = 0.518). A combination ofPvuII andXhoI showed the highest discriminatory ability (index of discrimination = 0.590) for these isolates. A group of 44 DUP-1038 isolates and a group of 12 DUP-1042 isolates were identical to each other even when the combined data for all three enzymes were used. We conclude that automated ribotyping using different enzymes allows improved discrimination ofL. monocytogenesisolates, including epidemic serotype 4b strains. We furthermore confirm that most of the isolates representing the genotypes linked to the two major epidemicL. monocytogenesclonal groups form two genetically homogeneous groups.
Extensive Allelic Variation among
Francisella tularensis
Strains in a Short-Sequence Tandem Repeat Region
Authors: Johansson Anders , Göransson Ingela , Larsson Pär , Sjöstedt Anders 
Published: July 2002

ABSTRACT

Members of the genus
Francisella
and the species
F. tularensis
appear to be genetically very similar despite pronounced differences in virulence and geographic localization, and currently used typing methods do not allow discrimination of individual strains. Here we show that a number of short-sequence tandem repeat (SSTR) loci are present in
F. tularensis
genomes and that two of these loci, SSTR9 and SSTR16, are together highly discriminatory. Labeled PCR amplification products from the loci were identified by an automated DNA sequencer for size determination, and each allelic variant was sequenced. Simpson's index of diversity was 0.97 based on an analysis of 39 nonrelated
F. tularensis
isolates. The locus showing the highest discrimination, SSTR9, gave an index of diversity of 0.95. Thirty-two strains isolated from humans during five outbreaks of tularemia showed much less variation. For example, 11 of 12 strains isolated in the Ljusdal area, Sweden in 1995 and 1998 had identical allelic variants. Phenotypic variants of strains and extensively cultured replicates within strains did not differ, and, for example, the same allelic combination was present in 55 isolates of the live-vaccine strain of
F. tularensis
and another one was present in all 13 isolates of a strain passaged in animals. The analysis of short-sequence repeats of
F. tularensis
strains appears to be a powerful tool for discrimination of individual strains and may be useful for a detailed analysis of the epidemiology of this potent pathogen.
Prevalence of Molecular Types and
mecA
Gene Carriage of Coagulase-Negative Staphylococci in a Neonatal Intensive Care Unit: Relation to Nosocomial Septicemia
Authors: Krediet Tannette G. , Jones Mark E. , Janssen Karin , Gerards Leo J. , Fleer André 
Published: July 2002

ABSTRACT
Molecular typing of isolates revealed that neonatal coagulase-negative staphylococcal (CONS) septicemia is most frequently caused by predominant, antibiotic-resistant CONS types, which are widely distributed among both neonates and staff of the neonatal unit, suggesting cross-contamination. Therefore, infection control measures may be valuable in the prevention of this common nosocomial septicemia.
Heteroresistance to Vancomycin in
Enterococcus faecium
Authors: Alam M. Rabiul , Donabedian Susan , Brown William , Gordon James , Chow Joseph W. , Zervos Marcus J. , Hershberger Ellie 
Published: July 2002

ABSTRACT

This study presents the first report of vancomycin heteroresistance in an
Enterococcus faecium
isolate from a patient. The original isolate was susceptible in vitro to vancomycin. E-tests showed growth of subcolonies in a zone of inhibition with a vancomycin MIC of >256 μg/ml. Both the susceptible and resistant colonies were from the same strain as determined by PFGE, and both contained the
vanA
gene as determined by PCR.
Molecular Typing of the Etiologic Agent of Human Granulocytic Ehrlichiosis
Authors: Carter Sarah E. , Ravyn M. Dana , Xu Yaning , Johnson Russell C. 
Published: July 2002

ABSTRACT

The
p44
gene of the agent of human granulocytic ehrlichiosis (aoHGE) encodes a 44-kDa major outer surface protein. A technique was developed for the typing of the aoHGE based on the PCR amplification of the
p44
gene followed by a multiple restriction digest with
Hin
dIII,
Eco
RV, and
Asp
I to generate restriction fragment length polymorphism patterns. Twenty-four samples of the aoHGE were collected from geographically dispersed sites in the United States and included isolates from humans, equines, canines, small mammals, and ticks. Six granulocytic ehrlichiosis (GE) types were identified. The GE typing method is relatively simple to perform, is reproducible, and is able to differentiate among the various isolates of granulocytic ehrlichiae in the United States. These characteristics suggest that this GE typing method may be an important epizootiological and epidemiological tool.
βlasEN: Microdilution Panel for Identifying β-Lactamases Present in Isolates of
Enterobacteriaceae
Authors: Sanders Christine C. , Ehrhardt Anton F. , Moland Ellen Smith , Thomson Kenneth S. , Zimmer Barbara , Roe Darcie E. 
Published: July 2002

ABSTRACT

A dried investigational use-only microdilution panel named βlasEN (a short named derived from the panel’s purpose, to identify β-lactamases in
Enterobacteriaceae
) containing 10 β-lactam drugs with and without β-lactamase inhibitors was developed to identify β-lactamases among clinical isolates of
Escherichia coli
,
Klebsiella pneumoniae
,
Klebsiella oxytoca
,
Citrobacter koseri
,
Citrobacter freundii
group,
Enterobacter
spp., and
Serratia marcescens
. The MICs obtained with a collection of 383 organisms containing well-characterized β-lactamases were used to develop numeric codes and logic pathways for computerized analysis of results. The resultant logic pathways and βlasEN panel were then used to test and identify β-lactamases among 885 isolates of
Enterobacteriaceae
recovered in cultures obtained at six different hospital laboratories across the United States. β-Lactamases present in 801 (90.5%) of the 885 isolates were identified by βlasEN by using the existing logic pathways and codes or after minor modifications were made to the existing codes. The 84 strains that gave codes that βlasEN could not identify were collected, reidentified, and retested by using βlasEN. Three strains had been misidentified, 54 strains gave different codes upon repeat testing that could be identified by βlasEN, and 27 strains repeated new codes. The β-lactamases in these strains were identified, and the new codes were added to the βlasEN logic pathways. These results indicate that βlasEN can identify clinically important β-lactamases among most isolates of
Enterobacteriaceae
. The results also show that good quality control and attention to proper performance of the tests are essential to the correct performance of βlasEN.
Active Copper- and Zinc-Containing Superoxide Dismutase in the Cryptic Genospecies of
Haemophilus
Causing Urogenital and Neonatal Infections Discriminates Them from
Haemophilus influenzae
Sensu Stricto
Authors: Langford Paul R. , Sheehan Brian J. , Shaikh Taheed , Kroll J. Simon 
Published: July 2002

ABSTRACT

The presence of active copper- and zinc-containing superoxide dismutase in isolates of the cryptic genospecies of
Haemophilus
, responsible for urogenital, neonatal, and mother-infant infections, can be used as a biochemical marker to discriminate them from
H. influenzae
sensu stricto strains.
Identification of Four Distinct Genotypes of
Candida dubliniensis
and Detection of Microevolution In Vitro and In Vivo
Authors: Gee Sarah F. , Joly Sophie , Soll David R. , Meis Jacques F. G. M. , Verweij Paul E. , Polacheck Itzhack , Sullivan Derek J. , Coleman David C. 
Published: July 2002

ABSTRACT

The present study investigates further the population structure of
Candida dubliniensis
and its ability to exhibit microevolution. Using 98 isolates (including 80 oral isolates) from 94 patients in 15 countries, we confirmed the existence of two distinct populations within the species
C. dubliniensis
, designated Cd25 group I and Cd25 group II, respectively, on the basis of DNA fingerprints generated with the
C. dubliniensis
-specific probe Cd25. The majority of Cd25 group I isolates (48 of 71, 67.6%) were from human immunodeficiency virus (HIV)-infected individuals, whereas the majority of Cd25 group II isolates (19 of 27, 70.4%) were from HIV-negative individuals (
P
≤ 0.001). Nucleotide sequence analysis of the internal transcribed spacer (ITS) regions of the rRNA genes from 19 representative isolates revealed the presence of four separate genotypes. All of the Cd25 group I isolates tested belonged to genotype 1, while the Cd25 group II population was comprised of three distinct genotypes (genotypes 2 to 4), which corresponded to distinct clades within the Cd25 group II population. These findings were confirmed using genotype-specific PCR primers with 70 isolates. We also showed that
C. dubliniensis
can exhibit microevolution in vivo and in vitro as occurs in other yeast species. DNA fingerprinting using the
C. dubliniensis
probes Cd25, Cd24, and Cd1 and karyotype analysis of multiple oral isolates recovered from the same specimen from each of eight separate patients revealed microevolution in six of eight of the clonal populations. Similarly, sequential clonal isolates from various anatomical sites in two separate patients exhibited microevolution. Microevolution was also shown to occur when two clinical isolates susceptible to fluconazole were exposed to the drug in vitro. The epidemiological significance of the four
C. dubliniensis
genotypes and the ability of
C. dubliniensis
to undergo microevolution has yet to be established.
Lectin Typing of
Campylobacter concisus
Authors: Aabenhus Rune , Hynes Sean O. , Permin Henrik , Moran Anthony P. , Andersen Leif P. 
Published: July 2002

ABSTRACT

A total of 44 clinical isolates and the type strain of the putative pathogen
Campylobacter concisus
were grouped based on their reactions with plant lectins. The optimized lectin typing system used
C. concisus
strains proteolytically pretreated and subsequently typed by using a panel of four lectins. The system grouped all 45 strains into 13 lectin reaction patterns, leaving no strain untypeable due to autoagglutination. Lectin types were both stable and reproducible.
Culture-Negative Endocarditis Due to
Chlamydia pneumoniae
Authors: Gdoura R. , Pereyre S. , Frikha I. , Hammami N. , Clerc M. , Sahnoun Y. , Bebear C. , Daoud M. , de Barbeyrac B. , Hammami A. 
Published: July 2002

ABSTRACT

We report on the case of a 54-year-old woman diagnosed as having culture-negative endocarditis (clinical and histopathologic evidence compatible with a recent episode of endocarditis). The responsibility of
Chlamydia pneumoniae
in this episode of endocarditis was suggested by a serological study and was then confirmed by the positive results of PCR and in situ hybridization tests with aortic and mitral valves tissues. To our knowledge, this is the first case of endocarditis due to
C. pneumoniae
confirmed by molecular biology-based techniques.