bluuebunny/crossref_metadata_2025_split huggingface dataset:
Emergence and Rapid Spread of Carbapenem Resistance during a Large and Sustained Hospital Outbreak of MultiresistantAcinetobacter baumannii
Authors: Corbella Xavier , Montero Abelardo , Pujol Miquel , Domínguez M. Angeles , Ayats Josefina , Argerich M. José , Garrigosa Frederic , Ariza Javier , Gudiol Francesc 
Published: December 2019

ABSTRACTBeginning in 1992, a sustained outbreak of multiresistantAcinetobacter baumanniiinfections was noted in our 1,000-bed hospital in Barcelona, Spain, resulting in considerable overuse of imipenem, to which the organisms were uniformly susceptible. In January 1997, carbapenem-resistant (CR)A. baumanniistrains emerged and rapidly disseminated in the intensive care units (ICUs), prompting us to conduct a prospective investigation. It was an 18-month longitudinal intervention study aimed at the identification of the clinical and microbiological epidemiology of the outbreak and its response to a multicomponent infection control strategy. From January 1997 to June 1998, clinical samples from 153 (8%) of 1,836 consecutive ICU patients were found to contain CRA. baumannii. Isolates were verified to beA. baumanniiby restriction analysis of the 16S-23S ribosomal genes and the intergenic spacer region. Molecular typing by repetitive extragenic palindromic sequence-based PCR and pulsed-field gel electrophoresis showed that the emergence of carbapenem resistance was not by the selection of resistant mutants but was by the introduction of two new epidemic clones that were different from those responsible for the endemic. Multivariate regression analysis selected those patients with previous carriage of CRA. baumannii(relative risk [RR], 35.3; 95% confidence interval [CI], 7.2 to 173.1), those patients who had previously received therapy with carbapenems (RR, 4.6; 95% CI, 1.3 to 15.6), or those who were admitted into a ward with a high density of patients infected with CRA. baumannii(RR, 1.7; 95% CI, 1.2 to 2.5) to be at a significantly greater risk for the development of clinical colonization or infection with CRA. baumanniistrains. In accordance, a combined infection control strategy was designed and implemented, including the sequential closure of all ICUs for decontamination, strict compliance with cross-transmission prevention protocols, and a program that restricted the use of carbapenem. Subsequently, a sharp reduction in the incidence rates of infection or colonization withA. baumannii, whether resistant or susceptible to carbapenems, was shown, although an alarming dominance of the carbapenem-resistant clones was shown at the end of the study.
Rapid Detection of Contagious Caprine Pleuropneumonia Using a
Mycoplasma capricolum
subsp.
capripneumoniae
Capsular Polysaccharide-Specific Antigen Detection Latex Agglutination Test
Authors: March J. B. , Gammack C. , Nicholas R. 
Published: December 2019

ABSTRACT

Latex microspheres (diameter, 8 μm) were coated with anti-
Mycoplasma capricolum
subsp.
capripneumoniae
polyclonal immunoglobulin G (IgG) antiserum (anti-F38 biotype). The coated microspheres, when used in a latex agglutination test (LAT), detected
M. capricolum
subsp.
capripneumoniae
antigen in the serum of goats with contagious caprine pleuropneumoniae (CCPP). Beads also agglutinated strongly in the presence of purified
M. capricolum
subsp.
capripneumoniae
capsular polysaccharide (CPS). Preabsorption of CPS-specific antibodies prior to coating of the beads removed agglutinating activity in the presence of
M. capricolum
subsp.
capripneumoniae
, strongly suggesting that CPS is the likely soluble antigen recognized by the test. In addition, the specificity of the LAT exactly mirrored that of an
M. capricolum
subsp.
capripneumoniae
CPS-specific monoclonal antibody (WM25): of the 8 other mycoplasma species tested, agglutination was observed only with bovine serogroup 7. The LAT detected all 11 strains of
M. capricolum
subsp.
capripneumoniae
examined in this study, with a sensitivity level of 2 ng of CPS, or the equivalent of 1.7 × 10
4
CFU, in a reaction volume of 0.03 ml of serum. With field sera from goats with CCPP, the results of the LAT exhibited a 67% correlation with the results of the currently used complement fixation test (CFT), with the main discrepancy in diagnosis resulting from the increased sensitivity of the LAT compared to that of CFT. This antigen-detection LAT should prove particularly useful in identifying animals in the earliest stages of CCPP and combines sensitivity and low cost with ease of application in the field, without the need for any specialist training or equipment.
Production of Bovine Herpesvirus Type 1-Seronegative Latent Carriers by Administration of a Live-Attenuated Vaccine in Passively Immunized Calves
Authors: Lemaire Mylène , Meyer Gilles , Baranowski Eric , Schynts Frédéric , Wellemans Guy , Kerkhofs Pierre , Thiry Etienne 
Published: December 2019

ABSTRACT

The consequences of the vaccination of neonatal calves with the widely used live-attenuated temperature-sensitive (
ts
) bovine herpesvirus type 1 (BHV-1) were investigated. The
ts
strain established acute and latent infections in all vaccinated calves either with or without passive immunity. Four of seven calves vaccinated under passive immunity became clearly BHV-1 seronegative by different serological tests, as did uninfected control calves after the disappearance of maternal antibodies, and they remained so for long periods. A cell-mediated immune response was detected by a BHV-1 gamma interferon assay, but this test failed to detect the seronegative latent carriers (SNLCs). While they are not detected, SNLCs represent a threat for BHV-1-free herds or countries. This study demonstrates that SNLCs can be easily obtained by inoculation with a live-attenuated BHV-1 under passive immunity and that latent carrier animals without any antibody do exist. Consequently, this situation could represent a good model to experimentally produce SNLCs.
Evaluation of a New Culture Medium for
Borrelia burgdorferi
Authors: Marques Adriana R. , Stock Frida , Gill Vee 
Published: December 2019

ABSTRACT

We evaluated the new MPM medium for the growth of
Borrelia burgdorferi
. All 18 blood samples from 17 patients with Lyme disease were negative. Growth studies showed that by day 4, most organisms in MPM were not viable. Our results reinforce the use of BSK medium as the primary choice for growing
B. burgdorferi.
Improved Pulsed-Field Gel Electrophoresis for Typing Vancomycin-Resistant Enterococci
Authors: Turabelidze Durmishkhan , Kotetishvili Mamuka , Kreger Arnold , Morris J. Glenn , Sulakvelidze Alexander 
Published: December 2019

ABSTRACT
A rapid protocol for subtyping vancomycin-resistant enterococci by pulsed-field gel electrophoresis is reported. The procedure is simple and potentially cost-effective and allows reproducible subtyping of the strains in approximately 1 day.
Quantitative Gram Stain Interpretation Criteria Used by Microbiology Laboratories in Alberta, Canada
Authors: Church Deirdre , Melnyk Elizabeth , Unger Barbara 
Published: December 2019

ABSTRACT
Microbiology laboratories in Alberta, Canada, were surveyed to determine the quantitative interpretive criteria used to routinely read and report Gram stains. There was a wide variability in the quantitative reporting criteria cited for both cells and bacteria, with only 11 of 32 (34.4%) laboratories surveyed using the criteria recommended by the external proficiency-testing program. Lack of standardized criteria not only poses a problem in the grading of proficiency testing results but may also impact the quality of patient care.
Is
Chlamydia pneumoniae
Present in Brain Lesions of Patients with Multiple Sclerosis?
Authors: Hammerschlag Margaret R. , Ke Zheng , Lu Fengmin , Roblin Patricia , Boman Jens , Kalman Bernadette 
Published: December 2019

ABSTRACT

We investigated the presence of
Chlamydia pneumoniae
in 81 normal and pathological specimens obtained from postmortem brain tissues of patients with multiple sclerosis and with other neurological or nonneurological diseases. The assays used included PCR amplification of all DNA samples in the initial study. Culture and a second PCR amplification of the organism in a subset of 19 brain specimens were also performed in two separate laboratories. All results were negative. Thus, this study on a large number of brain tissues suggests that
C. pneumoniae
is not involved in inflammatory demyelination.
Acinetobacter baumannii-Infected Vascular Catheters Collected from Horses in an Equine Clinic
Authors: Vaneechoutte Mario , Devriese Luc A. , Dijkshoorn Lenie , Lamote Benedicte , Deprez Piet , Verschraegen Gerda , Haesebrouck Freddy 
Published: December 2019

ABSTRACTAcinetobacter baumanniiwas isolated from tips clipped from seven intravenous jugular catheters collected from horses in the Ghent University equine clinic. They originated from seven different horses. Three of the seven showed evidence of local infection.
Citrobacter rodentium
, the Causative Agent of Transmissible Murine Colonic Hyperplasia, Exhibits Clonality: Synonymy of
C. rodentium
and Mouse-Pathogenic
Escherichia coli
Authors: Luperchio Steven A. , Newman Joseph V. , Dangler Charles A. , Schrenzel Mark D. , Brenner Don J. , Steigerwalt Arnold G. , Schauer David B. 
Published: December 2019

ABSTRACT

Citrobacter rodentium
(formerly
Citrobacter freundii
biotype 4280 and
Citrobacter
genomospecies 9) was described on the basis of biochemical characterization and DNA-DNA hybridization data and is the only
Citrobacter
species known to possess virulence factors homologous to those of the human pathogens enteropathogenic
Escherichia coli
and enterohemorrhagic
E. coli
. These virulence factors are encoded on the locus of enterocyte effacement (LEE), a pathogenicity island required for the characteristic attaching and effacing (AE) pathology seen in infection with these three pathogens.
C. rodentium
, which apparently infects only mice, provides a useful animal model for studying the molecular basis of AE pathology. No work has been done to assess differences in pathogenicity between
C. rodentium
isolates from diverse sources. Here, we report the examination of 15
C. rodentium
isolates using a battery of genetic and biochemical approaches. No differences were observed between the isolates by repetitive-element sequence-based PCR analysis, biochemical analysis, and possession of LEE-specific virulence factors. These data suggest that members of the species are clonal. We further characterized an atypical
E. coli
strain from Japan called mouse-pathogenic
E. coli
(MPEC) that, in our hands, caused the same disease as
C. rodentium
. Applying the same battery of tests, we found that MPEC possesses LEE-encoded virulence factors and is indistinguishable from the previously characterized
C. rodentium
isolate DBS100. These results demonstrate that MPEC is a misclassified
C. rodentium
isolate and that members of this species are clonal and represent the only known attaching and effacing bacterial pathogen of mice.
Evaluation of Nucleic Acid Amplification Tests as Reference Tests for
Chlamydia trachomatis
Infections in Asymptomatic Men
Authors: Johnson Robert E. , Green Timothy A. , Schachter Julius , Jones Robert B. , Hook Edward W. , Black Carolyn M. , Martin David H. , St. Louis Michael E. , Stamm Walter E. 
Published: December 2019

ABSTRACT

Urine ligase chain reaction (LCR) and PCR tests and urethral swab culture were compared for their abilities to detect
Chlamydia trachomatis
infection in 3,639 asymptomatic men by using one-, two-, and three-test reference standards. Frozen urine at four of five participating centers was also tested by a transcription-mediated amplification assay which was used as a reference test. LCR increased the yield of positive results by 27% and PCR increased the yield of positive results by 26% over the yield of positive results by culture (
n
= 295). LCR and PCR sensitivities were similar, ranging from 80.4 to 93.5%, depending on the reference standard. Culture sensitivity was substantially less. A multiple-test standard yielded LCR, PCR, and culture specificities of 99.6%, with or without discrepant analysis. Test performance varied among centers partly due to different interpretations of the testing protocols. The study confirms that urine LCR and PCR for the detection of
C. trachomatis
have substantially improved sensitivities over that of urethral swab culture for testing of asymptomatic men, enabling screening of this important target group. These tests, perhaps in combination, are also candidate reference tests for the conduct of test evaluation studies.
Molecular Epidemiology of Human Group A Rotavirus Infections in the United Kingdom between 1995 and 1998
Authors: Iturriza-Gómara Miren , Green Jon , Brown David W. G. , Ramsay Mary , Desselberger Ulrich , Gray James J. 
Published: December 2019

ABSTRACT
The G and P types of 2,912 rotavirus-positive fecal specimens collected from eight geographical areas of the United Kingdom between 1995 and 1998 were determined by reverse transcription-PCR. Although 15 different G-P combinations were identified, G1P[8], G2P[4], G3P[8], and G4P[8] strains constituted 95% of all the rotaviruses typed. Other genotypes included G9P[6] and G9P[8], which were first identified in the United Kingdom in 1995, or other uncommon G and/or P types of strains that may have had an animal origin. Unusual combinations of G1 or G4 with P[4] and G2 with P[8] which may have arisen by reassortment between human strains were also identified. G1P[8] was the genotype most frequently found (57 to 87%) in each season, followed by G2P[4] in the 1995–1996 (18%) and 1997–1998 (16%) seasons, although the incidence of infection with this virus decreased significantly to 2% during the 1996–1997 season. Significant differences were seen in the distributions of G1P[8], G2P[4], and G9P[8] strains between children and adults, in the temporal distributions of G4P[8] and G9P[8] strains within a season, and in the geographical distributions of each of the four most common genotypes from one season to the next.
Molecular Characterization and Diagnostic Value of
Taenia solium
Low-Molecular-Weight Antigen Genes
Authors: Sako Yasuhito , Nakao Minoru , Ikejima Takashi , Piao Xian Zhi , Nakaya Kazuhiro , Ito Akira 
Published: December 2019

ABSTRACT

Neurocysticercosis (NCC) caused by infection with the larvae of
Taenia solium
is an important cause of neurological disease worldwide. In order to establish an enzyme-linked immunosorbent assay (ELISA) for this infection using recombinant proteins, we carried out molecular cloning and identified four candidates as diagnostic antigens (designated Ag1, Ag1V1, Ag2, and Ag2V1). Except for Ag2V1, these clones could encode a 7-kDa polypeptide, and Ag2V1 could encode a 10-kDa polypeptide. All of the clones were very similar. Except for Ag2V1, recombinant proteins were successfully expressed using an
Escherichia coli
expression system. Immunoblot analysis of NCC patient sera detected recombinant proteins, but because reactivity to recombinant Ag1 was too weak, Ag1 was not suitable as an immunodiagnostic antigen. So, Ag1V1 and Ag2 were chosen as ELISA antigens, and the Ag1V1/Ag2 chimeric protein was expressed. Of 49 serum samples from NCC patients confirmed to be seropositive by immunoblot analysis, 44 (89.7%) were positive by ELISA. No assays of serum samples from patients with other parasitic infections recognized the Ag1V1/Ag2 chimeric protein. The Ag1V1/Ag2 chimeric protein obtained in this study had a high value for differential immunodiagnosis.
Distinct Differences in Repertoires of Low-Molecular-Mass Secreted Antigens of
Mycobacterium avium
Complex and
Mycobacterium tuberculosis
Authors: Olsen Ingrid , Reitan Liv J. , Wiker Harald G. 
Published: December 2019

ABSTRACT

Antigens in a 4-week-old culture filtrate (CF) of
Mycobacterium avium
subsp.
avium
were separated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified by Western blotting. The culture had minimal lysis of bacilli, giving a CF preparation consisting mainly of secreted proteins. Comparison with a similar CF of
Mycobacterium tuberculosis
with almost no contamination with intracellular proteins showed the presence of cross-reactive antigens homologous to the four components of the antigen 85 complex, as well as MPT32. These were major constituents of the
M. avium
subsp.
avium
CF. In addition, there were several low-molecular-mass bands (<15 kDa) in both species that did not cross-react with polyclonal and polyvalent rabbit antibodies in Western blotting. Furthermore, these bands were not detected in corresponding sonicate preparations, indicating high localization indexes, which is typical of soluble secreted proteins. A 14-kDa protein was selected for purification and more detailed characterization. The N-terminal amino acid sequence was determined, and a matching gene was found within the genomic sequence of
M. avium
subsp.
avium
which was highly homologous to Rv0455c of
M. tuberculosis
. The gene encoded a signal peptide typical of secreted mycobacterial proteins. A rabbit antiserum was raised against the purified protein, and the antigen was demonstrated by Western blotting in CFs of
M. avium
subsp.
avium
,
Mycobacterium avium
subsp.
paratuberculosis
,
Mycobacterium intracellulare
, and
Mycobacterium scrofulaceum
but was not detected in
M. tuberculosis
. This is a new example of a highly homologous gene being differentially expressed by different mycobacterial species.
Variable Numbers of TTC Repeats inMycobacterium lepraeDNA from Leprosy Patients and Use in Strain Differentiation
Authors: Shin Yoo-Chul , Lee Hyejon , Lee Hyeyoung , Walsh Gerald P. , Kim Joo-Deuk , Cho Sang-Nae 
Published: December 2019

ABSTRACTStrain differentiation ofMycobacterium lepraewould be of great value for epidemiological investigation to identify the infectious sources of leprosy, to understand transmission patterns, and to distinguish between relapse and reinfection. From theM. lepraegenome sequence database, TTC DNA repeats were identified. Primer sets designed to amplify the region flanking TTC repeats revealed PCR products of different sizes, indicating that the number of repeats at each locus may be variable amongM. lepraestrains. The TTC repeats were not found inMycobacterium tuberculosis,Mycobacterium avium,Mycobacterium marinum, or human tissues, which indicated their specificity toM. leprae. Sequence analysis of the TTC repeat region in each of theM. lepraestrains showed a variation of 10 to 37 repeats. In theM. lepraestrains of 34 multibacillary patients at Cebu, Philippines,M. lepraewith 24 and 25 TTC repeats was most common, and this was followed by strains with 14, 15, 20, 21, and 28 repeats. This study thus indicates that there are variable numbers of TTC repeats in a noncoding region ofM. lepraestrains and that the TTC region may be useful for strain differentiation for epidemiological investigations of leprosy.
Genetic Relatedness within Serotypes of Penicillin-Susceptible
Streptococcus pneumoniae
Isolates
Authors: Overweg Karin , Bogaert Debby , Sluijter Marcel , Yother Janet , Dankert Jacob , de Groot Ronald , Hermans Peter W. M. 
Published: December 2019

ABSTRACT

The molecular epidemiological characteristics of all
Streptococcus pneumoniae
strains isolated in a nationwide manner from patients with meningitis in The Netherlands in 1994 were investigated. Restriction fragment end labeling analysis demonstrated 52% genetic clustering among these penicillin-susceptible strains, a value substantially lower than the percentage of clustering among Dutch penicillin-nonsusceptible strains. Different serotypes were found within 8 of the 28 genetic clusters, suggesting that horizontal transfer of capsular genes is common among penicillin-susceptible strains. The degree of genetic clustering was much higher among serotype 3, 7F, 9V, and 14 isolates than among isolates of other serotypes, i.e., 6A, 6B, 18C, 19F, and 23F. We further studied the molecular epidemiological characteristics of pneumococci of serotype 3, which is considered the most virulent serotype and which is commonly associated with invasive disease in adults. Fifty epidemiologically unrelated penicillin-susceptible serotype 3 invasive isolates originating from the United States (
n
= 27), Thailand (
n
= 9), The Netherlands (
n
= 8), and Denmark (
n
= 6) were analyzed. The vast majority of the serotype 3 isolates (74%) belonged to two genetically distinct clades that were observed in the United States, Denmark, and The Netherlands. These data indicate that two serotype 3 clones have been independently disseminated in an international manner. Seven serotype 3 isolates were less than 85% genetically related to the other serotype 3 isolates. Our observations suggest that the latter isolates originated from horizontal transfer of the capsular type 3 gene locus to other pneumococcal genotypes. In conclusion, epidemiologically unrelated serotype 3 isolates were genetically more related than those of other serotypes. This observation suggests that serotype 3 has evolved only recently or has remained unchanged over long periods.
Comparative Genotyping of
Candida albicans
Bloodstream and Nonbloodstream Isolates at a Polymorphic Microsatellite Locus
Authors: Dalle Frédéric , Franco Norelie , Lopez José , Vagner Odile , Caillot Denis , Chavanet Pascal , Cuisenier Bernadette , Aho Serge , Lizard Sarab , Bonnin Alain 
Published: December 2019

ABSTRACT

Molecular typing studies have shown that the predominant form of reproduction of
Candida albicans
is clonal and that, in a majority of situations, persistent or recurrent infections are due to a unique strain. Characterization of distinct subpopulations and correlation with clinical features may thus be important to understanding the pathogenesis of candidiasis. In a clonal model, a unique polymorphic marker may identify populations with different biological properties. We therefore compared 48 bloodstream isolates and 48 nonbloodstream matched strains of
C. albicans
at the elongation factor 3-encoding gene (CEF3) polymorphic microsatellite locus of
C. albicans
. Sizing of the alleles was performed by automated capillary electrophoresis. A new, 137-bp allele was characterized, and seven nondescribed combinations were observed, resulting in 15 and 11 distinct CEF3 profiles in bloodstream and control strains, respectively. Genotypes 126-135, 130-136, and 131-131 accounted for 60.4% of both bloodstream and control strains. Four bloodstream isolates but no control strains displayed the 135-135 combination. None of the other genotypes was present at an increased frequency in bloodstream isolates. Bloodstream and nonbloodstream strains of
C. albicans
thus have a heterogeneous structure at the CEF3 locus, with three major and multiple minor allelic combinations.