bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficacy of Ciprofloxacin and Moxifloxacin against
Nocardia brasiliensis
In Vitro and in an Experimental Model of Actinomycetoma in BALB/c Mice
Authors: Chacon-Moreno Brenda Edith , Welsh Oliverio , Cavazos-Rocha Norma , de la Luz Salazar-Cavazos Maria , Garza-Lozano Hector Gerardo , Said-Fernandez Salvador , Ocampo-Candiani Jorge , Vera-Cabrera Lucio 
Published: October 2008

ABSTRACT

The efficacy of ciprofloxacin and moxifloxacin against
Nocardia brasiliensis
was evaluated by applying 25 mg of each drug/kg subcutaneously every 8 h in BALB/c mice infected with
N. brasiliensis
. A statistically significant difference was observed only with moxifloxacin. A moxifloxacin-trimethoprim-sulfamethoxazole combination was as active as when each compound was used alone.
Testing of Experimental Compounds in a Relapse Model of Tuberculosis Using Granulocyte-Macrophage Colony-Stimulating Factor Gene-Disrupted Mice
Authors: Woolhiser Lisa K. , Hoff Donald R. , Marietta Karen S. , Orme Ian M. , Lenaerts Anne J. 
Published: October 2008

ABSTRACT

This study describes an in vivo model for evaluating the sterilizing activity of compounds against persisting
Mycobacterium tuberculosis
. The initial treatment with isoniazid and rifampin in granulocyte-macrophage colony-stimulating factor gene-disrupted mice reduced the number of bacteria more than 99% within 3 weeks. A subsequent treatment with individual drugs was performed to assess their activity on the 1% of remaining bacilli and disease relapse.
Animal Models ofStreptococcus pneumoniaeDisease
Authors: Chiavolini Damiana , Pozzi Gianni , Ricci Susanna 
Published: October 2008

SUMMARYStreptococcus pneumoniae is a colonizer of human nasopharynx, but it is also an important pathogen responsible for high morbidity, high mortality, numerous disabilities, and high health costs throughout the world. Major diseases caused by S. pneumoniae are otitis media, pneumonia, sepsis, and meningitis. Despite the availability of antibiotics and vaccines, pneumococcal infections still have high mortality rates, especially in risk groups. For this reason, there is an exceptionally extensive research effort worldwide to better understand the diseases caused by the pneumococcus, with the aim of developing improved therapeutics and vaccines. Animal experimentation is an essential tool to study the pathogenesis of infectious diseases and test novel drugs and vaccines. This article reviews both historical and innovative laboratory pneumococcal animal models that have vastly added to knowledge of (i) mechanisms of infection, pathogenesis, and immunity; (ii) efficacies of antimicrobials; and (iii) screening of vaccine candidates. A comprehensive description of the techniques applied to induce disease is provided, the advantages and limitations of mouse, rat, and rabbit models used to mimic pneumonia, sepsis, and meningitis are discussed, and a section on otitis media models is also included. The choice of appropriate animal models for in vivo studies is a key element for improved understanding of pneumococcal disease.
Candida parapsilosis, an Emerging Fungal Pathogen
Authors: Trofa David , Gácser Attila , Nosanchuk Joshua D. 
Published: October 2008

SUMMARYCandida parapsilosis is an emerging major human pathogen that has dramatically increased in significance and prevalence over the past 2 decades, such that C. parapsilosis is now one of the leading causes of invasive candidal disease. Individuals at the highest risk for severe infection include neonates and patients in intensive care units. C. parapsilosis infections are especially associated with hyperalimentation solutions, prosthetic devices, and indwelling catheters, as well as the nosocomial spread of disease through the hands of health care workers. Factors involved in disease pathogenesis include the secretion of hydrolytic enzymes, adhesion to prosthetics, and biofilm formation. New molecular genetic tools are providing additional and much-needed information regarding C. parapsilosis virulence. The emerging information will provide a deeper understanding of C. parapsilosis pathogenesis and facilitate the development of new therapeutic approaches for treating C. parapsilosis infections.
Human Genetic Factors and Respiratory Syncytial Virus Disease Severity
Authors: Miyairi Isao , DeVincenzo John P. 
Published: October 2008

SUMMARYTo explain the wide spectrum of disease severity caused by respiratory syncytial virus (RSV) and because of the limitations of animal models to fully parallel human RSV disease, study of genetic influences on human RSV disease severity has begun. Candidate gene approaches have demonstrated associations of severe RSV in healthy infants with genetic polymorphisms that may alter the innate ability of humans to control RSV (surfactants, Toll-like receptor 4, cell surface adhesion molecules, and others) and those that may control differences in proinflammatory responses or enhanced immunopathology (specific cytokines and their receptors). These studies are reviewed. They are valuable since an understanding of the direction of a polymorphism's effect can help construct a meaningful human RSV disease pathogenesis model. However, the direction, degree, and significance of the statistical association for any given gene are equivocal among studies, and the functional significance of specific polymorphisms is often not even known. Polymorphism frequency distribution differences associated with RSV infection arising from diversity in the genetic background of the population may be confounded further by multiple-hypothesis testing and publication bias, as well as the investigator's perceived importance of a particular pathogenic disease process. Such problems highlight the limitation of the candidate gene approach and the need for an unbiased large-scale genome-wide association study to evaluate this important disease.
Emergence and Disappearance of a Virulent Clone of
Haemophilus influenzae
Biogroup aegyptius, Cause of Brazilian Purpuric Fever
Authors: Harrison Lee H. , Simonsen Vera , Waldman Eliseu A. 
Published: October 2008

SUMMARY
In 1984, children presented to the emergency department of a hospital in the small town of Promissão, São Paulo State, Brazil, with an acute febrile illness that rapidly progressed to death. Local clinicians and public health officials recognized that these children had an unusual illness, which led to outbreak investigations conducted by Brazilian health officials in collaboration with the U.S. Centers for Disease Control and Prevention. The studies that followed are an excellent example of the coordinated and parallel studies that are used to investigate outbreaks of a new disease, which became known as Brazilian purpuric fever (BPF). In the first outbreak investigation, a case-control study confirmed an association between BPF and antecedent conjunctivitis but the etiology of the disease could not be determined. In a subsequent outbreak, children with BPF were found to have bacteremia caused by Haemophilus influenzae biogroup aegyptius (H. aegyptius), an organism previously known mainly to cause self-limited purulent conjunctivitis. Molecular characterization of blood and other isolates demonstrated the clonal nature of the H. aegyptius strains that caused BPF, which were genetically distant from the diverse strains that cause only conjunctivitis. This led to an intense effort to identify the factors causing the unusual invasiveness of the BPF clone, which has yet to definitively identify the virulence factor or factors involved. After a series of outbreaks and sporadic cases through 1993, no additional cases of BPF have been reported.
Current World Status of
Balantidium coli
Authors: Schuster Frederick L. , Ramirez-Avila Lynn 
Published: October 2008

SUMMARY
Balantidium coli is a cosmopolitan parasitic-opportunistic pathogen that can be found throughout the world. Pigs are its reservoir hosts, and humans become infected through direct or indirect contact with pigs. In rural areas and in some developing countries where pig and human fecal matter contaminates the water supply, there is a greater likelihood that balantidiosis may develop in humans. The infection may be subclinical in humans, as it mostly is in pigs, or may develop as a fulminant infection with bloody and mucus-containing diarrhea; this can lead to perforation of the colon. The disease responds to treatment with tetracycline or metronidazole. Balantidiosis is a disease that need never exist given access to clean water and a public health infrastructure that monitors the water supply and tracks infections. Its spread can be limited by sanitary measures and personal hygiene, but it is a disease that will be around as long as there are pigs. Immunocompromised individuals have developed balantidiosis without any direct contact with pigs, perhaps with rats or contaminated produce as a possible source of infection. For the clinician, balanatidiosis should be included in the differential diagnosis for persistent diarrhea in travelers to or from Southeast Asia, the Western Pacific islands, rural South America, or communities where close contact with domestic swine occurs. Warming of the earth's surface may provide a more favorable environment, even in the now-temperate areas of the world, for survival of trophic and cystic stages of Balantidium, and its prevalence may increase. Effective sanitation and uncontaminated water are the most useful weapons against infection. Fortunately, balantidiosis responds to antimicrobial therapy, and there have been no reports of resistance to the drugs of choice.
New Insights on Classification, Identification, and Clinical Relevance ofBlastocystisspp
Authors: Tan Kevin S. W. 
Published: October 2008

SUMMARYBlastocystisis an unusual enteric protozoan parasite of humans and many animals. It has a worldwide distribution and is often the most commonly isolated organism in parasitological surveys. The parasite has been described since the early 1900s, but only in the last decade or so have there been significant advances in our understanding ofBlastocystisbiology. However, the pleomorphic nature of the parasite and the lack of standardization in techniques have led to confusion and, in some cases, misinterpretation of data. This has hindered laboratory diagnosis and efforts to understand its mode of reproduction, life cycle, prevalence, and pathogenesis. Accumulating epidemiological, in vivo, and in vitro data strongly suggest thatBlastocystisis a pathogen. Many genotypes exist in nature, and recent observations indicate that humans are, in reality, hosts to numerous zoonotic genotypes. Such genetic diversity has led to a suggestion that previously conflicting observations on the pathogenesis ofBlastocystisare due to pathogenic and nonpathogenic genotypes. Recent epidemiological, animal infection, and in vitro host-Blastocystisinteraction studies suggest that this may indeed be the case. This review focuses on such recent advances and also provides updates on laboratory and clinical aspects ofBlastocystisspp.
MgrA Represses Biofilm Formation in
Staphylococcus aureus
Authors: Trotonda María Pilar , Tamber Sandeep , Memmi Guido , Cheung Ambrose L. 
Published: October 2008

ABSTRACT

MgrA is a pleiotropic regulator that controls autolysis, virulence, and efflux pump activity in
Staphylococcus aureus
. We recently found that
mgrA
mutants of strains RN6390, SH1000, and MW2 also displayed enhanced biofilm formation compared with their respective parents. The biofilms formed by
mgrA
mutants of RN6390 and MW2 are independent of
sigB
and
ica
loci, two genetic elements that have been previously associated with biofilm formation in
S. aureus
. Biofilms formed by
mgrA
mutants are dependent on the expression of surface proteins mediated by the sortase gene
srtA
. Extracellular DNA was also a crucial component of the early biofilm of
mgrA
mutants. Genetic analysis indicated that biofilm formation in
mgrA
mutants is mediated in part by
agr
RNAIII, a genetic locus regulated by
mgrA
. Additionally, SarA is important to biofilm formation in
mgrA
mutants since the double
sarA mgrA
mutants failed to form biofilms compared to single
mgrA
mutants of RN6390 and MW2. However, the SarA-mediated effect is independent of
agr
and proteases such as V8 protease and aureolysin. Collectively, our data showed MgrA to be a repressor of biofilm formation, and biofilms formed by
mgrA
mutants have features that are distinct from other reported biofilm types in
S. aureus
.
Vaccine-Induced Cellular Immune Responses Differ from Innate Responses in Susceptible and Resistant Strains of Mice Infected withCoccidioides posadasii
Authors: Shubitz Lisa F. , Dial Sharon M. , Perrill Robert , Casement Rachael , Galgiani John N. 
Published: October 2008

ABSTRACTSusceptibility toCoccidioidesspp. varies widely in humans and other mammals and also among individuals within a species. Among strains of mice with various susceptibilities, immunohistopathology revealed that C57BL/6 mice were highly susceptible to the disease following intranasal infection, DBA/2n mice were intermediate, and Swiss-Webster mice were innately resistant. Resistant Swiss-Webster mice developed prominent perivascular/peribronchiolar lymphocytic cuffing and well-formed granulomas with few fungal elements and debris in the necrotic center, surrounded by a mantle of macrophages, lymphocytes, and fibrocytes. Susceptible C57BL/6 mice became moribund between 14 and 18 days postinfection, with overwhelming numbers of neutrophils and spherules and very few T cells, the drastic reduction of which was associated with failure and death, while intermediate DBA/2n mice controlled the fungal burden but demonstrated progressive lung inflammation with prominent suppuration, and they deteriorated clinically. Vaccinated C57BL/6 mice had an early and robust lymphocyte response, which included significantly higher Mac2+, CD3+, and CD4+cell scores on day 18 than those of innately resistant SW mice and DBA/2n mice; they also had prominent perivascular/peribronchiolar lymphocytic infiltrates not present in their unvaccinated counterparts, and they appeared to be resolving lesions by day 56 compared to the other two strains, based on significantly lower disease scores and observably smaller and fewer lesions with few spherules and neutrophils.
Purification and characterization of a psychrophilic catalase from AntarcticBacillus
Authors: Wang Wei , Sun Mi , Liu Wanshun , Zhang Bin 
Published: October 2008

Catalase from Bacillus sp. N2a (BNC) isolated from Antarctic seawater was purified to homogeneity. BNC has a molecular mass of about 230 kDa and is composed of four identical subunits of 56 kDa. The catalase showed optimal activity at 25 °C and at a pH range of 6–11. The enzyme could be inhibited by azide, hydroxylamine, and mercaptoethanol. These characteristics suggested that BNC is a small-subunit monofunctional catalase. The activation energy of BNC was 13 kJ/mol and the apparent kcat/Kmvalues were 3.6 × 106and 4 × 106L·mol–1·s–1at 4 and 25 °C, respectively. High catalytic efficiency of BNC at low temperatures enables this bacterium to scavenge H2O2efficiently. BNC exhibited activation energy, catalytic efficiency, and thermostability comparable with some mesophilic homologues. Such similarity of enzymatic characteristics to mesophilic homologues, although uncommon among the cold-adapted enzymes in general, has also been observed in other psychrophilic small-subunit monofunctional catalases.
Identification of genes differentially expressed in a strain of the moldAspergillus nidulanscarrying a loss-of-function mutation in thepalAgene
Authors: Silva Emiliana M. , Freitas Janaína S. , Gras Diana E. , Squina Fábio M. , Leal Juliana , Silveira Henrique C.S. , Martinez-Rossi Nilce M. , Rossi Antonio 
Published: October 2008

To identify genes differentially expressed in a strain of the mold Aspergillus nidulans carrying a loss-of-function mutation in palA, a gene in the pH-responsive signal transduction pathway, suppression subtractive hybridization was performed between RNA isolated from the biA1 and biA1 palA1 strains grown under limiting inorganic phosphate at pH 5.0. We have identified several genes upregulated in the biA1 palA1 mutant strain that play important roles in mitotic fidelity, stress responses, enzyme secretion, signal transduction mechanisms, development, genome stability, phosphate sensing, and transcriptional regulation among others. The upregulation of eight of these transcripts was also validated by Northern blot. Moreover, we show that a loss of function mutation in the palA gene drastically reduced the neutral sugar content of the acid phosphatase PacA secreted by the fungus A. nidulans grown at pH 5.0 compared with a control strain.
Transposon Tn5281 is the main distributor of the aminoglycoside modifying enzyme gene among isolates of Enterococcus faecalis in Tehran hospitals
Authors: Feizabadi Mohammad Mehdi , Shokrzadeh Leila , Sayady Sara , Asadi Soroor 
Published: October 2008

Infections with high levels of gentamicin-resistant (HLGR) isolates of Enterococcus faecalis are common in Tehran hospitals. Genes encoding such resistance are transmissible by conjugation at high frequency. The purpose of this study was to determine the existence of Tn5281 and its flanking aminoglycoside modifying enzyme gene aac(6′)-aph(2″) among 102 HLGR isolates of E. faecalis cultured from patients at three hospitals in Tehran, Iran. These isolates were detected by disks containing 120 μg of gentamicin and made 65% of all E. faecalis during the study period. DNA was extracted from HLGR isolates and subjected to PCR assays targeting aac(6′)-aph(2″) and conjugative transposon Tn5281. The amplified aac(6′)-aph(2″) gene was labeled with digoxigenin and probed with Tn5281 amplicons in dot blot hybridization assays. The aac(6′)-aph(2″) gene was detected in 91%–92% (n = 93) of the HLGR isolates. All isolates containing aac(6′)-aph(2″) were positive in long-PCR targeting Tn5281 and the probe hybridized with Tn5281 amplicons. The number of HLGR isolates of E. faecalis has increased considerably in Tehran hospitals. Tn5281 is the main cause of transmission of aac(6′)-aph(2″) to different isolates of E. faecalis in the hospitals studied.
Genetic analysis of theSalmonellatranscription factor HilA
Authors: Daly Rebecca A. , Lostroh C. Phoebe 
Published: October 2008

HilA, a Salmonella transcription factor, activates the invF-1 and prgH promoters through binding to the HilA box, which contains 2 copies of a TTKHAT motif separated by a T centered at –45 relative to the start sites of transcription. The N-terminal 112 amino acids of HilA are similar to winged helix-turn-helix DNA binding/transcription activation domains (wHTH DBDs). The remaining 441 amino acids are not similar in sequence to any other well-characterized transcription factors. Here, we report that the wHTH DBD is essential for activation of both promoters, but amino acids 113–554 are only required for normal activation of invF-1. Some alanine substitutions in the putative α loop, which connects the recognition and positioning helices in wHTH DBDs, cause a loss-of-activation phenotype. A hilA allele encoding a protein with an alanine substituted for arginine at position 71 in the α loop has a loss-of-activation defect exclusively at the prgH promoter. The results suggest distinct roles for one or more domains formed by amino acids 113–554 and for arginine 71 in activation of the 2 promoters.
Alternative flagellar filament types in the haloarchaeon Haloarcula marismortui
Authors: Pyatibratov Michael G. , Beznosov Sergey N. , Rachel Reinhard , Tiktopulo Elizabeth I. , Surin Alexei K. , Syutkin Alexei S. , Fedorov Oleg V. 
Published: October 2008

Many Archaea use rotation of helical flagellar filaments for swimming motility. We isolated and characterized the flagellar filaments of Haloarcula marismortui , an archaeal species previously considered to be nonmotile. Two Haloarcula marismortui phenotypes were discriminated—their filaments are composed predominantly of either FlaB or FlaA2 flagellin, and the corresponding genes are located on different replicons. FlaB and FlaA2 filaments differ in antigenicity and thermostability. FlaA2 filaments are distinctly thicker (20–22 nm) than FlaB filaments (16–18 nm). The observed filaments are nearly twice as thick as those of other characterized euryarchaeal filaments. The results suggest that the helicity of Haloarcula marismortui filaments is provided by a mechanism different from that in the related haloarchaeon Halobacterium salinarum , where 2 different flagellin molecules present in comparable quantities are required to form a helical filament.
A 2.5D TRACTION BOUNDARY ELEMENT METHOD FORMULATION APPLIED TO THE STUDY OF WAVE PROPAGATION IN A FLUID LAYER HOSTING A THIN RIGID BODY
Authors: ANTÓNIO J. , TADEU A. , MENDES P. AMADO 
Published: October 2008

This paper models three-dimensional wave propagation around two-dimensional rigid acoustic screens, with minimal thickness (approaching zero), and placed in a fluid layer. Rigid or free boundaries are prescribed for the flat fluid surfaces. The problem is computed using the Traction Boundary Element Method (TBEM), which is appropriate for modeling thin-body inclusions, overcoming the difficulty posed by the conventional direct Boundary Element Method (BEM). The problem is solved as a summation of two-dimensional problems for different wave numbers along the direction for which the geometry does not vary. The source in each problem is a spatially sinusoidal harmonic line load. The influence of the horizontal boundaries of the fluid medium on the final wave field is computed analytically using appropriate 2.5D Green's functions for each model developed. Thus, only the boundary of the rigid acoustic screen needs to be discretized by boundary elements. The computations are performed in the frequency domain and are subsequently inverse Fourier transformed to obtain time domain results. Complex frequencies are used to avoid aliasing phenomena in the time domain results.
Cenozoic basin development and stratigraphy of the Faroes area
Authors: Sørensen Aage Bach 
Published: October 2008

The present paper reviews the geological development of the Faroes part of the NE Atlantic Margin in the Cenozoic Era. The Faroes area is located west of the post-Caledonian rift basin system formed in the Devonian after the collapse of the Caledonian mountains. Tectonic movements and plate reorganizations during several phases have strongly influenced sedimentation and erosion along the Caledonian front. During the Cenozoic four main tectonic phases with uplift, non-deposition or erosion, had a major influence on basin development and structural setting. First, the arrival of the Icelandic plume to the Faroes area caused a series of uplift phases, which are recorded in the Selandian–Early Ypressian sedimentary succession. Second, tectonic uplift in the Middle Eocene ended the period of almost continuous subsidence of the Judd Basin since the Danian. In the Middle and Late Eocene new depocentres formed in the northern part of the Faroe–Shetland Trough and in the Faroe Bank Basin. Third, due to uplift and sea-level fall in the Late Oligocene, widespread erosion of the Eocene and Oligocene successions resulted in a major unconformity on the shelf. Finally, in Neogene times, folding and uplift of the Fugloy Ridge occurred contemporaneously with renewed subsidence in the northern part of the Faroe–Shetland Trough and the Faroe Bank Basin.
Maps of Cenozoic key horizons illustrate this geological development from the start of the Palaeogene volcanism to the present day. Four regional maps are presented, two maps showing depths to Top Basalt and Top Palaeogene, and two isochore maps of the corresponding post-Basalt sediment sequences, the Palaeogene and the Neogene.
The petroleum system in the Judd Basin was strongly influenced by inversion in Middle Eocene to Recent times. Reservoirs and source rocks were uplifted up to about 600 m, with gas flushing, seal breakage and interruption in petroleum generation as consequences. Petroleum systems may also exist in the Faroe Bank Basin and in the northern part of the Faroe–Shetland Trough.