bluuebunny/crossref_metadata_2025_split huggingface dataset:
Young Adult Follow‐up of Adolescent Girls in Juvenile Justice Using the Columbia Suicide Severity Rating Scale
Authors: Kerr David C. R. , Gibson Brandon , Leve Leslie D. , DeGarmo David S. 
Published: January 2014

This study focused on the reliability and validity of the Columbia Suicide Severity Scale (C‐SSRS). Severely delinquent adolescent girls (n = 166) participated in a treatment trial and repeated assessments over time. Lifetime suicide attempt history was measured using the C‐SSRS in early adulthood (n = 144; 7–12 years postbaseline). Nonclinician raters showed strong interrater reliability using the C‐SSRS. Self‐reports, caseworker reports, and caregiver reports of girls' suicide attempt histories collected at baseline correlated with adult participants' recollections of their baseline attempt histories. Suicidal ideation measured prospectively across a 7‐ to –12‐year period was associated with retrospectively reported suicide attempt across the same period.
Sesquiterpene Lactone in Nanostructured Parenteral Dosage Form Is Efficacious in Experimental Chagas Disease
Authors: Branquinho Renata Tupinambá , Mosqueira Vanessa Carla Furtado , Oliveira-Silva Jaquelline Carla Valamiel de , Simões-Silva Marianne Rocha , Saúde-Guimarães Dênia Antunes , Lana Marta de 
Published: January 2014

ABSTRACT

The drugs available for Chagas disease treatment are toxic and ineffective. We studied the
in vivo
activity of a new drug, lychnopholide (LYC). LYC was loaded in nanocapsules (NC), and its effects were compared to free LYC and benznidazole against
Trypanosoma cruzi
. Infected mice were treated in the acute phase at 2.0 mg/kg/day with free LYC, LYC-poly-ε-caprolactone NC (LYC-PCL), and LYC-poly(lactic acid)-co-polyethylene glycol NC (LYC-PLA-PEG) or at 50 mg/kg/day with benznidazole solution by the intravenous route. Animals infected with the CL strain, treated 24 h after infection for 10 days, evaluated by hemoculture, PCR, and enzyme-linked immunosorbent assay exhibited a 50% parasitological cure when treated with LYC-PCL NC and 100% cure when treated with benznidazole, but 100% of the animals treated during the prepatent period for 20 days with these formulations or LYC-PLA-PEG NC were cured. In animals with the Y strain treated 24 h after infection for 10 days, only mice treated by LYC-PCL NC were cured, but animals treated in the prepatent period for 20 days exhibited 100, 75, and 62.5% cure when treated with LYC-PLA-PEG NC, benznidazole, and LYC-PCL NC, respectively. Free LYC reduced the parasitemia and improved mice survival, but no mice were cured. LYC-loaded NC showed higher cure rates, reduced parasitemia, and increased survival when used in doses 2five times lower than those used for benznidazole. This study confirms that LYC is a potential new treatment for Chagas disease. Furthermore, the long-circulating property of PLA-PEG NC and its ability to improve LYC efficacy showed that this formulation is more effective in reaching the parasite
in vivo
.
Preclinical Safety Evaluation of Intravenously Administered SAL200 Containing the Recombinant Phage Endolysin SAL-1 as a Pharmaceutical Ingredient
Authors: Jun Soo Youn , Jung Gi Mo , Yoon Seong Jun , Choi Yun-Jaie , Koh Woo Suk , Moon Kyoung Sik , Kang Sang Hyeon 
Published: January 2014

ABSTRACT
Phage endolysins have received increasing attention as potent antibacterial agents. However, although safety evaluation is a prerequisite for the drug development process, a good laboratory practice (GLP)-compliant safety evaluation has not been reported for phage endolysins. A safety evaluation of intravenously administered SAL200 (containing phage endolysin SAL-1) was conducted according to GLP standards. No animals died in any of the safety evaluation studies. In general toxicity studies, intravenously administered SAL200 showed no sign of toxicity in rodent single- and repeated-dose toxicity studies. In the dog repeated-dose toxicity test, there were no abnormal findings, with the exception of transient abnormal clinical signs that were observed in some dogs when daily injection of SAL200 was continued for more than 1 week. In safety pharmacology studies, there were also no signs of toxicity in the central nervous and respiratory system function tests. In the cardiovascular function test, there were no abnormal findings in all tested dogs after the first and second administrations, but transient abnormalities were observed after the third and fourth administrations (2 or 3 weeks after the initial administration). All abnormal findings observed in these safety evaluation studies were slight to mild, were apparent only transiently after injection, and resolved quickly. The safety evaluation results for SAL200 support the implementation of an exploratory phase I clinical trial and underscore the potential of SAL200 as a new drug. We have designed an appropriate phase I clinical trial based on the results of this study.
Post-β-Lactamase-Inhibitor Effect of Tazobactam in Combination with Ceftolozane on Extended-Spectrum-β-Lactamase-Producing Strains
Authors: Sader Helio S. , Rhomberg Paul R. , Jones Ronald N. 
Published: January 2014

ABSTRACT

The post-β-lactamase-inhibitor effect (PBLIE) of tazobactam combined with ceftolozane was evaluated by time-kill assays on two clinical
Escherichia coli
strains producing CTX-M-15 with or without TEM-1. The organisms were exposed (2 h) to 4 μg/ml/4 μg/ml of ceftolozane-tazobactam (4× MIC), 4 μg/ml of ceftolozane, and medium containing no drug, washed, and resuspended in medium alone or medium containing ceftolozane-tazobactam or ceftolozane. The PBLIE was determined as 1.3 to 2.1 h, and a postantibiotic effect was measured as 0.8 to 0.9 h.
Study of Macrophage Functions in Murine J774 Cells and Human Activated THP-1 Cells Exposed to Oritavancin, a Lipoglycopeptide with High Cellular Accumulation
Authors: Lemaire Sandrine , Mingeot-Leclercq Marie-Paule , Tulkens Paul M. , Van Bambeke Françoise 
Published: January 2014

ABSTRACTOritavancin, a lipoglycopeptide antibiotic in development, accumulates to high levels in the lysosomes of eukaryotic cells. We examined specific functions of macrophages (phagocytic capacity, lysosomal integrity, metabolic activity, and production of reactive oxygen species [ROS]) in correlation with the cellular accumulation of the drug, using J774 mouse macrophages and THP-1 human monocytes differentiated into macrophages using phorbol 12-myristate 13-acetate. Oritavancin did not affectPseudomonas aeruginosaphagocytosis, lysosomal integrity, or metabolic activity in cells incubated for 3 h with extracellular concentrations ranging from 5 to 50 μg/ml. At extracellular concentrations of ≥25 μg/ml, oritavancin reduced latex bead phagocytosis by approximately 50% and doubled ROS production in J774 macrophages only. This may result from the fact that the cellular accumulation of oritavancin was 15 times higher in J774 cells than in activated THP-1 cells at 3 h. Human pharmacokinetic studies estimate that the concentration of oritavancin in alveolar macrophages could reach approximately 560 μg/ml after administration of a cumulative dose of 4 g, which is below the cellular concentration needed in the present study to impair latex bead phagocytosis (1,180 μg/ml) or to stimulate ROS production (15,000 μg/ml) by J774 cells. The data, therefore, suggest that, in spite of its substantial cellular accumulation, oritavancin is unlikely to markedly affect macrophage functions under the conditions of use investigated in current phase III trials (a single dose of 1,200 mg).
Selective Target Inactivation Rather than Global Metabolic Dormancy Causes Antibiotic Tolerance in Uropathogens
Authors: Goneau Lee W. , Yeoh Nigel S. , MacDonald Kyle W. , Cadieux Peter A. , Burton Jeremy P. , Razvi Hassan , Reid Gregor 
Published: January 2014

ABSTRACT

Persister cells represent a multidrug-tolerant (MDT), physiologically distinct subpopulation of bacteria. The ability of these organisms to survive lethal antibiotic doses raises concern over their potential role in chronic disease, such as recurrent urinary tract infection (RUTI). Persistence is believed to be conveyed through global metabolic dormancy, which yields organisms unresponsive to external stimuli. However, recent studies have contested this stance. Here, various antibiotics that target different cellular processes were used to dissect the activity of transcription, translation, and peptidoglycan turnover in persister cells. Differential susceptibility patterns were found in type I and type II persisters, and responses differed between
Staphylococcus saprophyticus
and
Escherichia coli
uropathogens. Further, SOS-deficient strains were sensitized to ciprofloxacin, suggesting DNA gyrase activity in persisters and indicating the importance of active DNA repair systems for ciprofloxacin tolerance. These results indicate that global dormancy
per se
cannot sufficiently account for antibiotic tolerance. Rather, the activity of individual cellular processes dictates multidrug tolerance in an antibiotic-specific fashion. Furthermore, the susceptibility patterns of persisters depended on their mechanisms of onset, with subinhibitory antibiotic pretreatments selectively shutting down cognate targets and increasing the persister fraction against the same agent. Interestingly, antibiotics targeting transcription and translation enhanced persistence against multiple agents indirectly related to these processes. Conducting these assays with uropathogenic
E. coli
isolated from RUTI patients revealed an enriched persister fraction compared to organisms cleared with standard antibiotic therapy. This finding suggests that persister traits are either selected for during prolonged antibiotic treatment or initially contribute to therapy failure.
Antiviral Susceptibility of Variant Influenza A(H3N2)v Viruses Isolated in the United States from 2011 to 2013
Authors: Sleeman K. , Mishin V. P. , Guo Z. , Garten R. J. , Balish A. , Fry A. M. , Villanueva J. , Stevens J. , Gubareva L. V. 
Published: January 2014

ABSTRACT

Since 2011, outbreaks caused by influenza A(H3N2) variant [A(H3N2)v] viruses have become a public health concern in the United States. The A(H3N2)v viruses share the A(H1N1)pdm09 M gene containing the marker of M2 blocker resistance, S31N, but do not contain any known molecular markers associated with resistance to neuraminidase (NA) inhibitors (NAIs). Using a fluorescent NA inhibition (NI) assay, the susceptibilities of recovered A(H3N2)v viruses (
n
= 168) to FDA-approved (oseltamivir and zanamivir) and other (peramivir, laninamivir, and A-315675) NAIs were assessed. All A(H3N2)v viruses tested, with the exception of a single virus strain, A/Ohio/88/2012, isolated from an untreated patient, were susceptible to the NAIs tested. The A/Ohio/88/2012 virus contained two rare substitutions, S245N and S247P, in the NA and demonstrated reduced inhibition by oseltamivir (31-fold) and zanamivir (66-fold) in the NI assay. Using recombinant NA (recNA) proteins, S247P was shown to be responsible for the observed altered NAI susceptibility, in addition to an approximately 60% reduction in NA enzymatic activity. The S247P substitution has not been previously reported as a molecular marker of reduced susceptibility to the NAIs. Using cell culture assays, the investigational antiviral drugs nitazoxanide, favipiravir, and fludase were shown to inhibit the replication of A(H3N2)v viruses, including the virus with the S247P substitution in the NA. This report demonstrates the importance of continuous monitoring of susceptibility of zoonotic influenza viruses to available and investigational antiviral drugs.
Structural Basis for the Inhibition of the Chromatin Repressor BAHD1 by the Bacterial Nucleomodulin LntA
Authors: Lebreton Alice , Job Viviana , Ragon Marie , Le Monnier Alban , Dessen Andréa , Cossart Pascale , Bierne Hélène 
Published: January 2014

ABSTRACT

The nucleus has emerged as a key target for nucleomodulins, a family of effectors produced by bacterial pathogens to control host transcription or other nuclear processes. The virulence factor LntA from
Listeria monocytogenes
stimulates interferon responses during infection by inhibiting BAHD1, a nuclear protein involved in gene silencing by promoting heterochromatin formation. So far, whether the interaction between LntA and BAHD1 is direct and sufficient for inhibiting BAHD1 activity is unknown. Here, we functionally characterized the molecular interface between the two proteins
in vitro
and in transfected or infected human cells. Based on the known tridimensional structure of LntA, we identified a dilysine motif (K180/K181) in the elbow region of LntA and a central proline-rich region in BAHD1 as crucial for the direct LntA-BAHD1 interaction. To better understand the role played by the dilysine motif in the functionality of LntA, we solved the crystal structure of a K180D/K181D mutant to a 2.2-Å resolution. This mutant highlights a drastic redistribution of surface charges in the vicinity of a groove, which likely plays a role in nucleomodulin target recognition. Mutation of the strategic dilysine motif also abolished the recruitment of LntA to BAHD1-associated nuclear foci and impaired the LntA-mediated stimulation of interferon responses upon infection. Last, the strict conservation of residues K180 and K181 in LntA sequences from 188
L. monocytogenes
strains of different serotypes and origins further supports their functional importance. Together, these results provide structural and functional details about the mechanism of inhibition of an epigenetic factor by a bacterial nucleomodulin.

IMPORTANCE
Pathogens have evolved various strategies to deregulate the expression of host defense genes during infection, such as targeting nuclear proteins. LntA, a secreted virulence factor from the bacterium
Listeria monocytogenes
, stimulates innate immune responses by inhibiting a chromatin-associated repressor, BAHD1. This study reveals the structural features of LntA required for BAHD1 inhibition. LntA interacts directly with a central domain of BAHD1 via a surface patch of conserved positive charges, located nearby a groove on the elbow region of LntA. By demonstrating that this patch is required for LntA function, we provide a better understanding of the molecular mechanism allowing a bacterial pathogen to control host chromatin compaction and gene expression.
Systemic Spread and Propagation of a Plant-Pathogenic Virus in European Honeybees, Apis mellifera
Authors: Li Ji Lian , Cornman R. Scott , Evans Jay D. , Pettis Jeffery S. , Zhao Yan , Murphy Charles , Peng Wen Jun , Wu Jie , Hamilton Michele , Boncristiani Humberto F. , Zhou Liang , Hammond John , Chen Yan Ping 
Published: January 2014

ABSTRACTEmerging and reemerging diseases that result from pathogen host shifts are a threat to the health of humans and their domesticates. RNA viruses have extremely high mutation rates and thus represent a significant source of these infectious diseases. In the present study, we showed that a plant-pathogenic RNA virus, tobacco ringspot virus (TRSV), could replicate and produce virions in honeybees,Apis mellifera, resulting in infections that were found throughout the entire body. Additionally, we showed that TRSV-infected individuals were continually present in some monitored colonies. While intracellular life cycle, species-level genetic variation, and pathogenesis of the virus in honeybee hosts remain to be determined, the increasing prevalence of TRSV in conjunction with other bee viruses from spring toward winter in infected colonies was associated with gradual decline of host populations and winter colony collapse, suggesting the negative impact of the virus on colony survival. Furthermore, we showed that TRSV was also found in ectoparasiticVarroamites that feed on bee hemolymph, but in those instances the virus was restricted to the gastric cecum ofVarroamites, suggesting thatVarroamites may facilitate the spread of TRSV in bees but do not experience systemic invasion. Finally, our phylogenetic analysis revealed that TRSV isolates from bees, bee pollen, andVarroamites clustered together, forming a monophyletic clade. The tree topology indicated that the TRSVs from arthropod hosts shared a common ancestor with those from plant hosts and subsequently evolved as a distinct lineage after transkingdom host alteration. This study represents a unique example of viruses with host ranges spanning both the plant and animal kingdoms.IMPORTANCEPathogen host shifts represent a major source of new infectious diseases. Here we provide evidence that a pollen-borne plant virus, tobacco ringspot virus (TRSV), also replicates in honeybees and that the virus systemically invades and replicates in different body parts. In addition, the virus was detected inside the body of parasiticVarroamites, which consume bee hemolymph, suggesting thatVarroamites may play a role in facilitating the spread of the virus in bee colonies. This study represents the first evidence that honeybees exposed to virus-contaminated pollen could also be infected and raises awareness of potential risks of new viral disease emergence due to host shift events. About 5% of known plant viruses are pollen transmitted, and these are potential sources of future host-jumping viruses. The findings from this study showcase the need for increased surveillance for potential host-jumping events as an integrated part of insect pollinator management programs.
New Insights into Dissemination and Variation of the Health Care-Associated Pathogen Acinetobacter baumannii from Genomic Analysis
Authors: Wright Meredith S. , Haft Daniel H. , Harkins Derek M. , Perez Federico , Hujer Kristine M. , Bajaksouzian Saralee , Benard Michael F. , Jacobs Michael R. , Bonomo Robert A. , Adams Mark D. 
Published: January 2014

ABSTRACT

Acinetobacter baumannii
is a globally important nosocomial pathogen characterized by an increasing incidence of multidrug resistance. Routes of dissemination and gene flow among health care facilities are poorly resolved and are important for understanding the epidemiology of
A. baumannii
, minimizing disease transmission, and improving patient outcomes. We used whole-genome sequencing to assess diversity and genome dynamics in 49 isolates from one United States hospital system during one year from 2007 to 2008. Core single-nucleotide-variant-based phylogenetic analysis revealed multiple founder strains and multiple independent strains recovered from the same patient yet was insufficient to fully resolve strain relationships, where gene content and insertion sequence patterns added additional discriminatory power. Gene content comparisons illustrated extensive and redundant antibiotic resistance gene carriage and direct evidence of gene transfer, recombination, gene loss, and mutation. Evidence of barriers to gene flow among hospital components was not found, suggesting complex mixing of strains and a large reservoir of
A. baumannii
strains capable of colonizing patients
.

IMPORTANCE
Genome sequencing was used to characterize multidrug-resistant
Acinetobacter baumannii
strains from one United States hospital system during a 1-year period to better understand how
A. baumannii
strains that cause infection are related to one another. Extensive variation in gene content was found, even among strains that were very closely related phylogenetically and epidemiologically. Several mechanisms contributed to this diversity, including transfer of mobile genetic elements, mobilization of insertion sequences, insertion sequence-mediated deletions, and genome-wide homologous recombination. Variation in gene content, however, lacked clear spatial or temporal patterns, suggesting a diverse pool of circulating strains with considerable interaction between strains and hospital locations. Widespread genetic variation among strains from the same hospital and even the same patient, particularly involving antibiotic resistance genes, reinforces the need for molecular diagnostic testing and genomic analysis to determine resistance profiles, rather than a reliance primarily on strain typing and antimicrobial resistance phenotypes for epidemiological studies.
Twin-Arginine Translocation System in Helicobacter pylori: TatC, but Not TatB, Is Essential for Viability
Authors: Benoit Stéphane L. , Maier Robert J. 
Published: January 2014

ABSTRACT

The twin-arginine translocation (Tat) system, needed to transport folded proteins across biological membranes, has not been characterized in the gastric pathogen
Helicobacter pylori
. Analysis of all
H. pylori
genome sequences available thus far reveals the presence of single copies of
tatA
,
tatB
, and
tatC
needed for the synthesis of a fully functional Tat system. Based on the presence of the twin-arginine hallmark in their signal sequence, only four
H. pylori
proteins appear to be Tat dependent: hydrogenase (HydA), catalase-associated protein (KapA), biotin sulfoxide reductase (BisC), and the ubiquinol cytochrome oxidoreductase Rieske protein (FbcF). In the present study, targeted mutations were aimed at
tatA
,
tatB
,
tatC
, or
queA
(downstream gene control). While double homologous recombination mutations in
tatB
and
queA
were easily obtained, attempts at disrupting
tatA
proved unsuccessful, while deletion of
tatC
led to partial mutants following single homologous recombination, with cells retaining a chromosomal copy of
tatC
. Double homologous recombination
tatC
mutants were obtained only when a plasmid-borne, isopropyl-β-
d
-thiogalactopyranoside (IPTG)-inducible copy of
tatC
was introduced prior to transformation. These conditional
tatC
mutants could grow only in the presence of IPTG, suggesting that
tatC
is essential in
H. pylori
.
tatB
and
tatC
mutants had lower hydrogenase and catalase activities than the wild-type strain did, and the ability of
tatC
mutants to colonize mouse stomachs was severely affected compared to the wild type. Chromosomal complementation of
tatC
mutants restored hydrogenase and catalase activities to wild-type levels, and additional expression of
tatC
in wild-type cells resulted in elevated Tat-dependent enzyme activities. Unexpectedly, the
tat
strains had cell envelope defects.

IMPORTANCE
This work reports the first characterization of the twin-arginine translocation (Tat) system in the gastric pathogen
Helicobacter pylori
. While
tatB
mutants were easily obtained, only single-crossover partial
tatC
mutants or conditional
tatC
mutants could be generated, indicating that
tatC
is essential in
H. pylori
, a surprising finding given the fact that only four proteins are predicted to be translocated by the Tat system in this bacterium. The levels of activity of hydrogenase and catalase, two of the predicted Tat-dependent enzymes, were affected in these mutants. In addition, all
tat
mutants displayed cell envelope defects, and
tatC
mutants were deficient in mouse colonization.