Publications by authors named "Anca M Segall"

Motivation: Phage therapy is a viable alternative for treating bacterial infections amidst the escalating threat of antimicrobial resistance. However, the therapeutic success of phage therapy depends on selecting safe and effective phage candidates. While experimental methods focus on isolating phages and determining their lifecycle and host range, comprehensive genomic screening is critical to identify markers that indicate potential risks, such as toxins, antimicrobial resistance, or temperate lifecycle traits.

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Background: One of the stranger phenomena that can occur during gene translation is where, as a ribosome reads along the mRNA, various cellular and molecular properties contribute to stalling the ribosome on a slippery sequence and shifting the ribosome into one of the other two alternate reading frames. The alternate frame has different codons, so different amino acids are added to the peptide chain. More importantly, the original stop codon is no longer in-frame, so the ribosome can bypass the stop codon and continue to translate the codons past it.

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Twelve strains were isolated from fecal samples of inflammatory bowel disease patients and matched "household control" individuals. These include the species , , , , , and .

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Bacteroides, the prominent bacteria in the human gut, play a crucial role in degrading complex polysaccharides. Their abundance is influenced by phages belonging to the order. Despite identifying over 600 genomes computationally, only few have been successfully isolated.

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species colonization of Cystic Fibrosis respiratory airways is an increasing concern. Two adult patients with Cystic Fibrosis colonized by CF418 or CF116 experienced fatal exacerbations. spp.

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Background: Cystic fibrosis (CF) is a genetic disease associated with lung disease characterized by chronic pulmonary infection, increasingly caused by multiple drug-resistant pathogens after repeated antibiotic exposure, limiting antibiotic treatment options. Bacteriophages can provide a pathogen-specific bactericidal treatment used with antibiotics to improve microbiologic and clinical outcomes in CF.

Methods: Achromobacter species isolates from sputum of a chronically infected person with CF, were assessed for susceptibility to bacteriophages: 2 highly active, purified bacteriophages were administered intravenously every 8 hours, in conjunction with a 14-day piperacillin/tazobactam course for CF exacerbation.

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Background: One of the stranger phenomena that can occur during gene translation is where, as a ribosome reads along the mRNA, various cellular and molecular properties contribute to stalling the ribosome on a slippery sequence, shifting the ribosome into one of the other two alternate reading frames. The alternate frame has different codons, so different amino acids are added to the peptide chain, but more importantly, the original stop codon is no longer in-frame, so the ribosome can bypass the stop codon and continue to translate the codons past it. This produces a longer version of the protein, a fusion of the original amino acids, followed by all the alternate frame amino acids.

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Unlabelled: Bacteroides, the prominent bacteria in the human gut, play a crucial role in degrading complex polysaccharides. Their abundance is influenced by phages belonging to the order. Despite identifying over 600 genomes computationally, only few have been successfully isolated.

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For any given bacteriophage genome or phage-derived sequences in metagenomic data sets, we are unable to assign a function to 50-90% of genes, or more. Structural protein-encoding genes constitute a large fraction of the average phage genome and are among the most divergent and difficult-to-identify genes using homology-based methods. To understand the functions encoded by phages, their contributions to their environments, and to help gauge their utility as potential phage therapy agents, we have developed a new approach to classify phage ORFs into ten major classes of structural proteins or into an "other" category.

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An essential step in the morphogenesis of tailed bacteriophages is the joining of heads and tails to form infectious virions. Our understanding of the maturation of complete virus particles remains incomplete. Through an unknown mechanism, phage T4 gene product 4 (gp4) plays an essential role in the head-tail joining step of T4-like phages.

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Although millions of distinct virus species likely exist, only approximately 9000 are catalogued in GenBank's RefSeq database. We selectively enriched for the genomes of circular DNA viruses in over 70 animal samples, ranging from nematodes to human tissue specimens. A bioinformatics pipeline, Cenote-Taker, was developed to automatically annotate over 2500 complete genomes in a GenBank-compliant format.

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Increasingly, clinical infections are becoming recalcitrant or completely resistant to antibiotics treatment and multidrug resistance is rising alarmingly. Patients suffering from infections that used to be treated successfully by antibiotic regimens are running out of the treatment options. Bacteriophage (phage) therapy, long practiced in parts of Eastern Europe and the states of the former Soviet Union, is now being reevaluated as a treatment option complementary to and synergistic with antibiotic treatments.

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Widespread antibiotic use in clinical medicine and the livestock industry has contributed to the global spread of multidrug-resistant (MDR) bacterial pathogens, including We report on a method used to produce a personalized bacteriophage-based therapeutic treatment for a 68-year-old diabetic patient with necrotizing pancreatitis complicated by an MDR infection. Despite multiple antibiotic courses and efforts at percutaneous drainage of a pancreatic pseudocyst, the patient deteriorated over a 4-month period. In the absence of effective antibiotics, two laboratories identified nine different bacteriophages with lytic activity for an isolate from the patient.

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Citrobacter rodentium is a Gram-negative, murine-specific enteric pathogen that infects epithelial cells in the colon. It is closely related to the clinically relevant human pathogen, enterohemorrhagic Escherichia coli (EHEC), a leading cause of haemorrhagic colitis and haemolytic uremic syndrome. We have previously reported that a novel antimicrobial peptide, wrwycr, compromises bacterial DNA repair and significantly reduces the survival of acid-stressed EHEC, suggesting an antimicrobial strategy for targeting the survival of ingested EHEC.

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The Critical Assessment of protein Structure Prediction (CASP) experiment would not have been possible without the prediction targets provided by the experimental structural biology community. In this article, selected crystallographers providing targets for the CASP11 experiment discuss the functional and biological significance of the target proteins, highlight their most interesting structural features, and assess whether these features were correctly reproduced in the predictions submitted to CASP11. Proteins 2016; 84(Suppl 1):34-50.

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Current investigations into phage-host interactions are dependent on extrapolating knowledge from (meta)genomes. Interestingly, 60 - 95% of all phage sequences share no homology to current annotated proteins. As a result, a large proportion of phage genes are annotated as hypothetical.

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Gene amplification is a phenotype-causing form of chromosome instability and is initiated by DNA double-strand breaks (DSBs). Cells with mutant p53 lose G1/S checkpoint and are permissive to gene amplification. In this study we show that mammalian cells become proficient for spontaneous gene amplification when the function of the DSB repair protein complex MRN (Mre11/Rad50/Nbs1) is impaired.

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Coxsackievirus B3 (CVB3), a member of the picornavirus family and enterovirus genus, causes viral myocarditis, aseptic meningitis, and pancreatitis in humans. We genetically engineered a unique molecular marker, "fluorescent timer" protein, within our infectious CVB3 clone and isolated a high-titer recombinant viral stock (Timer-CVB3) following transfection in HeLa cells. "Fluorescent timer" protein undergoes slow conversion of fluorescence from green to red over time, and Timer-CVB3 can be utilized to track virus infection and dissemination in real time.

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Effective treatments for cancer are still needed, both for cancers that do not respond well to current therapeutics and for cancers that become resistant to available treatments. Herein we investigated the effect of a structure-selective d-amino acid peptide wrwycr that binds replication fork mimics and Holliday Junction (HJs) intermediates of homologous recombination (HR) in vitro, and inhibits their resolution by HJ-processing enzymes. We predicted that treating cells with HJ-binding compounds would lead to accumulation of DNA damage.

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Bacteriophages encode auxiliary metabolic genes that support more efficient phage replication. For example, cyanophages carry several genes to maintain host photosynthesis throughout infection, shuttling the energy and reducing power generated away from carbon fixation and into anabolic pathways. Photodamage to the D1/D2 proteins at the core of photosystem II necessitates their continual replacement.

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DNA repair pathways in bacteria that use homologous recombination involve the formation and subsequent resolution of Holliday junction (HJ) intermediates. We have previously identified several hexameric peptides that bind to HJs and interfere with HJ processing enzymes in vitro. The peptide WRWYCR and its D-amino acid stereoisomer wrwycr, are potent antibacterial agents.

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Antibiotics with novel and/or multiple targets are highly desirable in the face of the steady rise of clinical antibiotic resistance. We have screened and identified small molecules, typified by the compound TPI1609-10 (aka SM10), with antibiotic activity against both gram-positive and gram-negative bacteria. SM10 was screened in vitro to bind branched Holliday junction intermediates of homologous recombination and tyrosine recombinase-mediated recombination; thus, the cellular targets of the small molecules were expected to include the RuvABC Holliday junction resolvasome and the XerCD complex involved in proper segregation of replicated chromosomes to daughter cells.

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