journal
MENU ▼
Read by QxMD icon Read
search

MSphere

journal
https://www.readbyqxmd.com/read/28317028/mycobacterial-caseinolytic-protease-gene-regulator-clgr-is-a-substrate-of-caseinolytic-protease
#1
Yoshiyuki Yamada, Thomas Dick
The mycobacterial caseinolytic protease ClpP1P2 is a degradative protease that recently gained interest as a genetically and pharmacologically validated drug target for tuberculosis. The first whole-cell active ClpP1P2 inhibitor, the human proteasome inhibitor bortezomib, is currently undergoing lead optimization to introduce selectivity for the bacterial target. How inhibition of ClpP1P2 translates into whole-cell antimicrobial activity is little understood. Previous work has shown that the caseinolytic protease gene regulator ClgR is an activator of the clpP1P2 genes and also suggested that this transcription factor may be a substrate of the protease...
March 2017: MSphere
https://www.readbyqxmd.com/read/28317027/the-type-a-and-type-b-polysaccharide-capsules-predominate-in-an-international-collection-of-invasive-kingella-kingae-isolates
#2
Eric A Porsch, Kimberly F Starr, Pablo Yagupsky, Joseph W St Geme
Kingella kingae is an encapsulated Gram-negative bacterium and an important etiology of osteoarticular infections in young children. A recent study examining a diverse collection of carrier and invasive K. kingae isolates from Israel revealed four distinct polysaccharide capsule types. In this study, to obtain a global view of K. kingae capsule type diversity, we examined an international collection of isolates using a multiplex PCR approach. The collection contained all four previously identified capsule types and no new capsule types...
March 2017: MSphere
https://www.readbyqxmd.com/read/28317026/toxoplasma-gondii-ap2ix-4-regulates-gene-expression-during-bradyzoite-development
#3
Sherri Huang, Michael J Holmes, Joshua B Radke, Dong-Pyo Hong, Ting-Kai Liu, Michael W White, William J Sullivan
Toxoplasma gondii is a protozoan parasite of great importance to human and animal health. In the host, this obligate intracellular parasite persists as a tissue cyst that is imperceptible to the immune response and unaffected by current therapies. The tissue cysts facilitate transmission through predation and give rise to chronic cycles of toxoplasmosis in immunocompromised patients. Transcriptional changes accompany conversion of the rapidly replicating tachyzoites into the encysted bradyzoites, and yet the mechanisms underlying these alterations in gene expression are not well defined...
March 2017: MSphere
https://www.readbyqxmd.com/read/28317025/marker-recycling-in-candida-albicans-through-crispr-cas9-induced-marker-excision
#4
Manning Y Huang, Aaron P Mitchell
We describe here a new approach to marker recycling, a controlled sequence of steps in which a genetic marker is selected and then lost. Marker recycling is important for genetic manipulation, because it allows a single selection marker to be used repeatedly. Our approach relies upon the ability of the CRISPR-Cas9 system to make a targeted double-strand break in DNA and the expectation that a double-strand break within a selection marker may promote recombination between directly repeated sequences that flank the marker...
March 2017: MSphere
https://www.readbyqxmd.com/read/28289728/opticlust-an-improved-method-for-assigning-amplicon-based-sequence-data-to-operational-taxonomic-units
#5
Sarah L Westcott, Patrick D Schloss
Assignment of 16S rRNA gene sequences to operational taxonomic units (OTUs) is a computational bottleneck in the process of analyzing microbial communities. Although this has been an active area of research, it has been difficult to overcome the time and memory demands while improving the quality of the OTU assignments. Here, we developed a new OTU assignment algorithm that iteratively reassigns sequences to new OTUs to optimize the Matthews correlation coefficient (MCC), a measure of the quality of OTU assignments...
March 2017: MSphere
https://www.readbyqxmd.com/read/28289727/seroprevalence-of-zika-virus-in-wild-african-green-monkeys-and-baboons
#6
Connor R Buechler, Adam L Bailey, Andrea M Weiler, Gabrielle L Barry, Meghan E Breitbach, Laurel M Stewart, Anna J Jasinska, Nelson B Freimer, Cristian Apetrei, Jane E Phillips-Conroy, Clifford J Jolly, Jeffrey Rogers, Thomas C Friedrich, David H O'Connor
Zika virus (ZIKV) has recently spread through the Americas and has been associated with a range of health effects, including birth defects in children born to women infected during pregnancy. Although the natural reservoir of ZIKV remains poorly defined, the virus was first identified in a captive "sentinel" macaque monkey in Africa in 1947. However, the virus has not been reported in humans or nonhuman primates (NHPs) in Africa outside Gabon in over a decade. Here, we examine ZIKV infection in 239 wild baboons and African green monkeys from South Africa, the Gambia, Tanzania, and Zambia using combinations of unbiased deep sequencing, quantitative reverse transcription-PCR (qRT-PCR), and an antibody capture assay that we optimized using serum collected from captive macaque monkeys exposed to ZIKV, dengue virus, and yellow fever virus...
March 2017: MSphere
https://www.readbyqxmd.com/read/28289726/regulation-of-the-candida-albicans-hypha-inducing-transcription-factor-ume6-by-the-cdk1-cyclins-cln3-and-hgc1
#7
Sigal Mendelsohn, Mariel Pinsky, Ziva Weissman, Daniel Kornitzer
The ability to switch between proliferation as yeast cells and development into hyphae is a hallmark of Candida albicans. The switch to hyphal morphogenesis depends on external inducing conditions, but its efficiency is augmented in stationary-phase cells. Ume6, a transcription factor that is itself transcriptionally induced under hypha-promoting conditions, is both necessary and sufficient for hyphal morphogenesis. We found that Ume6 is regulated posttranslationally by the cell cycle kinase Cdc28/Cdk1, which reduces Ume6 activity via different mechanisms using different cyclins...
March 2017: MSphere
https://www.readbyqxmd.com/read/28289725/cooperation-of-adhesin-alleles-in-salmonella-host-tropism
#8
Leon De Masi, Min Yue, Changmin Hu, Alexey V Rakov, Shelley C Rankin, Dieter M Schifferli
Allelic combinations and host specificities for three fimbrial adhesins, FimH, BcfD, and StfH, were compared for 262 strains of Salmonella enterica serovar Newport, a frequent human and livestock pathogen. Like FimH, BcfD had two major alleles (designated A and B), whereas StfH had two allelic groups, each with two alleles (subgroup A1 and A2 and subgroup B1 and B2). The most prevalent combinations of FimH/BcfD/StfH alleles in S. Newport were A/A/A1 and B/B/B1. The former set was most frequently found in bovine and porcine strains, whereas the latter combination was most frequently found in environmental and human isolates...
March 2017: MSphere
https://www.readbyqxmd.com/read/28289724/flagellar-synchronization-is-a-simple-alternative-to-cell-cycle-synchronization-for-ciliary-and-flagellar-studies
#9
Soumita Dutta, Prachee Avasthi
The unicellular green alga Chlamydomonas reinhardtii is an ideal model organism for studies of ciliary function and assembly. In assays for biological and biochemical effects of various factors on flagellar structure and function, synchronous culture is advantageous for minimizing variability. Here, we have characterized a method in which 100% synchronization is achieved with respect to flagellar length but not with respect to the cell cycle. The method requires inducing flagellar regeneration by amputation of the entire cell population and limiting regeneration time...
March 2017: MSphere
https://www.readbyqxmd.com/read/28261670/tracking-the-subtle-mutations-driving-host-sensing-by-the-plant-pathogen-streptomyces-scabies
#10
Samuel Jourdan, Isolde M Francis, Benoit Deflandre, Rosemary Loria, Sébastien Rigali
The acquisition of genetic material conferring the arsenal necessary for host virulence is a prerequisite on the path to becoming a plant pathogen. More subtle mutations are also required for the perception of cues signifying the presence of the target host and optimal conditions for colonization. The decision to activate the pathogenic lifestyle is not "taken lightly" and involves efficient systems monitoring environmental conditions. But how can a pathogen trigger the expression of virulence genes in a timely manner if the main signal inducing its pathogenic behavior originates from cellulose, the most abundant polysaccharide on earth? This situation is encountered by Streptomyces scabies, which is responsible for common scab disease on tuber and root crops...
March 2017: MSphere
https://www.readbyqxmd.com/read/28261669/environmental-viral-genomes-shed-new-light-on-virus-host-interactions-in-the-ocean
#11
Yosuke Nishimura, Hiroyasu Watai, Takashi Honda, Tomoko Mihara, Kimiho Omae, Simon Roux, Romain Blanc-Mathieu, Keigo Yamamoto, Pascal Hingamp, Yoshihiko Sako, Matthew B Sullivan, Susumu Goto, Hiroyuki Ogata, Takashi Yoshida
Metagenomics has revealed the existence of numerous uncharacterized viral lineages, which are referred to as viral "dark matter." However, our knowledge regarding viral genomes is biased toward culturable viruses. In this study, we analyzed 1,600 (1,352 nonredundant) complete double-stranded DNA viral genomes (10 to 211 kb) assembled from 52 marine viromes. Together with 244 previously reported uncultured viral genomes, a genome-wide comparison delineated 617 genus-level operational taxonomic units (OTUs) for these environmental viral genomes (EVGs)...
March 2017: MSphere
https://www.readbyqxmd.com/read/28261668/staurosporine-induces-filamentation-in-the-human-fungal-pathogen-candida-albicans-via-signaling-through-cyr1-and-protein-kinase-a
#12
Jinglin L Xie, Teresa R O'Meara, Elizabeth J Polvi, Nicole Robbins, Leah E Cowen
Protein kinases are key regulators of signal transduction pathways that participate in diverse cellular processes. In fungal pathogens, kinases regulate signaling pathways that govern drug resistance, stress adaptation, and pathogenesis. The impact of kinases on the fungal regulatory circuitry has recently garnered considerable attention in the opportunistic fungal pathogen Candida albicans, which is a leading cause of human morbidity and mortality. Complex regulatory circuitry governs the C. albicans morphogenetic transition between yeast and filamentous growth, which is a key virulence trait...
March 2017: MSphere
https://www.readbyqxmd.com/read/28261667/protein-malnutrition-modifies-innate-immunity-and-gene-expression-by-intestinal-epithelial-cells-and-human-rotavirus-infection-in-neonatal-gnotobiotic-pigs
#13
Anastasia N Vlasova, Francine C Paim, Sukumar Kandasamy, Moyasar A Alhamo, David D Fischer, Stephanie N Langel, Loic Deblais, Anand Kumar, Juliet Chepngeno, Lulu Shao, Huang-Chi Huang, Rosario A Candelero-Rueda, Gireesh Rajashekara, Linda J Saif
Malnutrition affects millions of children in developing countries, compromising immunity and contributing to increased rates of death from infectious diseases. Rotavirus is a major etiological agent of childhood diarrhea in developing countries, where malnutrition is prevalent. However, the interactions between the two and their combined effects on immune and intestinal functions are poorly understood. In this study, we used neonatal gnotobiotic (Gn) pigs transplanted with the fecal microbiota of a healthy 2-month-old infant (HIFM) and fed protein-deficient or -sufficient bovine milk diets...
March 2017: MSphere
https://www.readbyqxmd.com/read/28251184/epitope-addition-and-ablation-via-manipulation-of-a-dengue-virus-serotype-1-infectious-clone
#14
Emily N Gallichotte, Vineet D Menachery, Boyd L Yount, Douglas G Widman, Kenneth H Dinnon, Steven Hartman, Aravinda M de Silva, Ralph S Baric
Despite the clinical relevance, dengue virus (DENV) research has been hampered by the absence of robust reverse genetic systems to manipulate the viral serotypes for propagation and generation of mutant viruses. In this article, we describe application of an infectious clone system for DENV serotype 1 (DENV1). Similar to previous clones in both flaviviruses and coronaviruses, the approach constructs a panel of contiguous cDNAs that span the DENV genome and can be systematically and directionally assembled to produce viable, full-length viruses...
January 2017: MSphere
https://www.readbyqxmd.com/read/28251183/opposing-transcriptional-mechanisms-regulate-toxoplasma-development
#15
Dong-Pyo Hong, Joshua B Radke, Michael W White
The Toxoplasma biology that underlies human chronic infection is developmental conversion of the acute tachyzoite stage into the latent bradyzoite stage. We investigated the roles of two alkaline-stress-induced ApiAP2 transcription factors, AP2IV-3 and AP2IX-9, in bradyzoite development. These factors were expressed in two overlapping waves during bradyzoite development, with AP2IX-9 increasing expression earlier than AP2IV-3, which peaked as AP2IX-9 expression was declining. Disruption of the AP2IX-9 gene enhanced, while deletion of AP2IV-3 gene decreased, tissue cyst formation, demonstrating that these factors have opposite functions in bradyzoite development...
January 2017: MSphere
https://www.readbyqxmd.com/read/28251182/unexplored-archaeal-diversity-in-the-great-ape-gut-microbiome
#16
Kasie Raymann, Andrew H Moeller, Andrew L Goodman, Howard Ochman
Archaea are habitual residents of the human gut flora but are detected at substantially lower frequencies than bacteria. Previous studies have indicated that each human harbors very few archaeal species. However, the low diversity of human-associated archaea that has been detected could be due to the preponderance of bacteria in these communities, such that relatively few sequences are classified as Archaea even when microbiomes are sampled deeply. Moreover, the universal prokaryotic primer pair typically used to interrogate microbial diversity has low specificity to the archaeal domain, potentially leaving vast amounts of diversity unobserved...
January 2017: MSphere
https://www.readbyqxmd.com/read/28251181/maternal-immunoreactivity-to-herpes-simplex-virus-2-and-risk-of-autism-spectrum-disorder-in-male-offspring
#17
Milada Mahic, Siri Mjaaland, Hege Marie Bøvelstad, Nina Gunnes, Ezra Susser, Michaeline Bresnahan, Anne-Siri Øyen, Bruce Levin, Xiaoyu Che, Deborah Hirtz, Ted Reichborn-Kjennerud, Synnve Schjølberg, Christine Roth, Per Magnus, Camilla Stoltenberg, Pål Surén, Mady Hornig, W Ian Lipkin
Maternal infections during pregnancy are associated with risk of neurodevelopmental disorders, including autism spectrum disorders (ASDs). Proposed pathogenetic mechanisms include fetal infection, placental inflammation, and maternal cytokines or antibodies that cross the placenta. The Autism Birth Cohort comprises mothers, fathers, and offspring recruited in Norway in 1999 to 2008. Through questionnaire screening, referrals, and linkages to a national patient registry, 442 mothers of children with ASD were identified, and 464 frequency-matched controls were selected...
January 2017: MSphere
https://www.readbyqxmd.com/read/28251180/the-pathogenic-potential-of-a-microbe
#18
Arturo Casadevall
Virulence is a microbial property that is realized only in susceptible hosts. There is no absolute measurement for virulence, and consequently it is always measured relative to a standard, usually another microbe or host. This article introduces the concept of pathogenic potential, which provides a new approach to measuring the capacity of microbes for virulence. The pathogenic potential is proportional to the fraction of individuals who become symptomatic after infection with a defined inoculum and can include such attributes as mortality, communicability, and the time from infection to disease...
January 2017: MSphere
https://www.readbyqxmd.com/read/28251179/fluorocycline-tp-271-is-potent-against-complicated-community-acquired-bacterial-pneumonia-pathogens
#19
Trudy H Grossman, Corey Fyfe, William O'Brien, Meredith Hackel, Mary Beth Minyard, Ken B Waites, Jacques Dubois, Timothy M Murphy, Andrew M Slee, William J Weiss, Joyce A Sutcliffe
TP-271 is a novel, fully synthetic fluorocycline antibiotic in clinical development for the treatment of respiratory infections caused by susceptible and multidrug-resistant pathogens. TP-271 was active in MIC assays against key community respiratory Gram-positive and Gram-negative pathogens, including Streptococcus pneumoniae (MIC90 = 0.03 µg/ml), methicillin-sensitive Staphylococcus aureus (MSSA; MIC90 = 0.25 µg/ml), methicillin-resistant S. aureus (MRSA; MIC90 = 0.12 µg/ml), Streptococcus pyogenes (MIC90 = 0...
January 2017: MSphere
https://www.readbyqxmd.com/read/28217744/effect-of-tcdr-mutation-on-sporulation-in-the-epidemic-clostridium-difficile-strain-r20291
#20
Brintha P Girinathan, Marc Monot, Daniel Boyle, Kathleen N McAllister, Joseph A Sorg, Bruno Dupuy, Revathi Govind
Clostridium difficile is an important nosocomial pathogen and the leading cause of hospital-acquired diarrhea. Antibiotic use is the primary risk factor for the development of C. difficile-associated disease because it disrupts normally protective gut flora and enables C. difficile to colonize the colon. C. difficile damages host tissue by secreting toxins and disseminates by forming spores. The toxin-encoding genes, tcdA and tcdB, are part of a pathogenicity locus, which also includes the tcdR gene that codes for TcdR, an alternate sigma factor that initiates transcription of tcdA and tcdB genes...
January 2017: MSphere
journal
journal
52743
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"