Adaptation to endogenous oxidative stress is an integral aspect of Streptococcus pneumoniae colonization and virulence. In this work, we identify key transcriptomic and proteomic features of the pneumococcal endogenous oxidative stress response. The thiol peroxidase TpxD plays a critical role in adaptation to endogenous H2O2 and serves to limit protein sulfenylation of glycolytic, capsule, and nucleotide...
January/February 2017; volume 2, issue 1
Molecular Biology and Physiology
- Research Article | Molecular Biology and PhysiologyBiological and Chemical Adaptation to Endogenous Hydrogen Peroxide Production in Streptococcus pneumoniae D39
- Research Article | Molecular Biology and PhysiologyOptimized CRISPR-Cas9 Genome Editing for Leishmania and Its Use To Target a Multigene Family, Induce Chromosomal Translocation, and Study DNA Break Repair Mechanisms
Leishmania parasites cause human leishmaniasis. To accelerate characterization of Leishmania genes for new drug and vaccine development, we optimized and simplified the CRISPR-Cas9 genome-editing tool for Leishmania. We show that co-CRISPR targeting of the miltefosine transporter gene and serial transfections of an oligonucleotide donor significantly eased isolation of edited mutants. This cotargeting strategy...
Ecological and Evolutionary Science
- Research Article | Ecological and Evolutionary Science
Non-Western populations have been shown to have distinct gut microbial communities shaped by traditional diets. The hitherto-uncharacterized microbiome of the Inuit may help us to better understand health risks specific to this population such as diabetes and obesity, which increase in prevalence as many Inuit transition to a Western diet. Here we show that even Inuit consuming a mostly traditional diet have a broadly Western-like...
- Research Article | Ecological and Evolutionary ScienceHost Range Restriction of Insect-Specific Flaviviruses Occurs at Several Levels of the Viral Life Cycle
Most viruses of the genus Flavivirus, e.g., YFV and dengue virus, are mosquito borne and transmitted to vertebrates during blood feeding of mosquitoes. Within the last decade, an increasing number of viruses with a host range exclusively restricted to insects in close relationship to the vertebrate-pathogenic flaviviruses were discovered in mosquitoes. To identify barriers that could block the arboviral vertebrate tropism, we...
- Research Article | Host-Microbe Biology
Cytoadhesion of P. falciparum-infected erythrocytes in the microcirculation is a major virulence determinant. P. falciparum is descended from a subgenus of parasites that also infect chimpanzees and gorillas and exhibits strict host species specificity. Despite their high genetic similarity to P. falciparum, it is unknown whether ape parasites encode adhesion properties similar to those of P. falciparum...
- Research Article | Host-Microbe BiologyBacterial Lysis through Interference with Peptidoglycan Synthesis Increases Biofilm Formation by Nontypeable Haemophilus influenzae
Most, if not all, bacteria form a biofilm, a multicellular structure that protects them from antimicrobial actions of the host immune system and affords resistance to antibiotics. The latter is especially disturbing with the increase in multiresistant bacterial clones worldwide. Bacterial biofilm formation is a multistep process that starts with surface adhesion, after which attached bacteria divide and give rise to biomass. The actual...
Clinical Science and Epidemiology
- Research Article | Clinical Science and EpidemiologyGlobal Assessment of the Activity of Tigecycline against Multidrug-Resistant Gram-Negative Pathogens between 2004 and 2014 as Part of the Tigecycline Evaluation and Surveillance Trial
Multidrug resistance among bacterial pathogens is an ongoing global problem and renders antimicrobial agents ineffective at treating bacterial infections. In the health care setting, infections caused by multidrug-resistant (MDR) Gram-negative bacteria can cause increased mortality, longer hospital stays, and higher treatments costs. The aim of the Tigecycline Evaluation and Surveillance Trial (TEST) is to assess the in vitro...
Applied and Environmental Science
- Research Article | Applied and Environmental ScienceEffects of Exogenous Yeast and Bacteria on the Microbial Population Dynamics and Outcomes of Olive Fermentations
Food fermentations are subject to tremendous selective pressures resulting in the growth and persistence of a limited number of bacterial and fungal taxa. Although these foods are vulnerable to spoilage by unintended contamination of certain microorganisms, or alternatively, can be improved by the deliberate addition of starter culture microbes that accelerate or beneficially modify product outcomes, the impact of either of those...
Clinical Science and Epidemiology