100K Pathogen Genome Project.

The 100K Pathogen Genome Project is producing draft and closed genome sequences from diverse pathogens. This project expanded globally to include a snapshot of global bacterial genome diversity. The genomes form a sequence database that has a variety of uses from systematics to public health

Amylases and Their Importance during Glycan Degradation: Genome Sequence Release of Salmonella Amylase Knockout Strains.

Amylases catalyze the cleavage of α-d-1,4 and α-d-1,6-glycosidic bonds in starch and related carbohydrates. Amylases are widely distributed in nature and are important in carbohydrate metabolism. This is the release of four single and two double deletions in Salmonella enterica serovar Typhimurium LT2 that are important for glycan degradation during infection

Draft Genome Sequences of Salmonella enterica Serovar Typhimurium LT2 with Deleted Chitinases That Are Emerging Virulence Factors.

Chitinases are glycosyl hydrolases that catalyze the hydrolysis of the β-1,4 linkages in complex carbohydrates and those that contain GlcNAc. These enzymes are considered emerging virulence factors during infection because the host glycan changes. This is the release of four single chitinase deletion mutants in Salmonella enterica serovar Typhimurium LT2

Complete Genome Sequences of a Clinical Isolate and an Environmental Isolate of Vibrio parahaemolyticus.

Vibrio parahaemolyticus is the leading cause of seafood-borne infections in the United States. We report complete genome sequences for two V. parahaemolyticus strains isolated in 2007, CDC_K4557 and FDA_R31 of clinical and oyster origin, respectively. These two sequences might assist in the investigation of differential virulence of this organism

Implication of Sialidases in Salmonella Infection: Genome Release of Sialidase Knockout Strains from Salmonella enterica Serovar Typhimurium LT2.

Sialidases, which are widely distributed in nature, cleave the α-ketosidic bond of terminal sialic acid residue. These emerging virulence factors degrade the host glycan. We report here the release of seven sialidase and one sialic acid transporter deletion in Salmonella enterica serovar Typhimurium strain LT2, which are important in cellular invasion during infection

Prebiotic Oligosaccharides Potentiate Host Protective Responses against L. Monocytogenes Infection.

Prebiotic oligosaccharides are used to modulate enteric pathogens and reduce pathogen shedding. The interactions with prebiotics that alter Listeria monocytogenes infection are not yet clearly delineated. L. monocytogenes cellular invasion requires a concerted manipulation of host epithelial cell membrane receptors to initiate internalization and infection often via receptor glycosylation. Bacterial interactions with host glycans are intimately involved in modulating cellular responses through signaling cascades at the membrane and in intracellular compartments. Characterizing the mechanisms underpinning these modulations is essential for predictive use of dietary prebiotics to diminish pathogen association. We demonstrated that human milk oligosaccharide (HMO) pretreatment of colonic epithelial cells (Caco-2) led to a 50% decrease in Listeria association, while Biomos pretreatment increased host association by 150%. L. monocytogenes-induced gene expression changes due to oligosaccharide pretreatment revealed global alterations in host signaling pathways that resulted in differential subcellular localization of L. monocytogenes during early infection. Ultimately, HMO pretreatment led to bacterial clearance in Caco-2 cells via induction of the unfolded protein response and eIF2 signaling, while Biomos pretreatment resulted in the induction of host autophagy and L. monocytogenes vacuolar escape earlier in the infection progression. This study demonstrates the capacity of prebiotic oligosaccharides to minimize infection through induction of host-intrinsic protective responses

Shigella Draft Genome Sequences: Resources for Food Safety and Public Health.

Shigella is a major foodborne pathogen that infects humans and nonhuman primates and is the major cause of dysentery and reactive arthritis worldwide. This is the initial public release of 16 Shigella genome sequences from four species sequenced as part of the 100K Pathogen Genome Project

Draft Genome Sequences of Campylobacter jejuni Strains That Cause Abortion in Livestock.

Campylobacter jejuni is an intestinal bacterium that can cause abortion in livestock. This publication announces the public release of 15 Campylobacter jejuni genome sequences from isolates linked to abortion in livestock. These isolates are part of the 100K Pathogen Genome Project and are from clinical cases at the University of California (UC) Davis

Scanning tunneling microscopy investigation of 2H-MoS_2: A layered semiconducting transition‐metal dichalcogenide

Scanning tunneling microscopy (STM) has been enormously successful in solving several important problems in the geometric and electronic structure of homogeneous metallic and semiconducting surfaces. A central question which remains to be answered with respect to the study of compound surfaces, however, is the extent to which the chemical identity of constituent atoms may be established. Recently, progress in this area was made by Feenstra et al. who succeeded in selectively imaging either Ga or As atoms on the GaAs (110) surface. So far this is the only case where such selectivity has been achieved. In an effort to add to our understanding of compound surface imaging we have undertaken a vacuum STM study of 2H-MoS_2, a material which has two structurally and electronically different atomic species at its surface

Host-to-host variation of ecological interactions in polymicrobial infections

Host-to-host variability with respect to interactions between microorganisms and multicellular hosts are commonly observed in infection and in homeostasis. However, the majority of mechanistic models used in analyzing host-microorganism relationships, as well as most of the ecological theories proposed to explain co-evolution of host and microbes, are based on averages across a host population. By assuming that observed variations are random and independent, these models overlook the role of inter-host differences. Here we analyze mechanisms underlying host-to-host variations, using the well-characterized experimental infection model of polymicrobial otitis media (OM) in chinchillas, in combination with population dynamic models and a Maximum Entropy (MaxEnt) based inference scheme. We find that the nature of the interactions among bacterial species critically regulates host-to-host variations of these interactions. Surprisingly, seemingly unrelated phenomena, such as the efficiency of individual bacterial species in utilizing nutrients for growth and the microbe-specific host immune response, can become interdependent in a host population. The latter finding suggests a potential mechanism that could lead to selection of specific strains of bacterial species during the coevolution of the host immune response and the bacterial species.Comment: 39 Pages 6 figure