A three-way comparative genomic analysis of Mannheimia haemolytica isolates

<p>Abstract</p> <p>Background</p> <p><it>Mannhemia haemolytica </it>is a Gram-negative bacterium and the principal etiological agent associated with bovine respiratory disease complex. They transform from a benign commensal to a deadly pathogen, during stress such as viral infection and transportation to feedlots and cause acute pleuropneumonia commonly known as shipping fever. The U.S beef industry alone loses more than one billion dollars annually due to shipping fever. Despite its enormous economic importance there are no specific and accurate genetic markers, which will aid in understanding the pathogenesis and epidemiology of <it>M. haemolytica </it>at molecular level and assist in devising an effective control strategy.</p> <p>Description</p> <p>During our comparative genomic sequence analysis of three <it>Mannheimia haemolytica </it>isolates, we identified a number of genes that are unique to each strain. These genes are "high value targets" for future studies that attempt to correlate the variable gene pool with phenotype. We also identified a number of high confidence single nucleotide polymorphisms (hcSNPs) spread throughout the genome and focused on non-synonymous SNPs in known virulence genes. These SNPs will be used to design new hcSNP arrays to study variation across strains, and will potentially aid in understanding gene regulation and the mode of action of various virulence factors.</p> <p>Conclusions</p> <p>During our analysis we identified previously unknown possible type III secretion effector proteins, clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated sequences (Cas). The presence of CRISPR regions is indicative of likely co-evolution with an associated phage. If proven functional, the presence of a type III secretion system in <it>M. haemolytica </it>will help us re-evaluate our approach to study host-pathogen interactions. We also identified various adhesins containing immuno-dominant domains, which may interfere with host-innate immunity and which could potentially serve as effective vaccine candidates.</p

Potomac Aqueduct, hydrographic survey of the Potomac River near Georgetown : shewing the position of the Aqueduct, its connection with the Ch. & Ohio Canal on the north bank, and with the Alexandria Canal on the south bank of the river /

"Survey made in the fall of 1832."Relief shown by hachures. Depths shown by contours and soundings.From the papers of the Virginia-District of Columbia Boundary Commission.Rubber-stamped and annotated in ink on recto and verso: District of Columbia-Virginia Boundary Commission ... State of Virginia Exhibit No. 63 ... Date: January 23/1935, Smith & Hulse, Official Reporters.In upper left corner: Plate 1.In right upper margin: Doc. 261

Geography, knowledge spillovers and small firms’ exports: an empirical examination for The Netherlands

Exports, Innovation, Scale economies, Small firms, L26, R12, Q31,