Query: NC_010519:1411347 Haemophilus somnus 2336 chromosome, complete genome
Lineage: Histophilus somni; Histophilus; Pasteurellaceae; Pasteurellales; Proteobacteria; Bacteria
General Information: This strain was isolated from the lung of a calf which had pneumonia. A group of organisms that are either obligate parasites or commensal organisms found in animal mucous membranes. Almost all species require the presence of important growth factors found in the blood of their hosts, including either X factor (protoporphyrin IX or heme) or V factor (nicotinamide adenine dinucleotide (NAD or NADP)). This organism is a major cause of disease in feedlot cattle. It causes constriction of blood vessels supplying major organs, restricting blood supply which leads to reduced oxygen delivery, and leads to tissue damage and death. The diseases that result are pneumonia, arthritis, myocarditis (inflammation of heart muscle), and reproductive problems resulting in the loss of millions of dollars in animals each year.
Subject: NC_004545:229771 Buchnera aphidicola str. Bp (Baizongia pistaciae), complete genome
Lineage: Buchnera aphidicola; Buchnera; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This organism is found in the aphid Baizongia pistaciae. Aphid endosymbiont. It is believed that the Buchnera provide the essential nutrients the host lacks. Besides a nutritional co-dependence, due to a co-existence of millions of years, Buchnera have lost the ability to produce cell surface components such as lipopolysaccharides. This makes for an obligate endosymbiont relationship between host and Buchnera. Buchnera are prokaryotic cells which belong to the gamma-Proteobacteria, closely related to the Enterobacteriaceae family. Phylogenetic studies using 16S rRNA indicate that the symbiotic relationship was established around 200-250 million years ago. Since Buchnera are closely related to Escherichia coli and Haemophilus influenzae, comparative genomic studies can shed light on the evolutionary mechanisms of intracellular endosymbiosis as well as the different underlying molecular basis between organisms with parasitic behavior and symbionts.