Query: NC_009792:4017510 Citrobacter koseri ATCC BAA-895, complete genome
Lineage: Citrobacter koseri; Citrobacter; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: Citrobacter koseri ATCC BAA-895 is a clinical isolate from a human infant. Causative agent of neonatal meningitis. Citrobacter koseri, previously known as Citrobacter diversus, Levinea diversus or Levinea malonatica resides in a wide range of environments, including soil, water and food products. It is an occasional inhabitant of human and animal intestines, but is mainly characterized as being a causative agent of neonatal meningitis with an extreme high rate of multiple brain abscess initiations and a concomitant high moratility rate. The bacteria are used in neonatal rat models to study the mechanism of blood-brain barrier penetration, host immune response evasion and its resistance to phagocytotic killing.
Subject: NC_004545:15650 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.