Query: NC_013928:370893 Streptococcus mutans NN2025, complete genome
Lineage: Streptococcus mutans; Streptococcus; Streptococcaceae; Lactobacillales; Firmicutes; Bacteria
General Information: This strain is a clinical serotype c strain isolated in Japan in 2002. Streptococci are Gram-positive, nonmotile, nonsporeforming, catalase-negative cocci that occur in pairs or chains. Members of this genus vary widely in pathogenic potential. Most streptococci are facultative anaerobes, and some are obligate anaerobes. Streptococcus mutans was first isolated in 1924 from human carious (cavities) lesions and is the main cause of tooth decay. This organism thrives in a bacterial community known as a dental plaque which forms on the surface of teeth. This organism has also been implicated in cases of infective endocarditis.
Subject: NC_004545:499709 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.