Query: NC_002488:2502000 Xylella fastidiosa 9a5c, complete genome
Lineage: Xylella fastidiosa; Xylella; Xanthomonadaceae; Xanthomonadales; Proteobacteria; Bacteria
General Information: This strain was derived from a pathogenic strain (8.1b) isolated in 1992 in France that had come from infected twigs derived from the sweet orange strain Valencia in Brazil in the same year. This organism was first identified in 1993 as the causal agent of citrus variegated chlorosis, a disease that affects varieties of sweet oranges. Other strains of this species cause a range of diseases in mulberry, pear, almond, elm, sycamore, oak, maple, pecan and coffee which collectively result in multimillion dollar devastation of economically important plants. Xylella fastidiosa is similar to Xanthomonas campestris pv. campestris in that it produces a wide variety of pathogenic factors for colonization in a host-specific manner including a large number of fimbrial and afimbrial adhesins for attachment. It does not contain a type III secretion system, but possesses genes for a type II secretion system for export of exoenzymes that degrade the plant cell wall and allow the bacterium to colonize the plant xylem.
Subject: NC_008710:386376 Borrelia turicatae 91E135, complete genome
Lineage: Borrelia turicatae; Borrelia; Spirochaetaceae; Spirochaetales; Spirochaetes; Bacteria
General Information: This strain was isolated in the USA from the soft tick Ornithodoros turicatae. Borrelia turicatae is the causative agent of tick-borne relapsing fever in the southwestern USA. Ticks become infected with Borrelia while feeding on an infected mammal, usually a rodent or squirrel. Borrelia then multiplies rapidly, causing a generalized infection throughout the tick. While feeding, the tick passes the spirochete into a mammalian host through its infectious saliva. Relapsing fever is characterized by period of chills, fever, headache, and malaise, followed by an asymptomatic, followed by another episode of symptoms. The cycle of relapsing is due to changes in the surface proteins of Borrelia, which allow it to avoid detection and removal by the host immune system. This antigenic variation is the result of homologous recombination of silent proteins into an expressed locus, causing partial or complete replacement of one serotype with another. These plasmids carry genes involved in antigenic variation and pathogenicity.