Holosporaceae
The Holosporaceae form a family within the Alphaproteobacteria. Like almost all bacteria of the order Rickettsiales are members of this family within the cells of the host (intracellular ) live parasites or symbionts.
The family consists of the genus:
- Holospora and from the to be regarded not as certain genera
- Caedibacter and
- Odyssella.
Occurrence
Representatives of Holospora and not securely associated species ( Candidatus ) Caedibacter were found in the Paramecium Paramecium caudatum. Holospora penetrates here in the nucleus of the host.
The also still in the taxonomic position uncertain, as Odysella thessalonicensis named species was found in aquatic living amoebae of the genus Acanthamoeba. As with almost all rickettsiae is not possible cultivation of the rod-shaped bacterium on artificial medium. Unlike Holospora this bacterium lives not in the nucleus but in the cytoplasm of the host. Odysella seems under normal conditions no harm in the host trigger.
Another basis of 16S rRNA analysis provisionally to this family Asked species was found in epithelial cells of the hepatopancreas ( digestive gland ) of shrimp. And giving rise to the Necrotizing Hepatopancreatitis ( NHP ), a lethal effect on the shrimp acting disease. One speaks in this type therefore often of the " NHP bacterium " ( NHPB ). Affected shrimp species are, inter alia, Litopenaeus vannamei ( Penaeus vannamei also called ) and Farfantepenaeus aztecus. In shrimp farms can cause major economic damage this bacterium. This disease of farmed shrimp first appeared on a shrimp farm in Texas in 1985, hence it is called by " Texas Pond Mortality Syndrome".