Simkaniaceae
Encyclopedia
Simkaniaceae is a family of bacteria in the order Chlamydiales
, class Chlamydiae
, phylum Chlamydiae
, domain Bacteria
. Species in this family have a chlamydia-like cycle of replication and their ribosomal RNA
genes are 80–90% identical to ribosomal genes in the Chlamydiaceae
. The Simkaniaceae are not recognized by monoclonal antibodies
that are specific for Chlamydiaceae lipopolysaccharide
. The family Simkaniaceae currently includes two genera
: Simkania and Fritschea. The type species is Simkania negevensis, and its natural host is not known. It is readily grown in monolayers of eukaryotic Vero cells. Serological evidence and PCR indicate that S. negevensis is widespread among humans.
Two Fritschea species have been identified in insects. These are candidatus
species because they only grow in insect bacteriocytes and have not been cultured in vitro
. Whiteflies are the host of Candidatus Fritschea bemisiae (strain Falk). Scale insects are the host of Candidatus Fritschea eriococci (strain Elm).
Simkania negevensis and Fritschea bemisiae have a group I intron in the 23S rRNA, unlike other characterized chlamydial rRNA genes. The introns are closely related to group I introns in the 23S rRNA of chloroplasts and mitochondria in algae and amoebae.
Chlamydiales
The bacterial order Chlamydiales includes only obligately intracellular bacteria that have a chlamydia-like developmental cycle of replication and at least 80% 16S rRNA or 23S rRNA gene sequence identity with other members of Chlamydiales. Chlamydiales live in animals, insects, and protozoa...
, class Chlamydiae
Chlamydiae
Chlamydiae is a bacterial phylum and class whose members are obligate intracellular pathogens. Many Chlamydiae coexist in an asymptomatic state within specific hosts, and it is widely believed that these hosts provide a natural reservoir for these species....
, phylum Chlamydiae
Chlamydiae
Chlamydiae is a bacterial phylum and class whose members are obligate intracellular pathogens. Many Chlamydiae coexist in an asymptomatic state within specific hosts, and it is widely believed that these hosts provide a natural reservoir for these species....
, domain Bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
. Species in this family have a chlamydia-like cycle of replication and their ribosomal RNA
Ribosomal RNA
Ribosomal ribonucleic acid is the RNA component of the ribosome, the enzyme that is the site of protein synthesis in all living cells. Ribosomal RNA provides a mechanism for decoding mRNA into amino acids and interacts with tRNAs during translation by providing peptidyl transferase activity...
genes are 80–90% identical to ribosomal genes in the Chlamydiaceae
Chlamydiaceae
Chlamydiaceae is a family of bacteria that belongs to the Phylum Chlamydiae, Order Chlamydiales. All Chlamydiaceae species are Gram-negative and express the family-specific lipopolysaccharide epitope αKdo--αKdo--αKdo . Chlamydiaceae ribosomal RNA genes all have at least 90% DNA sequence identity...
. The Simkaniaceae are not recognized by monoclonal antibodies
Monoclonal antibodies
Monoclonal antibodies are monospecific antibodies that are the same because they are made by identical immune cells that are all clones of a unique parent cell....
that are specific for Chlamydiaceae lipopolysaccharide
Lipopolysaccharide
Lipopolysaccharides , also known as lipoglycans, are large molecules consisting of a lipid and a polysaccharide joined by a covalent bond; they are found in the outer membrane of Gram-negative bacteria, act as endotoxins and elicit strong immune responses in animals.-Functions:LPS is the major...
. The family Simkaniaceae currently includes two genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
: Simkania and Fritschea. The type species is Simkania negevensis, and its natural host is not known. It is readily grown in monolayers of eukaryotic Vero cells. Serological evidence and PCR indicate that S. negevensis is widespread among humans.
Two Fritschea species have been identified in insects. These are candidatus
Candidatus
Candidatus is in scientific classification a component of the taxonomic name for a bacterium that cannot be maintained in a Bacteriology Culture Collection. It is an interim taxonomic status for noncultivable organisms. An example would be "Candidatus Phytoplasma allocasuarinae"...
species because they only grow in insect bacteriocytes and have not been cultured in vitro
In vitro
In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...
. Whiteflies are the host of Candidatus Fritschea bemisiae (strain Falk). Scale insects are the host of Candidatus Fritschea eriococci (strain Elm).
Simkania negevensis and Fritschea bemisiae have a group I intron in the 23S rRNA, unlike other characterized chlamydial rRNA genes. The introns are closely related to group I introns in the 23S rRNA of chloroplasts and mitochondria in algae and amoebae.