''Shimwellia blattae'' (formerly ''Escherichia blattae'') is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
bacterium
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
, one of two in the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Shimwellia
''Shimwellia'' is a genus of Gram-negative bacteria of the family Enterobacteriaceae. The two species of ''Shimwellia'' are '' Shimwellia blattae'' (formerly ''Escherichia blattae'') and ''Shimwellia pseudoproteus'' (formerly ''Obesumbacterium p ...
''. It is an
aerobic
Aerobic means "requiring air," in which "air" usually means oxygen.
Aerobic may also refer to
* Aerobic exercise, prolonged exercise of moderate intensity
* Aerobics, a form of aerobic exercise
* Aerobic respiration, the aerobic process of cel ...
enteric
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...
bacterium first isolated from the
hindgut of
cockroach
Cockroaches (or roaches) are a paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known as ...
es. Although it is related to human
pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...
s, including ''
Escherichia coli
''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...
'', ''S. blattae'' is not pathogenic to humans.
It is notable for its ability to synthesize
vitamin B12
Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which use it as a cofactor in DNA synthesis, in both fatty acid and amino acid metabolism. It ...
''de novo''.
History and taxonomy
The bacterium was first described in 1973 under the name ''Escherichia blattae'' after isolation from the
hindgut of the
cockroach
Cockroaches (or roaches) are a paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known as ...
species ''
Blatta orientalis
__NOTOC__
The oriental cockroach (''Blatta orientalis''), also known as the waterbug (as they live in damp areas) or black cockroaches (as their bodies are mostly dark), is a large species of cockroach, adult males being and adult females being ...
''.
It was reclassified in the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Shimwellia
''Shimwellia'' is a genus of Gram-negative bacteria of the family Enterobacteriaceae. The two species of ''Shimwellia'' are '' Shimwellia blattae'' (formerly ''Escherichia blattae'') and ''Shimwellia pseudoproteus'' (formerly ''Obesumbacterium p ...
'' based on
phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
analyses of its
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...
sequence.
Genome
The
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...
of ''S. blattae'' is about 4.2
megabase
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both D ...
s in size, slightly smaller than similar
enteric bacteria
Gut microbiota, gut microbiome, or gut flora, are the microorganisms, including bacteria, archaea, fungi, and viruses that live in the digestive tracts of animals. The gastrointestinal metagenome is the aggregate of all the genomes of the gut mi ...
found in humans. It has 56.5%
GC content
In molecular biology and genetics, GC-content (or guanine-cytosine content) is the percentage of nitrogenous bases in a DNA or RNA molecule that are either guanine (G) or cytosine (C). This measure indicates the proportion of G and C bases out ...
, significantly higher than ''
E. coli''. Genomic analysis suggests that the ability of ''S. blattae'' to synthesize
vitamin B12
Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which use it as a cofactor in DNA synthesis, in both fatty acid and amino acid metabolism. It ...
has its origins in
horizontal gene transfer
Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between Unicellular organism, unicellular and/or multicellular organisms other than by the ("vertical") transmission of DNA from parent to offsprin ...
.
References
{{Taxonbar, from=Q26285486, from2=Q62896442
Shimwellia