Thorselliaceae is a family of bacteria belonging to the class

Gammaproteobacteria ''Gammaproteobacteria'' is a class of bacteria in the phylum ''Pseudomonadota'' (synonym ''Proteobacteria''). It contains about 250 genera, which makes it the most genus-rich taxon of the Prokaryotes. Several medically, ecologically, and scienti ...

and it was first described in February 2015. It is not assigned to an order. The family consists of four species in two genera. The bacteria are

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

and rod shaped, approximately 1 μm wide and 2 μm long. They are facultative anaerobes and motile. Thorselliaceae bacteria have been found around the world associated with

vector Vector most often refers to: * Euclidean vector, a quantity with a magnitude and a direction * Disease vector, an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematics a ...

mosquitoes, mainly with vectors of

malaria Malaria is a Mosquito-borne disease, mosquito-borne infectious disease that affects vertebrates and ''Anopheles'' mosquitoes. Human malaria causes Signs and symptoms, symptoms that typically include fever, Fatigue (medical), fatigue, vomitin ...

. The first described species was ''Thorsellia anophelis''. It was isolated from the midgut of the malaria mosquito '' Anopheles arabiensis'' from Kenya. This new bacterium was given its name after the Swedish researcher Walborg Thorsell who worked with mosquitoes and insecticides against mosquitoes for many years. ''Thorsellia'' bacteria have now been found in mosquito species that are the major vectors of malaria in Africa, Asia and South America. The bacteria have also been found in the waters where the malaria mosquitoes breed. Some properties of ''Thorsellia'' suggest that they are adapted to the mosquito guts, they can accept an alkaline pH, which is found in mosquito larvae and they grow faster in blood culture. However, ''T. anophelis'' has also been found in the reproductive tissues of male and female ''

Anopheles gambiae The ''Anopheles gambiae'' complex consists of at least seven morphologically indistinguishable species of mosquitoes in the genus ''Anopheles''. The complex was recognised in the 1960s and includes the most important vectors of malaria in sub- ...

'' and ''An''. ''coluzzii'' mosquitoes. Currently, little is known about Thorselliaceae in nature apart from that it has been shown in several studies that ''Thorsellia anophelis'' dominate the malaria mosquito

gut flora 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 g ...

and their breeding waters. ''Thorsellia'' has besides in ''

Anopheles ''Anopheles'' () is a genus of mosquito first described by the German entomologist Johann Wilhelm Meigen, J. W. Meigen in 1818, and are known as nail mosquitoes and marsh mosquitoes. Many such mosquitoes are Disease vector, vectors of the paras ...

'' also been found to dominate the gut flora in the mosquito species '' Culex tarsalis'', which is a vector of among other things,

West Nile virus West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family ''Flaviviridae'', from the genus ''Flavivirus'', which also contains the Zika virus, dengue virus, and yellow fever virus. The virus ...

and

encephalitis Encephalitis is inflammation of the Human brain, brain. The severity can be variable with symptoms including reduction or alteration in consciousness, aphasia, headache, fever, confusion, a stiff neck, and vomiting. Complications may include se ...

. It as also been shown that ''T. anophelis'' is much more abundant in ''Cx''. ''nigripalpus'' than in ''Cx''. ''coronator''. ''Coetzeea'' (named after the South African mosquito researcher Maureen Coetzee) has so far only been found in Brazilian '' Anopheles darlingi''.

Application

A possible application of Thorselliaceae is in paratransgenesis to prevent the transmission of malaria. This would involve genetically transforming the bacteria with genes that produce effector molecules against malaria parasites inside the malaria mosquito gut. Thorselliaceae can be grown in the laboratory under normal conditions and are related to the bacterium ''

Escherichia coli ''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Escherichia'' that is commonly fo ...

'' which suggests that the molecular techniques needed could be similar to those available for ''E. coli''.

References

{{Taxonbar, from=Q19281135 Gammaproteobacteria Gram-negative bacteria Bacteria genera Enigmatic bacteria taxa