
''Bacillus thuringiensis''
serotype ''israelensis'' (Bti) is a group of bacteria used as
biological control agents for larvae stages of certain
dipterans. Bti, along with other ''
B. thuringiensis'' products, produces toxins which are effective in killing various species of
mosquitoes,
fungus gnats, and
blackflies, while having almost no effect on other organisms. The major advantage of ''
B. thuringiensis'' products is that they are thought to affect few non-target species. However, even though Bti may have minimal direct effects on non-target organisms, it may potentially be associated with knock-on effects on
food webs and other ecosystem properties, including biodiversity and ecosystem functioning.
Bti strains possess the pBtoxis
plasmid
A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria and ...
which encodes numerous Cry (a
δ-endotoxin) and Cyt toxins, including Cry4, Cry10, Cry11, Cyt1, and Cyt2. The crystal aggregation which these toxins form contains at least four major toxic components, but the extent to which each Cry and Cyt protein is represented is not known and likely to vary with strain and formulation. Both Cry and Cyt proteins are
pore-forming toxins; they
lyse midgut
epithelial cells by inserting into the target
cell membrane
The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extr ...
and forming pores.
Commercial formulations include "Mosquito Dunks", "Mosquito Bits", and "VectoBac". It is also available in bulk liquid or granular formulations for commercial and public agency use.
Discovery
Bacillus thuringiensis israelensis (Bti) was discovered in 1976 by
Yoel Margalith, a professor at
Ben Gurion University in Israel.
["Bacillus thuringiensis israelensis (Bti)"](_blank)
Biologisk Myggkontroll.
The initial field tests of Bti were conducted in 1978 against the floodwater mosquito species ''
Aedes vexans'' in the River
Rhine Valley of Germany.
This early experimentation demonstrated the efficacy of Bti in controlling mosquito populations, leading to its widespread adoption. Over the years, Bti has been extensively used by various organizations, including the
German Mosquito Control Association, ''Kommunale Aktionsgemeinschaft zur Bekämpfung der Schnakenplage e.V.'' (KABS), which has utilized Bti for almost four decades without encountering resistance issues.
Today, Bti is utilized globally across all continents to manage mosquito populations, although controlling certain vector species like ''
Aedes aegypti
''Aedes aegypti'' ( or from Greek 'hateful' and from Latin, meaning 'of Egypt'), sometimes called the Egyptian mosquito, dengue mosquito or yellow fever mosquito, is a mosquito that spreads diseases like dengue fever, yellow fever, malar ...
'' and ''
Aedes albopictus
''Aedes albopictus'' (synonym (taxonomy), synonym ''Stegomyia albopicta''), from the mosquito (Culicidae) family (biology), family, also known as the (Asian) tiger mosquito or forest mosquito, is a mosquito native to the tropical and Subtropics ...
'' remains challenging due to their breeding habits in small and hidden containers.
Long name
''Bacillus thuringiensis'' subspecies ''israelensis'' strain EG2215
See also
*
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 ...
References
External links
''Bacillus thuringiensis'' fact sheetEPA Controlling Mosquitoes at the Larval Stage
thuringiensis israelensis
Biological control agents of pest insects
Subspecies
{{Bacilli-stub