Team:SZU-China/Description
Description
Background
Cockroacher are among the most common and obnoxious household pests,they harbor in damp and unsanitary places such as sewers,garbage disposals,kitchens and bathroom,feed on human’s and pet’s food.Besides its importance as a sign of poor sanitation ,cockroaches have been implicated in the transmission of several pathogenic organisms such as E.coli and Salmonella enteritidis which can cause diarrhea, pneumonia and so on.<1>,also expose to cockroach feces and body parts of dead roaches over time can trigger allergies and asthma<2>.So it’s not safe to ignore these pests.
Current solution
People rack their brains about cockroach control.Currently,there are two mainstream ways to control the population of cockroaches,physical and chemical methods. However, chemical method like foggers ,boric acid and gel bait may cause environmental toxicity and the development of resistance in cockroaches<3>. Physical method such as “cockroach house”, only trap few cockroaches.Neither chemical nor physical method can’t achieve the goal of environment friendly and efficient control.
Our solution
This year’s SZU China team want to tackle the cockroach control issue by using synthetic biology.We choose a kind of entomogenous fungi,Metarhizium anisopliae ,as biological chassis.It is considered as a safe and prospective choice for causing disease in inscts only. But its lethality is still need to be improved,which limits its wide use.We construct a system to enhace its virulence.Our system contains three parts:HsbA,BbChit and MCL1.These three genes work sequentially during infecting cockroach,promote adhesion,penetration and immune-avoidance respectively.
HsbA
It encodes hydrophobic surface binding protein A,located on the surface od fugus.This protein works like “glue” by forming hydrophobic bond between spores and the waxy epicuticle of their host.
Bbchit
It encodes chitinase,which can hydrolyse chitin. Chitosan is the major part of insect body wall,chitinase can hydrolyze this to penetrate.
MCL1
It encodes collagen-like protein, which can combine with β-glucan.β-glucan is distributed on the cell wall surface of fungus,and is the recognization site for insect hemocytes to combine and clear invader. MCL1 acts like putting an “invisible cloak” on the fungus. so that fungus can evade being recognized by the host immune system.
Then, we design a trap box named GreenGround to bring our idea into real world. We mix spores,banana powder and oil together to form emulsifiable powder,which is applied to non-woven fabrics for use.
Reference
<1>Mpuchane S, Matsheka IM, Gashe BA, Allotey J, Murindamombe G, Mrema N. Microbiological studies of cockroaches from three localities in Gaborone, Botswana. Afr J Food Nutr Sci. 2006;6:56–59.
<2> Gore JC, Schal C,Cockroach allergen biology and mitigation in the indoor environment. Annu Rev Entomol. 2007; 52():439-63.
<3> Wu X, Appel AG.J Econ Entomol. 2017 Jun 1;110(3):1203-1209.