Team:UI-Indonesia/Project/Approach and Overview

From 2014.igem.org

Approach

Nowadays, the only way to banish biofilm is by avoiding its excretion on the first place. However, in cases when the biofilm has settled in the digestive tract, avoiding it is no longer possible. Synthetic biology is one of the developing knowledge in our everyday world. Here we proposed the novel strategy to combat biofilm infection by using ‘Genius E.coli (GE)’, one will be able to detect quorum sensing signal and destroy biofilm made by pathogenic bacteria. E. coli which is a normal flora in the intestines can be modified to secrete components such as alpha amylase, nuclease, and substilisin that will be able to destroy biofilm made by pathogenic bacteria and novel synthetic peptide called peptide 1018, originated from human immunity defense regulator which is enable target cellular stress responses prevent and eradicate biofilm formation.

Our team use Vibrio cholerae as pathogen model. Vibrio cholerae is an agent cause cholera disease. In general, the incidence of this disease reaches 500 cases out of 100,000 people annually[1]. In children aged less than one year, the incidence is 4 out of 1.000 cases per year[4]. Cholera is one of the diseases with dangerous clinical manifestations, and can even cause death when left untreated. The incidence of cholera increase when natural disaster occurred. Diarrheal disease happened after drinking water has been contaminated. An epidemic of diarrheal disease after flooding in Bangladesh in 2004 engage more than 17,000 cases; Vibrio cholerae(O1 Ogawa and O1 Inaba)[16].



Overview

Our team genetically enginereed E. coli to do hunt by specifically detect quorum sensing (QS) molecule from V. cholerae. The mutagenic E. coli is able to detect quorum sensing molecule by expressing CqsS histidine-kinases receptor which is naturally expressed in transmembrane domain of V. cholerae. This receptor will sense Cholerae Autoinducer-1 (CAI-1) which is secreted continously and used as a specific interspecies communication signal[14]. CAI-1 molecule act as “find me signal” for mutagenic E. coli when QS molecule binds CqsS receptor and activates motility gene, CheZ, which will enable the E. coli to migrate into the source of infection. It will also activate the killing gene which enables E. coli to produce biofilm enzyme degrading matrix such as: α-amylase, substilisin, and nuclease. After that, our E. coli will secrete peptide 1018, a novel antibiotic peptide indigenous to innate regulator immunity peptide from human cathelicidin, killing V. cholerae. By interconecting the principles of pathogen-directed motility with the dual system degrading and killing biofilm, we significantly develop a novel curative approach or even possibility of short term post-disaster vaccine, by connecting it with slow time based safety module.



Further Application

Our project can be applied in broad spectrum bacteria. Quorum sensing is a principal bacterial communication. We can detect others bacteria quorum sensing signal molecule by made a system to detect conserve quorum sensing molecule in gram negative and gram positive bacteria i.e. Autoinducer-2 (AI-2). Not only Vibrio cholerae but also other bacteria such as: Pseudomonas aerugoinosa, Bacillus substillis, Klebsiella pneumonia, Staphylococcus aureus, and E. coli Top 10. So we would like to examine the enzyme degrading matrix to those bacteria.