Team:Guanajuato Mx/Project

iGEM Guanajuato Mx

PROJECT DESCRIPTION


Introduction

    The state of Guanajuato is located amongst the 15 entities with more incidence of severe burns in Mexico. According to the World Health Organization (WHO, 2016) the majority of burns which are preventable, occur mainly at home. Besides that, it is estimated that every year 265 000 deaths are reported, and non-fatal burns are the main cause of morbidity, which are caused by sepsis produced by pathogenic microorganisms. In the state of Guanajuato, Mexico, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis are of special interest, as they are reported to be the main pathogenic bacteria found in skin burns (Moctezuma-Paz et al., 2015). The traditional health system provides a treatment based on the use of antibiotic, analgesic and antihistamine medications which sometimes results inefficient and expensive. According to Allevato (2007) “an alternative for this is the use of transdermal patches of prolonged liberation, which could release medicine or metabolites of therapeutic interest at a determined rate“. Recently, it was reported the development of two biosensors using Escherichia coli as chassis, to detect and kill P. aeruginosa, a Gram-negative bacteria. The first biosensor was designed to detect AHLs through the LasR protein, and to synthesize pyocin S5 together with an E7 lysis protein mechanism that lyses E. coli in order to release the pyocin S5 molecules that kill P. aeruginosa (Saeidi et al., 2011).

    The second biosensor synthesizes the LasR, CheZ, DNaseI and microcin S, to sense, move and destroy the biofilms and the bacteria (Hwang et al., 2013). In addition to this, the iGEM Groningen 2014 (http://2014.igem.org/Team:Groningen) developed a biosensor using Lactococcus lactis as chassis, which senses, and produces dispersin and lactonase to destroy the biofilm and to avoid quorum sensing in P. aeruginosa, respectively.

    In this work we designed two biosensors using two bacteria as chassis that are recognized as safe by the FDA, E. coli K12 and Lactococcus lactis. E. coli K12 is transformed with the lasR gene of P. aeruginosa PA01 (transcriptional regulator rhIR, Gene ID 878968,NCBI) and also with the alginate lyase gene (algy), in tandem with a bacteriocin (i.e. microcin S). It has been reported the alginate is one of the main components in the P. aeruginosa biofilms (Tielen et al., 2013), our modules will detect and destroy the biofilm and kill the bacteria. In our second biosensor, a nisin producer bacterium (i.e. L. lactis) is transformed with the genes required to detect P. aeruginosa, to produce alginate lyase and an additional copy of nisin. It has been reported that nisin at high concentrations, has an effect on P. aeruginosa viability (Giacommetti et al. 1996). Our biosensor will overexpress the bacteriocin in order to kill the pathogenic bacterium and the alginate lyase to destroy the biofilm. Additionally, we designed a patch made of poly(vinyl alcohol) and a nitrocellulose membrane, containing the bacterial biosensors that will allow the molecule to diffuse through the membrane in order to kill the pathogenic bacterium. Here, we show advances about the construction of bacterial biosensors and the patch modeling.


Main purpose

    Our objective is to develop a biopatch harboring a bacterial biosensor capable of detect and defeat infections caused by common pathogenic bacteria in burns, such as Pseudomonas aeruginosa.


OUR PROJECT

Biosense: Development of biosensors integrated into a patch, in order to kill pathogenic bacteria that produce common skin infections.