Desenvolvimento de biossensor óptico para detecção de microrganismos patogênicos
Abstract
Infections caused by super-resistant microorganisms represent a major clinical and
fiscal burden as a global problem. In addition, microorganisms are responsible for the
deterioration of foods that, if consumed, can cause great harm to consumer health. For
this reason, there is a need for constant monitoring both in the health area and in
industrial processes, in order to prevent infections from occurring. Conventional
methods for detecting micro-organisms are based on specific biological and biochemical
identification. Although these methods are sensitive, inexpensive, and provide
quantitative and qualitative information regarding the nature of the microorganism, they
are restricted because they require relatively long time and require initial sample
treatment for pathogens at low concentrations. The use of peptides in the detection of
pathogenic microorganisms has been the subject of studies since it allows a precise and
rapid detection. Peptides are known antimicrobial components used for a long time in
the fight against infections caused by pathogens. Previous studies have demonstrated
that the polycerradin peptide can be used in the development of sensors, since its
antimicrobial action inhibits the luminescence of microorganisms due to cell death. The
light signals from the antimicrobial action of this peptide against the microorganism
were analyzed for the microorganisms Escherichia coli, Staphylococcus aureus,
Enterococcus faecalis, Shigela sonnei, Furasim subglutinans, Colletotrichium
gloeosporioides e Candida albicans. The spectra obtained through the data, which were
collected by photoluminescence spectroscopy, showed that there was suppression of the
luminescence around λ = 700-750 nm, when the lipopeptide extract (ELP) was added in
all evaluated microorganisms. Thus, it was possible to determine the antimicrobial
action of this peptide against the microorganisms studied, as well as the presence of
these microorganisms through its emission spectrum. This technique was applied in the
development and construction of an optical sensor, using materials of low cost, for use
in the monitoring and identification of pathogenic microorganisms in several areas, such
as health and food industry.