Evaluation of the role of POLIAMINAS PotD transporter in the formation of biofilm in vitro by Streptococcus pneumoniae

Abstract

Streptococcus pneumoniae is a bacterium of great importance worldwide, responsible for more than one million annual deaths. Commonly acquired in the first years of life, pneumococcus colonizes the upper respiratory tract asymptomatically, forming biofilms that persist for months in the nasopharynx. However, under conditions that alter the bacterial environment, such as viral infections, pneumococci can escape biofilm and invade other niches, causing several diseases of varying severity. The polyamine transporter PotD is an important virulence factor of the pneumococcus. Immunization of mice with recombinant PotD is able to reduce subsequent colonization with the bacteria in a process that involves the production of high levels of cytokine IL-17. It has also been suggested that PotD is involved in the formation of pneumococcal biofilms. Thus, considering I) the protective role of PotD in limiting bacterial colonization and II) its possible involvement in biofilm formation, the present study aims to elucidate the role of PotD and polyamines in biofilm formation by pneumococci. Biofilm formation in wild pneumococci and Pot-negative mutants will be compared through microplate biofilm formation assays. Biofilm formation will then be evaluated in the presence of polyamines - a product transported by PotD, compared to media without the addition of polyamines. Together, the data from this study may contribute to determining the mechanism of biofilm formation in pneumococci, as well as its possible correlation with the colonization process.