The role of non-canonical extracellular DNA on the formation and resilience of Salmonella biofilms

• Grant number: 25/13439-8
• Support Opportunities: Scholarships abroad - Research
• Start date: March 16, 2026
• End date: October 30, 2026
• Field of knowledge: Agronomical Sciences - Food Science and Technology
• Principal Investigator: Maristela da Silva Do Nascimento
• Grantee: Maristela da Silva Do Nascimento
• Host Investigator: Rikke Louise Meyer
• Host Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Aarhus University, Denmark

Abstract

The persistence of Salmonella in food production environments poses a major threat to public health and food safety. This pathogen has the ability to form resilient biofilms on abiotic surfaces. Part of this resilience is related to the extracellular polymeric substance (EPS) matrix, which promotes nutrition and protection to the biofilm. Among the EPS compounds is the extracellular DNA (eDNA), essential against environmental stressors. Recent studies suggest that conformational changes in DNA, such as the transition from canonical B-DNA to the left-handed Z-DNA form, may influence the stability and antimicrobial resistance properties of biofilms, since Z-DNA is DNase resistant. In this project we will investigate the role of extracellular nucleic acid (eDNA) and non-canonical eDNA forms, including Z-DNA, in the formation and resilience of three types of Salmonella surface biofilms (one wet (WSB) and two dry (DSB)) before and after sanitation processes by immunolabeling assay. In addition, the EPS matrix composition and architecture of these biofilms will be analyzed by optical coherence tomography and confocal microscopy. Thereby the results obtained in this project will assist in the establishment of strategies to mitigate the formation and persistence of WSB and DSB in the food manufacturing environment. Furthermore, it will contribute to improving the knowledge of the proponent and to establishing a partnership between the research groups.