Exploring Leptospira spp. in urban biofilms, soil, and water in Lisbon: an environmental study

Leptospirosis is a re-emerging zoonosis with global distribution whose etiological agents are pathogenic Leptospira species.It is estimated that there are over 1,000,000 reported human cases and more than 60,000 deaths annually worldwide. These bacteria can be transmitted through direct or indirect contact with the urine of infected reservoirs. Rodents, as the main natural reservoir hosts, are primarily responsible for its spread, but other animals can also contribute to its transmission. Leptospires can survive in the environment, including water, soil, and biofilms, which are complex ecosystems that support microbial communities. There are few studies on the environmental burden of leptospirosis in Lisbon despite ECDC report recording 43 cases.
This work aims to investigate the presence of Leptospira spp. in urban biofilms across the Lisbon metropolitan area by collecting the samples at following areas: Cascais; São Pedro and Queluz. Biofilms will be collected from abiotic surfaces, riverbanks, and waste accumulation sites. Alongside, paired soil and water samples within a 1-meter radius will be collected. Samples will be analysed by qPCR for the detection of pathogenic Leptospira, followed by its isolation and further molecular and phenotypic characterization.