Legionnaires' disease in Switzerland: rationale and study protocol of a prospective national case-control and molecular source attribution study (SwissLEGIO).

Switzerland has one of the highest annual Legionnaires' disease (LD) notification rates in Europe (7.8 cases/100,000 population in 2021). The main sources of infection and the cause for this high rate remain largely unknown. This hampers the implementation of targeted Legionella spp. control efforts. The SwissLEGIO national case-control and molecular source attribution study investigates risk factors and infection sources for community-acquired LD in Switzerland. Over the duration of one year, the study is recruiting 205 newly diagnosed LD patients through a network of 20 university and cantonal hospitals. Healthy controls matched for age, sex, and residence at district level are recruited from the general population. Risk factors for LD are assessed in questionnaire-based interviews. Clinical and environmental Legionella spp. isolates are compared using whole genome sequencing (WGS). Direct comparison of sero- and sequence types (ST), core genome multilocus sequencing types (cgMLST), and single nucleotide polymorphisms (SNPs) between clinical and environmental isolates are used to investigate the infection sources and the prevalence and virulence of different Legionella spp. strains detected across Switzerland. The SwissLEGIO study innovates in combining case-control and molecular typing approaches for source attribution on a national level outside an outbreak setting. The study provides a unique platform for national Legionellosis and Legionella research and is conducted in an inter- and transdisciplinary, co-production approach involving various national governmental and national research stakeholders.

Development of a Kidney Calcification Inhibitor Employing Image-Based Profiling: A Proof-of-Concept Study.

Kidney calcification increases the risk of chronic kidney disease. However, to date, renal calcium phosphate crystallization, a main initiating and driving factor of kidney calcification, has not been explored as a drug target. Pre-clinical drug development is hampered by limited knowledge on the broad range of kidney calcification disorders, characterized by a multifactorial process of disease progression. In this work, we first established an in vitro calcification profiling platform to accelerate pre-clinical drug discovery. The image-based profiling assay allowed the rapid testing of several ionic stimuli and/or inhibitory molecules. We then leveraged a previously established library of inositol hexakisphosphate analogues to identify a renal calcium phosphate inhibitor. A lead compound showed in vitro and in vivo efficacy to prevent calcium phosphate-induced kidney damage. In conclusion, this work reports a renal calcium phosphate inhibitor that could efficiently reduce kidney damage and emphasizes the utility and translational value of the in vitro calcification platform.