Mariana Ossa-Yepes

Leptospirosis is a globally distributed zoonotic disease caused by pathogenic bacteria of the Leptospira genus. Currently, 77 genomic species have been described. Leptospira interrogans is the most extensively studied species due to its high prevalence worldwide and the severity of the disease it causes in humans and animals. However, Leptospira santarosai is an important pathogenic species in the Americas, the Caribbean islands, and Taiwan. This species has a high serological diversity: it can infect domestic, wild, and agricultural production animals, causing reproductive problems and substantial economic losses. Additionally, Leptospira santarosai has been detected in water sources and wet soils. In humans, infection with this species can lead to a wide range of clinical manifestations and severe complications. Therefore, this study aimed to synthesize available information on the serological diversity, geographical distribution, natural sources of infection, and human leptospirosis caused by Leptospira santarosai to better understand their role in the leptospirosis transmission cycle. Methods: A systematic review of the literature was conducted, following the criteria established by the PRISMA-2020 guide, the search for scientific articles was conducted in five specialized and multidisciplinary databases (PubMed, Scopus, Web of Science, SciELO, and LILACS), and a search engine (Google Scholar). Two different search strategies (Leptospira santarosai OR L. santarosai) were used. Result: Once the search was carried out in the databases, 2989 scientific articles were identified. These articles underwent a process of identification, screening, eligibility, and inclusion, resulting in 84 articles that met all established inclusion criteria. These articles were included in the qualitative synthesis and elaboration of the systematic review. Conclusions: Leptospira santarosai shows a high serological diversity, with 14 serogroups and 59 serovars. The species has a wide geographic distribution, having been reported on five continents and in 26 countries, and has been described as an infectious agent in at least 24 host animals. It has also been detected in environmental sources such as water and wet soils; 24 serovars have been identified as the causative agents of human leptospirosis, causing clinical manifestations that range from mild to severe forms of the disease and clinical complications such as myocarditis, uveitis, and neuroleptospirosis. Although L. santarosai is considered native to the Americas, it shows an expansion pattern to other continents and countries. Therefore, this pathogenic species of the Leptospira genus represents an important public health problem worldwide.

Microplastics are a threat to ecosystem health, and their impacts and effects are increasingly serious and need to be studied. This study assessed anthropogenic contamination, with emphasis on microplastics, in the water, sediment, and biota (i.e., microcrustaceans, macroinvertebrates, and fish) compartments in a tropical Andean reservoir, Antioquia, Colombia. For this purpose, sampling was carried out at three hydrological periods between 2022 and 2023. The obtained samples were subjected to specific digestion for each environmental compartment and the identified particles were quantified and classified in size, shape, and color. Fourier transform spectrophotometry was used to analyze polymer composition. An ANOVA was used to evaluate statistical differences in particle size and quantity between sampling times for each compartment. Discriminant analysis was used to evaluate the relationship of fish feeding habits with the quantity of particles found in fish. Anthropogenic particles were found in all abiotic and biotic compartments. Blue fibers were predominant in all compartments, with omnivorous fish exhibiting the highest particle concentration. Microplastics comprised 12% of the particles, mainly polypropylene, polyester and polyethylene, the rest were rayon, cellulose and cotton. A conceptual model addressing the dynamics of pollution in Peñol-Guatapé reservoir is proposed, suggesting how anthropogenic particles transfer between environmental compartments and species.