Leptospirosis is a disease caused by the bacteria of the Leptospira genus, which can usually be acquired by humans through contact with urine from infected animals; it is also possible for this urine to contaminate soils and bodies of water. The disease can have deadly consequences in some extreme cases. Fortunately, until now, patients with leptospirosis have responded adequately to treatment with doxycycline and azithromycin, and no cases of antibiotic resistance have been reported. However, with the extensive use of such medications, more bacteria, such as Staphylococci and Enterococci, are becoming resistant. The purpose of this study is to determine the presence of genes related to antibiotic resistance in the Leptospira genus using bioinformatic tools, which have not been undertaken in the past. Whole genomes from the 69 described Leptospira species were downloaded from NCBI’s GeneBank and analyzed using CARD (The Comprehensive Antibiotic Resistant Database) and RAST (Rapid Annotations using Subsystem Technology). After a detailed genomic search, 12 genes associated with four mechanisms were found: resistance to beta-lactamases, vancomycin, aminoglycoside adenylyltransferases, as well as multiple drug efflux pumps. Some of these genes are highly polymorphic among different species, and some of them are present in multiple copies in the same species. In conclusion, this study provides evidence of the presence of genes related to antibiotic resistance in the genomes of some species of the genus Leptospira, and it is the starting point for future experimental evaluation to determine whether these genes are transcriptionally active in some species and serovars.

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.

Leptospirosis is a globally distributed zoonotic disease caused by pathogenic bacteria of the Leptospira genus. Genome editing in Leptospira has been difficult to perform. Currently, the functionality of the CRISPR-Cas system has been demonstrated in species such as Leptospira interrogans. However, the different CRISPR-Cas systems present in most of the 77 species are unknown. Therefore, the objective of this study was to identify these arrays across the genomes of all described Leptospira species using bioinformatics tools. Methods: a bioinformatics workflow was followed: genomes were downloaded from the NCBI database; Cas protein detection was carried out using the CRISPR-CasFinder and RAST web servers; functional analyses of Cas proteins were performed with InterProScan, ProtParam, Swiss Model, Alphafold3, Swiss PDB Viewer, and Pymol; conservation pattern detection was conducted using MEGA12, and Seqlogos; spacer identification was carried out with the Actinobacteriophages database and BLAST version 1.4.0; and bacteriophage detection was performed using PHASTER, and PHASTEST. Results: Cas proteins were detected in 36 out of the 77 species of the Leptospira species, including Cas1 to Cas9 and Cas12. These proteins were classified into Class 1 and Class 2 systems, corresponding to types I, II, and V. Direct repeats and spacers were detected in 19 species, with the direct repeats exhibiting two conserved nucleotide motifs. Analysis of spacer sequences revealed 323 distinct bacteriophages. Additionally, three intact bacteriophages were detected in the genomes of four Leptospira species. Notably, two saprophytic species have complete CRISPR-Cas systems. Conclusions: The presence of Cas proteins, direct repeats, and spacer sequences with homology to bacteriophage genomes provides evidence for a functional CRISPR-Cas system in at least 19 species.

Leptospirosis is a globally distributed zoonotic disease caused by pathogenic bacteria of the Leptospira genus. Genome editing in Leptospira has been difficult to perform. Currently, the functionality of the CRISPR-Cas system has been demonstrated in species such as Leptospira interrogans. However, the different CRISPR-Cas systems present in most of the 77 species are unknown. Therefore, the objective of this study was to identify the CRISPR-Cas systems present in the genomes of the Leptospira genus using bioinformatics tools. Methods: bioinformatics workflow was followed: the genomes were downloaded from the NCBI database, Cas proteins detection was carried out using the CRISPR-CasFinder and RAST web servers, functional analysis of Cas proteins (InterProScan, ProtParam, Swiss Model, Alphafold3, Swiss PDB Viewer, and Pymol), conservation pattern detection (MEGA12, and Seqlogos), spacer identification (Actinobacteriophages db and BLAST), and bacteriophage detection (Phaster, and Phastest). Results: Cas proteins were detected in 36/77 species of the Leptospira genus, these proteins were (Cas1-Cas9, and Cas12). The proteins were classified into class 1 and class 2 systems, and types I, II, and V. Direct repeats and spacers were detected in 19 species. The direct repeats presented two nucleotide conservation motifs. With the spacer sequences, 270 different bacteriophages were identified. Three intact bacteriophages were detected in the genome of four Leptospira species. Two saprophytic species have complete CRISPR-Cas systems. Conclusions: The presence of Cas proteins, direct repeats, and spacer sequences homologous to bacteriophage genomes suggests a functional CRISPR-Cas system in at least 19 species.