Mycobacterium bovis is an important animal pathogen worldwide that parasitizes wild and domesticated vertebrate livestock as well as humans. A comparison of the five M. bovis complete genomes from the United Kingdom, South Korea, Brazil, and the United States revealed four novel large-scale structural variations of at least 2,000 bp. A comparative phylogenomic study including 2,483 core genes of 38 taxa from eight countries showed conflicting phylogenetic signal among sites. By minimizing this effect, we obtained a tree that better agrees with sampling locality. Results supported a relatively basal position of African strains (all isolated from Homo sapiens), confirming that Africa was an important region for early diversification and that humans were one of the earliest hosts. Selection analyses revealed that functional categories such as “Lipid transport and metabolism,” “Cell cycle control, cell division, chromosome partitioning” and “Cell motility” were significant for the evolution of the group, besides other categories previously described, showing importance of genes associated with virulence and cholesterol metabolism in the evolution of M. bovis. PE/PPE genes, many of which are known to be associated with virulence, were major targets for large-scale polymorphisms, homologous recombination, and positive selection, evincing for the first time a plethora of evolutionary forces possibly contributing to differential adaptability in M. bovis. By assuming different priors, US strains originated and started to diversify around 150–5,210 ya. By further analyzing the largest set of US genomes to date (76 in total), obtained from 14 host species, we detected that hosts were not clustered in clades (except for a few cases), with some faster-evolving strains being detected, suggesting fast and ongoing reinfections across host species, and therefore, the possibility of new bovine tuberculosis outbreaks.

The secretion of α-hemolysin by uropathogenic Escherichia coli (UPEC) is commonly associated with the severity of urinary tract infections, which makes it a predictor of poor prognosis among patients. Accordingly, this toxin has become a target for diagnostic tests and therapeutic interventions. However, there are several obstacles associated with the process of α-hemolysin purification, therefore limiting its utilization in scientific investigations. In order to overcome the problems associated with α-hemolysin expression, after in silico prediction, a 20.48 kDa soluble α-hemolysin recombinant denoted rHlyA was constructed. This recombinant is composed by a 182 amino acid sequence localized in the aa542–723 region of the toxin molecule. The antigenic determinants of the rHlyA were estimated by bioinformatics analysis taking into consideration the tertiary form of the toxin, epitope analysis tools, and solubility inference. The results indicated that rHlyA has three antigenic domains localized in the aa555–565, aa600–610, and aa674–717 regions. Functional investigation of rHlyA demonstrated that it has hemolytic activity against sheep red cells, but no cytotoxic effect against epithelial bladder cells. In summary, the results obtained in this study indicate that rHlyA is a soluble recombinant protein that can be used as a tool in studies that aim to understand the mechanisms involved in the hemolytic and cytotoxic activities of α-hemolysin produced by UPEC. In addition, rHlyA can be applied to generate monoclonal and/or polyclonal antibodies that can be utilized in the development of diagnostic tests and therapeutic interventions.

Evolutionary analyses of mitogenomes have provided insights into species evolution and conservation. Studies on snakes revealed a higher diversity especially involving variation in tRNA clusters. However, despite the increase in assemblies in databases, the available information for Brazilian species remains scarce in mitogenomic surveys. Based on this, we sequenced and provided the first description of the mitogenome of Bothrops insularis, a critically endangered taxon. We also used the B. insularis assembly and 128 molecules available in databases up to March 2022 to explore rearrangements and evolution of the mtDNA under a phylogenomic perspective. Comparative analyses revealed 24 mitotypes due to rearrangements within four tRNA clusters and within control regions. Mitotype 1 (M1) and Mitotype 2 (M2) are restricted to Scolecophidia and M3 is highly distributed within Alethinophidia. In addition, the M3 is suggested as the most likely ancestral mitotype during the mitogenome evolution. Regarding Bothrops, we recovered the same mitotype for B. jararaca and B. insularis, which structure differs from other Bothrops species. Nucleotide variation suggests 1.5% divergence between B. jararaca and B. insularis. Therefore, we suggest that B. insularis can be considered an evolutionary significant unit, and the data generated herein can be valuable for insights into genome evolution and conservation.

Sporotrichosis is a subcutaneous infection caused by fungi from the genus Sporothrix . The disease is transmitted by inoculation of infective particles found in plant-contaminated material or diseased animals, characterizing the classic sapronotic and emerging zoonotic transmission, respectively. Since 1998, Brazil has experienced a zoonotic sporotrichosis epidemic due to S. brasiliensis , centered in the state of Rio de Janeiro. Our observation of feline sporotrichosis cases in Brasília (Midwestern Brazil), around 900 km away from Rio de Janeiro, led us to question whether the epidemic caused by S. brasiliensis has spread from the epicenter in Rio de Janeiro, emerged independently in the two locations, or whether the disease has been present and unrecognized in Midwestern Brazil. A retrospective analysis of 91 human and 4 animal cases from Brasília, ranging from 1993 to 2018, suggests the occurrence of both sapronotic and zoonotic transmission. Molecular typing identified S. schenckii as the agent in two animals and all seven human patients from which we were able to recover clinical isolates. However, in two animals, the disease was caused by S. brasiliensis . Whole-genome sequence typing of seven S. brasiliensis strains suggests that isolates from Brasília are genetically distinct from those obtained at the epicenter of the outbreak in Rio de Janeiro, both in phylogenomic and population genomic analyses. The two S. brasiliensis populations seem to have separated 2.24 - 3.09 million years ago, indicating independent outbreaks or that the zoonotic S. brasiliensis outbreak might have started earlier and be spread wider in South America than previously recognized.