Genomics has revolutionized our understanding of the microbial world. From the surveillance and epidemiology of emerging pathogens to comprehending the evolution and adaptation of bacteria to their hosts. Despite enormous advances, significant gaps persist, particularly in the study of the diversity and evolution of bacteria residing in wildlife microbiomes and the emergence of bacterial pathogens affecting livestock in low- and middle-income countries. In the present work, using different comparative genomics approaches, I study three bacterial species: the pathogenic Salmonella Typhimurium isolated from guinea pig (Cavia porcellus) in Peru and Kerstersia gyiorum and Neisseria sp. isolated from free-living brown-throated sloths (Bradypus variegatus) in Brazil. Salmonella Typhimurium is the main pathogen infecting guinea pigs in Peru. First, I perform a genomic characterization of S. Typ...

Realiza un análisis pangenómico y filogenómico para estudiar la diversidad genómica de esta bacteria y determinar si las cepas de distintos hospederos y enfermedades contienen diferencias en cuanto a contenido genético. Según el análisis, Pasteurella multocida posee un pangenoma abierto de 4881 genes y un genoma core de 1205 genes (25%). El genoma accesorio y único (75%) contienen mayormente secuencias profago y proteínas de función desconocida, junto con la alta presencia de recombinación en el genoma core (45%) son los principales generadores de diversidad mediante transferencia horizontal de genes y recombinación homóloga. El análisis filogenómico del genoma core y pangenoma muestra el agrupamiento de cepas asociadas a enfermedades específicas sugiriendo una especialización en esta bacteria con presencia de genes de manera diferencial en cepas asociadas a enfermedades...

The present study evaluated the presence of 10 genes encoding various virulence factors of biological importance in 100 Salmonella Typhimurium isolates, where 90 isolates came from sick guinea pigs and 10 from apparently healthy ones. DNA was extracted from all isolates and analyzed using the Multiple PCR technique to assess the presence of the spvB, spiA, cdtB, sipB, tolC, sitC, lpfC, sifA, sopB and pefA genes. A similar genetic pattern was obtained, with variable detection frequencies greater than 60%, both in healthy and sick guinea pigs, except for the cdtB gene, which was not detected. There were no significant differences between the presence of Salmonella Typhimurium virulence factors isolated from sick guinea pigs and apparently healthy guinea pigs.