Seleção diversificadora em Corynebacterium Pseudotuberculosis

Detalhes bibliográficos
Ano de defesa: 2018
Autor(a) principal: Alessandra Lima da Silva
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Minas Gerais
UFMG
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://hdl.handle.net/1843/BUOS-B5SG5J
Resumo: Corynebacterium pseudotuberculosis is a Gram-positive, facultative intracellular bacterium with veterinary and medical importance and a global distribution. It infects a variety of mammals, such as sheep, goats, horses, buffalo and humans, and causes economic losses in animal production. Biovar Equi is nitrate positive and has horse and buffalo as exclusive hosts. Biovar Ovis is nitrate negative and has preference for sheep and goats. Antibiotic treatments have reduced efficiency due to the protection provided by the abscesses and current vaccines have different protection efficiency in different hosts. The analysis of positive (diversifying) selection is useful to identify adaptive mutations in this pathogen and to reveal mechanisms of host adaptation and probable targets for control methods. A genome-scale positive selection analysis was performed in C. pseudotuberculosis using 29 strains from different hosts, biovars and countries. The phylogenomic analysis suggested that Ovis diverged recently from Equi biovar, probably after specialization for a new host range. Positive selection was detected in 11 genes, most involved in host colonization processes. The results provide information about the adaptive mutations related to the species lyfestile and suggest a probable drug target.