Análise da produção e caracterização de bacteriocinas em cepas de Escherichia coli extraintestinais
Data
2021-08-03
Autores
Araujo, Ester Castro 
Orientadores
Guth, Beatriz Ernestina Cabilio
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Escherichia coli extraintestinais (ExPEC) são importantes agentes de infecções em diferentes sítios do hospedeiro humano. Bacteriocinas são peptídeos de ação antimicrobiana e que podem estar envolvidos na patogenicidade de diferentes cepas de E. coli. No Brasil ainda são escassos os estudos que identifiquem a produção e os tipos de bacteriocinas em cepas de EXPEC isoladas de hemoculturas, assim como a associação dessas moléculas aos demais fatores de virulência observados nesse grupo. O presente estudo teve por objetivo analisar distintas cepas de ExPEC quanto à sua capacidade de produzir bacteriocinas através de testes fenotípicos, identificar molecularmente os genes relacionados à síntese desses peptídeos através da técnica da Reação em Cadeia da Polimerase (PCR), verificar a quais grupos filogenéticos essas cepas pertencem, bem como avaliar a relação entre fatores de virulência observados em ExPEC com os diferentes tipos de bacteriocinas identificados. Das análises realizadas, 27% das cepas de E. coli isoladas de quadros de bacteremia produziram bacteriocinas. Identificou-se que a frequência de microcinas foi maior em relação à frequência observada para colicinas nesses isolados (69% e 60% respectivamente) e os determinantes genéticos mais prevalentes estavam associados às microcinas M (37%), V (36%) e colicinas Ib e Ia (35% e 32% respectivamente). Vinte perfis genéticos foram identificados, sendo o perfil cinco, também associado à microcina M, o mais frequente (29%). Além disso, o grupo filogenético B2 foi o mais prevalente dentre esses isolados (46%), seguido pelo filogrupo B1 (15%). Observou-se que 72% das cepas bacteriocinogênicas estavam associadas a no mínimo oito tipos distintos de genes de virulência, onde marcadores associados à invasividade (ompA - 97%), adesão (mat e fimA - 96% e 93% respectivamente) e sistemas de aquisição de ferro (sitA - 92%) foram os mais frequentes, o que pode ter promovido a translocação e permanência desses isolados em diferentes sítios. Os achados aqui descritos contribuem para uma melhor compreensão das características de virulência observadas em ExPEC e as relações estabelecidas entre elas dentro de um nicho, assim como sua influência na progressão de infecções extraintestinais.
Extraintestinal Escherichia coli (EXPEC) are important agents of infections in different sites of the human host. Bacteriocins are antimicrobial peptides that may be involved in the pathogenicity of different E. coli strains. There are few studies in Brazil looking for the production and types of bacteriocins in EXPEC strains isolated from cases of bacteremia, as well as the association of these molecules with other virulence factors observed in this group of pathogens. This study aimed to analyze through phenotypic tests the ability of ExPEC strains to produce bacteriocins, molecularly identify the genes related to the synthesis of these peptides through the Polymerase Chain Reaction (PCR) technique, and verify the relationship between the presence of bacteriocins with phylogenetic groups and the virulence factors presented by the ExPEC isolates. From the analyzes performed, 27% of the E. coli strains isolated from bacteremia produced bacteriocins. The frequency of microcins was higher than colicins (69% and 60% respectively), and the most prevalent genetic determinants identified were associated with microcins M (37%), V (36%) and colicins Ib and Ia (35% and 32%, respectively). Twenty genetic profiles were identified, with profile five, also associated with microcin M, the most frequent (29%) observed. Furthermore, phylogenetic group B2 was the most prevalent among these isolates (46%), followed by phylogroup B1 (15%). It was observed that 72% of the bacteriocinogenic strains were associated with at least eight distinct types of virulence genes, where markers associated with invasiveness (ompA - 97%), adhesion (mat and fimA - 96% and 93% respectively) and iron acquisition systems (sitA - 92%) were the most frequently detected, what may suggest their involvement in the translocation and permanence of these isolates in different sites. The findings described herein contribute to a better understanding of the virulence characteristics observed in ExPEC and the relationships established between them within a niche, as well as their influence on the progression of extraintestinal infections.
Extraintestinal Escherichia coli (EXPEC) are important agents of infections in different sites of the human host. Bacteriocins are antimicrobial peptides that may be involved in the pathogenicity of different E. coli strains. There are few studies in Brazil looking for the production and types of bacteriocins in EXPEC strains isolated from cases of bacteremia, as well as the association of these molecules with other virulence factors observed in this group of pathogens. This study aimed to analyze through phenotypic tests the ability of ExPEC strains to produce bacteriocins, molecularly identify the genes related to the synthesis of these peptides through the Polymerase Chain Reaction (PCR) technique, and verify the relationship between the presence of bacteriocins with phylogenetic groups and the virulence factors presented by the ExPEC isolates. From the analyzes performed, 27% of the E. coli strains isolated from bacteremia produced bacteriocins. The frequency of microcins was higher than colicins (69% and 60% respectively), and the most prevalent genetic determinants identified were associated with microcins M (37%), V (36%) and colicins Ib and Ia (35% and 32%, respectively). Twenty genetic profiles were identified, with profile five, also associated with microcin M, the most frequent (29%) observed. Furthermore, phylogenetic group B2 was the most prevalent among these isolates (46%), followed by phylogroup B1 (15%). It was observed that 72% of the bacteriocinogenic strains were associated with at least eight distinct types of virulence genes, where markers associated with invasiveness (ompA - 97%), adhesion (mat and fimA - 96% and 93% respectively) and iron acquisition systems (sitA - 92%) were the most frequently detected, what may suggest their involvement in the translocation and permanence of these isolates in different sites. The findings described herein contribute to a better understanding of the virulence characteristics observed in ExPEC and the relationships established between them within a niche, as well as their influence on the progression of extraintestinal infections.
Descrição
Citação
Araujo, E.C. Análise da produção e caracterização de bacteriocinas em cepas de Escherichia coli extraintestinais.Trabalho de conclusão de curso de graduação. 2021. 64 f. Trabalho de conclusão de curso (Graduação em Ciências Biológics) - Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, 2021.