A carregar...
Publicação
Age dependency of Escherichia coli K1 systemic infection in the neonatal rat
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 1.22 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
Background: Escherichia coli (E. coli) K1 is responsible for about 85% of cases of E. coli neonatal bacterial sepsis and meningitis. E. coli K1 strains are vertically transmitted from mother to child during birth. E. coli O18:K1 A192PP, the strain used in this study, demonstrated to have age dependent disease severity and to be fatal when administrated to 2-day-old animals. The knowledge of the E. coli K1 distribution trends numbers along the different regions of the small intestine in susceptible and resistant animals can be used in the development of new therapeutic strategies
Methods: In this work, 2 (P2) (susceptible) and 9-day-old (P9) (resistant) pathogen-free Wistar rats were used to investigate the intestinal colonization of E. coli K1 in vivo. Tissues from proximal, middle and distal regions were collected from the 24 hr and 48 hr post infection from both susceptible and resistant animals. In an attempt to understand the pattern of colonization in susceptible and resistance animals, total DNA was extracted from the rat tissues and E. coli K1 counts and total bacterial numbers were quantified using real time PCR. The viable E. coli K1 counts were compared between 2 and 9-day-old animals in the three different intestinal regions, using serial dilutions from homogenized tissues and subculturing for K1.
Results: The results from E. coli K1 viability suggest that susceptible animals have higher numbers of CFU/g overall in all intestinal regions than resistant animals, particularly in the middle intestine. The data obtained from real time PCR supports the high colonization pattern observed in susceptible animals not only for total bacterial counts but also for E. coli K1 numbers.
Conclusion: This study has shown that susceptible animals have a decreased capability of keeping E. coli K1 numbers under control in proximal and middle regions of the small intestine. The highly significant abundance of K1 numbers in the middle small intestine of susceptible animals suggests this intestinal region is a probable area of translocation from gut to the bloodstream. Furthermore, it is predicted that E. coli K1 translocation occurs from middle intestine approximately 24 hr post infection. Further studies should focus on understanding the bacterial translocation process used by the E. coli K1.
Descrição
Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2014
Palavras-chave
Mestrado Integrado - 2014