Year: 2006
Type: dissertation
Abstract: Shigella dysenteriae and Shigella flexneri are Gram-negative facultative intracellular pathogens that cause bacillary dysentery.Iron is an essential micronutrient for these pathogens and they have evolved several systems to obtain iron.The Feo and Sit systems are involved in acquisition of ferrous iron and the TonB-dependant systems transport ferric iron and heme.In S. flexneri, a strain with a defect in the Sit system exhibited decreased fitness in the intracellular environment compared to the wild type.Although the TonB, Sit and Feo iron transport systems are present in both S. dysenteriae and S. flexneri, S. dysenteriae strains with defects in iron transport exhibited different phenotypes than similar mutants in S. flexneri.In S. dysenteriae, the TonB-dependent iron transport systems were important for growth in low-iron environments, while the Feo system was important for growth when iron was abundant.The Feo system was the only system found to be important for competition with the wild type strain in vitro or in the intracellular environment.An S. dysenteriae strain with a mutation in feoB formed
Author: Nicola Mary Lisa Davies
Language: English
Subfield: Microbiology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W1898541963