The influence of pH on Staphylococcus saprophyticus iron metabolism and the production of siderophores

Publication date: December 2019Source: Microbes and Infection, Volume 21, Issue 10Author(s): Bianca Silva Vieira de Souza, Karla Christina Sousa Silva, Ana Flávia Alves Parente, Clayton Luiz Borges, Juliano Domiraci Paccez, Maristela Pereira, Célia Maria de Almeida Soares, Marcia Giambiagi-deMarval, Mirelle Garcia Silva-Bailão, Juliana Alves Parente-RochaAbstractStaphylococcus saprophyticus is a gram-positive coagulase negative bacteria which shows clinical importance due to its capability of causing urinary tract infections (UTI), as well as its ability to persist in this environment. Little is known about how S. saprophyticus adapts to the pH shift that occurs during infection. Thus, in this study we aim to use a proteomic approach to analyze the metabolic adaptations which occur as a response by S. saprophyticus when exposed to acid (5.5) and alkaline (9.0) pH environments. Proteins related to iron storage are overexpressed in acid pH, whilst iron acquisition proteins are overexpressed in alkaline pH. It likely occurs because iron is soluble at acid pH and insoluble at alkaline pH. To evaluate if S. saprophyticus synthesizes siderophores, CAS assays were performed, and the results confirmed their production. The chemical characterization of siderophores demonstrates that S. saprophyticus produces carboxylates derived from citrate. Of special note is the fact that citrate synthase (CS) is down-regulated during incubation at acid pH, corroborating this result. This da...
Source: Microbes and Infection - Category: Infectious Diseases Source Type: research