Ciprofloxacin-Resistant Staphylococcus aureus Displays Enhanced Resistance and Virulence in Iron-Restricted Conditions.

The unreasonable misuse of antibiotics has led to the emergence of large-scale drug-resistant bacteria, seriously threatening human health. Compared with drug-sensitive bacteria, resistant bacteria are difficult to clear by host immunity. To fully explore the adaptive mechanism of resistant bacteria to the iron-restricted environment, we performed data-independent acquisition-based quantitative proteomics on ciprofloxacin (CIP)-resistant (CIP-R) Staphylococcus aureus in the presence or absence of iron. On bioinformatics analysis, CIP-R bacteria showed stronger amino acid synthesis and energy storage ability. Notably, CIP-R bacteria increased virulence by upregulating the expression of many virulence-related proteins and enhancing the synthesis of virulence-related amino acids under iron-restricted stress. This study will help us to further explain the adaptive mechanisms that lead to bacterial resistance to antibiotics depending on the host environment and provide insights into the development of novel drugs for the treatment of drug-resistant bacterial infections.