The Yersinia high-pathogenicity island and iron-uptake systems in clinical isolates of Escherichia coli.

The ability to acquire iron is crucial for bacteria during an infection. The capacity of 35 strains of Escherichia coli, isolated from clinical specimens, to use various strategies to obtain iron was analysed. The isolates employed several iron-uptake mechanisms, including production of enterobactin (86 %) and aerobactin (71 %). The majority of the isolates also excreted yersiniabactin, which is encoded by the Yersinia high-pathogenicity island (HPI). However, PCR analysis of the Yersinia HPI revealed diversity in its genetic organization. Use of human transferrin (91 %), lactoferrin (94 %), haemoglobin (80 %) and haemoglobin-haptoglobin complex (63 %) as the sole source of iron was common among E. coli isolates. Multiple iron-uptake systems may be of benefit to bacteria during an infection.