Involvement of host iron-withholding strategy on Streptococcus pyogenes strain KSU-1 growth and pathogenicity

Background and objectives Streptococcus pyogenes is a highly adaptable human pathogen that can cause a wide spectrum of infections ranging from mild to a life-threating systemic infection. This study discussed the effectiveness of iron-depriving strategy on growth, survival, and virulence of S. pyogenes. Materials and methods Some comparisons between different iron-saturated and iron-depleted forms of the main human iron reservoirs (hemoglobin, hemin, transferrin, lactoferrin, and human milk) were tested for their effect on growth and pathogenicity of S. pyogenes. Results and conclusion Although the iron-saturated forms enhanced the growth and survival, the iron-free forms had a bacteriostatic/bactericidal activity against the microbe, and these results were emphasized by the in vivo study. Finally, the bacterial surface proteins as virulence factors were secreted upon iron depletion as indicated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. This study proved that iron-depletion environment increased the resistance and virulence factors of S. pyogenes. Moreover, these results can give an insight about the interaction between the host and pathogen, which can lead to designing of new antimicrobial agents or vaccine that may target these pathways.