Effect of chelating agents on the growth, surface polypeptide synthesis and interaction of Streptococcus agalactiae with human epithelial cells

Abstract

Abstract. In the present study, the influence of the chelating agents of ethylenediaminetetraacetic acid (EDTA), ethylene glycol-bis (ß-aminoethyl ether) (EGTA) and 1,10-phenanthroline (PHEN) on growth rate, cytoadherence ability and surface protein expression was examined in a clinical strain of Streptococcus agalactiae isolated from a blood sample. EDTA and EGTA at 10 mM did not inhibit the growth of S. agalactiae, while PHEN significantly arrested bacterial proliferation in a concentration range of 10-0.01 mM. The in vitro interaction between S. agalactiae and A549 cells was a time-dependent process; adherence and bacterial intracellular viability were more pronounced after 3 h of contact. The pre-treatment of bacterial cells with EDTA adversely influenced the adhesive properties of S. agalactiae to A549 cells after 2 and 3 h, whereas EGTA only blocked this process after 3 h. Viable intracellular bacteria were just detected after 3 h of interaction, and EDTA and EGTA inhibited intracellular viability in a similar fashion. Conversely, PHEN inhibited neither the adherence nor the intracellular viability of the microorganism. Furthermore, EDTA robustly suppressed surface polypeptide synthesis, suggesting a decline in the possible bacterial ligands responsible for S. agalactiae adhesive properties.

The Lung Microbiome in COPD and Lung Cancer: Exploring the Potential of Metal-Based Drugs

“…This antimicrobial action has been attributed to the chelating capabilities of phen and the sequestering nature of metal ions [243]. Thus, it selectively disturbs the essential metal cellular metabolism interference with metal acquisition and bioavailability for crucial reactions impeding the microbial nutrition, growth, virulence, and pathogenesis of a variety of microorganisms, including Leishmania spp., Aspergillus spp., Candida albicans, Fonsecaea pedrosoi, and Streptococcus agalactiae [244,245]. Accordingly, metal chelators, such as phen, have been investigated for their therapeutic potential against microbial infections, as metals such as Fe, Cu, and zinc (Zn) play an important role in cellular homeostasis [190].…”