title: Effect of chelating agents on the growth, surface polypeptide synthesis and interaction of Streptococcus agalactiae with human epithelial cells.
abstract: In the present study, the influence of the chelating agents of ethylenediaminetetraacetic acid (EDTA), ethylene glycol-bis (β-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.
authors.affiliation: Departamento de Biologia Celular, Instituto Biologia Roberto Alcântara Gomes (IBRAG), Universidade do Estado do Rio de Janeiro (UERJ), 20550-013 Rio de Janeiro, RJ, Brazil.
authors.forename: Michelle Hanthequeste Bittencourt
authors.initials: MH
authors.lastname: Dos Santos
authors.forename: Andréia Ferreira Eduardo
authors.initials: AF
authors.lastname: Da Costa
authors.forename: Gabriela
authors.initials: G
authors.lastname: Da Silva Santos
authors.forename: André Luis Souza
authors.initials: AL
authors.lastname: Dos Santos
authors.forename: Prescilla Emy
authors.initials: PE
authors.lastname: Nagao