Einfluss einer 5'-Nukleotidase auf die Virulenz von Streptococcus pyogenes

In verschiedenen pathogenen Bakterien sind 5'-Nukleotidasen als Virulenzfaktoren beschrieben. Ziel dieser Arbeit war die Untersuchung eines möglichen Einflusses einer 5'-Nukleotidase auf die Virulenz von Streptococcus pyogenes. Es wurden Stämme der Serotypen M6, M18 sowie M49 verwendet. Insbesondere wurde die Fähigkeit zur Biofilmbildung, zum Überleben in humanem Blut und Plasma sowie im Galleria mellonella Infektionsmodell untersucht. Die Daten aus dieser Arbeit deuten darauf hin, dass die 5'-Nukleotidase keinen signifikanten Einfluss auf die Virulenz von S.pyogenes hat.5'-nucleotidases have been described as virulence factors in various pathogenic bacteria. The aim of this examination was to investigate a possible influence of a 5'-nucleotidase activity on the virulence of Streptococcus pyogenes. Strains of serotypes M6, M18 as well as M49 were used. Especially, the ability to form biofilms, to survive in human blood and plasma, and in the Galleria mellonella infection model was investigated. The data from this study indicate that the 5'-nucleotidase has no significant effect on the virulence of S.pyogenes

The 5'-nucleotidase S5nA is dispensable for evasion of phagocytosis and biofilm formation in Streptococcus pyogenes.

5'-nucleotidases are widespread among all domains of life. The enzymes hydrolyze phosphate residues from nucleotides and nucleotide derivatives. In some pathobiontic bacteria, 5'-nucleotidases contribute to immune evasion by dephosphorylating adenosine mono-, di-, or tri-phosphates, thereby either decreasing the concentration of pro-inflammatory ATP or increasing the concentration of anti-inflammatory adenosine, both acting on purinergic receptors of phagocytic cells. The strict human pathogen Streptococcus pyogenes expresses a surface-associated 5'-nucleotidase (S5nA) under infection conditions that has previously been discussed as a potential virulence factor. Here we show that deletion of the S5nA gene does not significantly affect growth in human blood, evasion of phagocytosis by neutrophils, formation of biofilms and virulence in an infection model with larvae of the greater wax moth Galleria mellonella in S. pyogenes serotypes M6, M18 and M49. Hence, the surface-associated 5'-nucleotidase S5nA seems dispensable for evasion of phagocytosis and biofilm formation in S. pyogenes