Interestingly, it was the only one that carried the cytolysin operon (Cyl), that encodes a secreted two-peptide lytic protein that damages host cells and promotes infection (39), and the aggregation substance AS, a pheromone-induced surface protein that facilitates plasmid conjugation and potentiates the pathogenic effect of Cyl (40). The gene discussed is CYLC1; the disease is infection.