Table 2.

Pathogenicity of 12 S. maltophilia strains, isolated from the same CF patient over 10 year-period, as assessed in G. mellonella.

Strains	Time (h) required to obtain LD50 at the following infective doses (CFU/larva)				Pathogenicity score
	103	104	105	106
ZC2005	< 24	< 24	< 24	< 24	8
ZC2006	24	24	< 24	< 24	7
ZC2007			72	< 24	3
ZC2008		72	24	< 24	4
ZC2009		24	24	< 24	6
ZC2010					1
ZC2011				24	2
ZC2012-STM1					1
ZC2012-STM2		24	24	< 24	6
ZC2013-STM1					1
ZC2013-STM2		48	< 24	< 24	5
ZC2014					1

Each strain was inoculated, at different doses (10³, 10⁴, 10⁵, and 10⁶ CFU/larva), in 20 larvae. Following infection, the larvae mortality was assessed at different times (24, 48, 72, and 96 h), and LD₅₀ (the dose required to kill 50% of the infected larvae) was recorded. For each strain, the “pathogenicity score” was calculated assigning decreasing values from the highest (score: 8) to the lowest (score: 1) virulence, as assessed considering both dose and time necessary to obtain LD₅₀. In some cases, 24 h-exposure to S. maltophilia caused the killing of all larvae (LD₅₀ < 24 h). Pulsotypes are indicated by colors: 1.1 (yellow), 1.2 (green), 2.1 (blue), and 2.2 (purple).