TABLE 2.

Invasiveness of PA14 ntrBC mutant strains was reduced in comparison to the wild-type (WT) in a CD-1 murine model of infection.

Organ	Number of mice exhibiting bacteria in various
	organs (bacterial counts; CFU)
	WT	ΔntrB	ΔntrC	ΔntrBC
Heart	8 (102–106)	2 (104–105)*	3 (102–103)*	0*
Lungs	9 (102–106)	7 (102–105)	3 (102–104)*	7 (102–106)
Liver	8 (102–105)	5 (102–107)	3 (103–106)*	1 (102)*
Spleen	9 (102–106)	4 (102–105)*	4 (102–105)*	5 (103–104)*
Kidneys	7 (102–107)	2 (104–105)*	3 (103–105)	1 (103)*

Briefly, mice were subcutaneously injected 10⁵–10⁷ planktonic cells and abscesses were formed for 24 h. At the experimental endpoint, organs were harvested in phosphate buffered saline (PBS), homogenized and plated on LB for bacterial enumeration. Dissemination of PA14 wild-type (WT) and ntrBC mutant strains from abscess to organs is shown as the frequency of bacterial recovery, and range of bacterial counts in instances of recovery, from four independent experiments each including 1–3 individual mice per bacterial strain (n = 9). Mutants were significantly reduced for dissemination to some organs compared to WT according to Fisher’s Exact Test (*P < 0.05).