FIG. 5.

Ability of SPI1 mutants to cause diarrhea and lethal morbidity in calves infected orally with a dose of 10¹⁰ CFU per animal. Lethal morbidity caused by the wild type or by Salmonella serotype Typhimurium mutants over time is shown in the upper graphs. The lower graphs show the severity of diarrhea over time, which was scored on a scale from 1 to 5, as follows: 1, normal feces; 2, soft feces with loss of distinct conformation; 3, diarrhea, loose feces with reduced solid matter; 4, diarrhea, aqueous feces with markedly reduced or little solid matter, or fibrin; 5, diarrhea, aqueous feces with no solid matter, fibrin and blood.