Table 1. Virulence of wild-type, fcpA- mutant and complemented strains of Leptospira interrogans in the hamster model of leptospirosis*.
| Strains | Mortality (%) | Time to death (days) |
|---|---|---|
| Motile Fiocruz LV2756 | 100 | 6,6,6,6,6,6,6,8 |
| Motility-deficient Fiocruz LV2756 | 0¶ | -¶ |
| Fiocruz LV2756 fcpA-/+§ | 100❖ | 6,6,8,8,9,9,10,10❖ |
| Fiocruz L1-130 WT | 100 | 6,6,6,8,8,8,8,8 |
| Fiocruz L1-130 fcpA- | 0¶⌘ | -¶ |
| Fiocruz L1-130 fcpA-/+ § | 100❖ | 6,6,6,8,8,8,8,8❖ |
Results are shown for one representative experiment among a total of three, which were performed. Groups of 8 animals were inoculated intraperitoneally with 108 bacteria for each strain and then followed for 21 days.
Mortality and survival was significantly (p<0.0001) decreased and increased, respectively, compared with motile Fiocruz LV2756 and Fiocruz L1-130 strains.
Strains were genetically complemented with fcpA gene.
Mortality and survival was significantly (p<0.0001) increased and decreased, respectively, compared with motility-deficient Fiocruz LV2756 and Fiocruz L1-130 fcpA- strains.
Mortality was 37.5% in one of the three experiments but was significantly lower (p=0.026) than the mortality (100%) for hamsters infected with the Fiocruz L1-130 strain.