- Whole genome sequences of naturally recombinant European type III and type II x III clones were analyzed
- While two of the type II x III recombinants showed an intermediate mouse virulence, a type III clone was highly virulent
- Of the three highly virulent clones, only two showed a virulent ROP18-ROP5 allele combination
- The mouse virulent type III clone without virulent ROP18-ROP5 allele combination showed the highest level of ROP5 mRNA expression
- Two genetically similar clones showed apparent differences in virulence and corresponding IL-12 mRNA expression in infected macrophages