Table 3.
Comparison of M. tuberculosis clustering based on MIRU-12 and MIRU-24 typing
| Characteristic | Dominant strain families | Total | ||||||
|---|---|---|---|---|---|---|---|---|
| Beijing | EAI** | Delhi/CAS | (N = 1128) | |||||
| (N = 309) | (N = 324) | (N = 158) | ||||||
| MIRU number of loci* | 12 | 24 | 12 | 24 | 12 | 24 | 12 | 24 |
| Number of clusters | 32 | 42 | 35 | 18 | 17 | 5 | 139 | 82 |
| Number of clustered isolates# | 249 | 125 | 190 | 44 | 69 | 12 | 695 | 227 |
| % clustering | 80.6 | 40.5 | 58.6 | 13.6 | 43.7 | 7.6 | 61.6 | 20.1 |
| Average cluster size | 8 | 3 | 5.4 | 2.4 | 4.1 | 2.8 | 5 | 2.8 |
| Transmission rate (%)## | 70.2 | 26.9 | 47.8 | 8.0 | 32.9 | 4.4 | 49.3 | 12.8 |
*MIRU - mycobacterial interspersed repetitive unit.
**EAI – East African Indian strain family (Lineage 3).
#Two or more strains with identical MIRU profiles were considered a cluster.
##Calculated as (number of clustered isolates - number of clusters)/total number of isolates.