Table 1. Characteristics of SDSE isolates included in this study.
| Collection site | No. of isolates | No. of different emm types | Diversity index, D a (95% C.I.)b | No. of different STs | Diversity index, D (95% C.I.) | STs unique to collection site | No. of isolates with group G carbohydrate | No. of isolates with group C carbohydrate | No. of invasive isolates | No. of non-invasive isolates |
| Australia | 55 | 17 | 0.926 (0.901–0.956) | 23 | 0.937 (0.908–0.970) | 14 | 47 | 8 | 24 | 25 |
| Portugal | 36 | 17 | 0.951 (0.930–0.972) | 22 | 0.956 (0.922–0.989) | 11 | 28 | 8 | 10 | 26 |
| USA | 72 | 34 | 0.984 (0.976–0.985) | 45 | 0.975 (0.961–0.988) | 33 | 48 | 23 | 70 | 1 |
| —NYMC | 11 | 8 | 0.927 (0.833–1.020) | 10 | 0.981 (0.936–1.020) | 5 | 6 | 5 | 9 | 0 |
| —CDC | 61 | 33 | 0.983 (0.979–0.988) | 37 | 0.972 (0.957–0.988) | 28 | 42 | 18 | 61 | 1 |
| Other | 15 | 12 | 0.971 (0.951–1.001) | 13 | 0.981 (0.951–1.011) | 10 | 7 | 7 | 1 | 6 |
| Total | 178 | 37 | 0.961 (0.954–0.967) | 80 | 0.966 (0.955–0.976) | n.a. | 131 | 46 | 106 | 59 |
a
D, Simpsons Index of Diversity.
b
CI, Confidence Interval.
n.a., not applicable.