Multilocus sequence typing of invasive group B Streptococcus in central area of Taiwan.

BACKGROUND

Group B Streptococcus (GBS) (Streptococcus agalactiae) is an important pathogen in neonates, pregnant women, and adults with underlying disease.

METHODS

Fifty clinical isolates were collected during the period 2001-2004 and analyzed by multilocus sequence typing and capsular serotyping.

RESULTS

The six major sequence types (STs) identified by multilocus sequence typing were ST1, ST12, ST19, ST17, ST23, and ST10. Five major clonal complexes (CCs) and one single ST (ST61) from 11 different STs were found. CC1 (n=14) was the most common one, followed by CC12 (n=13), CC19 (n=9), CC17 (n=7), and CC23 (n=6). The most common serotypes were serotype III, followed by Ib, V, Ia, and IV. The most invasive strains in adults belonged to ST1 (CC1) and serotype V, and those in neonates belonged to ST17 (CC17) and serotype III. In addition, ST19 was distributed in adults and neonates.

CONCLUSIONS

These results are similar to those of previous reports, but some geographic differences were found, suggesting that limited clonal lineages play important roles in GBS-associated diseases worldwide. Continued tracking of GBS in the population through clinical isolates is important for epidemiologic investigations and vaccine development.