Streptococcus suis Meningitis, United States

7).The remaining 1 is from Japan and assigned to ST28 (8).Unlike in previous reports, 80% of the human clinical isolates (16 isolates) characterized in this study were assigned to the ST27 complex.Although previous studies suggested that members of the ST27 complex may have lower potential to cause invasive diseases in swine ( 7), all the isolates were isolated from blood or cerebrospinal fl uid of the patients, suggesting a high degree of invasiveness (Table).Because it is unknown whether the ST27 complex is also dominant among isolates from diseased pigs in Thailand, future surveillance will be necessary to know the situation in pigs.However, our data indicate that the ST27 complex is another clonal group that should be assessed for its importance for human infection.Because mrp, epf, and sly are not appropriate as virulence markers for the ST27 complex members, development of novel virulence markers will be needed for effi cient discrimination of S. suis strains virulent for humans.This study made use of the Streptococcus suis Multilocus Sequence Typing website (http://ssuis.mlst.net);