[Series of studies concerning group B streptococci with reduced penicillin susceptibility (PRGBS)].

Group B Streptococcus (GBS, Streptococcus agalactiae) is the cause of neonatal sepsis and meningitides. Moreover, this bacterium causes invasive infections to elderly people and patients suffering from diabetes et al. All clinical isolates of GBS, similar to other β-hemolytic streptococci, have been considered to be uniformly susceptible to β-lactams since 1940s, when penicillin was introduced to clinical setting. However, we analyzed clinical isolates of group B streptococci with reduced penicillin susceptibility (PRGBS), recovered in Japan during 1995-2005, and established their existence. Moreover, we promote series of studies concerning PRGBS. In this review, we describe series of studies concerning PRGBS.