Non-haemolytic and non-pigmented group b streptococcus, an infrequent cause of early onset neonatal sepsis

The haemolysin of Group B streptococci (GBS), a leading cause of neonatal infections, is a key virulence factor that has been implicated in the development of invasive infection. The frequency of non-haemolytic (NH) GBS isolates is around 5% among GBS carriers. To determine if similar rates are observed among invasive strains, we evaluated the incidence of NH strains among 199 GBS strains isolated from neonatal blood cultures (first week of life). Overall, we found two (1%) NH strains. This finding suggests that the frequency of NH GBS strains causing early onset invasive neonatal infection is lower than the reported frequency of NH GBS among colonizing strains.