title: The occurrence of R-protein among isolates of group B streptococci from human sources.
abstract: A total of 241 clinical isolates of group B streptococci were tested for presence of R-protein by applying the double diffusion-in-gel technique on streptococcal extracts against monospecific anti-R protein serum, radio-labelled protein A and anti-R protein serum or S. aureus, Cowan I coated with antibodies against group A streptococci, T-type 28. The first two methods proved more sensitive than the latter. R-protein was detected in 51% of 43 type II strains and in 87% of 102 type III strains, whereas none of 79 type Ia and none of 17 type Ib strains contained R-protein. Among 30 isolates from blood and cerebrospinal fluid of infants with neonatal infections, R-protein was detected in 43%, one of two type II strains and 12/14 type III strains. Tests of 37 paired strains from infant/mother pairs showed concordant results with respect to presence or absence of R-protein in the isolates.
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000382:microbiology; D008581:Meningitis / Q000382:microbiology; D018805:Sepsis / Q000382:microbiology; D013290:Streptococcal Infections / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000032:analysis* / Q000145:classification / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins