New Granada Medium for detection and identification of group B streptococci

Abstract

A methotrexate-containing medium for the detection of beta-hemolytic group B streptococci from clinical specimens on the basis of detection of pigment is described. The medium contained peptone, starch, serum, MgSO4, glucose, pyruvate, methotrexate (as pigment enhancer), phosphate- morpholinepropanesulfonic acid buffer, and selective agents. The recovery of beta-hemolytic group B streptococci was comparable to that obtained with selective broth.