Should any special precautions be taken with specimens submitted for GBS screening?
Yes. There are detailed instructions in the MMWR guidelines for the collection, transport, and culturing of specimens submitted for GBS screening. Briefly, the swab or swabs are placed in a tube of selective medium (i.e., LIM broth or Trans-Vag broth supplemented with 5% defibrinated sheep blood). Following incubation of the broth for 18-24 h, an aliquot is subcultured to a blood agar plate (BAP). Following incubation of the BAP for 18-24 h, colonies of gram-positive, catalase-negative cocci are subjected to further testing. GBS may or may not be beta hemolytic. Various antigenic or molecular tests can be used for definitive identification, or the CAMP test can be used for presumptive identification of GBS. The culture can be considered negative for GBS if there are no suspicious colonies following 48 h incubation of the BAP. 3. Should the laboratory routinely perform antimicrobial susceptibility tests on GBS isolated from prenatal screening cultures? No. Antimicrobial susceptibility t
