title: Rapid recognition of group B streptococci by pigment production and counterimmunoelectrophoresis.
abstract: Streptococci from clinical isolates were studied for their ability to produce pigment in stab cultures in Columbia agar. Serological grouping of these organisms was done by counterimmunoelectrophoresis using Burroughs-Wellcome antisera. In this group of isolates, 66 of the 68 organisms grouped as B by serological testing produced pigment in the Columbia agar stab cultures. Pigment was not produced by any of the other 36 streptococci studied (11 group A, 9 group C, 4 group D, and 12 nongroupable). The use of the Columbia agar stab culture is recommended as a rapid and simple test for recognition of group B streptococci. The counterimmunoelectrophoresis test is also suggested as a convenient, rapid, and sensitive method for grouping the streptococci.
mesh_terms: D000328:Adult; D000362:Agar; D000942:Antigens, Bacterial / Q000032:analysis; D001414:Bacitracin / Q000494:pharmacology; D003378:Counterimmunoelectrophoresis; D004352:Drug Resistance, Microbial; D006626:Hippurates / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007223:Infant; D007231:Infant, Newborn; D010860:Pigments, Biological / Q000096:biosynthesis; D013290:Streptococcal Infections / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000145:classification* / Q000276:immunology / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D006626:Hippurates; D010860:Pigments, Biological; D001414:Bacitracin; D000362:Agar