title: Standardization and evaluation of the CAMP reaction for the prompt, presumptive identification of Streptococcus agalactiae (Lancefield group B) in clinical material.
abstract: Primary cultures of clinical material were screened for the presence of colonies suspected of being Streptococcus agalactiae (Lancefield group B). Sixty-three such cultures and 108 other isolates of beta-hemolytic streptococci (groups A, C, and G), encountered during the first 3 months of the investigation, were studied by Lancefield grouping, sodium hippurate hydrolysis, and a standardized CAMP test. All streptococci were inoculated perpendicularly to streaks of a beta-toxin-producing staphylococcus on sheep blood agar plates and incubated aerobically in a candle jar and anaerobically at 37 C. Plates were examined after 5 to 6 and 18 h of incubation. The production of a distinct "arrowhead" of hemolysis was indicative of a positive CAMP reaction. All group B streptococci produced a positive CAMP reaction in the candle jar or anaerobically, usually within 5 to 6 h, and aerobically after 18 h of incubation. All group A streptococci produced a positive reaction only under anaerobic conditions. Groups C and G streptococci were negative under all atmospheres. The CAMP reaction is a prompt and reliable procedure for the presumptive identification of group B streptococci when a candle jar atmosphere is used during incubation.
mesh_terms: D000332:Aerobiosis; D000362:Agar; D000693:Anaerobiosis; D000818:Animals; D001431:Bacteriological Techniques / Q000592:standards*; D001769:Blood; D002965:Classification / Q000379:methods*; D005069:Evaluation Studies as Topic; D005260:Female; D006461:Hemolysis; D006626:Hippurates / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000382:microbiology*; D012756:Sheep; D013210:Staphylococcus; D013290:Streptococcal Infections / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000145:classification* / Q000276:immunology / Q000378:metabolism; D014118:Toxins, Biological
chemical_list: D006626:Hippurates; D014118:Toxins, Biological; D000362:Agar