Differentiation of Haemophilus spp. in Respiratory isolate cultures by an indole spot test.
Indole spot tests using isolated, nonhemolytic colonies of Haemophilus species were positive for 90 of 151 (60%) respiratory isolates of Haemophilus influenzae, whereas 67 to 72 (93%) isolates of H. influenzae from cerebrospinal fluid and blood specimens were indole positive. Only 4 of 117 (3%) Haemophilus parainfluenzae isolates were positive for indole spot tests. Thus, indole-positive, nonhemolytic Haemophilus isolates in respiratory cultures can be presumptively identified as H. influenzae.
D001431:Bacteriological Techniques; D006190:Haemophilus / Q000145:classification*; D006801:Humans; D007211:Indoles / Q000302:isolation & purification*; D013183:Sputum / Q000382:microbiology*
D007211:Indoles