| Abstract: | Yolk sac suspensions infected with the Legionnaires disease bacterium (LDB) were plated onto 17 different bacteriological agar media. The LDB grew only on Mueller-Hinton agar supplemented with 1% Iso Vitale X and 1% hemoglobin (MH-IH). This medium was subsequently analyzed to determine the components required to support growth of the LDB. L-Cysteine hydrochloride can replace the Iso Vitale X reagent, and soluble ferric pyrophosphate can replace hemoglobin. A new medium, F-G agar, was formulated incorporating these chemicals. Different cultures conditions (oxygen tension, temperature, and pH) were also evaluated. The LDB grew optimally at 35 degrees C under 2.5% CO2 on the F-G agar adjusted to pH 6.9. When infected tissues were inoculated onto both F-G agar and MH-IH, the F-G agar produced colonies of the LDB more rapidly and in greater numbers than did MH-IH. |
