Effects of biotin, folic acid, and pantothenic acid on the growth of Mycoplasma meleagridis, a turkey pathogen.

The biotin, folic acid, and pantothenic acid requirements of Mycoplasma meleagridis were determined in vitro by examining the growth and survival of the organism in the presence of varying concentrations of these factors. Growth and survival were also studied in the presence of aminopterin and methotrexate which prevent utilization of folic acid, and in the presence of avidin, a known biotin antagonist. Whereas pantothenate appeared to have no obvious effect on growth or survival, folate was marginally stimulatory at only the highest concentration tested. Aminopterin exerted a slight, but not significant, inhibitory effect at four of the five concentrations tested. In contrast, the inhibition seen with methotrexate increased, dependent on dose. Biotin exerted a pronounced stimulatory effect at the two highest concentrations tested. Avidin inhibited growth only at one of the concentrations tested; however, this concentration did not correspond to the greatest amount of avidin. The possible significance of the avidin-biotin relationship to the etiology of Turkey Syndrome 1965 is explored on the basis of these in vitro observations and previous in vivo findings.