Growth-Inhibition Test for Identifying Mycoplasma meleagridis and Its Antibody

Abstract

The growth inhibition (GI) test was used successfully for identifying cultures of Mycoplasma meleagridis. Anti-M.-meleagridis serum had no inhibitory action on M. gallisepticum or avian serotypes B, F, K, and L. Similarly, anti-M.-gallisepticum or anti-F sera did not inhibit heterologous Mycoplasma. The GI test was found applicable for detection of actively and passively acquired M. meleagridis antibodies in turkeys. The sensitivity of the GI test was greatly influenced by the number of organisms used in the inocula. Also, the serum-drop method of conducting the test proved more sensitive and simple than the paper-disc method. GI activity of the antiserum was not significantly decreased from storage at -15 C for 12 months, heat inactivation, or drying on filter paper. The GI test for identification of Mycoplasma meleagridis and M. gallisepticum can be greatly simplified by using dried antiserum-impregnated discs. These discs provided many advantages, such as ease of application, prolonged storage, facility in distribution in minute amounts, and decreased chances of microbial contamination. Mycoplasma-free turkeys are an excellent source of specific antiserum against M. meleagridis. A single intravenous injection of viable organism is sufficient to cause a response resulting in high GI antibody titers in the