Spiramycin- and tylosin-resistant strains of Mycoplasma gallisepticum isolated from breeding chickens and pipped eggs
Kuniyasu, C.; Yoshida, Y.; Takano, M.
National Institute of Animal Health Quarterly 14(2): 48-53
1974
ISSN/ISBN: 0027-951X PMID: 4444733 Document Number: 76069
Twenty-seven strains of M. gallisepticum isolated from laying hens and pipped eggs in 1969 were examined in liquid medium for sensitivity to spiramycin (S) and tylosin (T). Nine of 16 strains from hens were inhibited by 10-100 mu g/ml and 1-10 mu g/ml T. Five of 11 strains from pipped eggs were inhibited by 100-1000 mu g/ml S and 10 mu g/ml T. Strain Kp-13 isolated in 1962 was inhibited by 0.1 mu g/ml and 0.01 mu g/ml T. Chickens were inoculated intranasally with strain Kp-13 or strain S4A (drug-resistant strain of hen origin) and then injected with S or T. Three injections of S or T eliminated strain Kp-13, but not the drug-resistant strain.