M. Marounek et V. Rada, SUSCEPTIBILITY OF POULTRY LACTOBACILLI TO IONOPHORE ANTIBIOTICS, Journal of veterinary medicine. Series B, 42(4), 1995, pp. 193-196
The susceptibility of four poultry Lactobacillus strains to monensin,
narasin, lasalocid, salinomycin and maduramicin was investigated using
two different systems of lactobacilli cultivation. In the MRS broth (
Oxoid) with glucose, the growth of lactobacilli was inhibited at ionop
hore concentrations as low as 0.4-5 mu g/ml. On the other hand, the gr
owth of lactobacilli in the mixture of a commercial concentrate with w
ater (1:2) was not influenced by ionophores at 100 mu g/g. It follows
from these results that lactobacilli are much more resistant to ionoph
ores in their natural environment than in laboratory cultures on gluco
se. It was concluded that: probiotic lactobacilli can be added to iono
phore-containing concentrates; antibiotic susceptibility data obtained
in liquid cultures with glucose are misleading.