Susceptibility of chicken Lactobacillus bacteria to coccidiostats

Abstract

The aim of this study was to determine the susceptibility of Lactobacillus bacteriato selected coccidiostats. Seventy-five Lactobacillus isolates obtained from chickens were classified by MALDI-TOF mass spectrometry and 16S rDNA restriction analysis into seven species, among which L. salivarius (33%) and L. johnsonii (24%) were dominant. Susceptibility of lactobacilli to coccidiostats was determined by broth microdilution method. The ranges of minimum inhibitory concentrations (MICs) were 0.5–≥128 μg/ml for monensin, 0.125–8 μg/ml for salinomycin, ≤0.03–2 μg/ml for lasalocid A, and 4–16 μg/ml for robenidine. Coccidiostats in low concentrations inhibited in vitro growth of most lactobacilli and therefore there is a high probability that administration of this drugs to chickens would reduce the number of lactobacilli in the gut.