Quantification of tetracycline and chloramphenicol resistance in digestive tracts of bulls and piglets fed with Toyocerin®, a feed additive containing Bacillus toyonensis spores

The complete genome sequencing of Bacillus toyonensis, the active ingredient of the feed additive Toyocerin®, has revealed the presence of tetM and cat genes, a tetracycline and a chloramphenicol resistance gene, respectively. The aim of this study was to determine whether the use of Toyocerin® (viable spores of B. toyonensis) as a probiotic in feedstuff increased the abundance of tetracycline and chloramphenicol resistant bacteria in the...