Background:

Kanamycin sulfate is an aminoglycoside bacteriocidal antibiotic which acts by binding to the bacterial 30S ribosomes.
Kanamycin sulfate at the concentration above 0.0025% has a significant inhibition on the growth of B. bifidum and has no influence on the other four probiotics at incubation 12 h or 24 h. The optimum selective concentration of kanamycin sulfate in MRS media is 0.005% for selective enumeration of B.bifidum[3]
The neurons damage of the DCN caused by kanamycin (500 mg/kg/day) is reversible and autophagy is upregulated in the neurotoxic course of kanamycin on DCN through JNK1-mediated phosphorylation of Bcl-2 pathway in rats. The serum BUN and Cr levels are both increased at the 1st day after the period of kanamycin administration. The neurons expressing LC3 are increased at 1, 7 and 14 days after kanamycin administration in comparison to the control group. Kanamycin treatment results in the increase of autophagy in a time-dependent manner[1]. Kanamycin sulfate (5 mg/kg) and sodium ampicillin (10 mg/kg) administered intramuscularly (i.m.) separately, and then together, to five pony mares, and the ampicillin concentration exceeds 5 mg/mL in inflamed synovial fluid for some 2.5 h after injection, and kanamycin sulfate concentration exceeds 2 mg/mL for 7 h in the pony[2].
Reference:
[1]. Fan GR, et al. Reversible neurotoxicity of kanamycin on dorsal cochlear nucleus. Brain Res. 2013 Jan 17. pii: S0006-8993(13)00068-1.
[2]. Mohamed el SW, et al. Tongue actinomycetoma due to Actinomadura madurae: a rare clinical presentation. J Oral Maxillofac Surg. 2012 Nov;70(11):e622-4.
[3]. Guo WS, et al. Effect of Kanamycin Sulfate and Gentamicin on Growth of Probiotics. Advanced Materials Research,2011, 366, 490-493.
[4]. Firth EC, et al. Effect of induced synovial inflammation on pharmacokinetics and synovial concentration of sodium ampicillin and kanamycin sulfate after systemic administration in ponies. J Vet Pharmacol Ther. 1988 Mar;11(1):56-62.