Antibiotic-Treated SPF Mice as a Gnotobiotic Model

Decontamination of specific pathogen-free (SPF) mice of BALB/c line was accomplished by administration of amoxicillin per os potentiated with potassium clavulanate at a dose of 387.11 mg/kg body weight and ciprofloxacin administered s.c. at a dose of 18.87 mg/kg body weight every 12 h for 5 days. This resulted in a decreased viability of microorganisms in feces and the cecal content of mice and decreased counts of cultivable microorganisms in the feces, which by day 3 of study declined below the recovery level and to the reduction of animal microbiota to two detected cultivable species, namely Escherichia coli (GenBank KX086704) and Enterococcus sp. (GenBank KX086705). Convalescence of decontaminated animals under gnotobiotic conditions for 10 days prevented restoration of species diversity of mice microbiota and sufficed to return the metabolic, hematological and morphological values to the physiological range. It also restored the fermentative activity of the intestine to the level similar to that observed before antibiotic treatment. Animals subjected to this procedure can be used in further studies. As a result, we created a mouse gnoto model with reduced and controlled microbiota without alteration of the overall health status of the respective animals.