Isolation and characterization of faecal bifidobacteria and lactobacilli isolated from dogs and primates

Although bifidobacteria and lactobacilli have been suggested beneficial for the host and are components of many probiotics and competitive exclusion mixtures, the knowledge on abundance, metabolic and probiotic characteristics in isolates from dogs and monkeys is still limited. The present study was aimed to isolate Bifidobacterium and Lactobacillus strains (faeces of 22 dogs and of 5 primates: Cebus apella, Eulemur fulvus, Erythrocebus patas, Macaca fascicularis, Papio hamadryas) with the MALDI-TOF identification system Lactobacillus murinus, Bifidobacterium animalis and Pediococcus acidilactici were more frequently isolated species in dogs while Lactobacillus plantarum was isolated in several species of primates. Ten strains of 6 species were assayed for enzymatic activities (only Lactobacillus reuteri strains showed no undesirable enzymatic activity), antimicrobial susceptibility (detected higher minimum inhibitory concentration levels for tetracycline and gentamicin), and inhibitory activity against 15 indicator bacteria. All strains inhibited Gram-negative indicators while lactobacilli showed larger inhibition zones than bifidobacteria. L. reuteri II/3b/a (isolate from M. fascicularis) showed the best antimicrobial properties. Resistance to bile (0.3% w/v) was observed in all tested strains (no decrease of CFU/ml) whereas the decrease of 68.4-94.4% (after 90 min exposition) and 78.4-99.9% CFU/ml (after 180 min) depending on the strain was detected in the artificial gastric juice.