Oral administration of bacteriocin-producing and non-producing strains of Enterococcus faecium in dogs

The current effort to incorporate microbial cultures in canine nutrition and thus intake of them on daily base increases our interest in careful and more complex study of their effects in dogs. Many of the commercially used strains have not been tested in dogs and are incorporated only on the base of beneficial effects observed in humans with specific disorders. Moreover, no information on the effects of bacteriocin-producing strains in dogs is available. Therefore, we decided to test and to compare overall effect of bacteriocin non-producing Enterococcus faecium DSM 32820 and enterocin B-producing E. faecium LMG 30881 strain (both of canine origin). Dogs were divided into three treatment groups of ten dogs each: control; DSM 32820 group; and LMG 30881 group, dosing 10⁹ CFU/day/dog. The experiment lasted 35 days with a 14-day treatment period (sample collection at days 0, 7, 14, 35). Despite bacteriocin production is believed that may provide a competitive advantage over neighbouring sensitive strains within shared environment, results indicated somewhat better survival for the DSM 32820 compared to the LMG 30881 group. Furthermore, dogs of DSM 32820 group had optimal faecal consistency throughout the experiment, significantly stimulated phagocytic activity (days 7 and 14) and metabolic burst activity of leukocytes (days 14 and 35) and lower serum glucose concentration (day 35). In contrast, dogs of LMG 30881 group showed higher faecal count of Gram-negative bacteria (day 35), lower haemoglobin and glucose concentration (day 35), and higher metabolic burst activity (days 14 and 35). These results are further evidence of the existence of inter-strain differences in efficacy despite the same origin.