Effect of competitive exclusion in rabbits using an autochthonous probiotic

Abstract

Animal nutrition has been severely challenged by the ban on antimicrobials as growth promoters. This has fostered the study of alternative methods to avoid colonisation by pathogenic bacteria as well as to improve the growth of animals and feed conversion efficiency. These new options should not alter the normal intestinal microbiota, or affect it as little as possible. The use of probiotics, which are live microorganisms that beneficially affect the host by improving its intestinal microbial balance, can be seen as a promising way to achieve that goal. In this study, New Zealand White rabbits were fed diets containing an autochthonous probiotic of Enterococcus spp., with the strains EaI, EfaI and EfaD, and Escherichia coli, with the strains ECI 1, ECI 2 and ECD, during a 25-d trial, to evaluate the impact of the probiotic on the faecal microbiota, including population dynamics and antimicrobial resistance profiles. A control group of rabbits, which was fed a diet containing a commonly used mixture of antimicrobials (colistin, oxytetracycline, and valnemulin), was also studied. To assess the colonisation ability of the mentioned probiotic, the faecal microbiota of the rabbits was characterised up to 10 d after the administration had ended. Isolates of enterococci and E. coli were studied for phylogenetic relationships using enterobacterial repetitive intergenic consensus (ERIC-PCR) and pulse-field gel electrophoresis (PFGE), respectively. Although partially affected by an unexpected clinical impairment suffered by the rabbits in the experimental group, our results showed the following. The difference between the growth rate of the animals treated with antimicrobials and those fed the probiotic was not statistically significant (P> 0.05). The competitive exclusion product was present in the faecal samples in a large proportion, but stopped being recovered by culture as soon as the administration ended and the housing conditions were changed. Multidrug-resistant strains of enterococci and E. coli were more commonly recovered from faecal samples of animals fed diets containing antimicrobials, than from rabbits fed diets with our probiotic formula. The use of E. coli probiotics to prevent infection by enteropathogenic strains must be carefully considered due to the possible occurrence of gastrointestinal signs. On the other hand, enterococci strains may be more effective, but lack the long-term colonisation ability.

Autochtonous Strain Enterococcus faecium EF2019(CCM7420), Its Bacteriocin and Their Beneficial Effects in Broiler Rabbits—A Review

“…Similarly to our results, Lauková et al [ 21 ] and Szabóová et al [ 35 ] also reported higher ADWG through bacteriocinogenic and probiotic E. faecium AL41 (CCM8558) and CCM4231 strains application in rabbits. Improved body weight in rabbits was also noted after probiotics administration by Bovera et al [ 30 ], Bhatt et al [ 32 ] and Kalma et al [ 51 ]. On the other hand, after PPB CCM7420 addition increased the body weight only slightly (by 2.2%, Table 2 ), but in this group, better FCR was achieved, compared to strain application.…”

“…The feed conversion ratio (FCR) was influenced only through the Ent7420 administration and the combinative application of the CCM7420 strain with Eleutherococcus senticosus extract. The effect of probiotics, including registered probiotic preparations and new beneficial microorganisms on the growth performance of rabbits have been already described/reviewed; they usually confirmed the increased body weight [ 14 , 15 , 17 , 19 , 24 , 25 , 31 , 32 ]. The most of these studies described faster growth and higher weight gain of rabbits using probiotic preparations and feed additives based on the following bacterial strains and yeasts alone or in their combinations: Saccharomyces cerevisiae , S. boulardii , Bacillus licheniformis , B. cereus , B. cereus var.…”

“…The use of several natural feed additives has already been reviewed in rabbit breeding [ 10 , 12 , 13 , 14 , 15 ]. The positive effects of probiotics and their antibacterial products—bacteriocins on health, growth performance, nutrient utilization and metabolism changes, microbial composition [ 14 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ], blood serum biochemistry, oxidative stress, immune response, intestinal morphology [ 21 , 24 , 28 , 29 , 30 , 31 , 34 , 36 , 37 , 38 ] and meat quality of rabbits [ 32 , 34 , 39 , 40 , 41 , 42 , 43 ] was described. However, in spite of the achieved results, there are still few declared probiotic preparations based (Lactina, Toyocerin; [ 44 , 45 ]; Prorabbit—declared in Slovakia; [ 25 ]) and detailed studies of microorganisms with beneficial properties that have also the ability to produce antimicrobial substances, enterocins.…”

Can Enterocin M in Combination with Sage Extract Have Beneficial Effect on Microbiota, Blood Biochemistry, Phagocytic Activity and Jejunal Morphometry in Broiler Rabbits?

“…To achieve better production in rabbit husbandries, one possible way is the use of natural compounds, such as probiotics, prebiotics, synbiotics, bacteriocins, organic and fatty acids, and plant extracts, which can improve the health status of animals [1][2][3][4]. There are many reviews presenting their beneficial effects, mostly of probiotic applications to rabbits, with emphasis on reduction of pathogens and parasites in the gastrointestinal tract (GIT), stimulation of immunity, better growth performance, metabolism and nutrient utilization, and improved meat quality [5][6][7]. Application of natural antimicrobials, including probiotics, bacteriocins, and herbal extracts, can modulate and balance the intestinal microbiota instead of beneficial lactic acid bacteria, and enhance the immune response.…”

Effect of a lytic bacteriophage on rabbits experimentally infected with pathogenic Escherichia coli

“…Because research into new antibiotics was scarce in European Union and United States (Wittebole et al, 2014), widespread appeals for alternatives to antibiotics have been voiced (Cunha et al, 2017).…”