Enterococcus moraviensis EMo 1-1Nik of horse origin:characteristics and potential bacteriocin-producing strain.

Abstract

Nowadays, developed more precisious identification techniques have allowed to validate newer enterococcal species. Among them, the species Enterococcus moraviensis was also validated, at first from surface waters. However, in this study, characteristics and potential to bacteriocin production by the strain E. moraviensis EMo 1-1Nik isolated from buccal mucosa of Slovak warm-blood horse breed has been studied. BLASTn analysis allotted this strain to the species E. moraviensis with percentage identity BLASTn 16S rRNA sequence in the strain up to 100% (99.93% similarity with E. moraviensis NR113937.1). The strain EMo 1-1Nik has been provided with GenBank accession number MW326085. It is hemolysis-negative (γ-hemolysis), deoxyribonuclease-negative and gelatinase-negative; absent of virulence factor genes, low-grade biofilm-positive (0.133 ± 0.36), mostly susceptible to tested antibiotics. Moreover, 60% of EMo1-1Nik colonies were found as bacteriocin-producing against the principal indicator Enterococcus avium EA5. The concentrated substance (CS, pH 4.5) of EMo1-1Nik showed the inhibitory activity against EA5 strain (800 AU/mL); CSs with pH 6.3 and 7.3 reached inhibitory activity 100 AU/mL against EA5 strain. CS was thermo-stable and it does not lost activity after enzymes treatment. Oppositelly, EMo 1-1Nik was susceptible to Mundticin EM 41/3 (800 AU/mL) produced by horse fecal strain E. mundtii EM 41/3 and enterocins (up to 51 200 AU/mL). In spite of the preliminary results, it has been shown a potential to produce bacteriocin substance of the safe strain E. moraviensis EMo1-1Nik. The additional studies are in processing.