Enterococcus bulliens sp. nov., a novel lactic acid bacterium isolated from camel milk

Abstract

Four lactic acid bacteria isolates obtained from fresh dromedary camel milk produced in Dakhla, a city in southern Morocco, were characterised in order to determine their taxonomic position. The four isolates had highly similar MALDI-TOF MS and RAPD fingerprints and identical 16S rRNA gene sequences. Comparative sequence analysis revealed that the 16S rRNA gene sequence of the four isolates was most similar to that of Enterococcus sulfureus ATCC 49903(T) and Enterococcus italicus DSM 15952(T) (99.33 and 98.59% similarity, respectively). However, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes revealed that the taxon represented by strain LMG 28766(T) was well separated from E. sulfureus LMG 13084(T) and E. italicus LMG 22039(T), which was further confirmed by DNA-DNA hybridization values that were clearly below the species demarcation threshold. The novel taxon was easily differentiated from its nearest neighbour species through sequence analysis of protein encoding genes, MALDI-TOF mass spectrometry and multiple biochemical tests, but had a similar percentage G+C content of about 39%. We therefore propose to formally classify these isolates as Enterococcus bulliens sp. nov., with LMG 28766(T) (=CCMM B1177(T)) as the type strain.

Occurrence, molecular and antimicrobial resistance of Enterococcus spp. isolated from raw cow’s milk trade by street trading in Meknes city, Morocco

“…The tree was constructed using MEGA7 with 1000 bootstrap italicus and E. bulliens, which were identified in fresh camel milk. 21 Enterococcus spp. have been isolated all over the world, for example in China E. faecalis, E. faecium and E. hirae were isolated in fresh goat milk.…”

Enterococci: Between Emerging Pathogens and Potential Probiotics

“…Enterococci are Gram-positive cocci that occur in pairs or short chains, nonspore forming, catalase and oxidase-negative, and facultative anaerobic [6, 7]. The genus Enterococcus belongs to lactic acid bacteria (LAB) and represents the third-largest LAB genus after Lactobacillus and Streptococcus with 37 species classified based on phylogenetic assessment using 16S rRNA sequencing and DNA-DNA hybridisation [3].…”

“…The prevalence of enterococci in milk has been traditionally considered as a result of faecal contamination, but many studies have reported that this occurrence is not always related to faecal contamination [7, 23, 24]. In fact, Enterococcus spp.…”

“…has the capacity of adaptation to diverse substrates and growth conditions. Indeed, enterococci could be present in both raw and pasteurised milk of cow, sheep, goat, or camel [7, 39, 40]. Enterococcal strains examples that have been isolated from raw milk are E. faecalis and E. casseliflavus [41], E. lactis [42], E. italicus , and E. faecium [43].…”

Bacteriocin-Producing Enterococcus faecium LCW 44: A High Potential Probiotic Candidate from Raw Camel Milk

“…The few published studies on its microbiota have shown that, like other milks, camel milk is a source of lactic acid bacteria, primarily lactobacilli, lactococci, and enterococci (Quigley et al, 2013; Kadri et al, 2015). Nevertheless, differences in the composition of camel milk compared to cow milk (Farah, 1993; Ochirkhuyag et al, 1998; Konuspayeva et al, 2007) and the desert environment away from anthropogenic pressure could underlie significant differences in its microbial ecosystem and the biological characteristics thereof.…”