Omics approach for safety and industrial potential assessment of food isolated Enterococci

MORTERA, P; MAGNI, C; D´ANGELO, M; ALARCÓN, S; MARTINO, G; BLANCATO, VS

Cordoba

Congreso; LII Reunión Anual de SAIB; 2016

SAIB

The use of Enterococcus in food industry is under debate, they contribute during the ripening process of cheese but can be potentially hazardous to human health. In this work, the genomes of four cheese isolated Enterococcus strains were analyzed and relevant findings verified in vitro. Phylogenomic studies indicated that strains IQ110, GM70 and GM75 are E. faecium species whereas IQ23 (previously described as E. faecium), is actually E. durans. Regarding their technological properties, genes related to bacteriocins synthesis and bile salt, citrate, casein, peptide and aminoacid degradation pathways were found. The volatile profiles of the strains were evaluated using solid-phase microextraction and GC-MS spectrometry, a correlation with the encoded pathways was found. In contrast, the presence of virulence and antibiotic resistance genes were also identified in silico. Then, we challenged G. mellonella larvae and found that while IQ23, IQ110, and GM75 were as lethal as E. faecalis JH2-2 isolated from urinary infection, GM70 was harmless. Finally, a differential pattern of resistance to ciprofloxacin, nitrofurantoin, chloramphenicol, and rifampicin were observed among strains. In conclusion, bioinformatic as well as biochemical approaches should be conducted to better understand the technological or pathogenic behavior of Enterococcus strains independently of their isolation source.