Bifidobacterium longum and Bifidobacterium breve isolates from preterm and full term neonates: comparison of cell surface properties.

We compared autoaggregation, surface hydrophobicity and Caco-2 cells adhesion capabilities of independent Bifidobacterium breve (n = 22) and Bifidobacterium longum (n = 25) strains isolated from preterm (n = 20) and full term neonates (n = 27). Concerning strains properties, a correlation between autoaggregation and surface hydrophobicity was found for B. longum (r = 0.40, p = 0.048), B. breve (r = 0.57, p = 0.005), and all strains independently of the species consideration (r = 0.46, p = 0.001). The absence of difference in adhesion capabilities between preterm and full term neonate strains suggests a strain-dependent property. However, B. longum strains from preterm neonates (n = 10) showed higher autoaggregation ability (p = 0.044). Additionally, independently of species consideration, preterm neonates strains showed lower surface hydrophobicity (p = 0.027). As far as species are considered, preterm neonate B. breve strains (n = 10) showed significantly lower surface hydrophobicity percentages (p = 0.043). Our results suggest the existence of variations in bifidobacteria membrane structure and/or composition that may reflect adaptation of these bacteria to the intestinal environment of either preterm or full term neonates. Such information is of interest when considering the use of bifidobacteria probiotic strains for modulation of preterm neonates gut microbiota.