Commensal gut bacteria: distribution of Enterococcus species and prevalence of Escherichia coli phylogenetic groups in animals and humans in Portugal

The gastrointestinal tract is continuously in contact with commensal bacteria that are composed of more than 500 different species, and has an important role in human nutrition and health, by promoting nutrient supply, preventing pathogen colonization and shaping and maintaining normal mucosal immunity. The present review demonstrates the distribution of the intestinal commensal bacteria spp. and the prevalence of phylogenetic groups in animals and humans in Portugal. The enterococcal population described in this review includes 1,909 enterococcal isolates recovered from a series of fecal samples of different animals (horses, swine, ostriches, partridges, mullet fish, garden dormice, seagulls, pets, poultry, wild boars, birds of prey, and wild rabbits) and healthy and clinical humans. We also compared the phylogenetic groups of isolates (n=203) recovered from healthy humans and animals (poultry, ostriches, seagulls, wild boars, birds of prey, and pigs). Phenotypic and molecular analysis allowed the identifying of as the predominant species followed by . In addition, the data from different studies showed that isolates of the A and B1 phylogenetic groups are predominant in the gut flora of animal origin and the phylogenetic group B2 isolates were the most common in healthy human samples.