Background: Bacteroidales species are predominant in human large intestine, particularly in colon. These microorganisms are able to develop resistance to several antimicrobial drugs. Aim: To determine the resistance profile and presence of genes encoding resistance to metals in intestinal Bacteroidales from children and calves. Methods: Forty four strains were tested. Antimicrobial resistance and presence of resistance genes were evaluated. Resistant strains were submitted to plasmid cure and the susceptibility was tested again. Results: Most of tested strains were resistance to metals and one B. vulgatus (human origin) showed 3.0 kb and 5.0 kb plasmids and one B. vulgatus (animal origin) showed a 4.0 kb plasmid in which the presence of genes czcA, czcB, and czcC was observed. Resistant strains lost the plasmids and resistance to metals was decreased. Conclusions: The presence of genes might be any association with the cadmium resistance. Further studies to characterize the resistance mechanisms or CzcCBA efflux system in Bacteroidales species are necessary.
Key words: Bacteroides vulgatus, Resistance to metals, Plasmids, Gene czc