[Extrachromosomal antibiotic resistance of the intestinal bacterial flora. II. The role of resistance acquired by endogenous intestinal bacterial flora (author's transl)].

In a previous paper, we have shown that multiple resistant bacteria in the human gut flora may have two origins: firstly, through food which carries resistant bacteria and secondly, our present study, resident intestinal bacteria which become resistant to antibiotics, either because they are chromosomic mutant or because they acquire resistance plasmid from an exogen strain. In all cases these resistant bacteria can implant and multiply in the gut only if there are disorders in the normal bacterial equilibrium. Antibiotherapy can create this inbalance and especially if it is not carefully followed up: it selects resistant bacteria, allows their implantation, and promotes plasmid R transfer. The resistant bacteria are able, in some cases, to spread out from the intestinal tract and give rise to further infections.