Clinical importance and public health concerns for the emergence of antibiotic resistant organisms in the human intestinal microflora.

Infections with antibiotic-resistant organisms clearly have an economic impact, although the extent remains uncertain. Major problems are: the problem of multiresistance, i.e., the mutation or rearrangement of a single gene to cause resistance to multiple antibiotics of several different classes at once; the linkage between virulence and resistance, and the influence of antibiotics on these two seemingly unrelated events; and the problem and consequences of gene dissemination. There are simply no data on antibiotic usage levels required for selection of some of these genetic events. This an area where much more information is needed.