New research indicates almost half of nursing home residents had more than one multidrug-resistant organism (MDRO) in or on them.

Researchers said 40% of the 200 residents studied had MDRO, and many were more likely to develop a urinary tract infection.They found complex interactions “with acquisition of each of six different MDRO species being influenced by different sets of antibiotics, and primary MDRO colonization in turn increasing the risk of acquisition and infection by other MDROs,” said Joyce Wang, Ph.D.

Results appeared in the Proceedings of the National Academy of Sciences