Risk factors for resistance to fluoroquinolone antibiotics change over time
Research Activities, July 2009, No. 347
Fluoroquinolones are the most commonly prescribed class of antibiotics to treat a variety of bacterial infections. Over the years, Escherichia coli bacteria have shown increased resistance to this class of antibiotics, making E. coli infections harder to treat. Up to 20 percent of hospitalized patients have fluoroquinolone-resistant strains of E. coli.
Researchers from the Center for Education and Research on Therapeutics (CERT) at the University of Pennsylvania School of Medicine have found that risk factors for such resistance change over time. They conducted a 3-year (2002-2004), case-control study of 774 hospitalized patients at 2 large medical centers. Gastrointestinal tract colonization with fluoroquinolone-resistant E. coli was identified in 89 (11.5 percent) of the patients. Prior fluoroquinolone use was significantly associated with resistant strains colonizing the gastrointestinal tract. In 2004, patients who had used fluoroquinolone were nearly ten times more likely to have resistant E. coli colonization than those who had not used the antibiotic. However, in 2002 and 2003, the link between fluoroquinolone use and E. coli resistance was not significant. This suggests that the clinical epidemiology of resistant organisms may change over time.
The study was supported in part by a grant from the Agency for Healthcare Research and Quality (HS10399) to the University of Pennsylvania School of Medicine CERT. For more information on the CERT program, please visit http://certs.hhs.gov/.
See "Gastrointestinal tract colonization with fluoroquinolone-resistant Escherichia coli in hospitalized patients: Changes over time in risk factors for resistance," by Ebbing Lautenbach, M.D., M.P.H., M.S.C.E., Joshua P. Metlay, M.D., Ph.D., Mark G. Weiner, M.D., and others, in the January 2009 Infection Control and Hospital Epidemiology 30(1), pp. 18-24.