Heidi Splete is a senior writer with Elsevier Global Medical News.WASHINGTON — Fluoroquinolone resistance rose significantly over an 8-year period in hospitalized adults aged 65 and older with gram-negative bacterial infections, according to a report at the annual meeting of the American Geriatrics Society.The safety and bioavailability of fluoroquinolones (FQs) have made them a popular choice for treating infections—especially urinary tract and intra-abdominal infections—in older adults, wrote Jon P. Furuno, PhD, of the University of Maryland, Baltimore, and his colleagues in a poster presented at the meeting.The investigators collected microbiology data from all cultures that tested positive for gram-negative bacteria in patients aged 65 years and older who were admitted to the University of Maryland Medical Center between January 1998 and December 2005.They analyzed a total of 1,839 Escherichia coli, 554 Proteus mirabilis, 1,044 Pseudomonas aeruginosa, 1,068 Klebsiella, and 480 Enterobacter cloacae isolates during the study period.FQ resistance increased significantly across all species, from 8.4% in 1998 to 26.9% in 2005. But resistance varied by species and within years. Species-specific significant increases in the percentage of resistant isolates were observed from 1998 to 2005 for E. coli (2.8% vs. 30.6%), P. mirabilis (7.4 % vs. 39.3%), and Klebsiella (1.7% vs. 9.3%). Resistance rates in P. aeruginosa and E. cloacae increased from 1998 to 2005, but the differences were not statistically significant.The investigators urged that prescribers consider the evidence of rising FQ resistance when choosing antibiotics for hospitalized older adults.“Numerous reports have documented significant adverse consequences when seriously ill patients fail to receive adequate empiric antibiotic coverage,” commented Paul Drinka, MD, medical director of the Bethany Home in Waupaca, Wis., and clinical professor of internal medicine at the University of Wisconsin.“I would encourage [long-term care facilities] to serially analyze antibiotic susceptibility of isolates obtained in the facility, including specimens collected during the first 2 days of hospitalization.…Changing resistance patterns should trigger a critical analysis of antibiotic utilization.”“Further research is necessary to assess whether increasing resistance is associated with worsening patient outcomes and whether these associations exist outside acute care facilities,” they noted.The study was supported in part by funding from the National Institutes of Health, the Centers for Disease Control and Prevention, and the Infectious Diseases Society of America. Dr. Furuno did not disclose any financial conflicts. Heidi Splete is a senior writer with Elsevier Global Medical News. WASHINGTON — Fluoroquinolone resistance rose significantly over an 8-year period in hospitalized adults aged 65 and older with gram-negative bacterial infections, according to a report at the annual meeting of the American Geriatrics Society. The safety and bioavailability of fluoroquinolones (FQs) have made them a popular choice for treating infections—especially urinary tract and intra-abdominal infections—in older adults, wrote Jon P. Furuno, PhD, of the University of Maryland, Baltimore, and his colleagues in a poster presented at the meeting. The investigators collected microbiology data from all cultures that tested positive for gram-negative bacteria in patients aged 65 years and older who were admitted to the University of Maryland Medical Center between January 1998 and December 2005. They analyzed a total of 1,839 Escherichia coli, 554 Proteus mirabilis, 1,044 Pseudomonas aeruginosa, 1,068 Klebsiella, and 480 Enterobacter cloacae isolates during the study period. FQ resistance increased significantly across all species, from 8.4% in 1998 to 26.9% in 2005. But resistance varied by species and within years. Species-specific significant increases in the percentage of resistant isolates were observed from 1998 to 2005 for E. coli (2.8% vs. 30.6%), P. mirabilis (7.4 % vs. 39.3%), and Klebsiella (1.7% vs. 9.3%). Resistance rates in P. aeruginosa and E. cloacae increased from 1998 to 2005, but the differences were not statistically significant. The investigators urged that prescribers consider the evidence of rising FQ resistance when choosing antibiotics for hospitalized older adults. “Numerous reports have documented significant adverse consequences when seriously ill patients fail to receive adequate empiric antibiotic coverage,” commented Paul Drinka, MD, medical director of the Bethany Home in Waupaca, Wis., and clinical professor of internal medicine at the University of Wisconsin. “I would encourage [long-term care facilities] to serially analyze antibiotic susceptibility of isolates obtained in the facility, including specimens collected during the first 2 days of hospitalization.…Changing resistance patterns should trigger a critical analysis of antibiotic utilization.” “Further research is necessary to assess whether increasing resistance is associated with worsening patient outcomes and whether these associations exist outside acute care facilities,” they noted. The study was supported in part by funding from the National Institutes of Health, the Centers for Disease Control and Prevention, and the Infectious Diseases Society of America. Dr. Furuno did not disclose any financial conflicts.