Multidrug-resistant urinary tract isolates of Escherichia coli prevalence and patient demographics in the United States in 2000

Concurrent resistance to antimicrobials of different structural classes has arisen in a multitude of bacterial species and may complicate the therapeu tic management of infections, including those of the urinary tract. To asse ss the current breadth of multidrug resistance among urinary isolates of Es cherichia coli, the most prevalent pathogen contributing to these infection s, all pertinent results in The Surveillance Network Database-USA from 1 Ja nuary to 30 September 2000 were analyzed. Results were available for 38,835 urinary isolates of E, coli that had been tested against ampicillin, cepha lothin, ciprofloxacin, nitrofurantoin, and trimethoprim-sulfamethoxazole. O f these isolates, 7.1% (2,763 of 38,835) were resistant to three or more ag ents and considered multidrug resistant. Among the multidrug-resistant isol ates, 97.8% were resistant to ampicillin, 92.8% were resistant to trimethop rim-sulfamethoxazole, 86.6% were resistant to cephalothin, 38.8% were resis tant to ciprofloxacin, and 7.7% were resistant to nitrofurantoin. The predo minant phenotype among multidrug-resistant isolates (57.98; 1,600 of 2,793) included resistance to ampicillin, cephalothin, and trimethoprim-sulfameth oxazole. This was the most common phenotype regardless of patient age, gend er, or inpatient-outpatient status and in eight of the nine U,S, Bureau of the Census regions. Rates of multidrug resistance were demonstrated to be h igher among males (10.4%) than females (6.06%), among patients > 65 years o f age (8.7%) than patients less than or equal to 17 (6.8%) and 18 to 65 (6. 1%) years of age, and among inpatients (7.6%) than outpatients (6.9%), Regi onally, the rates ranged from 4.3% in the West North Central region to 9.2% in the West South Central region, Given the current prevalence of multidru g resistance among urinary tract isolates of E. coil in the United States ( 7.1%), continued local, regional, and national surveillance is warranted.