In Vitro Susceptibilities of Gram-Negative Bacteria Isolated from Hospitalized Patients in Four European Countries, Canada, and the United States in 2000-2001 to Expanded-Spectrum Cephalosporins and Comparator Antimicrobials: Implications for Therapy

ABSTRACT Access to current antimicrobial agent surveillance data is an important prerequisite for the optimal management of patients with hospital-acquired infections. The present study used data collected in 2000 to 2001 from 670 laboratories in Europe (France, Germany, Italy, and Spain), Canada, and the United States to report on the in vitro activities of ceftriaxone, cefotaxime, and comparative agents against >125,000 isolates of gram-negative bacteria from hospitalized patients. All but two isolates of Enterobacteriaceae (one isolate of Proteus mirabilis from France and one isolate of Morganella morganii from Canada) were susceptible to imipenem. The susceptibility of Escherichia coli to ceftriaxone or cefotaxime was ≥97% in each country, and for P. mirabilis, susceptibility was 99% in each country except Italy. In contrast, susceptibility of E. coli to ciprofloxacin varied from 80.5% (Spain) to 94.0% (France); levofloxacin susceptibility ranged from 75.2% (Spain) to 91.6% (United States). Among Klebsiella pneumoniae and Klebsiella oxytoca isolates, ceftriaxone and cefotaxime susceptibilities ranged from 86.6 to 98.7% and 83.5 to 99.7%, respectively, depending upon the country. Considerable geographic variation in the susceptibilities (generally 85 to 95% susceptible) of Serratia marcescens and M. morganii to ceftriaxone and cefotaxime were observed. For S. marcescens, susceptibility to piperacillin-tazobactam varied from 81.5% (France) to 94.1% (Italy) and susceptibility to ciprofloxacin ranged from 66.2% (Germany) to 90.7% (Spain). Enterobacter cloacae and Enterobacter aerogenes were less susceptible to ceftriaxone and cefotaxime than were the other species of Enterobacteriaceae studied. The present study demonstrated that established parenteral expanded-spectrum cephalosporin antimicrobial agents retain significant in vitro activity against many clinically important gram-negative pathogens.