title: Factors associated with relative rates of antimicrobial resistance among Streptococcus pneumoniae in the United States: results from the TRUST Surveillance Program (1998-2002).
abstract: To identify factors associated with antimicrobial resistance, data were analyzed from 27,828 isolates of Streptococcus pneumoniae submitted to the Tracking Resistance in the United States Today (TRUST) surveillance program during 4 consecutive respiratory seasons. From the 1998-1999 season to the 2001-2002 season, the prevalence of azithromycin resistance increased by 4.8% to 27.5%, the prevalence of penicillin resistance increased by 3.7% to 18.4%, the prevalence of ceftriaxone resistance increased by 0.5% to 1.7%, and the prevalence of levofloxacin resistance increased by 0.3% to 0.9%. Isolates recovered from patients <18 years of age and lower respiratory tract specimens had elevated rates of penicillin, azithromycin, and trimethoprim-sulfamethoxazole resistance (P<.00001); penicillin resistance correlated with coresistance to trimethoprim-sulfamethoxazole (87.3%), azithromycin (76.3%), ceftriaxone (9.1%), and levofloxacin (1.3%) (P<.00001). Only 62 (0.2%) of 27,828 isolates were concurrently resistant to penicillin and levofloxacin. Minimum inhibitory concentrations (MICs) of penicillin correlated strongly with MICs of ceftriaxone (R2=0.90), trimethoprim-sulfamethoxazole (R2=0.53), and azithromycin (R2=0.41). Patient age, specimen source, and penicillin resistance were factors associated with antimicrobial resistance, particularly for nonfluoroquinolone antimicrobial agents.
authors.affiliation: Focus Technologies, Herndon, Virginia 20171-4603, USA. jkarlowsky@focusanswers.com
authors.forename: James A
authors.initials: JA
authors.lastname: Karlowsky
authors.forename: Clyde
authors.initials: C
authors.lastname: Thornsberry
authors.forename: Mark E
authors.initials: ME
authors.lastname: Jones
authors.forename: Alan T
authors.initials: AT
authors.lastname: Evangelista
authors.forename: Ian A
authors.initials: IA
authors.lastname: Critchley
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Sahm
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010406:Penicillins / Q000494:pharmacology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification; D014481:United States
chemical_list: D000900:Anti-Bacterial Agents; D010406:Penicillins; D017963:Azithromycin