222. Trends in E. coli and K. pneumoniae ESBL Rates in Urinary Tract Infections – TEST 2004-2010
Session: Poster Abstract Session: Antimicrobial Resistance: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1

Background: E. coli and K. pneumoniae are major pathogens in the etiology of urinary tract infections (UTIs).  The treatment of these species has been complicated with increasing rates of extended sprectum beta-lactamase (ESBL) production in recent years.   This study looks at the trends in ESBL producion from 2004 through 2010 and the effect on susceptibilities to common theraputic agents.  The Tigecycline Evaluation and Surveillance Trial (TEST) is an ongoing global surveillance designed to follow trends in antimicrobial activity of tigecycline and comparators.  Methods: 11,688 clinical isolates were collected from 1,338 cumulative investigator sites globally. Collection of isolates was limited to clinical UTI sources. Clinical isolates were identified to the species level at each participating site and confirmed by the central laboratory. Minimum Inhibitory Concentrations (MICs) were determined by the local laboratory using supplied broth microdilution panels and interpreted according to current CLSI and FDA (tigecycline) guidelines. Results: Tigecycline in vitro activity vs E. coli and K. pneumoniae has remained stable since 2004 with MIC50, MIC90, and %Sus of 0.5 mcg/ml, 2 mcg/ml, and 95%, respectively.  Regional ESBL rates varied from a low rate of 7% in North America to 31% in Asia. Trends in ESBL rates are presented in the following figure:


Conclusion: Overall ESBL production in E. coli and K. pneumoniae from UTIs has shown a steady rise worldwide during the seven year period of this study (p <0.001) with wide variations demonstrated regionally. Tigecycline in vitro activity against ESBL producing E. coli  and K. pneumoniae  from UTIs has not changed significantly since its introduction in 2005 (p >0.05) with an overall %Sus rate of 95%. 


Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

Samuel Bouchillon, MD1, Meredith Hackel, PhD1, Stephen Hawser, PhD2, Brian Johnson, BS1, Daryl Hoban, PhD1 and Michael Dowzicky, MS3, (1)IHMA, Inc., Schaumburg, IL, (2)IHMA Europe Sārl, Epalinges, Switzerland, (3)Pfizer, Inc., Collegeville, PA


S. Bouchillon, Pfizer, Inc.: Consultant, Consulting fee

M. Hackel, Pfizer, Inc.: Consultant, Consulting fee

S. Hawser, Pfizer, Inc.: Consultant, Consulting fee

B. Johnson, Pfizer, Inc.: Consultant, Consulting fee

D. Hoban, Pfizer, Inc.: Consultant, Consulting fee

M. Dowzicky, Pfizer, Inc.: Employee, Salary

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.