Program Schedule

419
Susceptibility trends for P. aeruginosa and A. baumannii from IAI in the USA: SMART 2009-2013

Session: Poster Abstract Session: Surveillance of Antimicrobial Resistance
Thursday, October 9, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC

Background: Because of their resistance to many antimicrobials, Pseudomonas aeruginosa and Acinetobacter baumannii remain pathogens of interest in intra-abdominal infections (IAI), representing approximately 10% and 3%, respectively, of aerobic gram-negative pathogens in IAI globally. This report from the Study for Monitoring Antimicrobial Resistance Trends (SMART) evaluates the susceptibility of P. aeruginosa and A. baumannii from IAI in the USA between 2009 and 2013.

Methods: 27 US laboratories each collected up to 100 consecutive aerobic or facultative gram-negative isolates from IAI each year. Susceptibility was determined using the CLSI broth microdilution method and breakpoints. Linear trends in susceptibility were assessed with the Cochran-Armitage test.

Results: Susceptibility trends and prevalence of 967 P. aeruginosa and 199 A. baumannii isolates are shown below. N and % of all gram-negative pathogens are listed in the legend.

A sensitivity analysis was conducted for P. aeruginosa susceptibility using only the 12 sites that submitted isolates in all 5 years. The significant increasing trends for ceftazidime and piperacillin-tazobactam were confirmed, the trend for cefepime approached significance (p=0.08), and an additional significant increasing trend was found for levofloxacin (p=0.03).

Conclusion: P. aeruginosa's prevalence was stable at around 12% of gram-negative pathogens isolated from IAI in the USA from 2009 to 2013. Its susceptibility to cefepime, ceftazidime and piperacillin-tazobactam showed statistically significant change (p<0.05), with these drugs demonstrating increasing susceptibility. A. baumanniis prevalence was lower and decreased significantly over the 5 years, but its susceptibility remained stable for all tested drugs between 2009 and 2013. Resistance does not appear to be increasing in these difficult-to-treat IAI pathogens.

 

Sibylle Lob, MD, MPH, Robert Badal, BS, Samuel Bouchillon, MD, Meredith Hackel, PhD, MPH, Aaron Johnson, BS, Dan Sahm, PhD and Daryl Hoban, PhD, International Health Management Associates, Inc., Schaumburg, IL

Disclosures:

S. Lob, Merck: Independent Contractor, Consulting fee

R. Badal, Merck: Independent Contractor, Consulting fee

S. Bouchillon, Merck: Independent Contractor, Consulting fee

M. Hackel, Merck: Independent Contractor, Consulting fee

A. Johnson, Merck: Independent Contractor, Consulting fee

D. Sahm, Merck: Independent Contractor, Consulting fee

D. Hoban, Merck: Independent Contractor, Consulting fee

Findings in the abstracts are embargoed until 12:01 a.m. EDT, Oct. 8th with the exception of research findings presented at the IDWeek press conferences.

Sponsoring Societies:

© 2014, idweek.org. All Rights Reserved.

Follow IDWeek