Program Schedule

413
In Vitro Activity of Tigecycline against Commonly-Isolated Pathogens of Skin and Skin Structure Infections in the United States – TEST 2011-2013

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

  Background: Tigecycline has been approved for the treatment of complicated skin and skin structure infections (SSTIs) in the United States (US) since 2005.   Since introduction, tigecycline has shown little development of resistance to common pathogens of SSTIs, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE) and extended-spectrum β-lactamase (ESBL) –producing Enterobacteriaceae.  The Tigecycline Evaluation Surveillance Trial (TEST) has been monitoring the activity of tigecycline and comparators against multiple pathogens collected worldwide since 2004. This study reports on the activity of tigecycline against recent clinical isolates from SSTIs in the US. Methods:   A total of 4,229 clinical isolates from SSTI were collected and identified in 124 cumulative sites in the US in 2011-2013. MICs were determined as specified by CLSI at each site using prepared broth microdilution panels and interpreted according to CLSI guidelines.  Susceptibility of tigecycline was interpreted using FDA breakpoints.  

Results : The ESBL rates for Escherichia coli and Klebsiella pneumoniae were 6.2% and 11.6%, respectively. 58.2% of S. aureus were methicillin-resistant. Summary MIC data (µg/ml) and %S for tigecycline vs. select isolates are shown below.

Organism

N

MIC 50

MIC 90

%S

Acinetobacter baumannii

271

0.25

2

na

Enterobacter spp.

545

0.5

1

96.2

Enterococcus spp.

377

0.06

0.12

99.7

  ALL VRE Isolates

61

0.06

0.12

100

Escherichia coli

369

0.12

0.25

99.7

  E. coli, ESBL

23

0.12

0.5

100

Klebsiella pneumoniae

268

0.5

1

95.5

  K. pneumoniae, ESBL

31

0.5

2

93.6

Pseudomonas aeruginosa

426

8

> 8

na

Serratia marcescens

228

1

2

96.9

S. aureus, MRSA

747

0.12

0.25

100

S. aureus, MSSA

537

0.12

0.12

100

na=No breakpoint available,

                         

Conclusion: Tigecycline exhibited excellent in vitro activity (93% susceptibility or higher) against major SSTI pathogens from the United States, including resistant phenotypes.  MIC90 values were 0.12 µg/ml and 0.25 µg/ml for VRE and MRSA, respectively. While MIC90 values for ESBL-positive isolates were ≤2 µg/ml, the high rate of ESBL-positive K. pneumoniae (11.6%) is cause for concern.

 

Meredith Hackel, PhD, MPH1, Sibylle Lob, MD, MPH1, Samuel Bouchillon, MD1, Dan Sahm, PhD1, Daryl Hoban, PhD1 and Heidi Leister-Tebbe, BS2, (1)International Health Management Associates, Inc., Schaumburg, IL, (2)Pfizer Inc., Collegeville, PA

Disclosures:

M. Hackel, Pfizer: Independent Contractor, Consulting fee

S. Lob, Pfizer: Independent Contractor, Consulting fee

S. Bouchillon, Pfizer: Independent Contractor, Consulting fee

D. Sahm, Pfizer: Independent Contractor, Consulting fee

D. Hoban, Pfizer: Independent Contractor, Consulting fee

H. Leister-Tebbe, Pfizer: Employee, Salary

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