255. Variability in Susceptibility of Anaerobes Isolated from Different Body Sites Results from the Tigecycline European Surveillance Trial, 2009 - 2010
Session: Poster Abstract Session: Antimicrobial Susceptibility and Resistance
Friday, October 21, 2011
Room: Poster Hall B1

Background:   The TEST program has surveyed a large number of isolates to determine the variability, if any, of tigecycline's in vitro activity against clinical pathogens taken from various infectious sources. This report evaluates differences in susceptibility of anaerobic isolates from different body sites collected in Europe between 2009-2010. Methods:   2,270 clinically significant anaerobes from 32 cumulative sites in 7 European countries were analyzed. Isolates were identified to the species level at the participating sites and confirmed by the central laboratory. Tigecycline MICs were determined using agar dilution and interpreted according to FDA breakpoints. MIC90 values and % susceptible were analyzed to identify any significant differences in antibiograms from different sources. Results: Summary data of tigecycline activity against selected pathogens and body sources are shown in the table below:

 

 

Tigecycline - MIC90 /%Susceptible

(n)

Organism

Blood

Gastro-

intestinal

Genito-

urinary

Skin / Skin Structures

Body

fluids

Other

Bacteroides spp.

2/100

(41)

2/100

(43)

2/100

(14)

2/96

(283)

2/99

(469)

4/95

(130)

Clostridium spp.

2/100

(25)

0.5/100

(24)

≤0.06/100

(20)

1/100

(87)

0.5/100

(150)

0.25/100

(142)

Peptoniphilus spp.

na/100

(3)

na/100

(1)

na/--

(0)

≤0.06/100

(27)

≤0.06/100

(16)

0.12/100

(20)

Peptostrept. spp

≤ 0.06/100

(14)

≤0.06/100

(11)

na/100

(2)

0.12/100

(164)

0.12/100

(131)

0.12/100

(68)

Prevotella spp.

na/100

(7)

1/93

(14)

0.12/100

(10)

0.5/99

(97)

0.5/100

(169)

1/99

(110)

na, MIC90 not calculated for n<10

Conclusion: Tigecycline showed excellent inhibitory activity against all groups of anaerobic pathogens regardless of isolation site. Bacteria isolated from different body sites had similar antibiograms, with no isolates from any single source showing significantly different percent susceptibility (p>0.05, Fisher's exact test). Tigecycline's MIC90 of £4 mcg/ml against all anaerobic isolates validates the potent activity of this antimicrobial against a variety of anaerobic pathogens.

 


Subject Category: A. Antimicrobial agents and Resistance

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

Disclosures:

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

S. Bouchillon, 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.