Anaerobes from SSTI Specimens: A Survey of Species from the Tigecycline European Surveillance Trial PS2-010 M. Hackel1, S. Bouchillon1, B. Johnson1, D. Hoban1, J. Johnson1, R. Badal1, S. Hawser2, H. Leister-Tebbe3 IHMA, Inc. 2122 Palmer Dr. 1International Health Management Associates, Inc., Schaumburg, IL, USA Schaumburg, IL 60173 Tel: +1.847.303.5003 2IHMA Europe Sàrl, Epalinges, Switzerland Fax: +1.847.303.5601 www.ihmainc.com 3Pfizer, Inc., Collegeville, PA, USA

Revised Abstract Results

Background: The Tigecycline European Surveillance Trial Figure 1. Geographic distribution of 3,551 anaerobic Figure 2. species isolated from SSTI (TEST) monitors susceptibility of European anaerobic to isolates from SSTIs, Europe, 2007-2011 specimens in Europe, 2007-2011 tigecycline (TIG), cefoxitin (FOX), (CC), meropenem (MER), piperacillin-tazobactam (PT), (PEN) and (MET). In this study we report on the different species of anaerobes isolated from skin and soft tissue (SSTI) from 2007-2011. Methods: 3,551 SSTI anaerobic were collected from 44 sites in 6 countries in Europe and sent to a central laboratory where MICs of tigecycline and five comparators were determined using CLSI agar dilution. TIG and FOX MICs were interpreted using FDA and CLSI breakpoints, respectively; EUCAST guidelines were used for all other drugs. Results: %S Figure 3. Bacteroides species isolated from SSTI specimens Figure 4. species isolated from SSTI specimens N N of species FOX CC MER MET PEN PT TIG in Europe, 2007-2011 in Europe, 2007-2011 Bacteroides spp. 1260 18 87.1 76.0 96.8 99.9 na 92.9 98.3 Clostridium spp. 641 20 na 73.0 98.1 99.5 53.9 91.0 99.7 Prevotella spp. 560 15 98.2 80.0 99.3 99.8 na 98.6 99.5 spp. 498 7 na 93.8 99.6 100 90.6 99.4 100 magna 294 1 na 80.3 100 99.7 92.5 100 100 Anaerococcus spp. 184 3 na 85.3 100 99.5 81.0 98.9 100 spp. 114 2 na 83.3 100 99.1 93.0 100 100 Conclusions: Bacteroides spp. (35%) were the most common isolates from SSTI in TEST, and included 18 different species, with B. fragilis the most frequent species (70%). Clostridium spp. (18%) was represented by 20 different species, with C. perfringins (39%) and C. difficile (31%) the most common. Prevotella spp. comprised 16% of the isolates, with 28% of these P. bivia, and 14% P. melaninogenica. Of the 7 Peptostreptococcus spp. (14%), Figure 5. Peptoniphilus species isolated from SSTI Figure 6. Peptostreptococcus species isolated from SSTI 55% were P. micros and 30% were P. anaerobius. 98% of the specimens in Europe, 2007-2011 specimens in Europe, 2007-2011 Peptoniphilus spp. were P. asaccharolyticus. MET, TIG, PT, MER showed >90% susceptibility against all isolates. Introduction

Skin and soft tissue infections (SSTIs) are common cause of morbidity and mortality in both hospitals and the community. These infections may be caused by a variety of bacteria, including anaerobes. At present, metronidazole, penems, and beta-lactam/beta-lactamase inhibitor combinations exhibit the most promising activity against anaerobes, though reports of increasing resistance to these agents are emerging [1]. Recent reports also suggest tigecycline exhibits promising activity and high susceptibilities against a wide range of anaerobes [2,3].

The Tigecycline European Surveillance Trial (TEST) is an on-going surveillance study designed to monitor the in vitro activity of select antibiotics against a variety of gram-negative and gram- Figure 7. Prevotella species isolated from SSTI specimens Table 1. In vitro activity of tigecycline and comparators positive organisms. In this study, we present a survey of anaerobic species collected in the in Europe, 2007-2011 against anaerobes from SSTI specimens in Europe, 2007- TEST study and compare the in vitro activity of six agents against these isolates collected in 2011 Europe between 2007 and 2011. MIC90 (mg/mL)/%S Number of N species FOX CC MER MET PEN PT TIG Bacteroides spp. 1260 18 32/87 >8/76 0.12/97 1/100 na 0.25/93 0.12/98 Clostridium spp. 641 20 na >8/73 0.5/98 2/100 0.5/54 8/91 2/100 Materials & Methods Prevotella spp. 560 15 8/98 >8/80 1/99 2/100 na 8/99 0.5/99 Peptostreptococcus spp. 498 7 na >8/94 0.12/100 0.5/100 4/91 0.12/99 0.12/100 Finegoldia magna 294 1 na >8/80 ≤0.06/100 1/100 ≤0.25/93 0.5/100 0.12/100 • TEST investigators collected anaerobic clinical isolates from the genuses Anaerococcus, Anaerococcus spp. 184 3 na 1/85 0.25/100 0.5/99 ≤0.25/81 0.25/99 0.12/100 Peptoniphilus spp. 114 2 na >8/83 0.12/100 2/99 ≤0.25/93 1/100 1/100 Bacteroides, Clostridium, Finegoldia, Peptostreptococcus, Peptoniphilus and Prevotella. This study analyzes 3,551 clinical isolates collected from skin and soft tissue infections (SSTIs) from 2007-2011 from five European countries (Belgium, Czech Republic, France, Germany, and Hungary). The collection and transportation of organisms, confirmation of identification, and construction and management of a centralized database were conducted and coordinated by Laboratories International for Studies (LIMS), a subsidiary of International Health Management Associates, Inc. (IHMA, Schaumburg, IL, USA). • Minimum inhibitory concentrations (MICs) were determined following CLSI guidelines for agar dilution [4] at the central laboratory (IHMA, Inc.). The following antimicrobial agents were tested with their dilution ranges (expressed in mcg/ml): tigecycline (0.06-32); clindamycin (0.25-8); metronidazole (0.12-16); piperacillin tazobactam (0.06/4-64/4); meropenem (0.06-8); cefoxitin, (gram-negative only, 2-32) and penicillin (gram-positive only, Conclusions 0.25-32). • MIC interpretive criteria followed published breakpoints established by EUCAST [4] where available, CLSI for cefoxitin and the FDA [5,6] for tigecycline. • Meropenem, metronidazole, piperacillin-tazobactam and tigecycline • Quality control followed CLSI guidelines using the following ATCC strains: Bacteroides fragilis ATCC 25285, and Bacteroides thetaiotaomicron ATCC 29741. all exhibited good in vitro activity against anaerobic bacteria from SSTIs with >90% susceptible. References • Eighteen different species of Bacteroides were identified, with B. 1. Boyanova, L., R. Kolarov, and I. Mitov. 2007. Antimicrobial resistance and the management of anaerobic infections. Exp. Rev. Anti. Infect. Ther. 5: 685-701. 2. Nagy, E., and M.J. Dowzicky. 2010. In vitro activity of tigecycline and comparators against a European compilation of fragilis (35%) the most frequent. anaerobes collected as part of the Tigecycline Evaluation and Surveillance Trial (TEST). Scand. J. Infect. Dis. 42: 33-38. 3. Hawser, S.P., M. Hackel, and D.J. Hoban. 2010. Antibiotic susceptibility profiles of European Bacteroides fragilis with reduced susceptibility. J. Antimicrob. Chemother. 65: 803 – 804. • Clostridium was represented by 20 different species, with C. 4. Clinical and Laboratory Standards Institute. Methods for Antimicrobial Susceptibility Tests of Anaerobic Bacteria. Eighth Edition: Approved Standard M11-87: CLSI, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898 USA, 2012. 5. Clinical and Laboratory Standards Institute, Performance Standards for Antimicrobial Susceptibility Testing; Twenty- Second perfringins (39%) and C. difficile (31%) the most common. Informational Supplement, in CLSI document M100-S22. 2012: CLSI, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898 USA. 6. Tygacil®, 2009. Food and Drug Administration product information. Wyeth Pharmaceuticals, Inc., Philadelphia, PA, USA • Two dominant species of Peptostreptococcus (P. micros 55% and P. anaerobius 30%) were isolated, while the most common species of Acknowledgements Prevotella was P. bivia (28%), followed by various other species. We gratefully acknowledge the contributions of the investigators, laboratory personnel, and all members of the Tigecycline Evaluation and Surveillance Trial (TEST) program group. This study was sponsored by Pfizer Inc.