1. U.S. Food and Drug Administration Notice: Archived Document The content in this document is provided on the FDA’s website for reference purposes only. It was current when produced, but is no longer maintained and may be outdated.

2. 2 Aspects of the use of 4 GCs in human and veterinary medicine in Europe Veterinary Medicine Advisory Committee Public Hearing, 25 September 2006 Pr. André Bryskier, MD

3. 3 Aspects under review I.Characterization of C3’quaternary ammonium cephalosporins class (4GCs) II.Clinical indications of 4GCs in Europe III.Mechanisms of resistance of 4GCs IV.Susceptibility surveillance programs for E.coli and non typhoidal Salmonella V.Summary and conclusions

4. 4 Penams (Penicillins) Cephems (Cephalosporins, Cephamycins, Oxa-1-cephems, Carbacephems, Isocephems) Monocyclic β-lactams (monobactams) Penems (carbapenems) I. Classification -  -lactam family C3’quaternary ammonium cephalosporins (4GCs) belong to the Cephem group. Together with 3GCs, they are identified as extended spectrum cephalosporins (ESC)

5. 5 S N NHNH COCH R7 COO - O N+N+ Zwitterionic cephems (4GCs) Cefepime Cefpirome Cefquinome* S N NHNH COCH R7 COO - O R Monoanionic cephems (3GCs) Cefotaxime Ceftriaxone Ceftiofur* Cefovecin* S N NHNH COCH COO - O N+N+ Dianionic cephems (3GCs) Ceftazidime *Cephems only used in veterinary medicine I. Characterization – Chemical structure of ESC

6. 6 I. Characterization – Dual mode of action  Rapid penetration of the outer membrane  Rapid crossing of the periplasmic space  Low affinity for β- lactamases  High affinity for Penicillin Binding Proteins (PBPs) Nikaido et al., 1990; Pucci et al. 1991

7. 7 II. Clinical indications of 4GCs in human medicine in Europe Cefepime – Cefpirome (injectable) Clinical indications-Respiratory tract infections/pneumonia -Bacteriemia/septicemia -Complicated urinary tract infections (UTI) -Biliary tract infections -Empiric therapy for neutropenic patients Clinical introduction 1993

8. 8 II. Clinical indications of cefquinome in veterinary medicine in Europe Cattle injectable Pig injectable Horse injectable Cattle Intra- mammary Clinical indications  Respiratory tract infections  Neonatal E.coli septicemia  Acute E.coli mastitis  Foot infections  Respiratory tract infections  Mastitis Metritis Agalactiae (MMA)  Meningitis  Epidermitis  Arthritis  Respiratory tract infections  Neonatal E.coli septicemia  Clinical mastitis Clinical introduction 1994199920051998

9. 9 III. Resistance mechanisms Outer-membrane Minor epidemiological impermeabilityrelevance in Gram negative Efflux pump β-lactamases Major epidemiological relevance in Gram negative Penicillin Binding Relevance in Gram positive Protein (PBP) alterations

10. 10 III. Resistance mechanisms – Major β-lactamases β-lactamases are divided in four classes (Ambler classification) –Class A: Narrow- spectrum β-lactamases: TEM-1, TEM-2, SHV-1 ESBLs: TEM, SHV-derivatives, CTX-M –Class B: Metallo enzymes: carbapenemases –Class C: AmpC: FOX, MOX, CMY, ACC, etc. –Class D: Oxacillinases Most important beta-lactamases are cephalosporinases (AmpC) and Extended Spectrum Beta-Lactamases (ESBLs)

11. 11 III. Mechanisms of resistance – Characteristics of ESBLs and AmpC ESBLAmpC Selection All beta-lactamsAll beta-lactams (except 4GCs, carbapenems) Spectrum of hydrolysis Aminopenicillins  -Carboxy-penicillins Narrow spectrum cephalosporins Extended spectrum beta- lactams Aminopenicillins α-carboxy- and ureidopenicillins Cephamycins oximino-cephalosporins aztreonam Location PlasmidChromosomal or plasmid Nordmann P, 1998

12. 12 III. Mechanisms of resistance – Prevalence of AmpC in Europe Bacterial species AmpC HumanVet (livestock) E.coli + (since 1994) (-) Salmonella enterica + (since 1990) (-) (-): sporadic cases have been reported Philippon A et al., 2002

13. 13 III. Mechanisms of resistance - Prevalence of ESBLs in Europe Bacterial species ESBLs HumanVet (livestock) E.coli + (since 1988) (-) Salmonella enterica + (since 1992) (-) (-): sporadic cases have been reported Lahey.org; Batchelor M et al., 2005; Miriagou V et al., 2004

14. 14 III. Mechanisms of resistance – Variety of ESBLs and AmpC Great variety in human medicine ESBLAmpC Lahey.org; Batchelor M et al., 2005

15. 15 III. Mechanisms of resistance - Conclusions –ESBL : –Broad spectrum of hydrolysis except carbapenems –Identified since 1988 in E.coli in human medicine –Great variety in human isolates –Sporadic cases in livestock in Europe –AmpC –Broad spectrum of hydrolysis except 4GCs and carbapenems –Identified since 1990 in human medicine –Some variants in human isolates –Sporadic cases in livestock in Europe

16. 16 IV. Susceptibility surveillance programs for E.coli and non typhoidal Salmonella Published susceptibility surveillance data to 4GCs (cefepime) are limited T.E.S.T and SENTRY surveillance programs identified as sources for human medicine EASSA surveillance program for veterinary medicine European surveillance programs are testing 3GCs as representatives of ESC EARSS (ceftazidime, ceftriaxone, cefotaxime), Enter-net (cefotaxime)

17. 17 IV. Cefepime susceptibility surveillance for E.coli and non typhoidal Salmonella  T.E.S.T Tigecycline Evaluation and Surveillance Trial  Collection of human clinical isolates from blood, respiratory tract, urine and other infections (skin, wound, fluids)  MIC determination of cefepime as tigecycline comparator by broth micro-dilution technique  Cefepime MIC interpretive criteria R≥ 32 µg/ml  SENTRY surveillance program  Funded 1993,  Collection of human clinical isolates  MIC determination of cefepime by broth micro-dilution technique  Cefepime MIC interpretative criteria R≥ 32 µg/ml  EASSA European Antimicrobial Susceptibility Surveillance in Animals  Collection of foodborne and commensals bacteria from healthy animals at slaughter  MIC determination of cefepime by broth micro-dilution technique  Cefepime MIC interpretative criteria R≥ 32 µg/ml

18. 18 IV. Cefepime susceptibility surveillance for E.coli T.E.S.T data Cefepime susceptibility data and percent of resistant Enterobacteriaceae and E.coli human clinical isolates collected in Europe in 2004-2005 Hoban D et al., E-326, ICAAC 2005 Bacterial species (Number of isolates) Cefepime Enterobacteriaceae (3841) MIC 50 MIC 90 %R ≤ 0.5 µg/ml 4 µg/ml 6.1 E.coli (723) MICI 50 MIC 90 %R ≤ 0.5 µg/ml 1 µg/ml 4.4

19. 19 IV. Cefepime susceptibility surveillance for E.coli and Salmonella SENTRY data Percent of resistant E.coli and Salmonella spp. isolates collected in pediatric infections in Europe in 2004 to cefepime Fedler KA et al., 2006 Bacterial species (Number of isolates) % R cefepime E.coli (663) 2.1 Salmonella spp. (73) 0

20. 20 IV. Cefepime susceptibility surveillance for E.coli and Salmonella EASSA data Susceptibility of E.coli and Salmonella spp. isolates collected from healthy livestock at slaughter to cefepime Animal species E. coli (MIC 90 µg/ml) Salmonella spp. (MIC 90 µg/ml) 1999-20012002-2003*1999-20012002-2003* Cattle 0.032 (n = 664) 0.063 (n = 490) ND0.125 (n = 15) Pig 0.063 (n = 652) 0.063 (n = 494) 0.125 (n = 146) 0.125 (n = 128) Chicken 0.063 (n = 802) 0.125 (n = 481) 0.125 (n = 118) 0.125 (n = 62) Bywater et al., 2004; *: unpublished data No resistant isolate reported

21. 21 IV. Susceptibility surveillance - European surveillance programs  EARSS European Antimicrobial Resistance Surveillance program  Funded by European Commission in 1999, partner of WHO  On going collection of antimicrobial susceptibility tests of invasive bacteria (Blood culture and CSF)  Enter-net International surveillance network for enteric infections Salmonella, verotoxigenic E.coli (VTEC) and Campylobacter  Funded by European Commission in 1993, partner of WHO  International database of fully characterized bacteria including data on epidemiology and antibiotic resistance

22. 22 IV. Surveillance surveillance - European surveillance programs In 2004 : 30119 isolates collected Average resistance rate : 2.9% Resistance breakpoints 1-32 µg/ml EARSS data Proportion of invasive E.coli isolates with resistance to 3GCs in 2004

23. 23 IV. Susceptibility surveillance - European surveillance programs N=6396N=10145N=8669 N=10078 Enter-net data Percent of resistant Salmonella spp isolates to ampicillin (21.7 to 27.5 %) and cefotaxime (0.2 to 0.4%) from 2001 to 2004 *: European enlargement and inclusion of Australia

24. 24 IV. Susceptibility surveillance - European surveillance programs Enter-net data Percent of resistant isolates of E.coli (VTEC, environmental and animal reservoirs) to cefotaxime from 2005 to first quarter 2006 Year Number of isolates % of resistance 20057940 1st quarter 2006 1620 No resistance to ESC in Europe cefotaxime R breakpoint > 1µg/ml

25. 25 IV. Susceptibility surveillance - Conclusions Resistance to ESC in human clinical cases Approximately 3 % in E.coli isolated from invasive infections Very low in Salmonella (< 1%) Not found in VTEC (0%)

26. 26 V. Summary and conclusions 4GC structure confers a low affinity for most β-lactamases including AmpC Resistance due to ESBL emerged about 15 years ago and evolved to a great variety in human isolates Only sporadic cases reported of ESBL and AmpC in veterinary medicine in Europe No 4GC resistance in E.coli and Salmonella spp. in animals at slaughter The use of cefquinome for more than 10 years in Europe has not promoted the emergence of resistance in human medicine.