Agricultural triazole fungicides should be withdrawn – PRO Katrien Lagrou , PharmD , PhD

1. Agricultural triazole fungicides should be withdrawn – PROKatrien Lagrou, PharmD, PhD University Hospitals Leuven and KU Leuven, BELGIUM

2. Emerging environmental azole resistance Few sporadic resistant isolates in Sweden, Spain, France and UK • Series of Dutch patients – including azole naïve patients- with invasive aspergillosis due to pan-azole-resistant strains • Resistance attributed to one predominant resistance mechanism, TR34/L98H • Verweij, NEJM 2007 Isolates with TR34/L98H reported from Denmark, Norway, Belgium, UK, Spain, France, Germany, Italy, China, India and Iran Itraconazole resistance in 2 cases Denning, AAC 1997 1995 2000 2005 2010 2015

3. Emerging environmental azole resistance • New environmental CYP51A-mediated resistance mechanism in the Netherlands, TR46/Y121F/T289A associated with voriconazole therapy failure • High-grade voriconazole resistance, variable itraconazole MICs • Van der Linden, CID 2013 Isolates with TR46/Y121F/T289A reported from Belgium, India and Germany 1995 2000 2005 2010 2015

4. Routes of resistancedevelopment Triazole fungicides in agriculture ENVIRONMENT TR34/L98H TR46/Y121F/T289A PATIENT Long-term triazole treatment for aspergilloma or cavitary lungdisease Variety of resistancemechanisms

5. TR34/L98H %agricultural fungicide use TR46/Y121F/T289A 37% 9% 24% 22% CR Stensvold et al. CurrFungal Infect Rep 2012, 6: 141-153.

6. Most identical docking with medical triazoles 1998: first TR34/L98H isolate cultured Evolution analysis of microsatellite genotypes: TR34/L98H developed from a single ancestor that emerged around 1997 PublishedMarch 1, 2012

7. Clinical implications of azole resistance in A. fumigatus • Prospective nationwide multicenter study (2007-2009) • 2062 isolates from 1385 patients • Prevalence itraconazole resistance in A. fumigatus = 5,3 % • Patients with hematologic or oncologic disease more likely to harbor azole resistant isolate • 64% azole naive • Case fatality rate 88% J. Van der Linden et al, EID 2011, 17: 1846-1854.

8. People affected worldwide by A. fumigatus D. Denning and P. Bowyer, CID 2013, 57: 521-523.

9. Stockholm, February 2013

10. Evidence for the environmental route • Azole resistance observed in azole naïve patients. • No isogenic isolates with a wild-type phenotype has been recovered from patients infected with an Aspergillus isolate with TR34/L98H or TR46/Y121F/T289A. • Dominant resistance mechanisms with two or three genomic changes. • Isolates with the same resistance mechanisms are found in the environment. • Several triazole fungicides used in agriculture have a similar molecular structure to medical triazoles.

12. Nucleic acids synthesis

13. Mitosis and cell division

14. Respiration

15. Amino acids and protein synthesis/ Signal transduction

16. Lipid synthesis and membrane integrity

17. Sterol synthesis in membranes

18. Cell wall biosynthesis/melanin synthesis in cell wall

19. Host plant defense induction

20. Unknown mode of action

21. Azole resistance: also a problem in agriculture!

22. Antifungal agents available to treat invasive fungal infections X

23. High degree of correlation between ISA and VORI MICs. L. Gregson et al., AAC 2013, 57: 5778-5780

24. Problems – problems – problems ….. • Isolate is only available in about 50% of patients for susceptibility testing. • Triazole resistance severely limits treatment options. • Treatment of central nervous system aspergillosis: better outcome with voriconazole compared to other drugs. (Schwartz et al., Blood, 2005, 106: 2641-2645). • Treatment of chronic Aspergillus diseases: azoles are only class that can be administered orally. • Pan-azole resistance or voriconazole highly resistant. • Resistant isolates with cyp51A mutations are not less virulent. • New resistant mechanisms evolve and spread.

25. Withdraw agricultural triazole fungicides before resistance in Aspergillus is widespread