Epidemiologie en mechanismen van Aspergillus resistentie Katrien Lagrou Gasthuisberg01mini SUCCESS HOST IMMUNE STATE LOCATION OF INFECTION/ MANAGEMENT OF INFECTION SOURCE DRUG SUSCEPTIBILITY PATHOGEN APPROPRIATE ANTIFUNGAL THERAPY TIMING APPROPRIATE DOSE SELECTION OF MOST POTENT AND SAFE DRUG PHARMACOKINETICS AND PHARMACODYNAMICS Future Medicine, 2011, 6, 1229-1232 Emerging azole resistance 1995 2000 2005 2010 2015 Itraconazole resistance in 2 cases Denning, AAC, 1997 Few sporadic resistant isolates in Sweden, Spain France and UK Many more resistant isolates in Nijmegen (7%) and Manchester (15-20%) Bueid, JAC, 2010 Verweij, NEJM, 2007;J. Van der Linden, EID, 2011 Resistant isolates in Denmark, Norway, Belgium, USA, China, Canada, India, … 5,8% resistance Artemis (mainly China) Lockhart S, AAC, 2011 4,5% resistance in CF patients Mortensen, JCM, 2011 Multi-azole resistance in A. fumigatus MIC itraconazole > 16 mg/L MIC voriconazole 2 - > 16 mg/L MIC posaconazole 0,5 – 1,0 mg/L Verweij P et al., N Engl J Med 2007;356:1481-1483 1945-1998 2002-2007 12% (10/81) 0% (0/170) Characteristics of nine patients from whom A. fumigatus resistant to multiple triazoles was cultured Verweij P et al., N Engl J Med 2007;356:1481-1483 Characteristics of nine patients from whom A. fumigatus resistant to multiple triazoles was cultured Verweij P et al., N Engl J Med 2007;356:1481-1483 Characteristics of nine patients from whom A. fumigatus resistant to multiple triazoles was cultured New mechanism of resistance in 12/13 isolates: L98H + TR J. Van der Linden et al, EID, Oct 2011 Prospective nationwide multicenter study 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% Azole resistance frequency in A. fumigatus 1997–2009 Bueid A et al. J. Antimicrob. Chemother. 2010;65:2116-2118 Prevalence of resistance = 8/569 = 1,4% Clinical characteristics UZ Leuven resistant isolates Patient Isolation-date Clinical characteristics UZ Leuven resistant isolates Patient Isolation-date Mutation analysis A: Male, 49 7-7-2009 BAL-fluid Pulmonary disease, corticosteroid therapy and SOT No ? >8 8 1 TR/L98H B: Male, 30 10-9-2009 Bronchial secretion CF No No >8 2 0.25 F46Y/G89/M172G/L358/C454 C: Male, 56 6-12-2009 Sputum Hemato-oncologic disease No No >8 2 0.5 TR/L98H D: Male, 69 20-01-2010 Sputum General internal disease, corticosteroid therapy Yes No >8 4 1 TR/L98H E: Male, 74 29-01-2010 BAL-fluid Pulmonary disease, corticosteroid therapy No ? >8 8 0.5 TR/L98H F: Male, 86 3-2-2010 BAL-fluid Pulmonary disease No No >8 8 1 TR/L98H G: Male, 73 3-2-2010 Bronchial secretion Pulmonary disease No No >8 4 1 TR/L98H H: Male, 63 4-2-2010 Biopsy Pulmonary disease, corticosteroid therapy and SOT VCZ Proven IA >8 8 0.5 TR/L98H Prevalence of reduced triazole susceptibility was 1.25% (3/240) Resistant isolates showed variable phenotypic and genetic profiles Lagrou et al., AAA 2008, Abstract 33 UZ Leuven study August 2006 - May 2007 240 A. fumigatus isolates (one isolate per patient) cultured from clinical samples Antifungal agent MIC breakpoint (mg/L) MIC breakpoint (mg/L) MIC breakpoint (mg/L) MIC breakpoint (mg/L) MIC breakpoint (mg/L) MIC breakpoint (mg/L) MIC breakpoint (mg/L) MIC breakpoint (mg/L) Antifungal agent fumigatus fumigatus flavus flavus niger niger A. terreus A. terreus S ≤ R > S ≤ R > S ≤ R > S ≤ R > Amphotericin B 1 2 1 2 - - Itraconazole 1 2 1 2 1 2 Voriconazole 1 2 Posaconazole 0,12 0,25 0,12 0,25 EUCAST Antifungal Clinical Breakpoints valid from Jan 2012 Same as Epidemiological cutoff values CLSI, J. Meletiadis et al, AAC, Feb 2012 Newsletter Aspergillus surveillance program Start: April 1ste, 2011 17 Aspergillus surveillance program 1/4/2011 – 01/02/2012 161 isolates from 143 patients 21% = IA, not classifiable with EORTC criteria Proven IA Probable IA Possible IA Unclassifiable IA - Histopathologic evidence of hyphae from needle aspiration or biopsy (with associated tissue damage) OR - Culture from normally sterile site, clinically and radiologically consistent with infection 1 EORTC Host criterium - neutropenia (<0.5 x 109/L for >10 d) - allo-HSCT - corticosteroids (>0.3 mg/kg for >3 w) - immunosuppressants* for >90 d - primary immunodeficiency 1 EORTC Host criterium EORTC host criterium, OR a clinical risk factor for IA: - ICU patients (COPD-patients, cirrhosis, solid organ malignancy, pancreatitis) - HIV - Histopathologic evidence of hyphae from needle aspiration or biopsy (with associated tissue damage) OR - Culture from normally sterile site, clinically and radiologically consistent with infection AND AND AND - Histopathologic evidence of hyphae from needle aspiration or biopsy (with associated tissue damage) OR - Culture from normally sterile site, clinically and radiologically consistent with infection 1 EORTC clinical criterium - Specific CT-lesions (halo, air-crescent, cavity) - Tracheobronchitis on bronchoscopy - Imaging showing sinusitis + black nasal eschar, acute localized pain or extension from the paranasal sinus across bony barriers - CNS infection: focal lesions on imaging or meningeal enhancement on MRI or CT 1 EORTC clinical criterium 1 EORTC- clinical criterium OR Pulmonary infiltrate or consolidation on RX without clinical response to broad spectrum antibiotics and without evidence for another etiology - Histopathologic evidence of hyphae from needle aspiration or biopsy (with associated tissue damage) OR - Culture from normally sterile site, clinically and radiologically consistent with infection AND WITHOUT AND - Histopathologic evidence of hyphae from needle aspiration or biopsy (with associated tissue damage) OR - Culture from normally sterile site, clinically and radiologically consistent with infection 1 EORTC Microbiological criterium - Culture, direct microscopy or cytology positive from BAL, bronchus aspirate, sputum or sinus aspirate - Galactomannan positive in BAL, serum or CSF 1 EORTC Microbiological criterium Microbiological criterium for IA - Aspergillus culture from BAL or bronchusaspirate - Galactomannan positive in BAL, serum or CSF - Histopathologic evidence of hyphae from needle aspiration or biopsy (with associated tissue damage) OR - Culture from normally sterile site, clinically and radiologically consistent with infection 1 EORTC Microbiological criterium - Culture, direct microscopy or cytology positive from BAL, bronchus aspirate, sputum or sinus aspirate - Galactomannan positive in BAL, serum or CSF 1 EORTC Microbiological criterium Note: If pulmonary disease progression is slow (months /years) in a patient who meets the criteria for “unclassifiable IA”, cases should be classified as chronic necrotisizing pulmonary aspergillosis (CNPA). These patients have specific serum Aspergillus Ab, in contrast to “acute” IA. Long-term therapy is warranted. A. fumigatus A. fumigatus A. fumigatus A. niger FUNGI DIFFER FROM BACTERIA WITH RESPECT TO THEIR TENDENCY TO DEVELOP RESISTANCE Selection: few a priori resistant species and strains exist which could be selected Mutation: Some fungi (e.g. C. albicans) are diploid No drug modifying enzymes are known in fungi Genetic transfer of resistance from one fungus to another does not occur! Comparison of resistance mechanisms operating in bacteria and fungi Comparison of resistance mechanisms operating in bacteria and fungi Comparison of resistance mechanisms operating in bacteria and fungi Resistance mechanism Bacteria Fungi Target modification Inhibition of target access (pores, pumps) Enzymatic modification/inactivation of antimicrobial compound Yes Yes Yes Yes Yes No MUTATION AZOLE RESISTANCE TARGET = lanosterol-14a-demethylase = product cyp51A and cyp51B gene Resistance is primarily linked to mutations in the Cyp51A gene Mutations in the Cyp51A promoter region: overexpression of the protein product Overexpression of efflux pumps described Scan10016.JPG Pan-azole resistant Pan-azole resistant Itraconazole Voriconazole Posaconazole Confirmed mutations L98H R R R Not yet confirmed S52T, G138C, G138R, Q141H, H147Y, Y431C, G434C, G448S R R R Itraconazole and posaconazole resistant Itraconazole and posaconazole resistant Itraconazole Voriconazole Posaconazole Confirmed mutations G54 mutations (G54E, G54K, G54R, G54V, G54W) M220 mutations (M220K, M220I, M220T, M220V) R R S Variable R R Not yet confirmed P216L, S297T, F495I R S R Itraconazole resistant Itraconazole resistant Itraconazole Voriconazole Posaconazole Not yet confirmed N22D, P394L, T440A, Y491H M236 mutations (M236K, M236T, M236V), G432S R R not reported S not reported S CYP51A mutations identified in azole-resistant isolates and their resistance patterns Vermeulen E et al., Acta Clinica Belgica, in press. Species Pathogenicity Susceptibility A. lentulus Reported as causative pathogen in invasive aspergillosis Case reports of colonization in cystic fibrosis - Reduced susceptibility to azole drugs - Reduced susceptibility to amphotericin B - Variable susceptibility to caspofungin. A. udagawae Reported as causative pathogen in invasive aspergillosis - Reduced susceptibility to voriconazole - Reduced susceptibility to amphotericin B N. pseudofisheri Reported as causative pathogen in invasive aspergillosis Case reports of colonization in cystic fibrosis - Reduced susceptibility to azole drugs - Variable susceptibility to amphotericin B A. fumigatiaffinis No clinical cases reported. - Reduced susceptibility to azole drugs - Reduced susceptibility to amphotericin B A. viridinutans Reported as causative pathogen in chronic invasive aspergillosis, with unusual clinical features - Reduced susceptibility to azole drugs - Reduced susceptibility to amphotericin B Intrinsic resistant species belonging to A. fumigatus ‘complex’ Aspergillus section Nigri comprises of several morphologically indistinguishable species A. awamori: 36% ITR® A. tubingensis: 90% ITR® A. niger: 33% ITR® A. acidus: 67% ITR® Unknown group ITR® Overall 51% itraconazole MIC ≥8 mg/L, clinical significance? Itraconazole resistance in the A. niger ‘complex’ Howard et al, AAC 2011, 55, 4802-4809 Development of azole resistance ‘In situ’ (in the lung) during treatment for acute invasive aspergillosis: highly unlikely unless the fungus undergoes asexual reproduction, for instance when the infection progresses to a cavitary lesion. in patients with aspergilloma or cavitary lung disease during long term treatment In the environment Resistentie ontwikkeling Aspergillus.jpg The risk of development of phenotypic resistance seems to be dependent on the mode of reproduction of the moulds Verweij PE et al., Lancet Infectious Diseases, 2009, 9: 789-795. Triazole fungicides septoria disease 2.jpg septoria disease.jpg Published March 1, 2012 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 Resistance to echinocandins/ amphotericin B Echinocandins: Little known about echinocandin resistance in Aspergillus, susceptibility testing is not routinely performed, technical difficulties, mechanisms not well understood Polyenes: Primary and secondary polyene resistance reported but generally considered a rare phenomenon No clear in vitro/in vivo correlation Aspergillus terreus: less ergosterol in membrane Clinical resistance Principal factors determining antifungal clinical resistance. Principal factors determining antifungal clinical resistance. Factor Implication Wrong diagnosis Weak diagnostics and/or IRIS Net state of immunosuppression Improvement in immunity of host is essential High burden of fungus at initiation of treatment Earlier treatment intervention improves outcome Strain acquisition of increased virulence Probably less of a problem than host factors but can be measured Pharmacokinetics and/or pharmacodynamics Drug toxicity, drug–drug interaction, drug levels Site of infection Drug penetration, tissue necrosis, foreign body Length of treatment and/or compliance Precision is not certain; patient and clinician may lose focus on long‐term drug administration Underlying disease Final arbitrator in most invasive mycoses http://www.journals.uchicago.edu/na102/home/ACS/publisher/uchic ago/journals/entities/2003.gif Kanafani and Perfect, CID, 2008: 46: 120-8. CONCLUSIONS Epidemiological characteristics continue to evolve, geographical differences: need for surveillance (species identification and susceptibility testing) We need diagnostics for sensitive detection of drug resistance We need therapeutic strategies to overcome existing resistance Novel dosing mechanisms? New drugs with novel mechanism of action