with Cefepime Meropenem and Ceftazidimeavibactam Generate Diverse Resistance Mechanisms Mariana Castanheira Jill Lindley Brieanna M Roth Timothy B Doyle Andrew P Davis Helio S ID: 1019456
Download Presentation The PPT/PDF document "In Vitro Selection of Enterobacter clo..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
1. In Vitro Selection of Enterobacter cloacae with Cefepime, Meropenem, and Ceftazidime-avibactam Generate Diverse Resistance MechanismsMariana Castanheira, Jill Lindley, Brieanna M. Roth, Timothy B. Doyle, Andrew P. Davis, Helio S. Sader1JMI Laboratories, North Liberty, IowaIDWeek 2020 ⏐ Presentation: 26
2. Achaogen AllecraAllerganAmplyxAntabio Arietis Corp.Arixa PharmaceuticalsAstellas PharmaAthelas Basilea Bayer Boston PharmaceuticalsCidara CorMedix DePuy SynthesDestiny PharmaDiscuva Ltd.Dr. Falk Pharma GmbHEmery Pharma Entasis TherapeuticalsEurofarma Brasil Fox Chase ChemicalDiversity Center, Inc. Gateway Pharmaceutical GenePOC Inc.Geom Therapeutics, Inc. GSK Harvard UniversityHelperby HiMedia LaboratoriesF. Hoffmann-La RocheJanssen ICON plcIdorsia PharmaceuticalsIterum TherapeuticsLaboratory SpecialistsMelinta TherapeuticsMerck Microchem LaboratoryMicromyxMicuRx PharmaceuticalsMutabilis Co. Nabriva Pocared PTC Therapeutics Rempex Novartis NAEJA-RGMParatek Pfizer PolyphorProkaryotics IncQpex BiopharmaRa PharmaceuticalsRoivant SciencesShionogi Spero TherapeuticsSummit Pharmaceuticals SynlogicTaisho PharmaceuticalTenNor Therapeutics Tetraphase The Medicines Co. Theravance VenatoRX Vyome TherapeuticsWockhardtYukon Pharmaceuticals Zai LabZavante Therapeutics Disclosure
3. E. cloacaeEnterobacter cloacae causes a variety of human infectionsThis organism was included in the ESKAPE pathogen list due to its ability to cause serious infections and develop resistance during treatment Acquired β-lactamases are not the most common β-lactam resistance mechanism in E. cloacaeDavin-Regli et al., CMR, 2019Davin-Regli et al., CMR, 2019Boucher et al., CID, 2009
4. β-lactam resistance in E. cloacaeDavin-Regli et al., CMR, 2019Important contributors to β-lactam resistance, alone and in combination, are:Overexpression of the constitutive AmpCOuter membrane mutations decreasing β-lactams permeabilityIncreased effluxESBLs and carbapenemases encoding resistance have been described in this species
5. Due to resistance to many β-lactam agents, cefepime and carbapenems have been used for treatment of E. cloacae infectionsThe increased use of carbapenems to treat infections caused by E. cloacae could have generated higher resistance levels in this speciesE. cloacae is the second most common carbapenem-resistant Enterobacterales (CRE; data from the SENTRY Program)Most CR-E. cloacae isolates do not produce carbapenemasesTreatment of E. cloacae infectionsDavin-Regli et al., CMR, 2019
6. Ceftazidime-avibactamCeftazidime-avibactam is approved by the United States Food and Drug Administration (US FDA) and by the European Medicine Agency (EMA)Avibactam restores the activity of ceftazidime in the presence of Ambler class A (ESBLs and KPC), class C (AmpC), and some class D (OXAs) enzymesComplicated urinary tract infections, including pyelonephritis Complicated intrabdominal infections with metronidazoleHospital acquired pneumonia
7. Objective We subjected 6 E. cloacae isolates to 10-day serial passage with cefepime, meropenem, and ceftazidime-avibactam to evaluate resistance level and mechanism in the mutant strains
8. MethodsBaseline and mutant isolates were susceptibility tested by reference broth microdilution (CLSI; M07, 2018) against cefepime, meropenem, and ceftazidime-avibactam (inhibitor at 4 mg/L)CLSI M7Ed10, 2018Serial passaging was performed in broth microdilution by inoculating the highest growth well from the broth microdilution panels into new panelsColonies growing in the highest antimicrobial concentrations were submitted to short-read whole genome sequencing (WGS) on a MiSeq (Illumina, San Diego, California, USA) and analyzed for -lactam resistance mechanisms-lactam resistance genesAmpCAmpRAmpDOmpCOmpFAcrAAcrBTolCMarAMarBMarRRamARamRCsrARobASoxS
9. MethodsFinal mutants displaying >2-fold changes from the baseline and baseline isolates were sequenced using a long-read technology in a MinIOn (Nanopore, Oxford, UK)FASTQ files generated using short and long reads were combined and used for single nucleotide polymorphism (SNP) analysisSNPs determined by MAUVE independently and mapped using BWA Variant call format (VCF) file had minimum read depth of 4X, >30 map quality, >50 average base quality, no significant strand bias, and >75% of mutations within reads to support the presence of any given alterationIndels and uncovered regions were identified using nucDiff (https://omictools.com/nucdiff-tool)
10. MIC (mg/L)ECL IsolateMeropenemCeftazidime-avibactamCefepimeResistance genes#10.030.50.5act-18, aph(6)-Ia#20.030.250.25act-17, fosA#30.030.250.5act-41-like, aadA2, sul1#40.060.50.5act-15-like, aph(6)-Ia#50.060.50.25act-12-like, fosA#60.030.250.25cmh-3-like, aph(6)-Ia, aph(6)-Id Results
11.
12.
13. Fold change for Meropenem MIC results andE. cloacae isolatesDay#1#2#3#4#5#6MedianModeGeo Mean1111111111.02111421111.43222442222.542421644444.052423244444.568443248647.17841664488810.1816416128416161614.3932416128832243220.2103281612886424825.4
14. Fold change for Ceftazidime-avibactam MIC results and E. cloacae isolatesDay#1#2#3#4#5#6MedianModeGeo Mean1111111111.02221221221.63221222221.84221222221.85241422222.26442422342.87842422323.28842822323.6932821622525.7103282822525.0
15. Fold change for Cefepime MIC results andE. cloacae isolatesDay#1#2#3#4#5#6MedianModeGeo Mean1111111111.02424822323.23844824444.548443284647.158446488889.06844641688810.17832412816812816.08323241281616243222.69643241281616241625.410323241281616243222.6
16. MIC Fold change for E. cloacae isolatesMeropenemCeftazidime-avibactamCefepimeDayMedianModeGeo MeanMedianModeGeo MeanMedianModeGeo Mean2111.4221.6323.23222.5221.8444.54444.0221.8647.15444.5222.2889.06647.1342.88810.178810.1323.212816.08161614.3323.6243222.69243220.2525.7241625.41024825.4525.0243222.6
17. SNP analysis
18. Conclusions Meropenem (range 8 to 128-fold; median 24) and cefepime (4 to 128-fold; median 24) mutants had higher MIC values compared to ceftazidime-avibactam (range 2 to 32; media 5)Two isolates had multiple alterations in each of the sequenced mutantsMutations in the genes encoding AmpC, OmpC, and efflux regulators were observed in ceftazidime-avibactam and meropenem, meropenem and ceftazidime-avibactam, and cefepime mutants3 of the 6 isolates had mutations in various genes that have not been described in relation to antimicrobial resistance and have roles in cell division, transcription regulation, RNA folding, and efflux
19. Conclusions This study suggests that exposure to cefepime and meropenem could generate isolates with elevated MIC values for these agents in 6 genetically distinct E. cloacae clinical isolatesThese high MICs were not observed with ceftazidime-avibactamTherapies that prevent the emergence of resistance could reduce the burden of antimicrobial resistance and should be part of stewardship efforts to control this problem
20. Acknowledgements This study was sponsored by Abbvie
21.