Nils Wetzstein1, Thomas A Kohl2, Sönke Andres3, Tilman G Schultze4, Ari Geil5, Eunhee Kim6, Teodora Biciusca6, Christian Hügel7, Michael Hogardt8, Annette Lehn9, Maria J G T Vehreschild5, Timo Wolf5, Stefan Niemann2, Florian P Maurer10, Thomas A Wichelhaus4. 1. Department of Internal Medicine, Infectious Diseases, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany. Electronic address: nils.wetzstein@kgu.de. 2. German Center for Infection Research, Research Center Borstel, Borstel, Germany; Molecular and Experimental Mycobacteriology, Research Center Borstel, Borstel, Germany; National and WHO Supranational Reference Center for Mycobacteria, Research Center Borstel, Borstel, Germany. 3. National and WHO Supranational Reference Center for Mycobacteria, Research Center Borstel, Borstel, Germany. 4. Institute of Medical Microbiology and Infection Control, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany. 5. Department of Internal Medicine, Infectious Diseases, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany. 6. Department of Radiology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany. 7. Department of Pneumology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany. 8. Institute of Medical Microbiology and Infection Control, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany; German National Consiliary Laboratory on Cystic Fibrosis Bacteriology, Germany. 9. Institute of Biostatistics and Mathematical Modeling, Goethe University, Frankfurt am Main, Germany. 10. National and WHO Supranational Reference Center for Mycobacteria, Research Center Borstel, Borstel, Germany; Institute of Medical Microbiology, Virology and Hospital Hygiene, University Medical Center Hamburg- Eppendorf, Hamburg, Germany.
Abstract
OBJECTIVE: Phenotypic (Sensititre Myco, pDST) and genotypic drug susceptibility testing (GenoType NTM DR, gDST) in M. avium complex (MAC) have become available as standardized assays, but comparable data is needed. This study aimed to investigate the phenotypic and genotypic drug susceptibility patterns in MAC clinical isolates. METHODS: Overall, 98 isolates from 85 patients were included. pDST and gDST were performed on all isolates and results compared regarding specificity and sensitivity using pDST as a reference method. The impact of drug instability on pDST results was studied using a biological assay over 14 days. In addition, the evolution of antimicrobial resistance was investigated in sequential isolates of 13 patients. RESULTS: Macrolide resistance was rare, 1.2% (95% CI 0.7-7.3) of isolates in the base cohort. No aminoglycoside resistances were found, but 14.1% of the studied isolates (95% CI 7.8-23.8) showed intermediate susceptibility. The GenoType NTM DR identified two out of four macrolide-resistant isolates. Antibiotic stability was demonstrated to be poor in rifampicin, rifabutin, and doxycycylin. CONCLUSIONS: pDST results in NTM for unstable antibiotics must be interpreted with care. A combination of pDST and gDST will be useful for the guidance of antimicrobial therapy in MAC-disease.
OBJECTIVE: Phenotypic (Sensititre Myco, pDST) and genotypic drug susceptibility testing (GenoType NTM DR, gDST) in M. avium complex (MAC) have become available as standardized assays, but comparable data is needed. This study aimed to investigate the phenotypic and genotypic drug susceptibility patterns in MAC clinical isolates. METHODS: Overall, 98 isolates from 85 patients were included. pDST and gDST were performed on all isolates and results compared regarding specificity and sensitivity using pDST as a reference method. The impact of drug instability on pDST results was studied using a biological assay over 14 days. In addition, the evolution of antimicrobial resistance was investigated in sequential isolates of 13 patients. RESULTS:Macrolide resistance was rare, 1.2% (95% CI 0.7-7.3) of isolates in the base cohort. No aminoglycoside resistances were found, but 14.1% of the studied isolates (95% CI 7.8-23.8) showed intermediate susceptibility. The GenoType NTM DR identified two out of four macrolide-resistant isolates. Antibiotic stability was demonstrated to be poor in rifampicin, rifabutin, and doxycycylin. CONCLUSIONS: pDST results in NTM for unstable antibiotics must be interpreted with care. A combination of pDST and gDST will be useful for the guidance of antimicrobial therapy in MAC-disease.
Authors: Nils Wetzstein; Thomas A Kohl; Tilman G Schultze; Sönke Andres; Carla Bellinghausen; Christian Hügel; Volkhard A J Kempf; Annette Lehn; Michael Hogardt; Hubert Serve; Maria J G T Vehreschild; Timo Wolf; Stefan Niemann; Florian P Maurer; Thomas A Wichelhaus Journal: J Clin Microbiol Date: 2020-11-18 Impact factor: 5.948
Authors: Alice Natanti; Marco Palpacelli; Marco Valsecchi; Adriano Tagliabracci; Mauro Pesaresi Journal: Int J Legal Med Date: 2021-06-29 Impact factor: 2.686