Comparison of methods available for identification of Mycobacterium chimaera

E. Lécorché (1, 2, 3) , S. Haenn (4) , F. Mougari (1, 2, 3) , S. Kumanski (2, 3) , N. Veziris (3, 5) , H. Benmansour (3, 2) , L. Raskine (3, 2) , Laurent Moulin (4) , E. Cambau (1, 3, 2) , A. Aubry (3, 2) , F. Brossier (3) , A. Chauffour (3) , J. Jaffre (3) , V. Jarlier (3) , J. Robert (3) , W. Sougakoff (3)

1 IAME (UMR_S_1137 / U1137) - Infection, Anti-microbiens, Modélisation, Evolution
2 Service de Bactériologie [CHU Lariboisière]
3 CHU Pitié-Salpêtrière [AP-HP]
4 Eau de Paris
5 CIMI - Centre d'Immunologie et de Maladies Infectieuses

Objectives: Mycobacterium chimaera is a recently described nontuberculous mycobacterium belonging to the M. avium complex (MAC). Because this species is implicated in a worldwide outbreak due to contaminated heater-cooler unit water tanks during open-heart surgery, it becomes mandatory for clinical microbiology laboratories to be able to differentiate M. chimaera from the other MAC species, especially M. intracellulare. Such identification was so far restricted to specialized laboratories, since it required the analysis of several gene sequences. The aim of this study was to evaluate commercialized methods for identifying M. chimaera with regard to the reference gene sequencing ITS, the internal transcribed spacer 16-23S. Methods: 47 clinical and environmental isolates including 41 MAC were identified using (i) PCR sequencing of the ITS gene and of the hsp65 gene, (ii) three molecular biology kits (INNO-LiPA Mycobacteria, GenoType Mycobacterium CM and GenoType NTM-DR), and (iii) matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDITOF MS) using MicroFlex software. Results: There was a high concordance for species determination between the reference ITS sequencing and the GenoType NTM-DR test (39/41, 95%), the INNO-LiPA test (38/41, 93%) and the hsp65 sequencing (38/41, 93%). The GenoType CM test did not distinguish M. chimaera from M. intracellulare. MALDI-TOF MS distinguished two M. chimaera - M. intracellulare groups separated from M. avium and from the other mycobacterial species on a score-oriented dendrogram, but did not differentiate the two species either. Conclusions: This study showed that INNO-LiPA and Genotype NTM-DR are efficient assays for M. chimaera identification in clinical microbiology laboratories.

Domaines: Biologie moléculaire; Génomique, Transcriptomique et Protéomique [q-bio.GN]; Interactions entre organismes; Santé; Bactériologie; Virologie; Protistologie; Parasitologie; Ecotoxicologie; Génie des procédés; Interactions cellulaires [q-bio.CB]; Bio-Informatique, Biologie Systémique [q-bio.QM]

E. Lécorché, S. Haenn, F. Mougari, S. Kumanski, N. Veziris, et al.. Comparison of methods available for identification of Mycobacterium chimaera. Clinical Microbiology and Infection, 2018, 24 (4), pp.409 - 413. ⟨10.1016/j.cmi.2017.07.031⟩. ⟨hal-01845213⟩