[Accepted Manuscript] Evaluation of OMNIgene ® •SPUTUM reagent for mycobacterial culture.

Zallet, J.; Olaru, I.D.; Witt, A.K.; Vock, P.; Kalsdorf, B.; Andres, S.; Hillemann, D.; Kranzer, K.; (2018) [Accepted Manuscript] Evaluation of OMNIgene ® •SPUTUM reagent for mycobacterial culture. The international journal of tuberculosis and lung disease. ISSN 1027-3719 DOI: https://doi.org/10.5588/ijtld.17.0020

Abstract

: National Mycobacterium Reference Laboratory, Borstel, Germany. : To evaluate the effectiveness of OMNIgene®•SPUTUM (OM-S) reagent in comparison with a method using N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH) with regard to mycobacterial recovery and contamination of broth and solid cultures. : Sputum samples from patients with tuberculosis and other respiratory diseases underwent decontamination with NALC-NaOH-based (MycoDDR™) or OM-S reagent. The decontamination procedure was assigned by block randomisation. Samples were inoculated on Löwenstein-Jensen, Stonebrink and MGIT™ (Mycobacterial Growth Indicator Tubes). Mycobacterial recovery from samples spiked with Mycobacterium tuberculosis following decontamination was determined. : Eighty-five samples were randomised to NALC-NaOH and 84 to OM-S reagent. Mycobacterial recovery was significantly lower for samples processed with OM-S reagent compared with the NALC-NaOH method across all media types. Culture contamination was lower with NALC-NaOH reagent on solid media (9.4-12.9% vs. 28.6-29.8%). Growth was not observed in MGIT among samples spiked with 10 600-16 800 colony-forming units of M. tuberculosis following decontamination with OM-S reagent. : Low mycobacterial recovery, especially in MGIT, observed in the present study suggests that OM-S reagent might not be compatible with the MGIT system. More extensive field evaluations of the OM-S reagent are warranted to demonstrate a significant benefit over currently used methods.