Sandwich antibody-based biosensor system for identification of Mycobacterium tuberculosis complex and nontuberculous mycobacteria

ABSTRACT

Mycobacterial infection, leading to pulmonary disease, remains a world health problem. Clinical symptoms of pulmonary disease caused by Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM) are very similar. A rapid method for the differentiation of MTBC and NTM infection is essential for appropriate therapy. In this study, we aim to establish an antibody-based biosensor system for the identification of MTBC and NTM infection. Monoclonal antibodies (mAbs) specific for Ag85B proteins of mycobacteria were generated and characterized. The generated anti-Ag85B mAb clones AM85B-5 and AM85B-8 reacted to Ag85B of Mycobacterium spp.; in contrast, clone AM85B-9 specifically reacted to Ag85B of MTBC. By employing the produced mAbs, single and sandwich antibody-based biosensors using bio-layer interferometry were established for determination of Ag85B proteins. The sandwich antibody-based biosensor system was demonstrated to be suitable for detection of Ag85B protein and identification of MTBC and NTM. Using anti-Ag85B mAbs AM85B-8 and AM85B-9 as immobilized antibodies on sensor chips and using mAb AM85B-5 as secondary antibody, the established sandwich antibody-based biosensor could discriminate MTBC and NTM. The developed biosensor system can be used for culture confirmation of mycobacteria and speciation to MTBC and NTM.

KEYWORDS:

• Tuberculosis
• Ag85B
• Mycobacterium tuberculosis complex
• nontuberculous mycobacteria
• antibody-based biosensor

Acknowledgments

We thank Mr. Anton Bassel, a native English speaker, for providing manuscript review.

Conflict of Interests

No conflict of interest declared.

Additional information

Funding

This study was supported by the Thailand Research Fund (TRF) (RGU6180003), the TRF Senior Research Scholar (RTA5980007), the TRF and the Thailand Office of Higher Education Commission (MUA-New Researcher Grant: MRG6080269 (SP) and MRG6180253 (WL)), partially supported by Chiang Mai University (Chiang Mai University Center of Excellence Project) and the Innovation Hubs of Thailand 4.0 project (in collaboration of Chiang Mai University and Mahidol University). KC is a doctoral candidate of the Royal Golden Jubilee Ph.D. program (PHD/0111/2561). SS is a post-doctoral fellowship supported by Chiang Mai University.