(Image from Eye of Science/Science Source)

Upon scanning through articles picked out by the algorithm within the different topics, various alternative concepts captured my attention mainly due to their unusual approaches. I believe these deserve mentioning, in order to keep our minds open to ideas beyond the conventional approaches in the field.

Plant compounds against MDR-TB

Celastrus vulcanicola

One small area identified in topic modelling involves the investigation of plant extracts utilized in traditional medicine in the killing of drug-resistant TB strains in vitro. As an example, Jimenez-Arellanes et al. screened a group of 22 plants used in Mexican traditional medicine to treat respiratory diseases for activity against MDR-TB and found some extracts with potent activity against MDR-TB clinical isolates. In another study, sesquiterpenes isolated from the leaves of the plant Celastrus vulcanicola were found to exhibit activity against an MDR-TB strain comparable to isoniazid or rifampicin.

Phage therapy to enhance antibiotic activity

Bacteriophages (green) attacking a bacterium (orange). Credit: Graham Beards

Phage therapy is making a comeback in the era of antibiotic resistant bacteria and is currently being tested against common bacterial pathogens such as S.aureus, E. coli and P. aeruginosa. In the case of TB, Li et al. demonstrated that when a mycobacteriophage infected a mycobacterium, it resulted in the bacterial cell becoming more susceptible to multiple antibiotics. This result led the authors to speculate that the application of phage therapy could include its use as a broad-spectrum antibiotic adjuvant in drug-resistant cases.

Photodynamic therapy against MDR and XDR-TB


Schematic illustration of photodynamic therapy. The production of reactive oxygen species (ROS) results in bacterial death. Credit: Dai et. al, 2012.

One of the more unusual concepts came from a study that tested the effects of photodynamic therapy on MDR and XDR-TB clinical strains in vitro. Sung et al. found that exposure to photosensitizers followed by irradiation with various doses of laser light inactivated M.tb strains, irrespective of drug resistance levels of the bacilli. Photodynamic therapy is not a fringe science, and has been FDA approved for use in cancer therapy. Although the research by Sung et al. was published in a low impact journal, its cross-disciplinary spirit should set an example for others to follow in the field of MDR-TB research.