The zebrafish model of tuberculosis - no lungs needed

Tuberculosis is still a global health burden. It is caused by Mycobacterium tuberculosis which afflicts around one third of the world's population and costs around 1.3 million people their lives every year. Bacillus Calmette-Guerin vaccine is inefficient to prevent overt infection. Additionally, the lengthy inconvenient course of treatment, along with the raising issue of antimicrobial resistance, result in incomplete eradication of this infectious disease. The lack of proper animal models that replicate the latent and active courses of human tuberculosis infection remains one of the main reasons behind the poor advancement in tuberculosis research. Danio rerio, commonly known as zebrafish, is catching more attention as an animal model in tuberculosis research field. This shift is based on the histological and pathological similarities between Mycobacterium marinum infection in zebrafish and Mycobacterium tuberculosis infection in humans. Being small, cheap, transparent, and easy to handle have added further advantages to the use of zebrafish model. Besides better understanding of the pathogenesis of tuberculosis, Mycobacterium marinum infected zebrafish model is useful for evaluating novel vaccines against human tuberculosis, high throughput small molecule screening, repurposing established drugs with possible antitubercular activity, and assessing novel antituberculars for hepatotoxicity.