Anti-TB drugs may not prevent reinfection: study

Category: Health published by Shameen published: March 24, 2019, 22:55 EST Update: March 24, 2019, 22:55 EST

Toronto: Antibiotic drugs have been shown to alter intestinal microbiota and increase susceptibility to Mycobacterium tuberculosis (Mtb), a leading reason why current treatments do not prevent re-infections.

The study showed that chronic use of antibiotics controlled tuberculous infection, but also resulted in disturbance of the gut microbiota. This, in turn, leads to a deregulation of the immune system, causing reinfection.

"TB treatments have been incredibly effective at tackling the TB epidemic by reducing the morbidity and mortality badociated with Mtb," said Irah King of McGill University in Canada.

"This study provides a foundation for new therapeutic strategies exploiting the intestinal-lung axis in Mtb infection," added King.

For the study, the researchers treated the mice with the most commonly used anti-TB drugs – isoniazid, rifampicin and pyrazinamide – for a period of eight weeks.

The results, published in the journal Mucosal Immunology, showed that, although the three drugs significantly altered the composition of the mouse intestinal microbiome, only mice treated with isoniazid badociated with pyrazinamide showed an increased vulnerability. to infection with Mtb due to compromised intestinal microbiota.

The researchers transplanted feces from mice treated with antituberculous drugs (particularly isoniazid and pyrazinamide) into untreated mice before infection and showed that fecal transplantation was sufficient to compromise the infection. immunity to Mtb.

In addition, the team found that after antituberculous treatment, alveolar macrophages – a type of immune cell located in the respiratory tract of mice and humans – were compromised in their ability to kill Mtb.

"We need to do more research to understand how the microbiome affects alveolar macrophages because these cells are essential for controlling early infection with TB," said King.

"We must also identify the molecular pathways involved in the gut-lung axis."

According to the World Health Organization, tuberculosis is one of the top 10 causes of death in the world.

In 2017, 10 million people contracted tuberculosis and 1.6 million died (including 0.3 million among HIV-positive people).

The infection also killed 230,000 children (including children with HIV-badociated TB) in 2017.

Source: IANS