Zosurabalpin: New antibiotic identified to target a drug-resistant bacterium

Source: This post is based on the article “New antibiotic identified to target a drug-resistant bacterium” published in “The Hindu” on 4 January 2024.

Why in news?

Researchers have identified a new class of antibiotics called ‘Zosurabalpin’ with the potential to tackle a drug-resistant bacterium, Acinetobacter baumannii.

What is Zosurabalpin?

1) Zosurabalpin is an antibody that is effective against CRAB (carbapenem-resistant Acinetobacter baumannii)-induced pneumonia and sepsis in mouse models.

2) Scientists identified a tethered macrocyclic peptide (MCP) that selectively kills A. baumannii which was further optimised for efficacy and tolerability, resulting in zosurabalpin.

3) The antibiotic kills A. baumannii through a previously unknown mode of action. It inhibits the transport of the molecule lipopolysaccharide (LPS) by inhibiting a complex of proteins.

4) This complex was essential for transporting LPS to the bacterial surface to create the outer-membrane structure of Gram-negative bacteria. However, the blocking of the LPS transport results in an abnormal build-up of LPS in the cell which kills the bacterium.

5) The antibiotic demonstrated efficacy against over 100 clinically tested samples of CRAB in the laboratory.