Antibiotic Resistance Crisis:
Extensive antibiotic use has led to a rise in antibiotic-resistant bacteria and microorganisms.
In 2021, ~1.2 million global deaths were attributed to antimicrobial resistance.
Indian hospital surveys show a 13% mortality rate for infections with drug-resistant bacteria.
The search for new antibiotics is a high-priority research area.
Antibiotics and Bacterial Cell Walls:
Antibiotics target bacteria without harming human cells.
Bacterial cells have unique cell walls made of peptidoglycan, a substance absent in human cells.
Peptidoglycan consists of glycan chains (NAG and NAM sugars) linked by peptide crosslinks.
This unique structure is a key target for antibiotic development and is recognized by the immune system.
Penicillin works by interfering with the crosslinking of peptidoglycans, weakening the cell wall.
Bacterial Resistance Mechanisms:
Bacteria evolve resistance by producing enzymes (e.g., penicillinase) that break down antibiotics.
They can also modify the antibiotic's target sites.
Bacterial Cell Division and Wall Synthesis:
Bacterial infection requires rapid cell division, dependent on cell wall synthesis.
Cell division involves adding new cell wall material.
Enzymes called endopeptidases and lytic transglycosylases (LTs) are crucial for breaking and reforming bonds in the existing wall to allow for growth and division.
Recent Research and Future Directions:
Dr. Manjula Reddy's group at CCMB studies bacterial cell division mechanisms.
Their research has shown that bacteria can compensate for the loss of crosslink-cutting enzymes by increasing the production of chain-cutting LT enzymes.
These findings contribute to understanding bacterial survival and may lead to new strategies for combating bacterial infections.
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