Breaking through superbugs' defensive barrier might be a more sound strategy than killing the bacteria directly — and scientists in the United Kingdom have revealed the process by which this works.
The discovery of University of East Anglia (UEA) researchers could usher in the development of drugs against antibiotic-resistant bacteria, which has become a global health emergency by causing hundreds of thousands of deaths every year.
The team probed a kind of bacteria known as Gram-negative bacteria through a scientific machine called Diamond Light Source. Diamond creates intense light that lets researchers investigate materials in such atomic detail.
Gram-negative bacteria are specifically antibiotic-resistant due to their cells' impermeable lipid-based outer membrane. This membrane serves as a defense mechanism against attacks from humans' immune system as well as the invasion of antibiotic medication, allowing the pathogen to survive.
To remove this barrier means to render the bacteria more vulnerable to weakness and death.
The Gram-negative bacteria boasts of a beta-barrel assembly machinery (BAM), which is responsible for beta-barrel proteins or gates form and bringing crucial nutrients and biological molecules in the cell wall.
What then is this powerhouse's Achilles heel?
"Stopping the beta-barrel assembly machine from building the gates in the cell wall cause the bacteria to die," said lead researcher and UEA professor Changjiang Dong.
The researchers analyzed E. coli's BAM, which contains five sub-units namely BamA to BamE, to know how the sub-units insert proteins into bugs' cell wall. They discovered that the five sub-units create a ring system, undertaking protein insertion through a new rotation and insertion technique.
Sub-unit BamA, explains the lead researcher, is a great target for next-generation drugs since it is exposed to and located in the bacteria's outer side.
In the mitochondria of humans, a similar network called the sorting and assembly machinery complex (SAM) is tasked to build the proteins in the outer membrane. Dysfunction of these proteins may lead to issues including diabetes, Parkinson's disease and other neurodegenerative conditions.
Thus exploring this mechanism also holds promise for understanding the link of human cell problems to the said disorders.
The findings were published in the journal Nature.
However, until scientists are able to take down these bacterial walls, doctors suggest protecting one's self from superbugs by avoiding the consumption of antibiotic-laced food, as well as taking antibiotic medication judiciously. Personal hygiene like regular and thorough hand washing, along with washing and cooking food properly, are other key steps.
Photo: NIAID | Flickr
