Gram-negative bacteria such as those responsible for salmonella, meningitis, heliobacter, legionella, gonorrhea, and cholera cause debilitating diseases and death in people who become infected.
Worryingly, these bacteria are building ever stronger defenses against our stocks of antibiotic drugs. At some stage, they will become totally resistant to our existing drugs. When this happens, we will enter a nightmarish world in which minor cuts and infections could quickly become fatal.
Gram-negative bacteria have a lipopolysaccharide outer coating whose impermeability assists the bugs in fending off attacks from antibiotics. You could think of this coating as full body-armor.
This coating is called LPS, consisting of lipid A, core polysaccharide, and O antigen. It has been growing increasingly impermeable as bugs follow an evolutionary pathway to defeat our antibiotics. The armor is getting very strong.
The journal Nature has reported that medical researchers from the University of East Anglia’s Norwich Medical School in the United Kingdom have found a way to block the pathway the bacteria use to put this outer coating together. One of the lead researchers commented:
‘This is a giant leap forward in the fight against superbugs. This discovery doesn’t come a moment too soon.’
Researchers have discovered that a protein called LptDE is vital in building the bacteria’s LPS outer coating of armor. They are excited by the fact that the same mechanism is used in all gram-negative bacteria.
This means, if you can find a way to disrupt the LPS outer coating being built in one type of gram-negative bacteria, it should work in all such bacteria.
The preferred method of disruption is to find a drug molecule smaller than the LptDE protein that builds the coating. Importantly, this drug molecule would not need to get inside a bacterial cell to disrupt the building of the cell coating.
The weakened cell coating would allow bugs to be attacked more easily both by our immune cell and antibiotic drugs.
Another aspect that makes the work so vital is that it offers a method which can potentially overcome the new strains of superbugs which are causing serious problems in many hospitals. Too many patients are getting ill in the hospitals where they are meant to get better.
Health experts have said that within a decade or two, routine surgical operations could lead to a large number of deaths, because of widespread, untreatable infections. It would be a return to the days when there were no antibiotics and life was something of a lottery.
The work on disrupting the LPS coating is at an early stage, but it’s encouraging that a viable route has now been identified so that we can continue taking the fight to our microscopic enemies.