Protein That Could Help Fight Antibiotic Resistance

Investigators have found a protein called transthyretin or TTR which inhibits biofilm

Bacterial growth can lead to many serious problems but when they are on medical devices, it is hazardous to patient health. Medical devices may include knee implants, artificial hip implants, and catheters. A catheter is a flexible tube used for removing fluid from the body cavity particularly from the bladder. It is inserted through a narrow opening into the body cavity. In fact, a study was done in 2001 in which it was found that 95% of ill patients having urinary tract infections are due to the catheters.

Now, investigators at The Scripps Research Institute (TSRI) and the University of Michigan (U-M), have found the protein which helps in fighting this problem.  A biofilm is formed by the collection of bacteria on the surfaces of medical devices which protects them from sterilization or antibiotics. Bacteria produce a protein called amyloid which helps to hold biofilm together by scaffolding.

The researchers in their new study, led by Matthew Chapman, Ph.D., a U-M professor of molecular, cellular and developmental biology, and Joel Buxbaum, M.D., professor emeritus in the department of molecular medicine at TSRI found a protein called transthyretin or TTR which is produced in human. It inhibits the formation of amyloids hence suppressing the formation of biofilm. This study was done in particular strain of E.coli which is the most common cause of urinary tract infection in humans. These biofilms also provide the bacteria resistant to antibiotics.

“These biofilms both make bacteria resistant to antibiotics and resistant to many of the host responses, If you could target that resistance, the host may be able to clear the infection, or you could potentially prescribe lower doses of antibiotics or shorten the duration of antibiotic usage, which would all be good things.” said Chapman.

In urinary tract infection, a biofilm is formed because bacteria strain settles into bladder forming coat of amyloid fibers. These biofilms both make bacteria resistant to antibiotics and resistant to many of the host responses. To inhibit the formation of biofilms, amyloids should be degraded. TTR protein is mixed with amyloid for biofilm degradation which leads to inhibition of antibiotic resistance in bacteria.

“As a biologic phenomenon, it is interesting that humans and bacteria have evolved in such a way that both express molecules with structures similar enough to interact in a biologically significant manner, even though they have quite different functions in their hosts,” said Buxbaum.

The new study, “Inhibition of curli assembly and Escherichia coli biofilm formation by the human systemic amyloid precursor transthyretin,” also included authors from Umeå University.