Investigate the resistance power of a hospital superbug

Microscopic images of Acinetobacter show a healthy bacterial cell with no colistin treatment on the left, then with colistin treatment, and a third with a disintegrated cell after exposure to higher level colistin treatment. Credit: Flinders University

The treatment of serious infections caused by pathogenic bacteria relies on “last resort” antibiotics, but the growing resistance of “superbugs” to most clinically approved drugs puts patients at risk of possible death.

Flinders University researchers are focusing on how bacterial cells adapt and resist antimicrobial drugs – with a new paper looking at the hospital strain of Acinetobacter baumannii and its cellular response to colistin, an important antibiotic.

The World Health Organization names antibiotic resistance as one of the biggest threats to global health, food security and development, with a growing number of infections, including pneumonia, tuberculosis, gonorrhea and salmonellosis, becoming more difficult to treat as the antibiotics used to treat them become less common. efficient.

Antibiotic resistance leads to longer hospital stays, higher medical costs and increased mortality, researchers warn.

“Around the world, there are fewer and fewer new antibiotics identified and produced for medical use, and this is compounded by the growing antibiotic resistance seen in bacterial strains causing infections,” says Dr Sarah Giles, microbial researcher at Flinders.

“If we can understand bacterial mechanisms, like this, we can potentially apply new therapies to treat patients, especially those with multidrug-resistant bacterial infections.”

“We noted that the bacterial strain A. baumannii had a two-part signaling system that altered its potential response to antibiotic treatment,” says Dr. Sarah Giles, as part of an NHMRC-Flinders University fellowship study .

This observed “two-component signal transduction” involves a response regulatory protein in the StkR/S system acting as a repressor and when hundreds of genetically suppressed transcriptional changes are observed.

Some of these changes affect the composition of the outer membrane of the bacterial cell, resulting in resistance to colistin.

“Colistin is known as an antibiotic of ‘last resort’ and therefore it is essential to identify and understand the mechanisms contributing to bacterial resistance to antibiotics,” says lead researcher Professor Melissa Brown.

Antimicrobial resistance (AMR) occurs when bacteria, viruses, fungi, and parasites change over time and no longer respond to drugs, making infections harder to treat and increasing the risk of spreading disease. serious illnesses and even death.

The article, The StkSR Two-Component System Influences Colistin Resistance in Acinetobacter baumannii (May 2022), by Sarah K Giles, Uwe H Stroeher, Bhavya Papudeshi, Rob Edwards, Jessica AP Carlson-Jones, Michael Roach and Melissa H Brown was published in the Microorganisms.

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More information:
Sarah K. Giles et al, The two-component system StkSR influences colistin resistance in Acinetobacter baumannii, Microorganisms (2022). DOI: 10.3390/microorganisms10050985

Provided by Flinders University

Quote: Investigation of the resistance power of a hospital superbug (2022, May 30) Retrieved May 31, 2022 from

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