Researchers discover how hydroquinine inhibits key drug-resistant bacteria

Researchers discover how hydroquinine inhibits key drug-resistant bacteria

Researchers say hydroquinine could be an effective weapon against a germ that can cause serious infections in people, mostly hospital patients

Scientists analyzing the effects of an organic compound on drug-resistant bacteria have discovered how they can inhibit and kill a germ that causes serious illness or, in some cases, death.

Pseudomonas aeruginosa is a type of bacteria that is common in hospital patients and can cause infections in the blood, lungs (pneumonia), or other parts of the body after surgery.

Hydroquinine, an organic compound found in the bark of some trees, has recently been found to have bactericidal activity against the germ and several other clinically important bacteria, including Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae.

The team behind the discovery, from the University of Portsmouth and Naresuan and Pibulsongkram Rajabhat Universities in Thailand, have now examined the molecular responses of Pseudomonas aeruginosa strains to hydroquinine. To do this, they examined which genes were turned on and which were turned off in response to the drug.

The new study, published in Antibiotics, showed that hydroquinine significantly altered the expression levels of Pseudomonas aeruginosa virulence factors. It also suggests that the compound disrupts the bacteria's assembly and movement.

There is a fairly long list of antibiotics that do not work on Pseudomonas. aeruginosa, but our experiments found that some of the genes that control the bacterium's motility were turned off quite dramatically by hydroquinine. Biofilm formation and swarming and swimming of the germ were significantly reduced.

"If we know that this drug works in a really unique or different way, then that first explains why it works on these drug-resistant cells, but it also means that you can potentially combine it with other existing antibiotics to make them more effective."

Dr. Robert Baldock, School of Pharmacy and Biomedical Sciences, University of Portsmouth

Drug-resistant bacteria occur in more than 2.8 million infections and are responsible for 35,000 deaths per year. Antibiotic resistance occurs when germs change over time and no longer respond to medications, making infections more difficult to treat.

Amoxicillin and trimethoprim are commonly prescribed antibiotics that treat certain strains of Pseudomonas. aeruginosa have become resistant. Hydroquinine is already known to be an effective antimalarial agent in humans and is also used in the Netherlands to treat nocturnal muscle cramps. To date, its drug-resistant properties have rarely been studied.

Dr. Jirapas Jongjitwimol from the Department of Medical Technology at Naresuan University added: “Antimicrobial resistance has become one of the biggest threats to public health worldwide, so the discovery of an organic compound has the potential to be used as an effective weapon in the fight.

“We now need to study how the compound works against a wider variety of bacterial strains so we can better understand why some germs are or are not affected.”

Source:

University of Portsmouth

Reference:

Rattanachak, N., et al. (2022) High-throughput transcriptomic profiling reveals the inhibitory effect of hydroquinine on virulence factors in Pseudomonas aeruginosa. Antibiotics. doi.org/10.3390/antibiotics11101436.

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