Bacterial antibiotic resistance: new mechanism found (Introduction)

by David Turell , Saturday, December 03, 2022, 18:41 (721 days ago) @ David Turell

In Streptococcus:

https://www.sciencealert.com/scientists-just-caught-bacteria-using-a-never-before-seen-...

"'This new form of resistance is undetectable under conditions routinely used in pathology laboratories, making it very hard for clinicians to prescribe antibiotics that will effectively treat the infection, potentially leading to very poor outcomes and even premature death," explains Telethon Kids Institute infectious disease researcher Timothy Barnett.

***

"'Bacteria need to make their own folates to grow and, in turn, cause disease. Some antibiotics work by blocking this folate production to stop bacteria growing and treat the infection," explains Barnett.

"'When looking at an antibiotic commonly prescribed to treat Group A Strep skin infections, we found a mechanism of resistance where, for the first time ever, the bacteria demonstrated the ability to take folates directly from its human host when blocked from producing their own."

"So Streptococcus has been acquiring already processed folate from outside its own cells; these molecules are abundant in our bodies.

"The process completely bypasses the action of sulfamethoxazole, an antibiotic that inhibits folate synthesis within the bacteria, thus rendering the drug ineffective.

"Rodrigo and the team identified at least one gene involved: thfT. It encodes part of the folate harvesting system, not unlike our own, as we also can't produce folate and must get it from our food.

"Streptococcus bacteria with this gene, therefore, have found a way to suck up folate and subvert sulfamethoxazole.

"In the lab, Group A Streptococcus does succumb to sulfamethoxazole antibiotics because it doesn't have another accessible source of folate.

"In this case, the bacteria are only resistant to the antibiotics when they're causing an actual infection inside our bodies. This means there's no easy way of detecting this antibiotic resistance in pathology labs yet.

***

"'Unfortunately, we suspect this is just the tip of the iceberg – we have identified this mechanism in Group A Strep, but it's likely it will be a broader issue across other bacterial pathogens," says Barnett.

"Understanding these mechanisms is the first step towards being able to test for them and counter them by prescribing other classes of antibiotics instead.

"'It is vital we stay one step ahead of the challenges of antimicrobial resistance and, as researchers, we should continue to explore how resistance develops in pathogens and design rapid accurate diagnostic methods and therapeutics," urges Rodrigo."

Comment: The battle continues. Here is dhw's wished for free-for-all. I think we will eventually win, as shown by recent research into chemicals that attack bacterial walls directly.