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Potential MRSA Treatment August 15, 2019

Posted by stuffilikenet in Awesome, Science.
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Scientists from UNC (North Carolina, not Northern Colorado) School of Medicine, in a study published in Cell Chemical Biology, found just adding molecules called rhamnolipids

Tobramycin.svg

to aminoglycoside antibiotics, such as tobramycin,

Tobramycin.svg

 

makes them hundreds of times more potent against Staphylococcus aureus, including the strains that are otherwise very hard to kill.

We’re talking about MRSA here, folks.  This is a big damned deal. CDC says there were 119,000 cases of serious bloodstream Staph infections in the United States in the last year for which data is available (2017), of which more than 20,000 were fatal.

Take time to process that.

These rhamnolipids effectively loosen up the outer membranes of S. aureus cells so that aminoglycoside molecules can get into them more easily. In a new study, Conlon, Radlinski and colleagues tested rhamnolipid-tobramycin combinations against S. aureuspopulations that are particularly hard to kill in ordinary clinical practice. The researchers found that rhamnolipids boost tobramycin’s potency against:

  • S. aureus growing in low-oxygen niches;
  • MRSA (methicillin-resistant S. aureus), which are a family of dangerous S. aureus variants with genetically-acquired treatment resistance;
  • tobramycin-resistant S. aureus strains isolated from cystic fibrosis patients;
  • and “persister” forms of S. aureus that normally have reduced susceptibility to antibiotics because they grow so slowly.

They found this effect works in related families of antibiotics including gentamicin, amikacin, neomycin, and kanamycin, for the same reason and on Clostridioides difficile, which is a bit of a killer in its own right.

 

Homework:

Chemical Induction of Aminoglycoside Uptake Overcomes Antibiotic Tolerance and Resistance in Staphylococcus aureus;