If you’ve been wondering how to make methicillin-resistant staphylococcus aureus (MRSA) more virulent, they’ve discovered how to do it—feed it antibiotics. The wrong kind of antibiotics:
A brand new study indicates that MRSA-induced diseases with the incorrect antibiotic could worsen the infection.
Researchers in America unveiled the findings of their study printed in the journal Cell Host & Microbe. The researchers detected that common or first-line antibiotics such as beta lactam antibiotics can make superbugs stronger and the infection more severe.
“Individuals infected with MRSA who receive a beta lactam antibiotic–one of the most typical types of antibiotics–could wind up being worse than if they received no treatment whatsoever,†George Liu of Cedars-Sinai Medical Center and co-senior study author said in a press release.
“Our findings underscore the urgent need to improve knowledge of MRSA and rapidly diagnose these diseases to prevent prescribing antibiotics that could put patients’ lives at risk,†he added.
Their study, which was conducted on lab mice, promises that MRSA does not only react to beta lactam antibiotics, it truly adjusts to them, becoming more powerful in the method. Apparently, beta-lactam antibiotic’s mechanism of action calls for neutralizing the enzymes in bacteria.
Examples of beta lactam antibiotics include cefazolin and cephalexin. I wonder how this study comports with the prescription of ceftaroline for MRSA. That’s supposed to be effective against MRSA but it’s a beta lactam antibiotic, too.
I think we have someone here who might be able to shed some light on that.
Shed light? Not me. But I do have MERSA. Picked it up somehow on an airline flight to SeaTac. There are three antibiotics that will still kill it. All are confined to inpatient hospital settings to control overuse of the antibiotics. Mine was on the outside of my calf, could have been worse. Treatment was incision, packing with antibiotic infused tape and intravenous and oral antibiotics. Didn’t have to go to hospital for sacred antibiotics. Depends on your immune system I guess. By the way, the docs and nurses up there change gloves every time they move room to room. Also One Doc said they’ve identified another resistant Bacteria the acronym for is VERSA. I said , what’s next? WORSA?
I would have to go look up exactly why ceftaroline works on MRSA, but in general cephalosporin (Beta-lactam antibiotics) resistance occurs when bacteria secrete lactamases that break down the antibiotic, the proteins to which these bind develop a low affinity for the antibiotic or the bacteria develop some way to keep the antibiotic out of the cell. My foggy old brain thinks I remember reading it had greater affinity for the proteins where beta lactams work, but if I wanted to know for sure I would call the ID lady. (Wife of one of my new hires.) Drugs like cefazolin are first generation cephalosporins that have been around quite a while. Still useful, but once you identify MRSA the antibiotic is changed. Ceftaroline is 5th generation I believe.
Steve
That article was oddly written (some sentences seems poor translations from another language.)
I dug a bit and found these:
http://www.cedars-sinai.edu/About-Us/News/News-Releases-2015/New-Research-Raises-Questions-About-Using-Certain-Antibiotics-to-Treat-Superbug-MRSA.aspx
And:
http://jac.oxfordjournals.org/content/66/suppl_3/iii11.full
The gist is that the problem with exposure of MRSA to most beta lactams is the induction of an alternate enzyme, PBP 2A, by the bacteria as a bypass to build its cell wall. The cell wall that results is different and provokes a more intense inflammatory reaction in the host.
But ceftaroline, unlike the older beta lactams, can bind to PBP 2A and inactivate it. So the reason that the drug works in killing the bacteria means that the exposure issue is moot.