Bacitracin: Bacteria from Tracey

Not even joking. No cap. The solemn truth. On the record. The truth, the whole truth, and nothing but da truth. Bacitracin was named after bacteria from a lady named Margaret Tracey. How is that for useless knowledge taking up space in your brain? Before we get into that story, me thinks the three of you reading this have probably used, or had been the target of use for, bacitracin as a kid. The little packets are ubiquitous in first aid kits across the world. Got a cut? Bacitracin. Burn or scrape? Bacitracin. Ran out of toothpaste? Bacitracin. I really hope that sarcasm was evident, the lack of humor nowadays is stunning. Please don't eat bacitracin. 

In 1943, a young girl named Margaret Tracy was seen at a hospital in New York, the precursor to Columbia-Presbyterian Medical Center. She had been hit by a car earlier that day and suffered a compound fracture of her tibia, which collected dirt from the road. The doctors cultures the wound which grew Bacillus subtilis and Staph aureus. The bacteriologist who examined it the next day saw that the S. aureus had died and after extensive work, Balbina Johnson discovered that the B. subtilis had done the killing. She named the subsequent compound after sample fromthe young lady from whom it had been cultured, labeled Tracey 1. Bacillus and Tracey, bacitracin. 

Bacitracin is available as an ointment, ophthalmic preparation, PO solution, and IM injections, the first two being most common. The IM injection is only really used for infantile Staph pneumonia. There is a risk for nephrotoxicity and that usually outweighs the risk, not to mention, there are other options available. As far as I found, the only use of PO bacitracin was in treatment of VRE with doxycycline, though the effects were not long lasting. Topical and ophthalmic applications are used for the prevention and treatment of superficial infections.     

Bacitracin does its work by inhibiting enzymes that move molecules needed for the peptidoglycan cell wall. This prevents the material from moving where it needs to go, causing cell death. Kinda like the cell is building faster than it has the material so it starts to build with holes in its wall, then, boom. Down it goes. That being said, it is mostly effective against gram positive buggies, most gram negatives are resistance to Tracey. Another common place for bacitracin to be found is in "triple antibiotic ointment", which is bacitracin, poly want a cracker, I mean polymyxin B, and neomycin, the chosen one. This combo is more effective against some gram negative bacteria due to the inclusion of neomycin, but that is for another time. 

Bacitracin is considered very safe for topical use, however it was named the 6th most prevalent allergen in patch tests in 05-06, the contact allergen of the year in 2003, and up to 12% of the U.S. population is sensitive or allergic. Otherwise, go ahead buddy. That doesn't stop it from being used time and time and time again to prevent skin infections. It probably will not stop anytime soon either. 

I am struggling to find rates of resistance, though I know via farm use it is growing (like every other fam used antibiotic). The resistance usually comes from the cell learning to pump the bacitracin out of the cell so it can continue building its wall. Maybe one day I will google enough to find out but for now, this is all you get from me buddy.

I just wanted to get this short blurb out there, I am drilling this weekend, it is gray outside, and I would like to nap so this is where I end. Now you know where bacitracin came from, go get yourself an ice cream cone kiddo, and listen to the podcast or share this with a friend or enemy. Love y'all, bye. 

References 

Bacitracin from the American Journal of Medicine 1949

Bacitracin from the NIH: National Library of Medicine

Bacitracin from PDR.net

Bacitracin resistance and enhanced virulence of Streptococcus suis via a novel efflux pump by Ma et al., in BMC Veterinary Research 2019

Image of a bacitracin molecule ball and stick model from Wikipedia

Margaret Tracy and Balbina Johnson: The Women Behind.... from "Bacitracin's Beginnings" here https://web.archive.org/web/20140428190211/https://files.nyu.edu/jmm257/public/other/bacitracin.html


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