 Hey everybody, Dr. O here. In this video, we're going to cover the carbapenems and the monobactyms, or the one monobactyms. So the reason I grouped them together is honestly monobactyms isn't that important. I mean, we need to talk about it, but we're going to spend almost all of our time talking about the carbapenems. And I'll explain why in just a little bit. So you see why they're related. They're both beta-lactam antibiotics, just like the penicillins and the cephalosporins we've already covered, which means they have that beta-lactam ring, that same penicillin nucleus basically, then they have their different side groups and different structures, which makes them behave differently. So as far as the only important monobactam, really the only one that's used is astreanam, which is called azactam, I believe. It is narrow-spectrum, and I'd say the reason that this is still very important and worth noting here is it's effective against pseudomonas. So one thing, you know, pseudomonas, we'll talk about the drug-resistant organisms in the future series, but pseudomonas is one of the really most terrifying ones. And I think of like these nightmare bacteria, the pseudomonas comes to mind. Like in the lab, when we're testing the effectiveness of antibiotics, I always have the students tested against pseudomonas because I want to see how it works, right? So it's relatively important, but let's talk about the carbapenems. So there are a variety of different semi-synthetic carbapenems. You've got imapenem is the one we'll talk about the most, myropenem and dorapenem. So these are very broad-spectrum, which means they've been used a lot, right? So one of the ways that antibiotics have been used, and you could argue misused, is the more broad-spectrum antibiotic is, the more likely it was to be used, especially early. If you don't know what someone has, you would do kind of a shotgun approach. So the good news and bad news about broad-spectrum antibiotics, right? They can be useful, but that means you're going to be using them so often and exposing so many microbes to them and forcing so many bacteria to evolve around them in their presence that you're going to see resistance. And this is where we're at a pretty scary situation. So the carbapenems, they're still primarily effective. They do have the broadest spectrum of any of the beta-lactam antibiotics we talked about. That's a key thing to remember. They can kill some of your gram negatives. And they are also resistant to the beta-lactamase enzymes that would destroy penicillin pretty easily. So let me give you an example and then we'll talk about the problem. So my favorite example is called Pramaxin. So this is going to be an imapenem antibiotic. So it has to be injected, but then you're going to add something called psilostatin to it or psilostatin, some would say. The reason you do that is this is an effective antibiotic, but it breaks down in the kidneys like uberfast. So here you see an example of a combination, not of two antibiotics, but an antibiotic and a compound that makes it more effective. So what psilostatin does is keeps it in circulation so it can work longer instead of just being, instead of being filtered out of the kidneys. At this point, Pramaxin, this imapenem antibiotic is still effective against a, you know, well over 90% of the organisms that are isolated from hospitals. So you can see this being a very powerful antibiotic. But when I think of antibiotics, I think of basically every antibiotic has a counter and every time you use it, that number is getting lower and when it gets to zero, the drugs aren't going to be useful anymore like what happened with methicillin. So it's still, it's very effective if you're trying to save lives today, but the reality is we will reach a point where this antibiotic is not near as effective. Three years ago, four years ago, I would have said this is effective against 98% of organisms in the hospital. I think that number is slowly starting to drop. So why does this matter so much? Well, maybe you've never heard of it, but if you go to Google or whatever, if you type in nightmare bacteria, or if you look at, you know, some of the biggest concerns that the CDC has when it comes to antibiotic resistance, they are going to be the CRE organisms, carbapenem resistant and enterobacteria C, I'll spell that on the screen has lots of vowels, right? But these enterobacteria C, this is a large family of organisms. So you're looking at chigella, clibcella, E. coli, pseudomonas, these kind of organisms, that group of organisms when they become resistant to carbapenems were basically like out of antibiotic options or almost out of them. Because if you're carbapenem resistant, then you're resistant to the other beta-lactam antibiotics we've talked about. So these are all superbugs, which means they're resistant to more than one type of drug. Some of these CRE organisms are resistant to every antibiotic we have, except for one called colistin, which I'll cover in a separate video. Here's the big concern. If the CRE organisms, which already exist, become colistin resistant, then we will not have an antibiotic to treat them unless something new comes along the line. So we do, and we do know that there are some organisms that are resistant to colistin. So if you take an organism that's resistant to the carbapenems and it learns how to become colistin resistant from the organisms that already exist, then you might truly have a situation where we have microbes where there is no treatment. I mean, there's already some untreatable strains, but we're talking about huge families of organisms that our antibiotics won't work against again anymore. So when people are talking about this kind of doomsday scenario, like what would the world look like without antibiotics? That's what we're talking about. CRE organisms that become resistant to the last-lamb defense, which is a polymixin E or colistin. So this is very terrifying. At this point, if someone gets a CRE infection in their bloodstream, even with treatment, half of them are going to die, like this is definitely a big, big concern. So I'd say the main reason to understand the carbapenems is their significance now. But as organisms start to resist them, we are really, really in trouble unless we can come up with new antibiotics or antibiotic alternatives. I'm an optimist. We're going to stay ahead of the situation. But this is a big concern. All right, so these are the last groups of beta-lactam antibiotics I wanted to cover, the monobactamins, and then, more importantly, the carbapenem antibiotics. I hope this helps. Have a wonderful day. Be blessed.