 Welcome back to our meds smarter lecture series where we're taking a smarter approach to preparing future physician Before we get started if you'll take just a quick minute and click that like button and also Subscribe and turn the bell on so that you'll be notified when we post new videos Let's continue on in our discussion of staph aureus and talk about MRSA MRSA specifically stands for Methicillin resistant staph aureus MRSA So what's the big deal about staph aureus? Well, this is where we see a lot of our hospital acquired and community acquired infections coming from from MRSA as it is not sensitive to a lot of our antibiotics Specifically what's happening with this resistance is that this staph aureus has acquired a resistance by altering that penicillin binding protein specifically it is a change in the mech a gene Which is from the staphococcal chromosome cassette, which involves the penicillin resistance so if we put a sample of This MRSA onto an auger plate and ran this for a sensitivity You would see that there was no change in the growth around the oxacillin Strip and that oxacillin strip is a particular type of antibiotic And as you can see up here on the top, there's very little to no growth around that oxacillin strip So this particular organism here is going to be Sensitive to methicillin because the methicillin does not grow in the presence of oxacillin But as we go down the strip especially in these bottom two what you're seeing here is that the presence of Oxacillin strip on this auger plate makes no difference to the growth of this staph aureus colony so this is Resistant oxacillin, which is what gives us the methicillin resistance staph aureus Furthermore staph aureus as we've mentioned can cause toxic shock syndrome. So what is toxic shock syndrome? Well, it's classified as fever vomiting rash Disquamation shock and then end organ failure. What's happening here is that this staph Infection is causing all of these potential side effects as well as AST, ALT and bilirubin elevations. So it's also going to be affecting our liver What is it most commonly associated with well the prolonged use of vaginal tampons or nasal packaging So using them for too long not taking them out and replacing them Both in the nasal packaging and the vaginal tampons can cause toxic shock syndrome as you can see on This picture over here. This patient's hands have undergone Disquamation where they are losing that are sloughing off that cell layer Due to toxic shock syndrome. Let's continue on and talk about staphococcus epidermidus Staph epidermidus is a gram positive catalase positive coagulase negative and Uriase positive cocci that it forms in clusters. Okay, you can see that here in this picture. You see the clusters Very small clusters. They kind of overrun into each other, but they're clustered up. They're not in a linear form and If we are going back to reference back to our algorithm for gram positive organisms We see originally they're gram positive. They are catalase positive coagulase negative and then also Uriase positive That helps us classify this particular organism as a staph epidermidus One other thing to note here is that it is sensitive to nova biocin. Also, it does not ferment mannitol and A key factor for staph epidermidus is that it's a normal flora found on our skin We have this all over us. It doesn't cause any type of a problem It doesn't cause any type of an infection under normal circumstances the problem comes in when it gets into a An area that allows that infection to settle in so if we have an open wound a cut Something like that. That's how we can get staph epidermidus Causing an infection when it's always there normally So what does this mean if it's normally found on the skin? Well, it can contaminate blood cultures It contaminate urine cultures. It can contaminate Swabs that kind of stuff. So if you do a blood culture from a vein and you don't do a good job of cleaning Before we make that IV access then you may have some contamination of staph staph epidermidus in that blood sample This also will infect a prosthetic devices and IV catheters So it actually produces these biofilms that adhere to those catheters or prosthetic devices And that allows it to grow on that particular structure. So we're talking about IV lines in your arm. That's why we change out the dressings often If you're in needing them for extended period of time, we use different types Because of the risk of this staph epidermidus that's normally on your skin potentially Producing this biofilm to adhere to that IV catheter and then potentially get into the body that way If you found this material helpful for your studying Please like and consider subscribing to the channel also share this video so that more people can benefit from it like you have