 Welcome back to MedSmarter where we're taking a smarter approach to preparing future physicians today We're gonna go over the gram positive micro bacteria algorithm As you can see here, we have the algorithm for gram positive bacteria This can look a little daunting but hang in here with me and we'll go through it together So the first thing you're going to see with these organisms is that making them gram positive on a gram stain They will be purple or blue colored That indicates the gram stain is a gram positive organism Then we can break it down into Bacilli coxi or branching filaments just by looking at them under our microscope If we're able to break it down to Bacilli we can then Determine if it's aerobic or anaerobic and that will help us determine if we're dealing with Listeria bacillus corneobactum or Clostridium cutibacterium which we used to call propionibacterium We're gonna skip over coxi for just a minute because there is a quite a bit more to that specific type of organism and go over to our branching filaments As you can see here branching filaments will be obvious under our microscope with our after our gram stain and We can to break them down into the aerobic or anaerobic If a gram positive branching filament is aerobic, then we know it is nocardia or weakly acid fast If it is anaerobic, then it's not going to be acid fast and that will be ectenomyces So let's come back here and look at our coxi Once we determine that we have coxi or it looks like those little ball shapes Then we can run this through a catalase test and that catalase test will help us determine if it is Catalase positive or catalase negative what this catalase test is doing it is testing for aerobic organisms That produce an enzyme called catalase how we do this is by adding hydrogen peroxide into the solution With that bacteria and if we get gas bubbles or oxygen being formed From that hydrogen peroxide then we have that considered catalase positive So adding hydrogen peroxide to staphylococcus will give us bubbles making it catalase positive Then we can come in and do our coagulase test. We know that it's staphylococcus at that point Then we have to determine which species of staphylococcus we're dealing with So we're gonna check the coagulase test coagulase is another enzyme that is produced by certain bacteria That are a virulence factor for that Organism and it will basically interact with fibrinogen That's on the cell surface. So what we do is we come in here and we're going to add Rabbit plasma all right we use Rabbit plasma instead of human plasma so that we don't have any worry of other viral Particles being present We also have EDTA along with that plasma and we add that into the solution and if that solution causes clumping or coagulating of the The blood there then that is considered to be coagulase positive So something that is coagulase positive that we've already determined with staphylococcus is now going to be determined as Staph aureus if it's coagulase negative we follow this part of our Algorithm down and we check for Nova Biasin sensitivity Staph epiderminitis and Staph saprophyticus Have different responses to Nova Biasin So if we add Nova Biasin, which is an antibiotic to our auger plate with this culture on it And it is sensitive meaning that there is no growth of That microorganism then that means it is Sensitive to Nova Biasin and therefore is going to be our Staph epiderminitis if adding Nova Biasin to our growth auger plate Does not inhibit growth. It is not sensitive to Nova Biasin and therefore we are dealing with Staph saprophyticus