So what we have here is what we call an in vitro pharmacodynamic model and what it is it’s a way to simulate dosing of antibiotics and antibiotics’ effect on resistance development and bacterial killing in a way that would mimic what happens in a patient. So, what we have as far as what the model consists of is on the left here we have broth medium which is a nutrient medium which will support growth of whichever bacterium we’re studying here. Then we have pumps here and here and I’ll get to those in a second. And then here is your central flask which is really the reaction chamber of the model and so this is a flask which again contains a nutrient broth that will support growth of the bacterium you’re testing. And then at the beginning of the experiment, and the experiments last for 72 hours, we inoculate this model with that bacterium and then we also inject a dose of whatever antibiotic we’re studying into the model. And so what the pumps do, they pump in fresh broth from the side into the model and then broth that contains the antibiotic and bacterium is displaced using this pump here and so what we can do is we simulate the clearance of the antibiotic from the patient’s body and then this broth here on the right is simply waste broth that contains antibiotic and we hope dead bacteria. And so what we do with the model, as I said we dose into this central chamber so we can measure the effect of different doses of the same antibiotic and to see whether a certain dose will help us prevent resistance or we can compare different drugs within the same class so we can determine whether a certain drug within the class should be the preferred agent from the standpoint that it kills better or, more importantly, prevents resistance better. Or we can even compare antibiotics in different classes. So, essentially what we’re trying to do is see if we can apply the results of this to clinical care in terms of “is there a certain antibiotic that would be the best to use from a resistance standpoint.”
