Anti-biotic development and design Titi-Mary Omotade
Overview • In theory, antibiotics are chemical compounds(natural or synthetic) that kill bacteria or prohibit their growth. • We will study the history of antibiotics from how the Egyptians used them to their mass production during WW II. • Then we will learn about how members of Kingdom Fungi contributed and still contribute to the production of antibiotics and other drug discovery efforts. • Next we will take a deeper look of what happens on a biochemical/molecular level when antibiotics perform their function.
overview • For the experimental portion, we will be using our own fungal cultures(about 5-6 species) and creating the most effective antibiotic. • Each pair will be given several fungal cultures and one bacterial culture. You will be tasked with designing your antibiotic ‘drug.’ • We will go through the phases of drug design and see who can create the most successful antibiotic. • A plethora of tools from scalpels to centrifugation machines will be available for you and partner to manipulate the fungi in a way that you believe with produce the most effective antibiotic.
Can you name some antibiotics? • When did you use them? • Do you know why you used them? Classes of Antibiotics ~ AMINOGLYCOLISIDES B-LACTAMS PENICILLINS CEPHALASPORINS CARBALEPENEMS MONOBACTAMS FLUOROQUINOLONE GLYCOPROTEINS KETOLIDES MACROLIDES TETRACYLINES Historical context
HISTORICAL CONTEXT • Antibiotics can be both natural or synthetic. But natural antibiotics such as fungi(yeasts molds) have been used directly and indirectly for wound infections across many cultures for centuries. • Egyptian • Chinese • English
Historical context • The commercialization of antibiotics did not really become popular until a chance discovery by Alexander Fleming. • Discovery of Penicillin • How it was used towards the war effort • Impact of his discovery • Contemporary Developments • New classes of antibiotics • Antibiotic abuse/importance of drug discovery
MECAHNISM • How do antibiotics work? • Example: Strep Throat & Streptococcus pneumoniae • How many people have suffered from sore throats? Name some of the symptoms. • S. pneumoniae is the causative agent of strep throat. It is a gram positive coccus bacteria that unleashes an arsenal of extracellular compounds to promote its colonizationand growth. ~What is the difference between gram positive and gram negative cells? Streptococcus pneumoniae cells
Antibiotics Exploit Natural Components of the cell. In fact, some of the best drugs follow this same pattern. There are multiple mechanisms that can be used by different antibiotics .. MECHANISM http://www.wiley.com/college/pratt/0471393878/student/activities/bacterial_drug_resistance/antibiotic_targets_web.gif
~Bacterial Growth Pattern ~ Cell Wall Synthesis ~Osmotic Pressure ~Integrity of bacterial cell wall. Penicillin mechanism http://water.me.vccs.edu/courses/ENV108/clipart/cellwall.gif http://lecturer.ukdw.ac.id/dhira/BacterialStructure/images/GramPosEM.gif
Each group will receive one bacterial species and a set of fungal species. • You will have about 10 minutes to discuss the parameters of your experiment/ask the mentors for their input. • Next, you are free to use any of the instruments at your lab bench to manipulate the fungi in manner that you want in order to develop your antibiotic. • We will perform the inoculation step together before anyone starts the experiment. Your question Your hypothesis and why you choose your bacteria and fungi Organize your lab notebook Follow your protocol – what you will do Record any changes in your protocol Your Protocol
For the inoculation step read the following directions. • 1-Obtain your plates of media and label it with your team name, bacterial name, and the date. • 2-Clean your inoculating loop and once it has cooled down swirl it around your bacterial test tube. • 3-Remove the loop carefully, and sweep it across the entire plate until every surface has been covered. • 4-If you need more bacteria quickly dip it back in to your test tube(do not obtain too much liquid culture, just enough to form a bubble in your loop. • 5- Once you are done plate upside down so it may dry as you prepare your fungi. Follow antiseptic technique. Inoculation step
Things to consider... • You are only limited by your imagination. • I will give you background information on all of the bacterial and fungal species so you can determine which organisms you would like to use. • Mentors will be walking around if you would like to bounce ideas off of them – but ultimately it is up to you to design your experiment. • We will keep a notebook throughout to record our data and the procedure that you created for your experiment. • Good Luck!!
Now it is time to design your experiment and discuss how you want to place your fungi on the plate of bacteria! Record your data carefully. What are your conclusions? You are a Scientist!