MICR20010 Lecture 1 2023 (3).pptx

MICR20010 Lecture 1 Microbiology Dr. Jennifer Mitchell Microbiology School of Biomolecular and Biomedical Science [email protected] Practicals • Practicals will be carried out face to face and you should be able to see your practical slots in your timetable. • Please check your allocated la...

MICR20010 Lecture 1 Microbiology Dr. Jennifer Mitchell Microbiology School of Biomolecular and Biomedical Science [email protected] Practicals • Practicals will be carried out face to face and you should be able to see your practical slots in your timetable. • Please check your allocated lab rotation is correct in brightspace and identify your lab room and seat number. • Please view introductory lecture on Brightspace • PRINT OUT THE LAB MANUAL AND BRING IT WITH YOU AND MARKER!!! Assessments • Practical accounts for 30% • 15% on the two Practical reports to be submitted online after the practicals • 15% on the Practical Exam to be held at date TBC • 70% on an end of term Final MCQ exam. Remember • Check you practical assignment on brightspace matches your timetable and that you can identify your lab room and seat number • The lab manual and pre-practical talk for practical 1 will be on brightspace before the lab. • Do not leave the lab without asking all questions about the write up. We will not address lab write up outside of lab. • If you have any questions please E-mail the module coordinator at [email protected] Learning Outcomes • • • • Define Microbiology Different types of microbes Role and application of microbes Importance of microbiology in: – Agriculture – Food industry – Animal and plant health • Role of Microbiologists • History of Microbiology What is Microbiology? • The study of microscopic organisms Microbes are tiny single-cell organisms They are the oldest form of life on Earth. Microbe fossils date back >3.5 billion years - when the Earth was covered with oceans that regularly reached the boiling point. Hundreds of millions of years before dinosaurs! → Incredible biodiversity - outpaced higher organisms Without microbes, we couldn’t eat or breathe. Without us, they’d probably be just fine. Understanding microbes is vital to understanding the past and the future of ourselves and our planet. Types of Microbes Types of Microbes Bacteria Often dismissed as “germs” that cause illness, bacteria help us do an amazing array of useful things, like make vitamins, break down some types of garbage, and maintaining our atmosphere. Archaea These bacteria look-alikes are living fossils that are providing clues to the earliest forms of life on Earth. Fungi From a single-celled yeast to a 3.5-mile-wide mushroom, fungi do everything from helping to bake bread to recycling to decomposing waste. Protista Plant-like algae produce much of the oxygen we breathe; animal-like protozoa (including amoeba) help maintain the balance of microbial life. Viruses Unable to do much of anything on their own, viruses go into host cells to reproduce, often wreaking havoc and causing disease. Their ability to move genetic information from one cell to another makes them useful for cloning DNA and could provide a way to deliver gene therapy. Role and Application of Microbes • Role of Microbiology in Biotechnology and pharmaceutical industry • Production of important pharmaceuticals: – Glucose polymers – Vitamins – Amino acids – Ion chelating agents – Enzymes – Antibiotics Bacteria as producers of human substances. The hormone erythropoietin, which is absolutely necessary for the proper development of red blood cells (erythrocytes), but very, very, difficult to isolate, is now available in high quantity Erythropoietin gene/ human insulin gene Cloned into bacteria Overproduced and purified Administered to patients who cannot make these substances themselves EPO: abused by some professional athletes. Increases RBC count Importance of Microbiology in Agriculture Decomposition and Recycling Waste treatment Soil fertility Food Production Diary industry Spoilage Animal and plant health Benefits Disease Agriculture: Legumes – plants with root nodules containing bacteria that fix nitrogen – reduce dependence on fertilisers Ruminant animals – cattle and sheep have special digestive vessel called the rumen filled with bacteria. Bacteria digest cellulose in grass and hay, without which animals would not thrive Nutrient cycling – carbon, nitrogen and sulphur. Microbial activities in soil and water convert these elements into forms plants can use (Plant nutrition) Microbial diseases – Foot and mouth virus, mad cow disease, potato blight (fungus) Role of Microbiology in the Food Industry • Food spoilage – enormous economic losses every year • Food borne pathogens – serious health risk • Dairy products – cheese, yogurt, buttermilk all produced by microbial activity • Baked goods, alcoholic beverages result from yeast activity • Animal Feed (Single cell protein – microbial biomass or proteins extracted from large scale cultivations of bacteria, yeast or fungi) • Food supplements (Probiotics) Probiotics Only 1% of microbes cause infection Probiotics are live microorganisms administered in adequate amounts which confer a beneficial health effect on the host. 1. Favorably alter the intestinal microflora balance 2. Inhibit the growth of harmful bacteria. Probiotic bacteria also produce substances called bacteriocins, which act as natural antibiotics to kill undesirable microorganisms 3. 4. Promote good digestion Boost immune function and increase resistance to infection. Beneficial bacteria (probiotics) are present in fermented dairy products namely live culture yogurt Yogurt is the original probiotic preparation—used as a folk remedy for hundreds, if not thousands, of years. However, different brands of yogurt can vary greatly in the bacterial cultures used and potency. Supplements in powder, liquid extract, capsule, or tablet form containing beneficial bacteria are other sources of probiotics. Role of Microbiology In plant and animal Health • Antimicrobial Use in Food Animals • In the US large quantities of antibiotics are consumed by animals being raised for food, such as cattle, dairy cows, pigs, and poultry • Contributes to antibiotic resistance. • Most of the antimicrobials given to food-producing animals each year are not used to treat sick animals. • Instead, antibiotics are routinely added to feed and water to prevent disease and to promote growth. Role of Microbiology In plant and animal Health • This long-term, low-dose exposure to antibiotics is more likely to result in resistant bacteria than short-term antibiotic use to treat sick animals. • Transmission to human pathogens • In 1999, the European Union banned the use of four antibiotics as growth promoters. Microbiology is an important medical discipline Prevention and treatment of infectious disease RTI, diarrhoeal diseases, mycobacteria are principal causes of death worldwide Drug resistance a major problem Emerging infections in immunocompromised patients Hospital-acquired infections Role of Microbiologists • Bacteriologists focus specifically on bacteria and how they help or hurt us. • Virologists specialize in viruses and how they infect cells. • Mycologists study fungi. • Protozoologists devote their efforts to protozoa. • Epidemiologists investigate infectious disease outbreaks to learn what caused them and if we’re facing a deadly new microbe. • Immunologists study how the body defends itself against microbial invaders. History of Microbiology • Discovery of microscopic life • Invisible living creatures were thought to exist and were thought to be responsible for disease long before they were observed • Mid 1600’s single celled organisms were discovered • Considered to be at an early stage of development into complex organism • 1684 Antony van Leeuwenhoek • Cloth merchant in Holland – used a magnifying glass to inspect quality of cloth • Developed into an amateur microscope builder – “wee animalcules” Leeuwenhoek did not invent microscopes. In fact compound microscopes (with two lenses) were invented 40 years before he was born. Only 20-30X at that time. Leeuwenhoek’s skill in grinding and polishing lenses with great curvature achieved 200X. “Father of Microscopy” Antonie van Leeuwenhoek would not tell anyone how he built his microscopes. It was over 100 years after Leeuwenhoek's death before anyone could manufacture a microscope that could match or surpass the magnifying quality of the microscopes he built. Although Leeuwenhoek's scientific discoveries were monumental, his secretive nature delayed the onset of the widespread study of microbiology for over a century.. Spontaneous Generation Living things produced from vital forces in non-living or decomposing matter Abiogenesis versus Biogenesis Spontaneous generation Production of life from vital forces in non-living matter Organisms arose from seeds or germs that had entered the food from the air 200 year debate among scientists Countered the argument that spontaneous generation could take place if broth was exposed to air, since the neck of the flask freely admits oxygen Countered the arguments that heating would kill the "life force" of the broth, since the heated broth supported growth after it was exposed to dust Louis Pasteur (1822-1895) Pasteur's explanation for re-growth in previously sterile media was due to contamination - the result of the ubiquitous presence of microbes. 1. Microorganisms present in air resembled those present in decaying material 2. Postulated that these microorganisms were constantly settling on all objects 3. To prove this he demonstrated that food treated to destroy microorganisms would not putrefy 4. Used HEAT to kill microorganisms & prevent putrification Importance of Sterilisation The experiments of Pasteur and other microbiologists in the 1800s also highlighted the importance of killing all the bacteria and other microorganisms in or on objects This process is termed sterilisation Mastitis in cattle is reduced by sterilising milking equipment Discovery of Penicillin • 1929 • Alexander Fleming discovers penicillin. Produced by the fungus Penicillium. Fleming noticed that the bacteria seemed to dissolve and cultures were contaminated with the fungus. • Not produced in major quantities until 1940s – launches the “Antibiotics Era,”. • Fleming is awarded the Nobel Prize in Medicine or Physiology in 1945. Further Reading • Microbiology an Introduction, Tortora, Funke and Case 12th Ed. Chapter 1 • “The Microbial World and You”