Transcript TLCppt
TLC Event Microbes Are Everywhere: Do They All Want To Kill Me? Part I: What is a microbe Amy Czura Part II: Micro lab: making slides Amy Czura & Paul Anderson Part III: Micro lab: observing your bacteria Amy Czura & Paul Anderson Microbes Are Everywhere: Do They All Want To Kill Me? NO! What are Microorganisms / Microbes: -they are typically unicellular -they are typically too small to see with the unaided eye -they include: bacteria & archaea fungi protozoa algae viruses Microorganisms / Microbes Continued: -they are located almost everywhere on the planet -only a small % are pathogens pathogen = organism that causes disease -most are involved in environmental / ecosystem balance: *breakdown waste *fix nitrogen *photosynthesis – carbon fixation foundation of food chains *digestion in animals Bacteria Coccus Bacillus Spiral How big is a bacterium? About one micrometer (µm): one one-thousandth of a thousandth of a meter. Very, very small. Average Human Cell = ~50µm Bacteria Average Bacterium = ~1-3µm A dime ($0.10) = 18,000µm It would take over 127 million bacteria to cover one face of a dime! Human Cheek Cell Archaea Methanogens Halophiles Thermophiles Fungi Protozoa Algae Viruses Virus: an obligate intracellular parasite Integrating Viruses Herpes HIV ChickenPox /Shingles The next new flu Influenza virus: constantly changing Prions “proteinaceous infectious particle” PrPC protein in neurons, folded incorrectly Prions Disease: spongiform encephalopathy Mad cow, Sheep scrapie, Kuru, Creutzfeldt-Jakob BioQUEST First bacteria appear in the fossil record 3.5 billion years ago, first cellular life on earth, but Microbes were not discovered until the 1670s: Antoni van Leeuwenhoek (bacteria & protozoa) Microbes not linked to disease until 1876: Robert Koch (Bacillus anthracis causes Anthrax) Koch’s Postulates Viruses were discovered in the late 1890s as “filterable infectious agents” but were not observed until the electron microscope was developed in the 1930s HEPA “high efficiency particulate air” filters trap things 0.2µm and larger: typical bacterium is 1µm typical virus is smaller than 0.1µm First antibiotic was discovered in 1928: Fleming (Penicillium mold contamination on Staphylococcus plates) Production of penicillin for public use not until the 1940s 1950s through 1970s and beyond: New antibiotics discovered, new chemotherapy agents designed in lab Late 1960s – early 1970s public health officials declare society is witnessing the end of infectious disease! (Meanwhile Penicillin went into public use in 1943 and the first Penicillin resistant strain of Staphylococcus was discovered in 1947) Widespread overuse and misuse of antibiotics & antimicrobial drugs has resulted in the evolution of multidrug resistant bacteria strains In the U.S. death rates from infectious disease increased 58% between 1980 and 1992 In 2009 infectious disease was still the 4th leading cause of death in the U.S. after heart disease, cancer, and stroke Worldwide, in the 21st century, infectious disease still accounts for 16-26% of all deaths annually Total microbes on earth that are pathogens is less than 10% Most microbes are beneficial! Normal Microbiota -colonize inside and outside surfaces: skin: Staphylococcus species mouth/nose: Staphylococcus and Streptococcus species large intestine: Enterobacteriaceae family e.g. E. coli vagina: Lactobacillus species -often protective: E. coli produce bacteriocins to kill Salmonella Lactobacillus create acid pH to prevent yeast growth All occupy space preventing pathogen colonization -other beneficial activities: vitamin production in gut Vitamin K for clotting factor synthesis Biotin for glucose metabolism Vitamin B5 for neurotransmitter synthesis Normal Microbiota -can be opportunistic pathogens Staphylococcus infections of wounds UTIs from intestinal bacteria -immunocompromised patients: organ transplant recipients cancer patients HIV positive / AIDS Microbes are good for the environment Recycling nutrients back into the food chain: Decomposition QuickTime™ and a YUV420 codec decompressor are needed to see this picture. Play Decomposers.mov Photosynthesis: Cyanobacteria & Algae Carbon fixation Harvesting light energy to convert carbon dioxide and water into glucose and oxygen Nitrogen fixation & Nitrification Microbes are very useful to humans Wastewater (Sewage) treatment www.wedotanks.com Compost Methane Bioremediation = using microbes to break down toxins e.g. Pseudomonas has enzymes to digest crude oil as a food source Commercial applications: Produce acetone, vinegar, methanol, ethanol... Household enzyme based cleaners and detergents Biodegradable plastic-like polymers Your favorite blue jeans: “Stone washed” denim: cellulase from fungus Cotton and polyester: polymers made by bacteria Peroxidase from mushrooms for bleaching Indigo dye from indole made in bacteria Agriculture: Insect Pest Control Bacillus thuringiensis Agriculture: Genetic Engineering of Plants Agrobacterium tumefaciens insert genes for: -pest control -nitrogen fixation -drought tolerance Therapeutics: Antibiotics Human gene products -insulin -growth hormone Vaccines Food