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Microbiology. Study of microscopic organisms Unicellular, multicellular , or acellular Different fields of study Virology – study of viruses Mycology – study of fungi Parasitology – study of parasites, hosts and relationships Bacteriology – study of bacteria
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Microbiology • Study of microscopic organisms • Unicellular, multicellular, or acellular • Different fields of study • Virology – study of viruses • Mycology – study of fungi • Parasitology – study of parasites, hosts and relationships • Bacteriology – study of bacteria • Protozoology – study of protozoa • Nematology – study of nematodes • Phycology – study of algae
What is a Microbe • Smaller than 0.1mm • Includes archaebacteria, bacteria, protozoans, fungi, viruses
Scientific names • Every organism that has been discovered is given a scientific name • Founded by Carolus Linnaeus (1735) • Genus species • G. species • Genus species • Two organisms sharing a common genus are related
Examples • Klebsiellapneumoniae • Clostridium difficile • Escherichia coli • Staphylococcus aureus • MRSA • Streptococcus pyogenes • Flesh eating disease
Why study Microbiology • Microbes are related to all life • In all environments • Industrial uses (fermentation, antibiotics, probiotics) • Related to life processes (food web, nutrient cycling) • Pathogenic (infectious diseases) • Most of our problems are caused by microbes
EID’s • Emerging infectious diseases • Weapons of mass destruction • New evolutionary features • Response to man encroaching on the environment
Patterns of Disease • Endemic – disease is present in low levels of a population at any time • Outbreak – sudden increase in prevalence of a particular disease • Epidemic – sudden increase in prevalence on a national scale • Pandemic – rapid spread of pathogen throughout the world (HIV, bubonic plague, cholera, tuberculosis, HIV/AIDS, influenza)
Biotechnology • Use of living systems and organisms to develop useful products • Biodegradable plastics, vegetable oil, biofuels (85% ethanol) • The use of biological information to make things or improve the human condition • Pharmacogenomics – study of how the genetic inheritance of an individual affects his/her body’s response to drugs • Gene therapy
Prokaryotic Cells • Include Bacteria and Archaea • Lacks a nucleus and other membrane bound organelles • Contain ribosomes • Pili – hair like structures used to attach to other cells or objects • Flagellum – tail like extension for motorboating (propeller) • Cell wall • Nucleoid – chromosomal DNA • Plasmids – small circular pieces of DNA • Capsule – composed of polysaccharides, protects cell against phagocytosis
Common Shapes of Prokaryotes • Coccus (Round) • N. meningitidis – meningitis • Bacillus (Rod) • B. anthracis - anthrax • Diplococci (Pair) • N. gonorrhoea – gonorrhoea • Streptococci (chain) • S. pyogenes – scarlet fever • Spirochete (Spiral) • T. pallidum – syphilis
Bacteria • Cell walls • Composed of peptidoglycan • Reproduce Asexually • Binary fission • Make energy, use organic chemicals, inorganic chemicals, or photosynthesis
Archaea • Lack peptidoglycan in cell wall • Reproduce via Binary Fission • Live in extreme environments • Methanogens • Live in environments that lack oxygen • Produce methan gas • Live in landfills • Extreme halophiles • Live in environments that love salt • Dead Sea, Great Salt Lake • Extreme thermophiles • Live in environments of extreme heat • Volcanic vents deep in the ocean
Binary Fission • Asexual Reproduction
Conjugation • Transfer of genetic material between bacterial cells • Creates genetic diversity • Antibiotic resistance
Protozoa (Eukaryotic Cells) • Unicellular eukaryotes • Animal-like • consumers • Plant- like • producers • Motility • Ciliates • Flagellates • Amoeboids • Sporozoan
Animal-like Protists • Ciliates • Move using short, thread like cilia that extend from plasma membrane • Sweep food into their bodies • Balantidium coli • Causes Balantidiasis • Paramecium
Balantidium coli • Trophozoite • Active feeding stage • Binary fission producing cysts • Invade the wall of large intestine • Cannot survive outside human host • Cyst • Dormant, resting stage • transmitted to humans • Survive outside human host
Animal-like Protists • Flagellates • Use a whipping action (propellor) of tail like flagella • Giardialamblia • Causes Giardiasis (beaver fever, backpackers disease) • Reproduce in the small intestine (binary fission)
Giardialamblia • Trophozoite • Invade wall of large intestine • Cause severe diarrhea • Cyst • Dormant, resting stage • transmitted to humans • Survive outside human host
Animal-like Protists • Amoeboids • Pseudopods – extension of cytoplasm creating foot-like structure for movement and catching food • Entamoeboahistolytica • Causes Amoebiasis
Entamoebahistolytica • Trophozoite • Invade extraintesinal sites (liver, brain, lungs) • Cause liver and brain abscess • Cyst • Ingested by humans
Fecal Oral Route • Pathogens in fecal matter pass from one host and is introduced to the oral cavity of another • Excystation /Encystment • Transforming from cyst to trophozoite and back to cyst
Animal-like Protists • Sporozoans • Cannot move on their own (nonmotile) • Reproduce both sexually (gametes) and asexually (mitosis) • Parasites • Transmitted through vectors (insects) • Plasmodium vivax • Causes malaria (most common) • Transmitted by female anopholes (mosquito)
Plasmodium vivax • Mosquito bites • Infects human with sporozoites • Sporozoites infect liver cells • Develop into merozoites • Merozoites infect RBC’s • Continue to infect RBC’s • Some develop into gametocytes • Mosquito bites infected human • Gametocytes fertilize, develop into oocyst • Oocyst ruptures releasing sporozoites
Plant-like Protists (Algae) • Eukaryotes • Cellulose cell walls • Use photosynthesis for energy (primary producers) • Produce molecular oxygen and organic compounds
Plant-like protists • Dinoflagellates • Marine plankton (flagella) • Red tide • Algal blooms produce dinotoxins • Toxic to humans • Diatoms • Phytoplankton • Cell wall is made up silica • Euglenoids • Contain chloroplasts • Also feed by phagocytosis • Green Algae • Macroscopic seaweeds
Fungi • Eukaryotes • Chitin cell walls • Use organic chemicals for energy (consumers) • Moulds • consist of masses of mycelia, which are composed of filaments called hyphae • Reproduce asexually (spores) • Yeasts • Round shape • Reproduce asexually (budding)
Viruses • Acellular – non-living • Consist of DNA orRNA core • Core is surrounded by a protein coat • Coat may be enclosed in a lipid envelope • Viruses are replicated only when they are in a living host cell
Multiplication of Viruses • Adsorption • Penetration • Uncoated • Synthesis • Replication and Protein Production • Assembly • Release
Universal precautions set up by CDC • Use gloves, gowns, masks and goggles • Minimize risk of needle sticks • Disinfections procedure • Preventative treatment after exposure • Reduce risk • Treat all patients the same