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Microbiology

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

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  1. 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

  2. What is a Microbe • Smaller than 0.1mm • Includes archaebacteria, bacteria, protozoans, fungi, viruses

  3. 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

  4. Scientific Names

  5. Examples • Klebsiellapneumoniae • Clostridium difficile • Escherichia coli • Staphylococcus aureus • MRSA • Streptococcus pyogenes • Flesh eating disease

  6. 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

  7. EID’s • Emerging infectious diseases • Weapons of mass destruction • New evolutionary features • Response to man encroaching on the environment

  8. 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)

  9. Patterns of Disease

  10. 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

  11. 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

  12. 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

  13. Parasite • Non-mutual relationship between organisms • Parasite benefits at expense of host • Smaller than their host • Microparasites • Viruses, bacteria • Macroparasites • Protozoa, fungi • Transferred by vectors • Carries and transmits an infectious pathogen into another living organism • Arthropods (mosquitoes, flies, sand flies, lice, fleas, ticks, mites)

  14. Bacteria • Cell walls • Composed of peptidoglycan • Reproduce Asexually • Binary fission • Make energy, use organic chemicals, inorganic chemicals, or photosynthesis

  15. Archaea • Lack peptidoglycan in cell wall • Reproduce via Binary Fission • Live in extreme environments • Methanogens • Live in environments that lack oxygen • Produce methane 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

  16. Binary Fission • Asexual Reproduction

  17. Conjugation • Transfer of genetic material between bacterial cells • Creates genetic diversity • Antibiotic resistance

  18. Protozoa (Eukaryotic Cells) • Unicellular eukaryotes • Animal-like • consumers • Plant- like • producers • Motility • Ciliates • Flagellates • Amoeboids • Sporozoan

  19. 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

  20. Balantidium coli • Trophozoite • Active feeding stage • Binary fission • Develop into cysts • Invade the wall of large intestine • Cannot survive outside human host • Cyst • Dormant, resting stage • transmitted to humans • Survive outside human host

  21. 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)

  22. Giardialamblia • Trophozoite • Invade wall of large intestine • Cause severe diarrhea • Cyst • Dormant, resting stage • transmitted to humans • Survive outside human host

  23. Animal-like Protists • Amoeboids • Pseudopods – extension of cytoplasm creating foot-like structure for movement and catching food • Entamoeboahistolytica • Causes Amoebiasis

  24. Entamoebahistolytica • Trophozoite • Invade extraintesinal sites (liver, brain, lungs) • Cause liver and brain abscess • Cyst • Ingested by humans

  25. 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

  26. 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)

  27. 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

  28. Plant-like Protists (Algae) • Eukaryotes • Cellulose cell walls • Use photosynthesis for energy (primary producers) • Produce molecular oxygen and organic compounds

  29. 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

  30. 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)

  31. Yeast Reproduction • Budding • New organism develops from outgrowth on another cell at a particular site • Ascus • Spore bearing cell in fungi

  32. Hyphae • Thread-like filamentous cells that provide nutrients • Spore formation • Form on the ends of hyphael cells • Spore Release • Carried away in the air • Germination • Under proper conditions germinates into new hyphael cell

  33. 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 • Spikes composed of glycoprotein used for attachment on cells

  34. Multiplication of Viruses • Adsorption • Penetration • Uncoated • Synthesis • Replication and Protein Production • Assembly • Release

  35. Infection Stages • Transmission of pathogen to host • Entry of pathogen into the body • Attachment • Surviving host defenses • Local multiplication and spread of pathogen • Local invasion, causing damage • Systemic spread and multiplication of pathogen • Exit of the pathogen from host

  36. Endotoxins and Exotoxins • Secreted by bacteria or are structural component of cell wall • Endotoxin • Composed of lipopolysaccharide • Produces fever, decrease blood pressure, inflammation, coagulation • Released upon destruction of bacterial cell wall • Exotoxin • Secreted by bacteria • Causes damage to host, disrupts normal cellular metabolism • Fatal to host • Causes sepsis – infects blood

  37. Transmission • Direct • Occurs when there is physical contact between infected person and susceptible person • Blood, bodily fluids (kissing, touching, sexual contact, etc) • Indirect • Occurs when there is no direct human-to-human contact • Sneezes, coughs droplets (droplets can travel 3 to 6 feet) • Vectors (mosquitoes, flies, mites, fleas, ticks, rodents)

  38. Host • Clears the pathogen and recovers • Cannot clear the pathogen (prescription drugs) • Succumbs to the infection (death)

  39. Non-specific Immunity • Physical and chemical barriers • Skin oils, sweat, tears, earwax, cilia, stomach acid • Sneezing, coughing, vomiting • Resident micro-organisms • Normally live on the skin and in the large intestine • Prevent colonization of pathogen • Inflammation • Red, warm, swollen, painful area • Stimulates immune system • Creates hostile living environment for bacteria • Immune cells and proteins • WBC’s (phagocytosis)

  40. Specific Immunity • Targets specific pathogens • Remembers pathogens for next time • Targets antigens • Carbohydrate or protein that is associated with pathogen triggering defenses • WBC’s take a sample of antigen • Present antigen to other WBC’s to destroy it • Present antigen to other WBC’s to produce antibodies (immune proteins) • Antibodies recognize specific antigen

  41. Vaccines • Injection of an inactive form of a microbe or virus • Contains antigen • Allows immune system to build antibodies • Clostridium tetani

  42. Antibiotics • Medications that destroy bacteria • Bactericidal (penicillin) • Destroys bacterial cell wall • Bacteriostatic (tetracycline) • Prevents bacteria from reproducing • Interfere with protein production, DNA replication, or cellular metabolism • Anti-resistance • MRSA, TB, Klebsiella

  43. Anti-fungal • Pharmaceutical fungicide used to treat fungal infection • Disrupt cell membrane function • Inhibit enzymes

  44. 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

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