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The GOOD, The BAD and The UGLY

The GOOD, The BAD and The UGLY. The GOOD, The BAD and The UGLY. Microbiology 1 Dr Viv Rolfe. Lecture Outline. The GOOD What is a microbe and microbiology? What are the different types of microbe? Microbes that are harmless. The BAD Common types of microbe that cause disease. The UGLY

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The GOOD, The BAD and The UGLY

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  1. The GOOD, The BAD and The UGLY The GOOD, The BAD and The UGLY Microbiology 1 Dr Viv Rolfe

  2. Lecture Outline The GOOD What is a microbe and microbiology? What are the different types of microbe? Microbes that are harmless. The BAD Common types of microbe that cause disease. The UGLY An introduction to infection.

  3. What is a Microbe and Microbiology? A MICROBE is a tiny organism that has to be viewed under a microscope. MICROBIOLOGY is the branch of biology which studies micro-organisms and their effects on the living host. The MICROSCOPE is the tool usedby all microbiologists.

  4. Confocal microscope and scanning electron microscope - state of the art technology for high power magnification. Microscopes Basic microscope - simple glass lenses for low power magnification.

  5. Does Size Matter? Microbes are measured in units called MICRONS... Micro = 1 / 1000 000 of a meter = mm

  6. pin head fungal spore smoke particle amoeba bacterium rain drop virus

  7. Virus < 0.05 mm Smoke particle 0.1 mm Bacteria 1-5 mm Fungus spore 30 mm Amoeba 500 mm Pin Head 2,000 mm Rain drop 10,000 mm in DIAMETER

  8. Virus < 0.05 mm Smoke particle 0.1 mm Bacterium 1-5 mm Fungus spore 30 mm Amoeba 500 mm Pin Head 2,000 mm microscopic Rain drop 10,000 mm in DIAMETER

  9. The GOOD Penicillin spores- damage bacterial cell walls giving us ANTIBIOTICS.

  10. The GOOD Probiotics - “friendly bacteria”

  11. …and where would we be without yeast?

  12. Types of Microbes There are 4 basic groups of microbe whichcan all cause infectious disease. • a. bacteria • b. fungi: yeasts and molds • c. viruses • d. protozoa

  13. A - Bacteria • There are thousands of bacterial species and many are pathogenic. • They cause infections because they are everywhere, multiply quickly and some secrete toxins causing illness. • Three basic shapes: • coccus • rod or bacillus • spiral

  14. 2) Paired diplococci 3) Chains or streptococcus Coccus - 4 types 1) Single coccus 4) Bunches or staphylococcus

  15. E.g. • Staphylococcus aureus • Releases toxins which cause food poisoning. • Big news because its a “super bug”. • It is resistant to antibiotics and causes majorhospital infection (MRSA).

  16. Rods / bacillus Rod-shaped bacteria 1) Single bacillus 2) In a chain of bacilli

  17. E.g. • Single - Escherichia coli (E coli for short) • Many different strains of E coli. • Some are COMMENSAL and live in your colon. • Others cause food poisoning, eg E coli 0157.

  18. E.g. • Chains - Bacillus anthracis. • Causes anthrax - animal infection that canspread to human (a zoonosis). • Causes ulcers leading to blood poisoningand can be fatal in humans.

  19. Spiral Shaped Three forms 1) Basic spiral 2) Spirillum (or spelt spirillium) 3) Spirochete - more twisted

  20. Identifying Bacteria • A simple way of identifying SOME bacteria is by GRAM STAINING. • Results… • Bacteria that stain purpleare termed gram-positive • Bacteria that stain pink are said to be gram-negative

  21. Gram positive (E.g. Staphylococcus, Streptococcus) Gram negative (e.g.E coli, Neisseria gonorrhoea)

  22. B - Fungi • Fungi include yeasts and molds. • Fungi have a rigid cell wall and absorb nutrients for energy. • Over 100,000 known species but only about 100 species are pathogenic (harmful).

  23. E.g. • Candida Albicans - YEAST • Part of our commensal flora. • Candida causes in vaginal or skin infection in people who are ill, immuno-suppressed, or on antibacterial therapy.

  24. Fungi - Molds • Made of a HYPHA - a tubular in structure which form a mass or MYCELIUM. • Molds reproduce by forming SPORES which can cause infection. • Infection ranges from short term irritation to being death threatening.

  25. Penicillin HYPHA

  26. Single spore - can causesallergy and asthma.

  27. C - Viruses Wide range of weird and wonderful shapes. Enveloped

  28. Viruses • Single cell with no organelles. • They reproduce in living cells at a fantastic rate. • They can mutate taking on new forms making them hard to treat.

  29. Viral Infection • Most viruses cause ACUTE infection – short duration and rapid recovery • Eg respiratory infections(e.g., cold viruses, influenza viruses). • Latent viral infection can remain dormant in the host for years. • Eg Herpes zoster - causes chicken pox and shingles. • HIV.

  30. D - Protozoa • Unicellular microbes inhabitingmainly soil and water whichcan cause severe disease. • 6% of global disease is causedby poor sanitation. (WHO 2004).

  31. Protozoa

  32. E.g. • Entamoeba histolytica • Single celled AMOEBA which lives in water. • Causes amoebic dysentery if ingested.

  33. E.g. • Trichomonas vaginalis • Single celled FLAGELLATE (flagella is Latin for WHIP). • Causes urinary tract and vaginal infections from sexual contact.

  34. Commensal Microbes • We are only about 10% human!!!! • The number of microbes is greater than the number of human cells in the entire body!!!

  35. Commensal microbes • Noun1. commensalism - the relationship between two different kinds of organisms when one receives benefits from the other without damaging it. • Commensals can live all over and in the body: • Gut - E coli • Reproductive system - Candida albicans • Nose - Staphylococci • Mouth - Streptococcus

  36. Commensal microbes • The microbes in your large intestine ferment undigested food such as fibre providing the body with energy…..

  37. …and wind!

  38. But - Commensals can Cause Infection If a commensal bacteria is in the WRONG PLACE at the WRONG TIME it can cause infection… E.g. - if the skin is cut, during immuno-suppression,in the elderly or very young.

  39. The BAD and the UGLY Pathogens and Infection

  40. Pathogens • A pathogen is a microbes that cause disease (pathogenicity) by rapidly growing, producing toxins or causing cell damage…. • Vibrio cholera - diarrhoea • Helicobacter pylori - stomach ulcers • Mycobacterium tuberculosis - TB

  41. What is an Infection? Infection is the invasion of the body by microbes which then multiply and cause tissue damage and disease. Can be a non-residentPATHOGEN whichenters the body Can be a COMMENSAL microbe which gets into the wrong place

  42. And finally… Guess the Infection Bacterium Virus Fungus Protozoa

  43. Measles - VIRUS

  44. Diarrhoea - BACTERIA, PROTOZOA e.g. vibrio cholera, amoebic dysentery

  45. Cold - influenza VIRUS

  46. Athlete's foot - FUNGUS

  47. Mumps - VIRUS Swelling of salivary glands

  48. Jock Itch or Furuncle - BACTERIA Staphylococcus aureus bacterial infection of hair follicle.

  49. Thrush - YEAST Candida albicans infection of mouth or genitals

  50. Thrush

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