Microbiology 2: PATHOGENS. Ppt. by Robin D. Seamon

Transcription

1 Microbiology 2: PATHOGENS Ppt. by Robin D. Seamon

2 Disease: normal body functions are disrupted Pathogen: any microbe that causes disease Noninfectious disease: can t be spread from person to person Genetic disorder (hemophilia) Smoking Lack of exercise High fat diet Infectious disease: passed from one organism to another

3 Immunity: ability to resist a disease 1.Air 2.Contaminated objects 3.person to person 4.Animal vector (mosquito) 5.Food & water Vectors: organisms that transmit pathogens from a host to a new organism Carrier: an organism with the infectious pathogen but no symptoms

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7 You bring them in. The key: Wash your hands properly. Experts advise that friction (especially between the fingers) and duration are both important (CDC, 2013). Wash for 20 to 30 seconds, or the amount of time it takes to sing "The Alphabet Song"

8 Dirty laundry Wet laundry

9 T R A N S M I S S I O N DIRECT CONTACT- communicable (mononucleosis) Kissing Shaking hands Touching open wounds or sores Sexual contact/bodily fluids INDIRECT CONTACT- objects: doorknobs, telephones, etc. Air (tuberculosis) Food (botulism) Water (typhoid fever) Vectors Animal bites (rabies, West Nile Virus)

10 P O R T A L S O F E N T R Y Respiratory Tract nose, mouth, lungs Gastrointestinal Tract throat, stomach, intestines Mucous membranes nose, eyes Penetration bites, cuts, injections

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12 B A C T E R I A L D I S E A S E S many are contagious prokaryotic, unicellular everywhere- some are beneficial Digestion, decomposers, photosynthesizers, critical components of ecosystems, bioremediation Some are pathogens in food, water, cuts Reproduce quickly, using nutrients the body needssickness Most pathogenic bacteria produce toxins that disrupt normal cell functions- sickness Antibiotics can kill or slow growth of bacteria Sinus infections, Tuberculosis, Strep throat, pneumonia, Lyme disease

13 1. Bacilli- rod-shaped SHAPES 2. Cocci- spherical 3. Spirilla- long spiral

14 EXAMPLES Cocci: Staphylococcus (Staph), Streptococcus (Strep Throat) Bacilli: Escherichia coli (E. coli; 0157:H7), Bacillus anthracis (Anthrax), Clostridium botulinum (Botulism Toxin Producer) Spirilla: Campylobacter jejuni (causes diarrhea esp. in children), Helicobacter pylori (causes peptic ulcers)

15 Endospore: dormant version of the bacteria When conditions improve, endospore splits & bacteria become active again Scientists found bacteria inside an insect preserved in amber 30 million years ago; when endosperm was moistened, bacteria began to grow again!

16 REPRODUCTION Binary fission single cell divides into two identical daughter cells

17 V I R A L D I S E A S E S All are pathogenic Strange code names based on how they were identified or isolated Not alive Not made of cells- only reproduce Lytic cycle: Need to hijack a living cell s nucleus, program it to make copies of itself to reproduce until that cell overworks, dies & spills out hundreds of copies of the virus Common cold- VECTOR: air/touch HIV- VECTOR: bodily fluids Influenza Mononucleosis (mono) ADVANCE

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19 Capsid; protein coat Nucleic Acid: DNA or RNA Virus purpose: REPRODUCTION- to pass on genetic information Bacteriophage BACK

20 Average person has 2 cold viruses a year: sore throat, sneezing, congestion, headache, runny nose Vaccines: contain dead pathogens so that the body fights a weak form of the invader; when the body encounters the live version in its lifetime, it will remember exactly how to kill it. Vaccines are given to young children so immune system can gain strength, to travelers Anti-viral medications: can help slow down some viruses

21 Herd immunity- protects groups; if 90% of the population is vaccinated, epidemics never take hold In vaccinated communities, germs have fewer bodies in which to infect, multiply Germs have nowhere to breed so infection fizzles out LINK: Animation of Herd immunity

22 Herd Immunization Theory PROBLEM: real populations of immunized & non-immunized aren t as evenly distributed as they are in the models.

23 Apple Scab Bacterial Canker Cedar Apple Rust Plants get diseases too. Dampening Off

24 P A R A S I T E D I S E A S E S Protists- unicellular microorganisms; many have insect vectors Giardia: nausea, cramps, diarrhea Malaria: Plasmodium Fungi- decomposers that don t wait until death to start feeding on organism; usually on skin Athlete s foot: fungus- skin flakes & itches Ringworm: fungus- skin itches in red circle patterns ADVANCE

25 G. lamblia BACK

26 Athlete s Foot

27 Ringworm BACK

28 Flatworms- parasitic Tapeworms Flukes (liver fluke) Schistosoma Liver fluke Tapeworm roundworms -nematodes; parasitic; most live in the intestines of host Pinworms (Enterobius vermicularis) Hookworms (Necator and Ancylostoma) Trichinella spiralis (larvae migrate to muscle) Pinworms

29 BACK

30 Liver fluke life cycle BACK

31 Hookworm Life Cycle NEXT

32 BACK

33 O T H E R : Dangerous chemicals- poison body (lead in water & air)- damages brain, kidney, liver, learning, behavioral problems Mutagens- substances that cause cells to mutate (change form) X-rays, cigarette smoke, sunlight/uv- skin cancer Epidemic: when a large percentage of people become infected in a specific geographical area Pandemic: when it crosses country & continental borders

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35 H I S T O R Y - F I G H T I N G D I S E A S E Until the 20 th C. surgery patients died of bacterial infections. Pasteurization- mid 1800s Louis Pasteur (French) discovered microorganisms that cause wine to spoil- bacteria Devised a method to kill the bacteria by heating it: pasteurization

36 Alexander Fleming discovered the first antibiotic Found a mold growing in his Petri dishes & noticed that the fungus was exuding a chemical that was killing the bacteria in his dish: named it penicillin

37 Edward Jenner (English) st successful vaccination: Jonas Salk s American virologist who developed the polio vaccine (viral disease affecting the nerves, leading to paralysis 1979 WHO said smallpox was wiped out due to vaccination

38 Atlanta, Ga TODAY Pharmaceutical companies study disease & medicine CDC- Center for Disease Control- US Government agency that studies infectious disease

39 SIZES: 1 inch = 250,000 virus germs end-to-end 1 inch = 25,000 bacteria end to end 1 inch = 5,000 protist end-to-end 1 inch = 2,500 fungus spore end to end M I C R O B U G S - T H E B I G 4 1. Fungus/molds Athlete s foot Thrush Ringworm Fungal nail infections 2. Protist/Protozoa Plasmodium- malaria Trypanosomes- sleeping sickness

40 3. Bacteria Tuberculosis Cholera Gonorrhea Syphilis Diptheria Whooping cough Typhoid Skin infections: boils, impetigo, stomach ulcers Food poisoning Diarrhea

41 4. Virus- 1-1,000 in a few hours All are pathogenic- they hijack host-cells Colds- flu Rubella Cold sores Herpes Rabies Chicken pox Measles AIDS Hepatitis yellow fever Cervical cancer H1N1- Swine Flu

42 S U P E R B U G S As living things multiply, slight mutations may occur in genetic material The vast numbers of pathogens as they multiply mean that mutations are likely Sometimes a chance mutation gives the bug a partial or complete resistance to the drug The resistant bug multiplies & spreads until scientists find a new drug to kill it Using antibiotics too often has caused a problem

43 PROBLEM: Nightmare Bacteria Recently, scientists & doctors have documented populations of bacteria that are pan-resistant: no form of antibiotic will kill it Nightmare bacteria (CDC s term) can pass resistance between different strains of bacteria outside of a host (in other vectors such as water) Some are able to lie dormant in carrier hosts, avoiding detection, thus spreading to others unknowingly WHAT DOES THIS MEAN FOR THE FUTURE OF DISEASE-CONTROL?

44 P A S T P A N D E M I C S PAST PANDEMICS/EPIDEMICS- Bubonic plague Tuberculosis Smallpox CURRENT PANDEMICS/EPIDEMICS- HIV/AIDS Regular flu- influenza (viruses called orthomyxoviruses)- some spread from animals to people

45 Tuberclosis

46 Bubonic Plague

47 Smallpox Epidemic 1870

48 R E C E N T P A N D E M I C S Flu pandemics/epidemics Every year the regular or seasonal flue kills 40,000 US citizens Spanish Influenza killed 80 million people H1N1 Swine Flu Virus- contains parts of several different viruses that previously had affected pigs, birds & then humans Influenza viruses spread- Coughing Sneezing Touching contaminated objects to nose/mouth

49 Bird Flu- (Avian Influenza) 1997 flu first jumped to humans 4 main virus strains (H5N1) Infects humans in contact with infected poultry- birds fluids enter human nose, mouth, cut Symptoms: fever, headache, joint ache, sickness, sore eyes, nose, throat Kills 2/3 of sufferers Antiviral drugs ease symptoms

50 Swine Flu Mexico & US Virus flue type H1N1 may have been in pigs for years before jumping to people Spreads person-to-person Kills fewer than 1 in 250 sufferers Vaccines were developed quickly

51 African sleeping sickness Most parasites don t kill host Take nutrients from it- sickens/weakens host Often attacks digestive or circulatory systems This parasite destroys red blood cells that carry oxygen through the body, making person tired & lethargic (sleepy) Tsetse fly

52 African Sleeping Sickness

53 HIV/AIDS Human Immunodeficiency Virus- targets T-Cells (immune cells) Leads to AIDS- auto immune deficiency Transmitted via sexual contact, used hypodermic needles Rapidly mutates differently in each host Not a cause of death- subsequent infections kill the host b/c immune system is compromised

54 2008 Data

55 Ebola 1976 West Africa, named for the Ebola River in the Congo Possible vectors- other primates virus spread through bodily fluids of a sick individual entering cut/eyes/nose person is contagious only AFTER feeling sick/showing symptoms (2 week incubation period) does NOT travel through the air, water, or food fever, headache, soreness, leading to deadly symptoms of hemorrhaging, organ failure & death patients can be treated so that their own bodies fight the disease- no cure or vaccine currently CDC stats: As of Jan 25, 2015: cases; 8,675 deaths

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57 I N F E C T I O U S D I S E A S E P R E V E N T I O N Good hygiene or keeping yourself clean Washing your hands and bathing regularly Cover your mouth when you sneeze or cough don't use hands, use arm Killing pathogens antibiotics kill bacteria but not viruses vaccines prevent both Certain medications help body build up immunity CDC- prevention brochure

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59 Wash for the length of the Alphabet song!