Microbiology 2 provides an overview of pathogens and infectious diseases. It defines pathogens, infectious and non-infectious diseases, and discusses different types of microbes that cause disease including bacteria, viruses, parasites, and fungi. The document also covers topics like transmission of diseases, immunity, historical discoveries related to fighting diseases, current pandemics, and methods of preventing infectious diseases.

1. Microbiology 2:
PATHOGENS
Ppt. by Robin D. Seamon
HOOK VIDEO: Nightmare Bacteria

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
VIDEO: WHO What you need to know about Infectious Disease

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
VIDEO: Why do Bats Transmit Diseases?
VIDEO: Loathsome Mosquitos

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"
http://www.healthline.com/health-slideshow/germy-places#1

8. Wet laundryDirty 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) VIDEO: Vector Borne Disease

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

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 needs-
sickness
• 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
2. Cocci- spherical
3. Spirilla- long spiral
SHAPES

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)
VIDEO: What is Bacteria?

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!
http://archives.microbeworld.org/scientists/all_profiles/interview2.aspx

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 replicate
• Lytic cycle: Need to hijack a living cell’s nucleus,
program it to make copies of itself to replicate
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

19. Capsid; protein coat
Nucleic Acid: DNA or RNA
Virus purpose:
REPRODUCTION- to pass on
genetic information
Bacteriophage
BACKVIDEO: Cell vs. Virus Battle for Health

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
VIDEO: How do Vaccinations Work

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
Dampening Off
http://www.planetnatural.com/pest-problem-solver/plant-disease/
Plants get diseases too.

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. BACK
G. lamblia

26. Athlete’s Foot

27. Ringworm
BACK

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

29. BACK

30. Liver fluke life cycle
BACK

31. Hookworm Life Cycle
NEXT

32. BACK

33. Epidemic: when a large percentage of people become
infected in a specific geographical area
Pandemic: when it crosses country & continental
borders
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
VIDEO: How Pandemics Spread

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 20th 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- 1928 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) 1796
1st successful vaccination:
Jonas Salk- 1950’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
VIDEO: How we Conquered Smallpox

38. TODAY
• Pharmaceutical companies study disease & medicine
• CDC- Center for Disease Control- US Government
agency that studies infectious disease
Atlanta,
Ga
VIDEO: Infectious Disease- Causes & Concerns

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
VIDEO: Flu Attacks!

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
VIDEO: What causes Antibiotic Resistance

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. PAST PANDEMICS/EPIDEMICS-
Bubonic plague
Tuberculosis
Smallpox
CURRENT PANDEMICS/EPIDEMICS-
HIV/AIDS
Regular flu- influenza (viruses called orthomyxoviruses)-
some spread from animals to people
P A S T P A N D E M I C S
VIDEO: 10 most Deadly Diseases

45. Tuberclosis
1800- 1922

46. Bubonic Plague

47. Smallpox Epidemic 1870

48. Flu pandemics/epidemics
• Every year the ‘regular’ or ‘seasonal’ flu kills 40,000 US
citizens
• 1918-1920- 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
R E C E N T P A N D E M I C S

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
2009- Mexico & US
Virus flu 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: http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/
• As of Feb 16, 2016: 28603 cases; 11301 deaths

56. VIDEO: What
we Know &
Don’t Know
about Ebola

57. Zika Virus
Tropical virus
vectors- mosquito
Symptoms in adults: fever, rash,
joint pain, and red eye
No current vaccine
• virus spread through mosquito bite & sexual contact.
• Causes microcephaly: birth defect of abnormally small
head in newborns. Mothers contract the virus with and
pass it to the baby while in the womb.
• What is Zika VIDEo (3 min)

58. 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

60. Wash for the length of the Alphabet song!