인간의 삶과 역사 속의 미생물

1. 인간의 삶과 역사 속의 미생물 강의자료ppt-7 2010-2학기

2. 미생물은어떤 존재인가?

3. 질병과미생물

4. 병 주는 미생물

5. Death rate and the leading causes of death in the U.S.

6. Death due to infectious disease

7. Worldwide death due to:

8. Causes of death in Africa, 2002

9. Causes of death in the Americas.

10. Airborne pathogens • Aerosols are important vehicles for person-to-person transmission of many infectious diseases • Most pathogens survive poorly in air, thus, are effectively transmitted among humans only over short distances

11. High-speed photograph of an unstifled sneeze

12. The Respiratory Tract of Humans

13. Sreptococcal diseases • Streptococcus pyrogenes • Commonly found in low numbers in the upper respiratory tract of healthy individuals • Causative agent of “strep throat” • Can also cause infections of the inner ear, mammary glands, and skin • Infections occur if host defenses are weakened or a new highly virulent strain is introduced

14. Typical Lesions of Impetigo (농가진[膿痂疹])

15. Erysipelas (단독[丹毒]) : A S. Pyogenes Infection of the Skin

16. Scarlet fever (성홍열[猩紅熱])

17. The Gram-Positive Pathogen Streptococcus pneumoniae

18. Corynebacteriumdiphtheriae • Diphtheria • A severe respiratory disease that typically infects children • Caused byCornyebacteriumdiphtheriae • A bacterium that forms irregular rods during growth • Preventable and treatable

19. Pseudomembrane (Arrows) in active case of diphtheria

20. Mycobacterium:tuberculosis, and Hansen’s disease • Tuberculosis is caused by Mycobacterium tuberculosis • Hansen’s disease (leprosy) is caused by M. leprae

21. Mycobacterium avium in an acid-fast stained lymph node

22. Mycobacterium:tuberculosis, and Hansen’s disease • Tuberculosis • An important infectious disease of humans worldwide • Incidence is increasing in part because of the emergence of drug-resistant strains • M. tuberculosis is transmitted by airborne droplets

23. Tuberculosis X-Ray An Advanced Case of Pulmonary Tuberculosis Normal Chest X-Ray

24. Mycobacterium:tuberculosis, and Hansen’s disease • Hansen’s disease (leprosy) • M. leprae is the causative agent • The armadillo is the only experimental animal that has been successfully used to grow M. leprae • Most serious form is characterized by folded, bulblike lesions on the body

25. Lepromatousleprosy lesions on the skin

26. Mycobacterium:tuberculosis, and Hansen’s disease • Pathogenicity of M. leprae • Due to a combination of delayed hypersensitivity and the invasiveness of the organism • Transmission is by both direct contact and respiratory routes • Incubation times vary from several weeks to years • The incidence of leprosy worldwide is low

27. Virusesand respiratory infections • Viruses are less easily controlled by chemotherapeutic methods than bacteria because the propagation of viruses depends on host cell function • The most prevalent human infections are caused by viruses • Most viral diseases are acute, self-limiting infections • A few serious viral diseases have been effectively controlled by vaccination (e.g., influenza, smallpox and rabies)

28. Virusesand respiratory infections • Measles • Often affects susceptible children as an acute, highly infectious, often epidemic disease • Virus enters the nose and throat by airborne transmission • Used to be a common childhood illness • Over 600,000 deaths per year worldwide

29. Measles in Children Begins on the head and neck Spreads to the chest, trunk, & limbs

30. Viral Diseases and Vaccines: Measles

31. Virusesand respiratory infections • Mumps • Highly infectious • Spread by airborne droplets • Characterized by inflammation of the salivary glands

32. Viral Diseases and Vaccines: Mumps

33. Virusesand respiratory infections • Chickenpox • Common childhood disease characterized by a systemic papular rash • Caused by varicella-zoster virus (VZV), a DNA herpesvirus • VZV is highly contagious and transmitted by infectious droplets • VZV virus establishes a lifelong latent infection in nerve cells • The virus occasionally migrates to the skin surface, causing a painful skin eruption (shingles)

34. Chickenpox

35. Colds • Colds • The most common of infectious diseases • Viral infections transmitted via airborne droplets • Infections are usually of short duration • Symptoms milder than other respiratory diseases

36. Colds: Common cold • Common Cold • Symptoms include rhinitis, nasal obstruction, watery nasal discharges, and malaise • Most antiviral drugs are ineffective against the common cold, but pyrazidine derivatives have shown promise for preventing colds after virus exposure • Each cold infection induces a specific, protective immunity, but the large number of viral cold pathogens precludes complete protective immunity or vaccines

37. Common Cold Viruses Human Rhinovirus Human Coronavirus

38. Colds: Influenza • Influenza is caused by an RNA virus of the orthomyxovirus group • There are three different types of influenza viruses (A, B, C) • Influenza A is the most important human pathogen Influenza virus

39. Colds: Influenza • Influenza outbreaks occur annually due to the plasticity of the influenza genome • Antigenic shift • Major change in influenza virus antigen due to gene reassortment • Antigenic drift • Minor change in influenza virus antigens due to gene mutation

40. Colds: Influenza • Influenza epidemics and pandemics occur periodically • 1957 outbreak of Asian flu • 1997 outbreak of avian influenza

41. An influenza pandemic

42. Avian Influenza

43. Colds: Influenza • Prevention • Controlled by immunization • Careful worldwide surveillance • Treatment • Use of various drugs • Most effective when administered early • Aspirin should be avoided

44. Colds and Influenza

45. Direct contact transmission of diseases: Staphylococcus • Staphylococci cause diseases including acne, boils, pimples, impetigo, pneumonia, osteomyelitis, carditis, meningitis, and arthritis • Many diseases result from pyogenic infection or from the actions of staphylococcal superantigenexotoxins

46. The structure and rupture of a boil The structure of a boil The rupture of a boil

47. Direct contact transmission of diseases: Helicobacter pylori and gastric ulcers • Helicobacter pylori • A gram-negative, highly motile, spiral-shaped bacterium • Associated with gastritis, ulcers, and gastric cancers • Colonizes the non-acid-secreting mucosa of the stomach and upper intestinal tract • Transmitted via person-to-person contact or ingestion of contaminated food or water

48. Direct contact transmission of diseases: Hepatitis viruses • Hepatitis • A liver inflammation caused by viruses or bacteria • Sometimes results in acute illness followed by destruction of functional liver anatomy and cells • A restricted group of viruses is often associated with liver disease • Hepatitis viruses are diverse HBV

49. Hepatitis in the United States

50. Sexually transmitted infections (STI) • Also called sexually transmitted diseasesor venereal diseases • Caused by a variety of bacteria, viruses, protists, and even fungi • Pathogens are generally only found in body fluids from the genitourinary tract that are exchanged during sexual activity