1. Diseases
Chapters 21-26

2. Microorganisms and human Disease
Things to cover
Diseases of Skin and Eyes
Diseases of the Nervous system
Diseases of the Cardiovascular & Lymphatic System
Diseases of the Respiratory System
Diseases of the Digestive System

3. How I will tackle these Structure and function. Normal Microbiota
Some of the diseases (More diseases to come)
Bacterial
Viral
Other
You will provide more of the details

4. Skin and Eyes Ch 21 Physical and chemical barrier against microbes
Moist areas have greater number of bacteria

7. Epidermis contains flattened cells of keratin and is essentially waterproof.
Dermis is the living part, contains follicles, ducts and glands that act as week point for bacterial invasion.
Sebum and perspiration can inhibit growth of microbes.
Same also provide nutrients to microbiota
The body and body cavities are lined with epithelia cells.
Mucous membranes secrete mucus.

8. What does the integument system do?

10. Microbiota Divide rapidly, resistant to desiccation and high salt.
Mostly gram positive cocci.
Never completely absent.
Propionibacterium metabolize oil
Pityrosporum ovale are yeast that grow in oily secretions, cause dandruff.

11. Staphylococcal Skin Infections
Folliculitis
Infections of hair follicles
Sty
Folliculitis of an eyelash
Furuncle
Abscess; pus surrounded by inflamed tissue
Carbuncle
Inflammation of tissue under the skin

12. Staphylococcal Skin Infections
Impetigo of the newborn
Toxemia
Scalded skin syndrome
Toxic shock syndrome
Figure 21.4

13. Streptococcal Skin Infections
Streptococcus pyogenes
Group A beta-hemolytic streptococci
M proteins
Figure 21.5

14. Streptococcal Skin Infections
Erysipelas
Impetigo
Figure 21.6, 7

15. Invasive Group A Streptococcal Infections
Streptokinases
Hyaluronidase
Exotoxin A, superantigen
Cellulitis
Necrotizing fasciitis
Figure 21.8

16. Infections by Pseudomonads
Pseudomonas aeruginosa
Gram-negative, aerobic rod
Pyocyanin produces a blue-green pus
Pseudomonas dermatitis
Otitis externa
Post-burn infections

17. Warts Papillomaviruses Treatment: Removal
Imiquimod (stimulate interferon production)
Interferon

18. Poxviruses Smallpox (Variola) Monkeypox
Smallpox virus (Orthopox virus)
Variola major has 20% mortality
Variola minor has <1% mortality
Monkeypox
Prevention by smallpox vaccination
Figure 21.9

19. Measles (Rubeola) Measles virus Transmitted by respiratory route
Macular rash and Koplik's spots
Prevented by vaccination
Encephalitis in 1 in 1000 cases
Subacute sclerosing panencephalitis in 1 in 1,000,000 cases
Figure 21.14

20. Cutaneous Mycoses Dermatomycoses: tineas or ringworm
Metabolize keratin
Trichophyton infects hair, skin, nails
Epidermophyton infects skin and nails
Microsporum infects hair and skin
Treatment
Oral griseofulvin
Topical miconazole

21. Cutaneous Mycoses
Figure 21.16

22. Candidiasis Candida albicans (yeast)
Candidiasis may result from suppression of competing bacteria by antibiotics
Occurs in skin; mucous membranes of genitourinary tract and mouth
Thrush is an infection of mucous membranes of mouth
Topical treatment with miconazole or nystatin

23. Candidiasis
Figure 21.17

24. Pediculosis Pediculus humanus capitis (head louse)
P. h. corporis (body louse)
Feed on blood
Lay eggs (nits) on hair
Treatment with topical insecticides
Figure 21.19

25. Microbial Diseases of the Eye
Conjunctivitis (pinkeye)
Haemophilus influenzae
Various microbes
Associated with unsanitary contact lenses
Neonatal gonorrheal ophthalmia
Neisseria gonorrhoeae
Transmitted to newborn's eyes during passage through the birth canal
Prevented by treatment newborn's eyes with antibiotics

26. Nervous System Ch22
CNS is brain and spinal cord. Is encased and protected by bone and membranes.
PNS are nerves outside of the Central nervous system. Is not protected as extensively and is a rout into the CNS.
Membranes of the CNS
Dura mater, arachnoid and piamater

30. More nervous
Cerebrospinal fluid instead of blood circulates between the arachnoid and piamater in the subarachnoid space.
Cerebrospinal fluid is totally separate from the blood and circulatory system.
Blood brain barrier
Entry to CNS by bacteria is through peripheral nerves, though blood and lymphatic system.

31. Meningitis is an infection of the meninges
Encephalitis is an infection of the brain.

32. What does the Nervous system do?

33. Normal Microbiota?

34. Bacterial Meningitis Fever, headache, stiff neck
Followed by nausea and vomiting
May progress to convulsions and coma
Diagnosis by Gram stain of CSF
Treated with cephalosporins

35. Bacterial Meningitis
Table 22.1

36. Tetanus Clostridium tetani
Gram-positive, endospore-forming, obligate anaerobe
Grows in deep wounds
Tetanospasmin released from dead cells blocks relaxation pathway in muscles
Prevention by vaccination with tetanus toxoid (DTP) and booster (dT)
Treatment with tetanus immune globulin

37. Botulism Clostridium botulinum
Gram-positive, endospore-forming, obligate anaerobe
Intoxication due to ingesting botulinal toxin
Botulinal toxin blocks release of neurotransmitter causing flaccid paralysis
Prevention:
Proper canning
Nitrites prevent endospore germination in sausages

38. Botulism Treatment: supportive care and antitoxin
Infant botulism results from C. botulinum growing in intestines
Wound botulism results from growth of C. botulinum in wounds.

39. Transmissible Spongiform Encephalopathies
Caused by prions
Sheep scrapie
Creutzfeldt-Jakob disease
Kuru
Bovine spongiform encephalopathy
Transmitted by ingestion or transplant or inherited
Chronic, fatal

40. Transmissible Spongiform Encephalopathies
Figure 22.17a

41. Cardiovascular and Lymphatic Systems Ch 23
Consists of heart, blood and blood vessels
Lymph, lymph vessels, lymph nodes and lymphoid organs.

42. Body Fluids and Flow
Heart circulates substances to and from tissue cells.
Blood is a mixture of plasma and cells.
Most substances are dissolved in plasma
RBC’s carry oxygen.
WBC’s are involved in defense.
Interstitial fluid is essentially plasma and exits from capillaries

48. Normal Microbiota?
Life Loads?

49. Sepsis and Septic Shock
Bacteria growing in the blood
Severe sepsis
Decrease in blood pressure
Septic shock
Low blood pressure cannot be controlled
Figure 23.3

50. Sepsis Gram-negative Sepsis Gram-Positive Sepsis
Endotoxins caused blood pressure decrease
Antibiotics can worsen condition by killing bacteria
Gram-Positive Sepsis
Nosocomial infections
Staphylococcus aureus
Streptococcus pyogenes
Group B streptococcus
Enterococcus faecium and E. faecalis

51. Viral Hemorrhagic Fevers
Classic
Yellow fever
Flavivirus
Aedes aegypti
Monkeys
Dengue & DHF
A. aegypti
A. albopictus
No known reservoir
Emerging
Marbug
Filovirus
Monkeys (?)
Ebola
Lassa fever
Arenavirus
Rodents
Argentine hemorrhagic fever
Bolivian hemorrhagic fever
Hantavirus pulmonary syndrome
Hantavirus

52. Malaria Plasmodium vivax, P. ovale, P malariae, P. falciparum
Anopheles mosquito
12.31b

53. Respiratory System Ch 24 Most common type of infection
Usually first on way to infection.

54. Microbial Diseases of the Upper Respiratory System
Laryngitis: S. pneumoniae, S. pyogenes, viruses
Tonsillitis: S. pneumoniae, S. pyogenes, viruses
Sinusitis: Bacteria
Epiglottitis: H. influenzae

55. Upper respiratory: nose, pharynx, middle ear and auditory tubes.
Filtration by coarse hairs
Ciliated mucous membranes of nose and throat trap airborne particles (greater than 10um)
Associated with lymphoid tissues (tonsils, and adenoids)

57. Lower respiratory system
Larynx, trachea, bronchial tubes and alveoli.
Ciliary escalator prevents microbes from reaching the lungs.
Alveolar macrophage protect lungs.
Respiratory mucus contains IgA antibodies

58. Microbial Diseases of the Lower Respiratory System
Bacteria, viruses, & fungi cause:
Bronchitis
Bronchiolitis
Pneumonia

60. What do the lungs do?

61. Normal Microbiota Of throat and nasal cavity can include pathogens.
Lower respiratory system is usually sterile because of ciliary escalator.

62. Opportunistic fungi involved in respiratory disease:
Aspergillus
Rhizopus
Mucor
Mucor rouxii
Figure 12.2b, 12.4

63. Digestive System Ch 25 Second most common illnesses
Usually ingestion of microbes and toxins.
Fecal-oral transmission is broken by proper disposal of sewage, disinfection of drinking water and proper food prep and storage.

64. Structure Function
GI or alimentary canal: mouth, pharynx, esophagus, stomach, small intestine and large intesting, colon, anus.
Accessory organs: teeth, tongue, salivary glands, liver, gallbladder and pancrease.
Charged with ingestion, digestion, absorption and elimination.

67. Normal microbiota Lots and unknown number occupy the mouth.
Streptococcus mutans in mouth produces acid.
Dextran from bacteria is plaque
Bacteria number are reduced in stomach.
Normal flora in lower gut.

68. Normal Microbiota >300 species in mouth
Large numbers in large intestine, including:
Bacteroides
E. coli
Enterobacter
Klebsiella
Lactobacillus
Proteus

69. What does the gut do?

70. Bacterial Diseases of the Lower Digestive System
Symptoms usually include diarrhea, gastroenteritis, dysentery
Treated with fluid and electrolyte replacement
Infection caused by growth of pathogen
Incubation from 12 hr to 2 wk
Intoxication caused by ingestion of toxin
Symptoms appear 1-48 hr after ingestion

71. Urinary and Reproductive systems
Regulates chemical components of blood excretes nitrogenous waste.
Infections can be from outside source or form normal microfloura.
Microbes can use a system to transfer gametes to also transfer themselves.
More than 150 years ago in London, an astute physician, John Snow, described the mode of transmission of cholera (nearly 30 years before Robert Koch discovered the causative agent, Vibrio cholerae; see photo and slide show), and a visionary engineer, Joseph Bazalgette, established an effective means of preventing it: the provision of municipal sanitation. Cholera is thus one of the first infections whose mode of transmission was understood and for which effective prevention measures, collectively referred to as "the sanitary revolution," were developed and implemented. Because of these early observations and interventions, cholera has become vanishingly rare in the United States and other developed countries. From NEJM 0309

72. Microbial Diseases of the Urinary and Reproductive Systems
Microbes usually enter the urinary system through the urethra
Microbes usually enter the reproductive system through the:
Vagina (females) or urethra (males)

76. Function?

77. Normal Microbiota Urinary bladder and upper urinary tract sterile
Lactobacilli predominant in the vagina
>1,000 bacteria/ml or 100 coliforms/ml of urine indicates infection

78. Sexually Transmitted Diseases (STDs )
Prevented by condoms
Treated with antibiotics

79. Websites.
STD’s