Microbiology Chapter 10.txt

  1. Bacterial Diseases
    • Are usually airborne
    • Affect respiratory system
  2. Upper respiratory system
    Everything above the vocal cords (larynx)
  3. Upper Respiratory Diseases
    • Streptococcus
    • Meningococcus Meningitis
    • Haemophilus Meningitis
  4. Pharyngitis
    • Sore throat
    • Usually a symptom of a viral infection, but some bacteria, especially streptococci can cause this
  5. Streptococcus
    • Alpha hemolytic
    • Beta hemolytic
    • Gamma hemolytic
    • Groups A-O
  6. Physical attributes of Streptococcus
    • Gram+
    • Sphere shaped chains
    • Small bright white colonies
    • Encapsulated
  7. Streptococci can be divided into two groups, based on how they affect sheep red blood cells
    • alpha-hemolytic
    • beta-hemolytic
  8. Beta-hemolytic streptococcus
    Complete destruction of red blood cells (hemoglobin)
  9. Serotyping
    • Surface anogen
    • Groups A-O
    • They can also be classified according to variants of a carbohydrate in the cell wall
  10. What is the most common streptococcus?
    Streptococcus pyogenes
  11. Streptococcus pyogenes characteristics
    • G+
    • Group A Beta Hemolytic
    • Encapsulated chains
    • Common in the nose and throat
    • Puerperal sepsis (child bed fever)
    • Septicemia
    • Erysipelas
  12. What enhances Streptococcus pyogenes
    • The pathogenicity of S. pyogenes is enhanced by M protein, which helps it:
    • adhere to pharyngeal tissue
    • retard phagocytosis
  13. What is Erysipelas
    • Deadly pustules on the skin caused by Streptococcus pyogenes.
    • Found on chickens, pigs and humans
  14. Streptococcal sore throat characteristics
    • Caused by S. pyogenes
    • Contains M protein which increases the ability the bacteria to attach to the throat (pharynx)
    • 60 types. You can only get each one once
    • 500000 cases per year
    • Becoming antibiotic resistant
    • Was deadly before antibiotic
    • Primary disease - can cause disease in healthy tissue
    • Spread by airborne droplets
  15. Streptococcal Pharyngitis sore throat symptoms
    • Take 1-3 days to develop
    • High fever
    • Swollen lymph nodes
    • Red pharyngeal ring tissue
  16. Streptococcal Pharyngitis Treatment
    Treat with antibiotics
  17. Scarlet Fever
    • Some patients with strep throat may develop scarlet fever, exhibiting a rash caused by erythrogenic exotoxins
    • Other symptoms are sore throat, fever, strawberry-like inflamed tongue.
    • Normally only get this once in a lifetime because recovery generates immunity.
    • Get better in 2 weeks without treatment.
  18. Scarlet fever treatment
    • Treat with antibiotic and antitoxin
    • Antibiotics can shorten duration of the symptoms and prevent serious complications.
  19. Erythrogenic exotoxins
    • In Scarlet Fever, the toxins produced by the bacteria cause a pink-red skin rash on the neck, chest, and soft skin areas of the arms.
    • The rash usually occurs in children under the age of 15.
    • Caused by blood leaking through the walls of capillaries damaged by toxins
  20. Erythro
  21. Exotoxin
    Poisonsous proteins secreted by some G+ and G- bacteria
  22. Rheumatic fever
    • A serious complication of scarlet fever
    • Most common in young school aged children
    • An inflammation response to the infection that primarily affects joints and heart
    • Fever and joint pain
    • Causes permanent scarring and distortion of the heart valves called rheumatic heart disease
    • This is caused by the body's antibodies to streptococcal M proteins cross reacting with similar proteins in the heart muscle.
    • A serious problem in developing nations
  23. Acute glomerulonephritis
    • A complication from streptococcal pharyngitis
    • A rare inflammatory response to specific types of streptococcal M proteins
    • The antigen-antibody complexes formed accumulate in the glomerulus of the kidney.
    • Most common in young patients
    • Progressive, irreversible renal damage may occur in adults
  24. Glomerulus
    The part of the kidney that controls filtering and excretion.
  25. Diphtheria Characteristics
    • Diphtheria is a local infection of the throat caused by Corynebacterium diphtheriae
    • G+
    • Aerobic
    • Club shaped rod
    • Coryne = club
    • Metachromatic
    • Not a lot of bacteria are present in the disease
    • Damage caused by the exotoxin
    • Diphtheria Is a Life-Threatening Illness
    • There are usually less than a dozen confirmed cases in the U.S. each year
    • Diphtheria is acquired by respiratory droplet transmission
  26. Diphtheria Symptoms
    • Initial symptoms are sore throat and low-grade fever
    • Pseudomembrane formation
    • The exotoxin stops protein synthesis in the lining of tubes and forms a pseudomembrane on the tonsils or pharynx
    • Mucus and coughing
    • The bacterial cells remain in clumps after multiplying and form a picket fence like arrangement called a "palisade arrangement"
    • Mild cases fade in a week
    • Severe cases 2-6 weeks
    • Untreated = 5-10% mortality rate
    • Will damage nerves if you don't rest enough during recovery
  27. Diphtheria incubation
    2-4 days
  28. Diphtheria exotoxin
    • Encoded by a virus that infects C. Diphtheriae
    • Inhibits the translation process by ribosomes resulting in the accumulation of dead tissue, mucus, white blood cells and fibrous material called a pseudomembrane.
  29. Diphtheria treatment
    • Antibiotics - penicillin or erythromycin
    • Antitoxin
    • Before antibiotics, this would kill 50% of children who got it.
  30. Diphtheria vaccine
    • Immunization with denatured diphtheria toxoid
    • Part of the DTaP vaccine
    • Makes you grow your own antitoxin
  31. Metachromatic granules
    • Dark staining granules in bacteria
    • Found in C. diphtheriae
  32. Prophage
    • A virus that infects a bacteria
    • C. diphtheriae is infected with a virus that cause it to create the exotoxin
  33. Pertussis
    • Bordetella pertussis
    • Per = through
    • Tussi = cough
    • Highly contagious upper respiratory infection
    • Whooping Cough
    • Also called the100 day cough
    • Number of cases has been rising since 1981, possibly due to a more virulent strain and better lab testing
  34. Bordetella pertussis characteristics
    • G-
    • Small
    • Aerobic
    • Bacillus
    • Spread by respiratory droplets that adhere to and aggregate on the cilia of the epithelial cells in the mouth and throat
  35. Pertussis statges
    Two stages lasting 4-12 weeks
  36. Pertussis initial stage
    • Catarrhal
    • General malaise
    • Low-grade fever
    • Increasingly severe cough
  37. Pertussis second stage
    • Paroxysmal stage
    • Disintegrating cells and mucus accumulate in the airways and cause labored breathing
    • Paroxysms - Rapid fire staccato coughs all in one exhalation followed by a forced inhalation over a partially closed glottis.
    • The rapid inhalation results in the characteristic whoop
    • 10-15 paroxysms occur daily each followed by exhaustion
    • Sporadic coughing continues during convalescence even after pathogen disappears
  38. Pertussis treatment
    • Antibiotics - erythromycin
    • If treatment is begun before the respiratory passageways are block the bacteria is generally successful.
    • Antibiotics only reduce the duration and severity of the illness
  39. Pertussis Vaccine
    • The aP part of the DTaP vaccine
    • Lose immunity 5-10 years after vaccination
    • There are now boosters
  40. Meninges
    The meninges are three membranous coverings of the brain and spinal cord
  41. Bacterial Meningitis
    • Upper respiratory infection caused by
    • Neisseria meningitides
    • Streptococcus Pneumoniae
    • Haemophilus influenza Type b
    • All 3 species can cross the blood-brain barrier, inflaming the meninges
    • This causes pressure on the brain and spinal cord
  42. How are the bacteria that cause meningitis acquired?
    • Respiratory droplets from prolonged contact such as
    • Coughing
    • Sneezing
    • Kissing
  43. Neisseria meningitides
    • Causes meningococcal meningitis
    • Spread through person-to-person transfer of droplet respiratory secretions
    • Can cause meningococcal pharyngitis and then may invade into the nonciliated epithelium and spread to the blood
  44. Meningococcal Meningitis
    • Neisseria meningitides
    • G- encapsulated diplococcus
    • Small, aerobic
    • Attaches to the nasopharyngeal mucosa by pili
    • Airborne droplets
    • Influenza like respiratory disease
    • Toxins can enter blood and cause death in 2 hours
    • 50% mortality rate
    • Forms 1 of 14 different serogroup capusules.
  45. Serogroup
    A group of microbes having similar surface proteins (antigens)
  46. Meningococcal Meningitis
    • Stiff arched neck, headache
    • Rash on skin
    • Bright red patches progressing to blue-black spots
    • 50% mortality rate
  47. Meningococcal Meningitis Treatment
    Antibiotics: rifampin, penicillin
  48. What is Waterhouse-Friderichsen syndrome?
    • A complication of meningococcal meningitis in young childrens. Lesions form on the adrenal glands and cause hormone imbalances.
    • Is the result of a bacterial endotoxin in the blood.
  49. Pneumococcal meningitis
    • Caused by Streptococcus pneumoniae
    • Community acquired
    • Affects infants, middle aged and elderly adults
    • Patients with an absent spleen, sickle cell disease, chronic alcoholism, and those with recent skull fractures or head injury are at high risk
    • Responsible for ~30% of meningitis cases
    • 20-30% mortality rate

    • Haemophilus influenzae type b (Hib)
    • G-, small, nonmotile, encapsulated, bacillus
    • Was thought to cause influenza, but actually causes Haemophilus meningitis
    • Used to be the most prevalent bacterial species causing meningitis in children 2 months to 5 years old
    • Vaccine drastically reduced occurrence
  50. Richard Pfeiffer
    • Isolated Haemophilus influenzae type b (Hib) during the flu epidemic of 1918
    • Thought it caused flu but it was a secondary infection
  51. Haemophilus Meningitis
    • Haemophilus influenzae type b
    • G- encapsulated bacillus
    • Secondary to influenza
    • Most common form of meningitis
    • Occurs in children 6-12 months
  52. Haemophilus Meningitis Symptoms
    • Stiff neck
    • Headache
    • Drowsiness
    • 18,000 cases a year in 1986 before vaccine
    • 5% mortality rate
  53. Haemophilus Treatment and Vaccine
    • HiB vaccine
    • Antibiotic rifampin
    • No single vaccine provides immunity to all causes of meningitis
  54. Meningitis can have the following lasting affects:
    • deafness
    • blindness
    • paralysis
    • if untreated it can lead to coma and death
  55. Lower respiratory diseases
    • Tuberculosis
    • Pneumococcal Pneumonia
    • Klebsiella Pneumonia
  56. Tuberculosis
    • Mycobacterium tuberculosis
    • A major cause of death worldwide � 2 million people die every year globally
    • Airborne droplets, multiple exposures
    • Usually need repeated exposures
    • A big problem for AIDS patients
  57. Tuberculosis Symptoms
    • 10% have immediate symptoms (3 months)
    • Chronic cough
    • Chest pain
    • High fever
    • Rust colored sputum
    • 90% will never develop an active infection
    • Form tubercle
    • Miliary TB: Consumption
  58. Primary TB infection
    • The person has a pulmonary infection but may not yet have the disease
    • Chest X-Ray and sputum test are negative
    • Macrophages, lymphocytes and fibroblasts surround the mass forming a tubercle
  59. Tubercle
    • Macrophages arrive in the lungs and attempt to phagocytize the Mycobacterium tuberculosis bacillus but are unable to destroy them.
    • Macrophages, lymphocytes and fibroblasts surround the mass forming a hard nodule
  60. Latent TB infection
    • The infection becomes arrested in 90 % of primary TB infections
    • The tubercles heal and undergo fibrosis and calcification
    • Carried by 2 billion people worldwide
  61. Primary active TB disease
    10% of the people that have a primary TB infection will develop a clinical disease
  62. Secondary active TB disease
    • Reactivation of the TB bacilli
    • Unable to keep bacilli in check
    • Many of the macrophages dies releasing he bacilli and producing a caseous (cheese-like) center in the tubercle
    • Miliary tuberculosis
    • Disseminated
    • Active tubercles debelope throughout the body
    • No toxins, but the growth is so unrelenting the respiratory and other body tissues are literally consumed
  63. Mycobacterium tuberculosis
    • Neither G+ or G-
    • Bacillus
    • Use an acid fast stain
    • Enters the respiratory tract in small aerosolized droplets
    • Survives for years outside the body
    • Tuberculosis is a particularly big problem for AIDS patients
  64. Clinical tuberculosis
    • Develops within 3 months, and can be transmitted to others
    • Macrophages accumulate in the lung form a tubercle that harbors M. tuberculosis
    • If a tubercle breaks apart, bacteria spread throughout the body
  65. Miliary tuberculosis
    The development of active tubercles throughout the body
  66. Mantoux test
    The tuberculin reaction in the Mantoux test can be used for early detection of TB exposure
  67. Tuberculosis Vaccine
    Attentuated M. bovis is used in immunization infrequently
  68. TB detection
    • Tuberculin reaction, a delayed hypersensitivity test that begins with the application of a purified protein derivative (PPD) of M. tuberculosis to the skin
    • Mantoux test � injection of PPD into forearm
    • A positive test may indicate immunization, previous TB test or past exposure to Mycobacterium tuberculosis
  69. Induration
    • A think, raised, red welt of a defined diameter
    • In a TB test, if the welt is bigger than 15 mm the test is positive
  70. TB Treatment
    • Antibiotics � Isoniazid and rifampin
    • 5% of new cases are multidrug-resistant tuberculosis
    • Multidrug-resistance Mycobacterium tuberculosis is affecting which antibiotics are used to treat TB
  71. Mycobacterium avium-intracellulare
    • A bird form of TB
    • Common in AIDS and Chemo patients and people with suppressed immune systems
  72. Pneumococcal Pneumonia
    • Streptococcus pneumonia is the leading cause of both pneumonia and bacterial meningitis
    • 80% of "typical" pneumonia cases are caused by Streptococcus pneumoniae
    • It is acquired through aerosolized droplets or contact
    • 40,000 deaths per year
    • Lobar
    • Double
    • Bronchopneumonia
    • Walking pneumonia
  73. Streptococcus pneumoniae
    • Small
    • G+
    • Bacillus
  74. Pneumococcal Pneumonia Symptoms
    • Fever
    • Chest Pain
    • Difficult Breathing
    • Rust-colored sputum
  75. Lobar pneumonia
    1 lung lobe
  76. Double pneumonia
    Both lungs
  77. Bronchopnuemonia
    Patches in the respirator passageways
  78. Pneumonia treatment
    • penicillin
    • tetracycline
    • Chloramphenical � last resort. Very hard on liver and kidneys
  79. Pneumonia vaccine
    80 strains known, vaccine for 23 strains
  80. Other causes of pneumonia
    • Haemophilus influenzae
    • Staphylococcus aureus
    • Klebsiella pneumoniae
  81. Haemophilus influenzae can cause:
    • "Typical" pneumonia
    • Otitis media sinusitis
  82. Staphylococcus aureus
    • A common hospital-acquired form of pneumonia
    • It may result in necrotizing pneumonia
  83. Klebsiella pneumoniae
    • can be a primary or secondary infection in people with impaired pulmonary function
    • G- encapsulated bacillus
    • 5% of bacterial pneumonia
    • Spread by airborne droplets
    • Common noscomial disease
  84. Noscomial disease
    Disease acquired in the hospital
  85. Atypical Pneumonia
    • Can Be Caused by a Diverse Group of Bacterial Species
    • Mycoplasma pneumoniae causes primary atypical pneumonia, often called walking pneumonia
    • Mycoplasma. pneumoniae has no sensitivity to penicillin because it has no cell wall
    • The cold agglutinin screening test (CAST) is used to assist diagnosis
    • Has "fried-egg" colony appearance
  86. Legionnaires disease
    • Causes a severe atypical pneumonia
    • Headache
    • Dry cough
    • Some diarrhea and vomiting
    • Treated with Erythromycin
    • Exists where water collects and then becomes airborne in wind or breezes
    • Disease develops within a week of inhalation of contaminated droplets
    • Necrotizing pneumonia may develop
    • L. pneumophila also causes Pontiac fever, an influenza-like infection
  87. Q Fever
    • Coxiella burnetii
    • G- bacillus
    • World wide
    • Affects livestock so outbreaks occur where animals are raised, housed or transported
    • Can get from raw milk or cheese
  88. Q Fever Symptoms
    • Bronchopneumonia
    • Severe headache
    • High fever
    • Dry cough
    • Occasional lung lesions

    • Q Fever Treatment
    • Antibiotic doxycycline
  89. Q Fever vaccine
    Available for high-risk occupations
Card Set
Microbiology Chapter 10.txt
Microbiology Chapter 10