micro exam #4

  1. What are the three primary defenses of the respiratory system?
    • mucocillary escalator: traps debris and bacteria, which are then moved to the esophagus and out the respiratory system --> problem viral infections can disrupt the function of respiratory epitheium, which allows bacteria to enter respiratory system
    • Aveolar macrophages are in important part of the host defense --> problem: bronchial carcinoma can obstruct a bronchus and infection can arise behind obstruction
    • Muscle of the chest wall and diaphragm are important in coughing and cleaning secretions from the respiratory system --> problem: trauma or abdominal surgery
  2. What are the virulence factors of Streptococcus pyogenes?
    • M protiens: inhibits phagocytosis
    • hemolysin O and S
    • DNase
    • streptokinase
    • pyrogenic toxins
  3. explain 21.11 entitled Mechanisms associated w/ nosocomial pneumonia.
    • a.) mucousal surfaces are a coated w/ fibronectin and normal flora. Remval of this layer allows gram-neg bacteria to colonize the oropharynx in significant #'s
    • b.) some ofthe contibutory factors for nosocomial pneumonia
  4. Image Upload 1what is this a picture of?
    The influenza A virus
  5. What are the three ways influenza can kill?
    • underlying disease: people w/ limited cardiovascular activity or pulmonary function
    • superinfection: bacterial pneumonia and dissiminated bacterial disease
    • direct rapid progression: overwhelming viral pneumonia and asphxia
  6. What causes diphtheria to be fatal?
    • development of pseudo membrane- blocks throat, like seran wrap → suffocation
    • Toxemia can make diptheria life threatening: can involve multiple organ systems; can cause acute myocarditis → systemic infection
  7. how is diptheria transmitted?
    • droplet aerosol
    • direct contact
    • fomiites (lesser degree)
  8. key things to know about nosocomial infections?
    • hospital acquired
    • occurs 48 hours after hospital admission
    • associated w/ S. Aureus
    • caused by gram - bacteria
  9. what is community aquired pneumonia known as? and its s/s?
    • lobar pneumonia
    • s/s: fever, chest pain, purulent sputum
  10. what are the 4 stages of lobar pnumonia and describe them?
    • Acute congestion- local cappillaries become engorged w/ neutrophils
    • Red hepatization- RBCs from the capillaries flow into the alveolar spaces
    • Grey hepatization- large # of dead neutrophils and degenerating red cellss
    • Resolution- adaptive immune response begins to produce antibodies (control the infection)
  11. key things to know about Mycoplasma pneumonia
    • bacteria that lacks a cell wall
    • mild form
    • caused by mycoplasma pneumoniae
    • accounts for 10% of all pneumonia
    • “walking pneumonia”
    • no need for hospitalizationmost
    • common age 5-15: causes 30% of all teenage pneumonias
  12. key things to know about Chlamydial Pneumonias
    • caused by chlamydia pneumoniae
    • responsible for 10% of pneumonia cases and 5% of bronchits cases
    • occurs through-out the year
    • spread person to person contact
    • more infections in the elderly
    • causes both nosocomial and community acquired
  13. Know the causative agents and identifying signs/symptoms of the following diseases: strepthroat
    • pharyangitis
    • Causative agent (most common): strep. pyogenes (can lead to scarlet fever)
    • S/S: sneezing, cough, watery eyes, mild headache, mild body aches, runny nose, low grade fever (these are from the CDC website... the book said nothing about it and neither did her ppt!)
  14. Know the causative agents and identifying signs/symptoms of the following diseases: scarlet fever
    • Causative agent= strep. pyogenes
    • s/s: begins with a rash over entire body and usually appears redder in the armpits and groin areas. rash lasts 2-5 days. flushing and very sore throat which can be accompanied by yellow or white papules. fever of 101or higher and lympadenopathy in neck region. headache body aches, and nausea can occur
  15. Know the causative agents and identifying signs/symptoms of the following diseases: diptheria
    • causative agent= Coryenbacterium diptheriae (a potent inhibitor of protein synthesis)
    • transmission: droplet aersol, direct contact w/ skin, fomites (to lesser degree)
    • S/S:it is a localized infection, usually presents as severe phargyntitis or tonsilittis, accompanied by a plaque-like pseudomembrane in the throat. Accompanied by fever, sore throat and malaise. membrane should be coughed up in 5-10 days.
    • tx: toxin neutralization/elimination
  16. Know the causative agents and identifying signs/symptoms of the following diseases: common cold rhinovirus infection
    • rhinovirus infection
    • Causative agents: There are several hundred serotypes of the rhinovirus. 50% that have been characterized are picornavirus (extremely small,
    • single-stranded RNA viruses that do not have envelopes, like the temp in the nasopharynx<33 degrees C>)
    • uses glycoprotein ICAM, which is an adhesion molecule, as a receptor to infect host cells
    • S/S:infection is usually mild w/ little damage to the body: sneezing, stuffy nose, sore throat, coughing, mild headaches, mild body aches, watery eyes (again from the CDC website)
  17. Know the causative agents and identifying signs/symptoms of the following diseases: pertusis
    • whooping cough
    • causitive agents: Bordetella pertussis (gram - coccobacillus, doesn’t survive in environment, reservoir is humans, affinity for ciliated bronchial
    • epithelium- produces trachel toxins that immobolizes are progressively destroys ciliated cells, causes persistent cough)
    • has an affinity for cilitated bronchial epithelium once attached the organism produces a tracheal toxin that immobilizes and progressively destroys the cilliated cells
    • S/S: similar to cold
    • Transmission: airborne droplets from patients in the early stages
    • highly contagious 80-100% of exposed susceptible individuals
    • spreads rapidly in schools, hospitals, offices & homes
  18. what are the four stages associated w/ pertussis?
    • catarrhal stage- persistent perfuse and mucoid rhinorrhea for 1-2 weeks. sneezing, malaise and anorexia. (communicable)
    • paroxysmal stage- strats w/ persistent coughing that can build to 50 times a day for 2-4 weeks. “whooping” is heard. increase in lymphocytes; apnea after coughing.
    • convalescent stage- frequency and severity of coughing and other symptoms gradually decrease
  19. Know the causative agents and identifying signs/symptoms of the following diseases: inahalation antharax
    • Causitive agent: Bacillus anthracis (pneumoniagram + rod, spore-forming, spore germinate in human tissues, antiphagocytic properties of the capsule aid its survival and
    • growth in large numbers
    • )Causes fulminate pneumonia → leading to respiratory failure and deathcomes on suddenly w/ great severity
    • Tx w/ specific antibiotics
    • Pathogenesis: results from the powerful exotoxin produced
    • Transmission: inhaled
    • S/S of pulmonary anthrax: 1-5 days of non specific malaise, mild fever, nonproductive cough, progressive respiratory distress and cyanosis, rapid and massive spread to the central nervous system and bloodstream is followed by death
  20. Know the causative agents and identifying signs/symptoms of the following diseases: Legionnaire’s disease
    • Causitive agent: Legionella pneumophila (gram - rod, can’t be stained or grown using normal techniques)
    • faculative intracellular parasite
    • aggrassively attacks the lungs
    • produces necrotizing mulifocal pneumonia
    • involves alveoli and terminal bronchioles
    • the inflammatory response produces an exudate containing: fibrin, polymorphonuclear leukocytes, and RBCs
    • transmission: humidified aersol from contaminated water systems
    • S/S:myalagia and eadachache followed by a rapidly rising fever. chills, pleuritic chest pain, vomitting, diarrhea, and occasional confusion and
    • delirium.
  21. Know the causative agents and identifying signs/symptoms of the following diseases: influenza
    • Causitive agents: orthomyxovirus (virions are surrounded by an envelope, genome is single stranded RNA in 8 segments <allows high rate of
    • mutation>)
    • 3 major serotypes of virus: A,B,C (differences based on antigens associated w/ the nucleoprotein)
    • S/S: fever, myalgia, headache, and occasional shaking chills; reaches its maximum severity in 6-12 hours and a non-productive cough developes
    • if severe enoguh it can infect the tracheobronchial tree and lungs, resulting in lethal pneumonia
    • Transmission: direct droplet transmission is most common
    • Influenza can cause death in 3 ways:
    • -undelying disease- people w/ limited cardiovascular activity or pulmonary function
    • -superinfection- bacterial pneumonia and disseminated bacterial disease
    • Streptococcus pneumoniae, haemophilus influenzae, staphylococcus aureus are all apart
    • of normal flora but are the most common bacteria responsible for superinfection
    • -Direct rapid progressionoverwhelming viral pneumonia and aspyxia
  22. Know the causative agents and identifying signs/symptoms of the following diseases: HPS
    • Hantavirus Pulmonary Syndrome
    • causative agent: ??
    • virus causes a fulminant respiratory infection; high mortality rate (50-70%)
    • 3 types of hantavirus:
    • -Sin Nombre is the most common
    • Transmission: inhalation of dried rodent excreta, by conjunctival route, or by direct contact through breaks in the skin
    • S/S: early → fatigue, fever, muscle aches (thigh hips and back), headache, dizziness, abdominal problems. late → coughing and SOB
  23. Know the causative agents and identifying signs/symptoms of the following diseases: tb
    • causative agent: Mycobacterium tuberculosis (rod shaped bacillus, acid-fast, nonspore forming, produces M. acid)
    • primary tb: intitial exposuresecondary tb: occurs years later drug resistance is becoming increasingly dangerous major reason is non compliance- many pt. stop taking drugs early
    • S/S: initial symptoms → fever, fatigue, weight loss, chest pain, SOB, congestion w/ coughing. early detection is vital
    • pathogenesis: .tuberculosis cell wall interferes w/ macrophage function and T cell activation; inhibits the formation of the phagolysosome. This allows it
    • to escape to the cytoplasm where it increases in number; eventually spread to lymph nodes. From here it enters the blood and is distributed throughout the body
  24. Penicillin is used to tx all of the following except?

    C. mycoplasmal pneumonia
  25. Pneumonia can be caused by all of the following except?

    E. all of the above
  26. which of the following does not produce any exotoxin?

    D. mycobacterium tb
  27. which of the following produces the most potent exotoxin?

    A. corynebacterium diptheriae
  28. the recurrence of influenza epidemics is due to

    A. antigenetic shift
  29. Legionella is transmitted by

    B. airborne transmission
  30. the patient has a sore throat. Which of the following would be involved?

    E. can't tell
Card Set
micro exam #4
chap 21