Lecture 14: Airborne Bacterial Diseases
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- What makes up the upper respiratory tract?
- throat, nose, sinuses, middle ear, eustachian tubes
- What makes up the lower respiratory tract?
- larynx, trachea, bronchial tubes, lungs
- Diseases can be found in the ___and ____ respiratory tract. Sometimes these tracts could be connected. Disease could start in uppper, go to lower if not treated
-
upper
lower - Pathogen can be spread through the air over a distance of more than a ___
-
meter
(3' distance) - What are the three main types of airborne transmission?
-
- From an infected person to a susceptible person by coughing or sneezing or even just talking (pathogen attached to mucus or saliva)
- From dust contaminated with a pathogen to a susceptible person
- From aerosols of water (air conditioning systems, sprays, etc) - Streptococci can be classified by what two systems?
-
1) based on hemolytic properties (how break red blood cells)
2) cell wall carbohydrate - What are the three types of hemolytic groups?
-
á (alpha)
â (beta)
ã (gamma) - What are the hemolytic properties of alpha-hemolytic streptococci?
- partial destruction- olive green cells
- What are the hemolytic properties of beta-hemolytic streptococci?
- complete destruction- clear zone around cells
- What are the hemolytic properties of gamma-hemolytic streptococci?
- no effect- no change
- Variants of a specific carbohydrate, the C substance, is used to classify streptococci. Groups A through ____ have been distinguished
-
S
(used to be O) - What is the worst streptococci for humans?
- Group A beta-hemolytic streptococci are worst for humans
- WHat are some diseases streptococci can cause?
-
strep throat
scarlet fever
flesh eating disease - What is the causing agent of strep throat?
-
Streptococcus pyogenes, G+ cocci
Group A - How is strep throat transmitted?
-
airborne droplets
(talk, cough, sneeze) - What are the symptoms of Strep Throat?
-
*Red pharyngeal tissues from tissue erosion*
-high fever, coughing, swollen lymph nodes
-usually no runny nose - The pathogenicity of S. pyogenes is enhanced by a substance called ____.
- M protein
- M protein is an adhesin protein anchored in the cell wall and ____. It adheres to _____ and retards ____
-
pili
pharyngeal tissues
phagocytosis - There are over 60 different types of M protein, making ______ to streptococcal disease difficult
-
complete immunity
- you can get strep throat again. most likely with a different M protein - What are six possible complications of STrep Throat?
-
1) scarlet fever
2) erysipelas
3) rheumatic fever
4) glomerulonephritis
5) necrotizing fascitis
6) septicemia (end pt of most diseases. blood infection, very serious) - Scarlet fever is strep throat accompanied by a ____
- skin rash
- Certain strains of S. pyogenes carry _______
- lysogenized bacteriophage
- Certain strains of S. pyogenes carry lysogenized bacteriophage. The bacteriophage encodes ________
-
erythrogenic toxin
Erythrogenic toxin is produced only by strains of S. pyogenes that carry a prophage that encodes the toxin. - If you have scarlet fever, a rash shows up where?
- in soft skin areas of mouth, neck, chest
- the red rash of scarlet fever is caused by blood leaking through walls of _______damaged by _____
-
capillaries
toxin - What is an acute infection of the dermal layer called?
- erysipelas
- What is a characteristic sign of Erysipelas?
- painful reddish patches recur periodically at the same body site
- Who does erysipelas mainly affect?
- Primarily in infants or people >30 with a history of strep throat
- An important complication of streptococcal disease is rheumatic Fever. This condition is caused by?
-
immune response to STreptococcus surface antigens
antibodies from immune response cross-react with antigens on human heart, joints, and kidneys - Rheumatic fever is caused from the immune response to STreptococcus surface antigens. Antibodies from immune response ____ with antigens on human heart, joints, and kidneys
- cross-react
- Rheumatic fever is characterized by what?
-
*scarring and distortion of heart valves*
fever
inflammation - What is the condition when there is pain and inflamation in the kidneys?
- Glomerulonephritis
- How is glomerulonephritis caused?
- Results when Ag-Ab complexes get lodged in the glomeruli
- What is the disease associated with the dissolving of flesh?
- Necrotizing fascitis
- What causes necrotizing fascitis?
- Caused by streptococcal infection of sheath (fascia) covering the skeletal muscles
- What is the characteristic sign of necrotizing fascitis?
- extensive destruction of subcutaneous tissue by ‘flesh-eating’ bacteria
- What is the name of the gram positive rod with metachromatic granules?
-
Corynebacterium diptheriae
- shaped like a club - Corynebacterium diptheriae remains _____ after division
- partially attached
- What does corynebacterium diptheriae look like?
- angular (like Chinese characters) or palisade formation-side by side
- How is diptheria transmitted?
- inhaling respiratory droplets from an infected person into the upper respiratory tract near the tonsils
- Diptheria. Pathogenicity. An exotoxin encoded by the bacteriophage _______ interferes with protein synthesis in epithelial cells
- lysogenic corynephage
- The bacteria produce a potent ____that inhibits protein synthesis in epithelial cells. It is encoded by lysogenic corynephage.
- exotoxin
- In diptheria, what is the pseudomembrane made up of?
-
mucus
WBC
dead tissue
fibrous material results in respiratory blockage - What do you treat diptheria with?
- antitoxin and antibiotics
- What do you vaccinate a person with to prevent diptheria?
- DTaP- diptheria toxoid
- What does a toxoid consist of?
-
formaldehyde + toxin
A toxoid consists of toxin molecules treated with formaldehyde or heat to destroy their toxic qualitites. - Pertussis is also known as?
- whooping cough
- What is the causing agent of pertussis?
- Bordetella pertussis, a G- rod
- How is pertussis transmitted?
- Transmitted by airborne droplets that use pili to adhere to cilia of epithelial cells.
- What happens when airborne droplets use pili to adhere to cilia of epithelial cells?
- Ciliated cells are destroyed and mucusoal escalator impaired
- What are the 3 stages of symptoms of pertussis?
-
1) Malaise, low-grade fever, worsening cough
2) Paroxysms- staccato coughs with rapid inhale resulting from disintegrating cells and mucus accumulating in the airways
3) 100-day cough - What vaccine is used to prevent pertussis?
- acellular pertussis, chemical extracts (less risky than whole organism), dTaP
- The term meningitis refers to several diseases of the meninges. What are meninges?
- 3 membranous coverings of the brain and spinal cord
- What is the causing agent of meningitis?
- Neisseria meningitidis, G- encapsulated diplococcus
- What happens after Neisseria meningitidis by airborne droplets enters the body?
- bacterial endotoxins spread into blood stream and CSF (cerebral spinal fluids) causing shock. Death may result in about two hours.
- If you have a mild case of meningitis, what are the symptoms?
- influenza-like upper respiratory infection
- If you have a serious case of meningitis, what are the symptoms?
- pounding headache and stiff neck due to inflammation of meninges. Rash (red to blue-black spots called petechiae) will also appear. 50% untreated cases may be fatal.
- The rash, a symptm of severe meningitis, is red to blue-black spots called ___
- petechiae
- How do you diagnose meningitis?
- diagnose with spinal tap
- How do you treat meningitis?
- rifampin, penicillin, or sulfonamide drugs. Rifampin used as a prophylactic antibiotic when exposure has occurred.
- Besides Neisseria meningitidis, what else can cause meningitis?
- viruses and Haemophilus influenzae B
- What is the causing agent of tuberculosis?
- mycobacterium tuberculosis
- In developing countries, more deaths occur from _____ than from any other bacterial disease
- tuberculosis
- Mycobacterium tuberculosis enters the respiratory tract in aerosolized droplets, usually through _____
- multiple exposures
- After M. tuberculosis is inhaled into the lungs through multiple exposures, it enters the ____
- aveolus
- 10% of the ppl infected with tuberculosis becomes ill in 3 months. What are the symptoms?
-
*blood in sputum*
cough, chest pain, fever - 90% of the ppl infected with tuberculosis have what symptoms?
- fever and weight loss (no real symptoms)
- The 90% of the people who have mild symptoms respond to the disease by forming a wall of white blood cells, salts, and fibrous materials around the bacilli. As these materials accumulate in the lung, a hard nodule called a _____arises
- tubercle
- THe tubercle may be visible by ___
- X-ray
- What happens if the tubercle breaks apart?
- bacteria spreads to other organs such as the liver, kidneys, meninges, and bone.
- If the tubercle breaks and spreads o other organs, the tuberculosis is now called ___
- miliary tuberculosis
- Tubercle bacilli produce no toxins, but there is such rapid growth that the tissues are literally consumed, a factor that gave tuberculosis its alternate name, ____
- consumption
- What test is used for tuberculosis?
- PPD test
- What does PPD stand for?
- purified protein derivative test
- MDR-TB is a new threat. why?
- It is multi-drug resistant
- What do you treat tuberculosis with?
- isoniazid, rifampin, ethambutol
- Pneumonia is a microbial disease of the _____ and ____
- bronchial tubes and lungs
- Over 80% of bacterial cases are due to 80 different strains of ______
- Streptococcus pneumoniae, a G+ encapsulated diplococci
- describe streptococcus pneumoniae
- G+ encapsulated diplococci
- How is pneumococcal pneumonia transmitted?
- transmitted by airborne droplets
- What are the symptoms of pneumococcal pneumonia?
- fever, fatigue, dry, hacking cough
- Who is affected by penumococcal pneumonia?
- only compromised affected- elderly, malnourished, smokers, viral-infected, immune-suppressed
- Why is penumococcal pneumonia a secondary disease?
- only compromised affected
- What is one of the smallest bacteria to cause human disease?
- Mycoplasma pneumoniae
- What is the causing agent of Primary Atypical Pneumonia?
- Mycoplasma pneumoniae
- Mycoplasma pneumoniae has no ____
- cell wall
- Mycoplasma pneumoniae has no cell wall. It is ____; that is, they assume a variety of shapes
- pleomorphic
- Primary Atypical Pneumonia is a primary disease because ___
- it occurs in healthy ppl
- What are the symptoms of Primary Atypical Pneumonia?
- Fever, dry hacking cough, fatigue
- Pathogenicity- it attaches to and destorys ____
- ciliated cells lining respiratory tract
- Where are epidemics of primary atypical pneumonia usually found?
- in crowded places
- What is primary atypical pneumonia treated with and not treated with?
- treated with erythromycin, tetracycline (blocks protein synthesis), but not penicillin because no cell wall (no peptidoglycan synthesis)
- What are primary atypical pneumonia's symptoms similar with?
- psittacosis
- psittacosis is caused by?
- (Chlamydiae psittaci)
- What is the bird disease transmissible to humans through dried droppings/dust?
- psittacosis (Chlamydiae psittaci)
- In 1976, there was an outbreak amongst Legionnaires at a conference in Philadelphia. 34 ppl died. Legionnaire's Disease is caused by what?
- Legionella pneumophila, G- rod
- Legionella pneumophila exists where?
- exists where water collects- air conditioners, puddles, humidifiers.
- How is Legionella pneumophila transmitted?
- aerosolized droplets into the respiratory tract. person-to-person transmission is uncommon
- What are the symptoms of Legionella pneumophila?
- Fever, dry cough, diarrhea and vomiting
- What do you treat a patient with Legionella pneumophila with?
- erythromycin
- What do you treat a water source with LEgionella pneumophila with?
- chlorine or heat
- Legionella cannot exist in water alone (fastidious). It actually grows inside _____
- waterborne protozoa (like a parasite)
- What are the three ways to prevent airborne diseaseS?
-
1) Eradication or control of source
2) Block access of pathogen to susceptible individuals
3) vaccination -
2 pts about eradication or control of source:
1) _____of contaminated materials
2) ____of patients -
disposal
confinement -
2 pts of blocking access of pathogen to susceptible individuals.
1) Wear ___and ____
2) Employ ______ and other therapies to reduce coughing and sneezing -
masks and goggles
antimicrobial therapies