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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
Pathogen can be spread through the air over a distance of more than a ___
(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

(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 ____

pharyngeal tissues

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 _____
What is an acute infection of the dermal layer called?
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
Rheumatic fever is characterized by what?
*scarring and distortion of heart valves*
What is the condition when there is pain and inflamation in the kidneys?
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.
In diptheria, what is the pseudomembrane made up of?
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 ___
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
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 ____
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
THe tubercle may be visible by ___
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, ____
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
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 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?
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
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

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