ALU 301 Ch 4 An Overview of Infectious Diseases UPDATED ACTUAL
Questions and CORRECT Answers
1. Koch's Postulates 1. the same pathogen must be found in all dz'd individuals w/ the same
Sx's
2. the pathogen must be isolated from the individual w/ the dz & grown
in a culture
3. the same dz must be induced in an experimental animal by transfer
of the cultured pathogen
4. after the dz develops, the same pathogen must be isolated from the
experimental animal
2. 1st primitive vaccine Developed in 1796 & used to prevent Smallpox
3. 1st effective Abx drug developed in 1935, Sulfonamide
4. Avg Life Span in US 1900 - 47yrs old
1950 - 68yrs old **attributed to successful tx of infections
5. The native habitat in 1. symptomatic individuals
which infective agent 2. carriers
lives & multiplies is called 3 animals
a reservoir -- there are 4 4. water, food, soil, air, fomites(inanimate objects that carry dz-carrying
types micobes.
6. Human host defense --cilia in respiratory tract
against microbes --complex rxn's of the immune system Ex:
**cellular system (macrophages, natural killer cells, T-lymphocytes);
**humoral system (antibodies/immunoglobulins)
Only if defense system fail can microbes invade the tissues
7. For disease to occur: 1. viruses must enter host cells in order to reproduce
2. viruses often inhibit the immune system
3. many bacteria produce toxins that damage host cells
4. many dz's are cause by pathogens growing in normally sterile
tissue
, 5. the inflammatory process triggered by the inmmune system com-
bating the dz is often responsible for the signs and sx's of the dz
8. Lab Diagnosis of Infec- Direct Detection Methods
tion Culture and Sensitivity
Immunodiagnosis
Nucleic Acid Probes
9. Direct Detection Methods - use the microsope to view the microcrobe obtained in tissue, body
fluid, or excreta sample. Various stains are used - 2 common stains are
Gram stain and acid-fast stain
10. Gram Stain A staining method that distinguishes between two different kinds
of bacterial cell walls (thick - take up stain readily - Gram (+) --Ex:
streptococci & staphylococci, and thin does not stain - Gram (-) - Ex:
Pseudomonas adn E. coli
11. Acid-fast stain used to identify organisms that retain the staining dye even after being
washed in an acid solvent
--helps identify mycobacterium species that cause TB and leprosy
12. Culture and Sensitivity sometimes necessary to grow the microbe on an artificial culture
medium in order to obtain enough of the organism to ID it. AGAR
(gelatin like medium) is used to culture bacteria since bacteria do not
use it for food
--must use living cells, monkey kidney cells & chicken embryos are ex
of the cells used
--can be used to test eflcacy of specific abx to test microbes sensitivity
to the drug
13. Immunodiagnosis Testing for the presence in serum of antibodies produced by the
immune system in reaction to an infection. Test for Hep A, B & C and
Helicobacter pylori use this technique.
, 14. Nucleic Acid Probes based on fact that every species of microbe, has some unique se-
quence of genes in either its DNA or RNA that differentiate if from all
other microbes.
--can be used to monitor response to therapy in some dz's, such as
HEP C and HIV, since these tests can monitor viral load or # of viral
copies
--amplification is needed sometimes; Polymerase chain reaction (PCR)
can amplify a single DNA molecule into many billions of molecules
15. Infectious Disease caus- 1. Bacteria
ing organisms are 2. viruses
3. fungi
4. parasites
16. Bacteria - single cell or- at least 10,000 species recognized. Some cause dz's, some have help-
ganisms ful biological fxns ie: digestion in many animals, nitrogen fixation in
plants, and organic decomposition
--symbiotic relationship w humans --exist in intestine, on skin, in
mouth. most are harmless & perform necessary fxn ie: prod of Vit k
by E.coli in the intestine
17. Bacteria also used in ge- Ex: human gene that codes insulin production in the pancreas can be
netic engineering implanted in E.coli bacteria , can then produce human insulin. 1982 -
we get Humulin for diabetics
18. Grouped Bacteria 1. Diplo - paired
2. Strepto - arranged in chains
3 Staphylo - arranged in clusters
19. Classification system 1. Cocci are sperical
used in identifying 2. Bacilli are rod shaped
dz-causing bacteria is 3. Spirochetes are Spiral
based on structural and 4. Vibrios are comma shaped
Questions and CORRECT Answers
1. Koch's Postulates 1. the same pathogen must be found in all dz'd individuals w/ the same
Sx's
2. the pathogen must be isolated from the individual w/ the dz & grown
in a culture
3. the same dz must be induced in an experimental animal by transfer
of the cultured pathogen
4. after the dz develops, the same pathogen must be isolated from the
experimental animal
2. 1st primitive vaccine Developed in 1796 & used to prevent Smallpox
3. 1st effective Abx drug developed in 1935, Sulfonamide
4. Avg Life Span in US 1900 - 47yrs old
1950 - 68yrs old **attributed to successful tx of infections
5. The native habitat in 1. symptomatic individuals
which infective agent 2. carriers
lives & multiplies is called 3 animals
a reservoir -- there are 4 4. water, food, soil, air, fomites(inanimate objects that carry dz-carrying
types micobes.
6. Human host defense --cilia in respiratory tract
against microbes --complex rxn's of the immune system Ex:
**cellular system (macrophages, natural killer cells, T-lymphocytes);
**humoral system (antibodies/immunoglobulins)
Only if defense system fail can microbes invade the tissues
7. For disease to occur: 1. viruses must enter host cells in order to reproduce
2. viruses often inhibit the immune system
3. many bacteria produce toxins that damage host cells
4. many dz's are cause by pathogens growing in normally sterile
tissue
, 5. the inflammatory process triggered by the inmmune system com-
bating the dz is often responsible for the signs and sx's of the dz
8. Lab Diagnosis of Infec- Direct Detection Methods
tion Culture and Sensitivity
Immunodiagnosis
Nucleic Acid Probes
9. Direct Detection Methods - use the microsope to view the microcrobe obtained in tissue, body
fluid, or excreta sample. Various stains are used - 2 common stains are
Gram stain and acid-fast stain
10. Gram Stain A staining method that distinguishes between two different kinds
of bacterial cell walls (thick - take up stain readily - Gram (+) --Ex:
streptococci & staphylococci, and thin does not stain - Gram (-) - Ex:
Pseudomonas adn E. coli
11. Acid-fast stain used to identify organisms that retain the staining dye even after being
washed in an acid solvent
--helps identify mycobacterium species that cause TB and leprosy
12. Culture and Sensitivity sometimes necessary to grow the microbe on an artificial culture
medium in order to obtain enough of the organism to ID it. AGAR
(gelatin like medium) is used to culture bacteria since bacteria do not
use it for food
--must use living cells, monkey kidney cells & chicken embryos are ex
of the cells used
--can be used to test eflcacy of specific abx to test microbes sensitivity
to the drug
13. Immunodiagnosis Testing for the presence in serum of antibodies produced by the
immune system in reaction to an infection. Test for Hep A, B & C and
Helicobacter pylori use this technique.
, 14. Nucleic Acid Probes based on fact that every species of microbe, has some unique se-
quence of genes in either its DNA or RNA that differentiate if from all
other microbes.
--can be used to monitor response to therapy in some dz's, such as
HEP C and HIV, since these tests can monitor viral load or # of viral
copies
--amplification is needed sometimes; Polymerase chain reaction (PCR)
can amplify a single DNA molecule into many billions of molecules
15. Infectious Disease caus- 1. Bacteria
ing organisms are 2. viruses
3. fungi
4. parasites
16. Bacteria - single cell or- at least 10,000 species recognized. Some cause dz's, some have help-
ganisms ful biological fxns ie: digestion in many animals, nitrogen fixation in
plants, and organic decomposition
--symbiotic relationship w humans --exist in intestine, on skin, in
mouth. most are harmless & perform necessary fxn ie: prod of Vit k
by E.coli in the intestine
17. Bacteria also used in ge- Ex: human gene that codes insulin production in the pancreas can be
netic engineering implanted in E.coli bacteria , can then produce human insulin. 1982 -
we get Humulin for diabetics
18. Grouped Bacteria 1. Diplo - paired
2. Strepto - arranged in chains
3 Staphylo - arranged in clusters
19. Classification system 1. Cocci are sperical
used in identifying 2. Bacilli are rod shaped
dz-causing bacteria is 3. Spirochetes are Spiral
based on structural and 4. Vibrios are comma shaped
