MicrobiologyExam2StudyGuide
1. Microbes and disease
Koch’s postulates – what are they and how can they be used to determine if a particular bacterium
causes a particular disease? -pgs 17-18
● Koch and pure cultures (1877); his postulates (published 1890) - Bacillus anthracis in sheep and
cattle; Pasteur and immunization – chicken cholera (1880), sheep anthrax
(1881), human rabies (1885) ●
Can concur that:
-The organism is found in each case of the disease
-A pure culture of the organism is obtained from the diseased animal
-When organisms from the pure culture are injected into a healthy experimental animal, the
disease is reproduced
-The same organism is isolated from the sick experimental animal
Host-microbe interactions – what is symbiosis, and what different types of symbiosis are there?
-pg 632
● Symbiosis: an interrelationship between two populations of organisms where there is a close
and permanent association
● Mutualism: A close and permanent association between 2 populations of organisms in which
both benefit from the association
● Commensalism: A close and permanent association between 2 species of organisms in which
one species benefits and the other is unharmed and unaffected
● Parasitism: A close association between 2 organisms in which 1 (parasite) feeds off the other
(host) and may cause injury to the host
Anthrax – what are the basics of the bacterium and the disease? -pgs 382-383
● Known since antiquity- it infects animals , sometimes humans. It is frequently fatal if untreated
● Important in showing that: Germs (microbes) can cause disease, and immunization can prevent
disease
● A bioterrorism and biological warfare worry
● Caused by Bacillus anthracis: Gram + rod, aerobic, spore forming
● Naturally acquired from infected and animal products or dust
● Virulence factors: Capsule inhibits phagocytosis (immune system clearance) and exotins
(3) cause disease,: blood vessel leakage, shock, collapse.
● HUMAN ANTHRAX BELOW
● Cutaneous )from abraded skin contact with spores)----papure -> black pustule; fatal in
20% in untreated cases
● Inhalation (from breathing in spores)-----Cold like signs and symptoms -> severe breathing
problems and shock, fatal if untreated
● Intestinal (from eating spores)- Acute intestinal inflammation including diarrhea, fatal in 25 to
60% if untreated
This study source was downloaded by 100000888218999 from CourseHero.com on 08 -08-2024 06:43:27 GMT -05:00
https://www.coursehero.com/file/15793481/MicrobiologyExam2StudyGuide/
, Signs and symptoms of disease – what is the difference?
● Signs: An indication of the presence of a disease, especially one observed by a doctor but not
apparent to the patient. Ex: fever or bacterial cells in the blood
● Symptoms: An indication of some disease or other disorder that is experience by the patient. Ex:
AIDS from HIV
Disease establishment and progression – what are the phases? -pgs 640-641
Parameters of disease: how do dose, virulence, entry, exit, and transmission affect disease progress?
● Portal of entry: the characteristic route by which an exogenous pathogen enters the host.
Varies for different organisms and a key factor for leading to establishment of disease. Entry
routes are: respiratory(air), gastrointestinal(fecal-oral), sexually transmitted, parental (direct
entry into an organism by a nonoral route; piercing the skin, mucous membranes, wounds)
● Dose: number of pathogens that need to be taken into the body to cause infection and possibly
disease. Food poisoning is an example
-Cholera: Millions, Typhoid 100,000, E. Coli 1,000, Cryptosporidium 30
● Portal of exit: site at which pathogen leaves the host ex. sneezing, coughing
● Virulence factors: Capsules, Adhesins, Enzymes, Toxins
● Basically look at the picture on page 642, read 642-643 Virulence factors – what are they and
how do they work?
● Virulence factors: A structure or molecule possessed by a pathogen that increases its ability to
invade or cause disease to a host.
● pgs 644-647, picture on pg 645
Basic concepts of epidemiology – communicable versus infectious disease; direct & indirect
transmission; nosocomial infections; zoonotic disease – what are they and how do they affect human
disease
● Communicable diseases: ex- tuberculosis, AIDS, chickenpox, measles. A disease that is readily
transmissible between hosts (contagious)
● Noncommunicable disease:A disease whose causative agent is acquired from the environment
and is not transmitted to another individual. Ex. penetration of soil containing Clostridium tetani
into the anaerobic tissue of a wound
● direct: personal contact, respiratory droplets, person to person, horizontal transmission. But
vertical transmission is the spread of pathogens such as HIV from a pregnant mother to her
unborn child.
● indirect: fomites (linens, syringes, etc), biological vectors (arthropods), contaminated food and
water (vehicle transmission). Aerosoles: particles can remain in air and can be moved by air
currents (ex. SARS, tuberculosis). Vectors: lice, fleas, ticks.
● Nosocomial infections: represent healthcare-associated infections (HAIs): 1.7 million infections.
99,000 deaths per year in the US. Involves a compromised host (patient), a source of hospital
pathogens, chain of transmission. Most of the sites are urinary tract, surgical site, lungs, blood -
chart of pg 659, pic on page 660
● zoonotic disease:disease that is transmitted from animals to humans. Ex: rabies, the plague,
West Nile virus. This makes animals a reservoir for human disease
E. coli O157:H7: identification, pathogenesis, virulence, relationship to nonvirulent strains pg
368 AND pg 370. Picture in powerpoint 3-5-14, page 296 AND page 297
● Gram negative rod. Motile, facultative, non spore-forming; spreads by fecal-oral route,
● Sorbitol-MacCONKEY agar and GUD test
-O57 does not ferment sorbitol, does not produce B-glucuronidase(GUD),
Genome sequence -> both pathways present but inactivated by mutation
● Serology: (detection by antibodies) O (sugar antigen on outer membrane LPS) and H antigens
(flagellar antigen)
This study source was downloaded by 100000888218999 from CourseHero.com on 08 -08-2024 06:43:27 GMT -05:00
https://www.coursehero.com/file/15793481/MicrobiologyExam2StudyGuide/
1. Microbes and disease
Koch’s postulates – what are they and how can they be used to determine if a particular bacterium
causes a particular disease? -pgs 17-18
● Koch and pure cultures (1877); his postulates (published 1890) - Bacillus anthracis in sheep and
cattle; Pasteur and immunization – chicken cholera (1880), sheep anthrax
(1881), human rabies (1885) ●
Can concur that:
-The organism is found in each case of the disease
-A pure culture of the organism is obtained from the diseased animal
-When organisms from the pure culture are injected into a healthy experimental animal, the
disease is reproduced
-The same organism is isolated from the sick experimental animal
Host-microbe interactions – what is symbiosis, and what different types of symbiosis are there?
-pg 632
● Symbiosis: an interrelationship between two populations of organisms where there is a close
and permanent association
● Mutualism: A close and permanent association between 2 populations of organisms in which
both benefit from the association
● Commensalism: A close and permanent association between 2 species of organisms in which
one species benefits and the other is unharmed and unaffected
● Parasitism: A close association between 2 organisms in which 1 (parasite) feeds off the other
(host) and may cause injury to the host
Anthrax – what are the basics of the bacterium and the disease? -pgs 382-383
● Known since antiquity- it infects animals , sometimes humans. It is frequently fatal if untreated
● Important in showing that: Germs (microbes) can cause disease, and immunization can prevent
disease
● A bioterrorism and biological warfare worry
● Caused by Bacillus anthracis: Gram + rod, aerobic, spore forming
● Naturally acquired from infected and animal products or dust
● Virulence factors: Capsule inhibits phagocytosis (immune system clearance) and exotins
(3) cause disease,: blood vessel leakage, shock, collapse.
● HUMAN ANTHRAX BELOW
● Cutaneous )from abraded skin contact with spores)----papure -> black pustule; fatal in
20% in untreated cases
● Inhalation (from breathing in spores)-----Cold like signs and symptoms -> severe breathing
problems and shock, fatal if untreated
● Intestinal (from eating spores)- Acute intestinal inflammation including diarrhea, fatal in 25 to
60% if untreated
This study source was downloaded by 100000888218999 from CourseHero.com on 08 -08-2024 06:43:27 GMT -05:00
https://www.coursehero.com/file/15793481/MicrobiologyExam2StudyGuide/
, Signs and symptoms of disease – what is the difference?
● Signs: An indication of the presence of a disease, especially one observed by a doctor but not
apparent to the patient. Ex: fever or bacterial cells in the blood
● Symptoms: An indication of some disease or other disorder that is experience by the patient. Ex:
AIDS from HIV
Disease establishment and progression – what are the phases? -pgs 640-641
Parameters of disease: how do dose, virulence, entry, exit, and transmission affect disease progress?
● Portal of entry: the characteristic route by which an exogenous pathogen enters the host.
Varies for different organisms and a key factor for leading to establishment of disease. Entry
routes are: respiratory(air), gastrointestinal(fecal-oral), sexually transmitted, parental (direct
entry into an organism by a nonoral route; piercing the skin, mucous membranes, wounds)
● Dose: number of pathogens that need to be taken into the body to cause infection and possibly
disease. Food poisoning is an example
-Cholera: Millions, Typhoid 100,000, E. Coli 1,000, Cryptosporidium 30
● Portal of exit: site at which pathogen leaves the host ex. sneezing, coughing
● Virulence factors: Capsules, Adhesins, Enzymes, Toxins
● Basically look at the picture on page 642, read 642-643 Virulence factors – what are they and
how do they work?
● Virulence factors: A structure or molecule possessed by a pathogen that increases its ability to
invade or cause disease to a host.
● pgs 644-647, picture on pg 645
Basic concepts of epidemiology – communicable versus infectious disease; direct & indirect
transmission; nosocomial infections; zoonotic disease – what are they and how do they affect human
disease
● Communicable diseases: ex- tuberculosis, AIDS, chickenpox, measles. A disease that is readily
transmissible between hosts (contagious)
● Noncommunicable disease:A disease whose causative agent is acquired from the environment
and is not transmitted to another individual. Ex. penetration of soil containing Clostridium tetani
into the anaerobic tissue of a wound
● direct: personal contact, respiratory droplets, person to person, horizontal transmission. But
vertical transmission is the spread of pathogens such as HIV from a pregnant mother to her
unborn child.
● indirect: fomites (linens, syringes, etc), biological vectors (arthropods), contaminated food and
water (vehicle transmission). Aerosoles: particles can remain in air and can be moved by air
currents (ex. SARS, tuberculosis). Vectors: lice, fleas, ticks.
● Nosocomial infections: represent healthcare-associated infections (HAIs): 1.7 million infections.
99,000 deaths per year in the US. Involves a compromised host (patient), a source of hospital
pathogens, chain of transmission. Most of the sites are urinary tract, surgical site, lungs, blood -
chart of pg 659, pic on page 660
● zoonotic disease:disease that is transmitted from animals to humans. Ex: rabies, the plague,
West Nile virus. This makes animals a reservoir for human disease
E. coli O157:H7: identification, pathogenesis, virulence, relationship to nonvirulent strains pg
368 AND pg 370. Picture in powerpoint 3-5-14, page 296 AND page 297
● Gram negative rod. Motile, facultative, non spore-forming; spreads by fecal-oral route,
● Sorbitol-MacCONKEY agar and GUD test
-O57 does not ferment sorbitol, does not produce B-glucuronidase(GUD),
Genome sequence -> both pathways present but inactivated by mutation
● Serology: (detection by antibodies) O (sugar antigen on outer membrane LPS) and H antigens
(flagellar antigen)
This study source was downloaded by 100000888218999 from CourseHero.com on 08 -08-2024 06:43:27 GMT -05:00
https://www.coursehero.com/file/15793481/MicrobiologyExam2StudyGuide/
