Principles of Pathogenesis

Question 1

where in the body are there high and very high numbers of microbes

Answer 1

high - genitals and armpit, small intestine

very high - large intestine and mouth

Question 2

where in the body are there medium numbers of microbes

Answer 2

scalp and stomach

Question 3

where in the body are low numbers of microbes

Answer 3

eyes, shoulder, and forearm?

Question 4

advantages of having a normal microbial population

Answer 4

• they occupy a location blocking microorganisms from coming up so colonization resistance
• production of factors the inhibit or block the growth of other microorganisms
• competitive use of available resources
• low level stimulating the immune system
• produce useful compounds like Vit K and biotin

Question 5

microbiome finding in psoriasis

Answer 5

increased ratio of firmicutes to actinobacteria

Question 6

microbiome finding in obesity

Answer 6

Reduced ratio of Bacteroidetes to Firmicutes

Question 7

microbiome finding in childhood onset of asthma

Answer 7

Absence of gastric H. pylori (esp. cytotoxin-associated gene A genotype

Question 8

microbiome finding in inflammatory bowel disease

Answer 8

Larger populations of Enterobacteriaceae

Question 9

areas in the body that are normally sterile

Answer 9

heart, blood, brain, liver

Question 10

what are potential outcomes of host pathogen interaction

Answer 10

inapparent/subclinical
immune clearance
commensalistic relationship (not harming or one is benefiting)
damage

Question 11

symptoms of damage due to host pathogen interaction

Answer 11

host mediated: immunopathogenesis

microbially mediated: toxins, enzymes, physical growth

Question 12

what are some non specific defenses by the body

Answer 12

Eyes
• Washing of tears and Lysozyme
Genitourinary tract
• Washing of urine, Acidity of urine, Lysozyme and (Vaginal lactic acid)
Skin
• Physical barrier and Antimicrobial secretions
Respiratory tract
• Mucus, Ciliated epithelium, and Alveolar macrophages
Digestive tract
• Stomach acidity, Normal flora, and Bile

Question 13

when we have a microbiallly mediated damage – where is it coming from?

Answer 13

cytolytic effect of replication
degradative enzymes
toxic structures
physical growth through tissues
bacterial toxins: damage host cell membrane, inhibit cellular functions

Question 14

what is the infectious disease process

Answer 14

exposure and entry
adhesion and colonization
invasion and multiplication
spread and dissemination

Question 15

answer for opportunistic and true pathogens: require pre existing host compromise, can infect uncompromised host, exposures are due to accidental exposure

Answer 15

opportunistic: Always, No, Usually
true: No, Yes, Sometimes

Question 16

can true pathogens be opportunistic

Answer 16

yes

Question 17

what population is more susceptible to infection especially really severe infection

Answer 17

very young and very old

Question 18

what is the difference between signs and symptoms

Answer 18

signs - one can directly see and measure

symptoms: what the pt describes that they are feeling

Question 19

what are the stage of an infectious disease

Answer 19

incubation period, acute infection, chronic infection

Question 20

what is incubation period

Answer 20

period of time from acquisition –> signs and symptoms

Question 21

what is incubation period dependent on

Answer 21

microbial and host factors

Question 22

just know that correlation between changes in microbiome and disease does not mean causation

Answer 22

OK