Lecture 5+6+DLA

Question 1

cell wall synthesis inhibitors

Answer 1

B lactams (penicillin, methicillin, cephalosporin)
vancomycin
lipoglycopeptides (telavancin and oritavancin)

Question 2

DNA synthesis inhibitors

Answer 2

fluoroquinolones (ciprofloxacin)

Question 3

cellular membrane dysfunction meds

Answer 3

lipopeptides (daptomycin)

Question 4

folate synthesis inhibitors

Answer 4

sulfamethoxazole (trimethoprim)

Question 5

protein synthesis inhibitors (30s)

Answer 5

aminoglycosides (doxycycline)

Question 6

protein synthesis inhibitors (50s)

Answer 6

Oxazolidinones (linezolid and tedizolid)

erythromycin

Question 7

broad spectrum antibiotic

Answer 7

targets most bacteria

new gen B lactams (cephalosporins)

Question 8

narrow spectrum antibiotic

Answer 8

very targeted therapy that works on a limited amount of bacteria

Ex. penicillin G

Question 9

cross resistance

Answer 9

resistance mechanism confers resistance to different
classes of antibiotics

ex. Pseudomonas efflux pump

Question 10

intrinsic resistance

Answer 10

all isolates are naturally resistant

ex. Mycoplasma

Question 11

acquired resistance

Answer 11

only some isolates have become resistant

ex. MRSA (Methicillin Resistant Staph aureus)

Question 12

plasmid mediated resistance

Answer 12

Antibiotic Resistance genes (Abr) are highly mobile via conjugation

Question 13

phage mediated resistance

Answer 13

(Abr) are highly mobile via transduction

Question 14

chromosomal resistance

Answer 14

highly stable

spontaneous mutation

incorporation of donor DNA, donor pro-phage, or plasmid

Question 15

rich/ complex media

Answer 15

Contains growth nutrients from complex biological source (ie. Yeast) to grow a variety of microbes

Question 16

defined media

Answer 16

Contains very specific defined ingredients that are tailored for an organism’s growth requirements

Can be used to determine the growth effects on a specific nutrient ( such as swapping glucose for sucrose)

Question 17

selective media

Answer 17

contains components that select for the growth of specific organisms.

Limits growth of others

Question 18

differential media

Answer 18

allows differentiation of growing bacteria based on different characteristics

Assists with classification

Question 19

MacConkey agar

Answer 19

allows for growth of E.coli and Salmonella restricting growth of other Gram + bacteria, especially for fecal samples

Question 20

why can adding lactose to agar be important

Answer 20

Lactose is added to identify bacteria that ferment lactose with a pH pink color indicator

E.coli will ferment lactose

salmonella will not ferment lactose

Question 21

Lowenstein-Jensen Agar

Answer 21

specific for Mycobacterium tuberculosis

very lipid rich

Question 22

Thayer-Martin Agar

Answer 22

will grow Neisseria gonorrhea

chocolate agar with antibotics will prevent growth of usual flora

Question 23

the growth calculation equation

Answer 23

colony forming units / amount plated mL x dilution factor

Question 24

growth dynamics: growth curve

Answer 24

lag- newly inoculated cells; adjust to environment; pop is sparse

exponential- growth occurs at max rate; continues as long as the environment is right

stationary- population reaches max number
rate of death = rate of growth

death- decline in growth rate
depletion of nutrients

Question 25

Psychrophiles and Psychrotrophs

Answer 25

growth best at cold temps <25° C relevant to food pathogens

Question 26

Mesophiles

Answer 26

grow best at human body temp most human pathogens are in this range

Question 27

Thermophiles and Hyperthermophiles

Answer 27

grow best at high temps >65°C Associated with thermal vents

Question 28

Neutrophiles Acidophile Alkaliphiles

Answer 28

Neutrophiles = most human pathogens live between 6 and 8 acidophile = grow at a low pH Lactobacillus as vagina microbiota (pH4) Helicobacter pylori in stomach (pH2) alkaliphiles = high pH due to high levels of minerals (pH 9-11)

Question 29

Halophiles Xerotolerant Osmotolerant

Answer 29

Halo = low Aw due to high NaCl concentrations Associated with saltwater microbes ex. Vibrio species including V. cholerae xero = can grow in lower Aw osmo = can withstand high osmotic pressure due to high solute concentration

Question 30

example of catalase + and -

Answer 30

catalase testes for oxygen consumption + = staph - = strep

Question 31

obligate aerobe

Answer 31

will be SOD and catalase + 02 is needed Ex: Mycobacterium tuberculosis

Question 32

Facultative aerobes

Answer 32

Can use both aerobic respiration (using O2) and fermentation/anaerobic respiration (without O2) will be both SOD and catalase + Ex: E.coli

Question 33

Aerotolerant

Answer 33

can grow in the presence or absence of O2 Will be SOD + Catalase - ex: strep

Question 34

obligate anaerobe

Answer 34

Cannot use O2, die when exposed to O2 negative for both catalase and SOD ex: Clostridium difficile

Question 35

Microaerophiles

Answer 35

require lesser amounts of oxygen SOD will be + catalase can be -/+ ex: Helicobacter pylori

Question 36

what is a chi- square test used for?

Answer 36

It is used to test if there is an association/ relationship between 2 categorical variables example: association between smoking and race for cancer

Question 37

what is a T-test used for

Answer 37

Two-sample t-tests are statistical tests used to compare the means of two groups. paired T-tests are used for dependent unpaired T-tests used for independent

Question 38

what is a paired T-test used for

Answer 38

is a statistical test that compares the averages/means and standard deviations of two related groups to determine if there is a significant difference between the two groups dependent

Question 39

what is an ANOVA used for

Answer 39

test of hypothesis that is appropriate to compare a continuous variable in three (3) or more independent comparison groups The (one-way) ANOVA procedure is used to compare the means of the comparison groups

Question 40

what does regression analysis allow?

Answer 40

description: relationships among the dependent variables estimation: the values of the dependent variables prognostication: risk factors that will influence that outcome

Question 41

monotonic relationship?

Answer 41

Correlation is a measure of a monotonic association between 2 variables ex: both variables will increase one will increase and other will decrease sometimes a linear line

Question 42

covariance

Answer 42

The degree to which the change in 1 continuous variable is associated with a change in another continuous variable

Question 43

Pearson’s Correlation Coefficient

Answer 43

describes a linear relationship describes the strength and direction of the relationship denoted by r (closer to 1 the stronger the relationship)

Question 44

Spearman’s Rank Correlation

Answer 44

used for data that is monotonic but nonlinear similar interpretation to r (-1 - +1)