Bacterial Structure and Classification-Dr. Kell Lecture

Question 1

Microbiology includes

Answer 1

viruses, bacteria, fungi and parasites

Question 2

what are the three different ways to classify bacteria

Answer 2

phenotypic methods, analyitic and genotypic

Question 3

chocolate agar is known as a

Answer 3

selective agar

Question 4

MaConkey is good for screening for

Answer 4

gram neg bacteria

Question 5

___is type of agar used for hemolysis

Answer 5

blood agar

Question 6

alpha hemolysis

Answer 6

partial hemolysis of RBC’s

Question 7

beta hemolysis

Answer 7

all blood cells are lysed

Question 8

gamma hemolysis

Answer 8

no hemolysis

Question 9

What are some examples of organisms that grow on chocolate agar

Answer 9

fastidious organisms, H. influenze, and N. gonorrhea

Question 10

________-type of agar selects for enterics

Answer 10

Macconkey

Question 11

________inhibits gram positive organisms

Answer 11

MacConkey

Question 12

_______differentiates between lactose fermenters and nonfermenters

Answer 12

Maconkey agar

Question 13

if something grows on buffered charcoal yeast it is probably

Answer 13

legionella

Question 14

if something grows on sabouraud dextrose it probably is

Answer 14

candida albicans

Question 15

if something gorws on lowenstein jensin it is

Answer 15

mycobacterium tuberculosis

Question 16

what are the reagents used in a gram stain procedure

Answer 16

crystal violet, grams iodine, decolorizer and safranin

Question 17

gram positive bacteria appear _____on a gram stain

Answer 17

purple

Question 18

gram negative bacteria appear ______on a gram stain

Answer 18

pink or red

Question 19

acid fast staining is particularly useful in staining

Answer 19

cell walls that contain waxes such as mycobacterium and nocardia sp

Question 20

__________ and ______-do NOT gram stain

Answer 20

mycobacteirm and nocardia sp

Question 21

if something appears to have grown “red snappers” and their cell walls contain waxes what is the most likely type of bacteira

Answer 21

mycobacterium sp

Question 22

catalase tests for

Answer 22

streptococci and staphhylococci (+)

Question 23

coagulase test for

Answer 23

staphylococci aurieus (+) between other staphylococci

Question 24

indole test for

Answer 24

enterics and ecoli (+)

Question 25

the urease test tests for

Answer 25

proteus species

Question 26

the _________test for presence of cytochrome oxidase C and tests for __________-

Answer 26

oxidase test psuedomonas aeruginosa

Question 27

serotyping

Answer 27

can identify those that are inert in biochemical testing, identify organisms that cannot be cultured, rapid identification, and involves antibody to organism sometimes flourecent tagging

Question 28

________-are often used for gonorrhea and chlaymydia and look for specific sequences unique to a genus, species or subspecies

Answer 28

molecular probes

Question 29

_________-is extrachromosomal DNA not essential for survival but are responsible for antimicrobial resistance and is more common in gram negative organisms

Answer 29

Plasmids

Question 30

plasmids are more common in what type of organism

Answer 30

gram negative

Question 31

what is the action of quinolones in gram negative bacteria

Answer 31

inhibition of DNA gyrase, unable to pack DNA into the cell, specific for bacterial DNA gyrase

Question 32

what is the action of quinolons in gram positive bacteria

Answer 32

inhibition of topoisomeriase IV

Question 33

what is the mechanism of flouroquinolones

Answer 33

bind two nuclear enzymes inhibitng DNA replication

Question 34

what are the different ribosome subunits in bacteria

Answer 34

30S and 50S=70S ribosome

Question 35

why is transcription and translation coupled in bacteira

Answer 35

allows the organism to grow very very quickly and you can have an enormous amount of growth

Question 36

chloroamphenicol, erthytromycin, tetraclcyine, and streptomycin all commonly do what ?

Answer 36

inhibit protein synthesis of antibiotics

Question 37

what type of bacteria have sterols

Answer 37

mycoplasma

Question 38

what is a mesosome

Answer 38

invagination where DNA binds to replicate; segregation of chromosomal DNA into daughter cells

Question 39

the bacterial cell wall is composed of what

Answer 39

peptidoglycan

Question 40

general characteristics of mycoplasma species

Answer 40

lack cell wall sterols in membrane require special media to grow not visible on the gram stain

Question 41

what type of bacteria have a thick peptidoglycan

Answer 41

gram positive

Question 42

characteristics of gram positive peptidogycna

Answer 42

highly polar surface is hydrophilic lysozyme can digest, (bactericidal) bile resistant

Question 43

__________interfere with the formation of the peptide side chains between adjacent strands of PTG by inhibitng the penicillin binding proteins

Answer 43

beta lacatam drugs

Question 44

________binds to the amino acid side chain of NAM molecules interfering with peptidoglycan synthesis

Answer 44

vancomycin

Question 45

___________interferes with the transport of peptidoglycan precursors across the cytoplasmic membrane

Answer 45

bacitracin

Question 46

__________inhibits reactions involved in the incorporation of alanine into the cell wall precursor

Answer 46

cyclyserine

Question 47

_________--bind to the terminal D ala, D alal residues preventing the incorporation of subunit into growing peptidoglycan

Answer 47

glycopeptides

Question 48

synthesis of peptidoglycan occurs in the

Answer 48

cytosol, cell membrane and periplasm or exteria

Question 49

teichoic acid and lipoteichoci acid are only found in

Answer 49

gram positive bacteira

Question 50

what is the purpose of teichoic and lipoteichoic acids

Answer 50

they are slightly immunogenic

Question 51

LPS is a characterisitc of

Answer 51

gram negative bacteria

Question 52

porin proteins are unique characteristics of

Answer 52

gram negative bacteria

Question 53

what are the three components of LPS (endotoxin)

Answer 53

O antigen, Core and Lipid A

Question 54

O antigen

Answer 54

linear polysaccharide with 50-100 repeating units with 407 sugars/unit used in serotyping

Question 55

Core

Answer 55

no associated activites, contains usual sugars, space between O antigen and Lipid A

Question 56

Lipid A

Answer 56

toxic portion, part that causes sepsis

Question 57

which type of bacteria has a thick or thin PPG

Answer 57

gram pos-thick | gram neg-thin

Question 58

characteristics of gram negative peptidoglycan

Answer 58

hydrophilic outer membrane, lipids add hydrophobic properties too

Question 59

outer membrane of gram neg

Answer 59

channels for passive diffusion-porins | attachment site for bacteriophages

Question 60

porins

Answer 60

permits entry of hydrophilic molecules, may restrict some antiseptics or disinfectants that act on cell membrane, restrict entry by size

Question 61

periplasmic space of gram neg

Answer 61

contains degradative enzymes, binding proteins, enzymes that inactivate antibiotics (beta lactamase)

Question 62

examples of enzymes that cleaves the beta lactam ring

Answer 62

penicillinases, cephalosporinases, ESBL's

Question 63

what is the purpose of a capsule

Answer 63

protects from phagocytosis, buffers environment, protects from dehydration and adherence

Question 64

flagella

Answer 64

for motility and chemotaxis, are antigenic, long hollow helical filaments

Question 65

pili

Answer 65

mostly gram -

Question 66

organisms with pilli

Answer 66

escherichia coli and N gonorrhoea

Question 67

what species have spores

Answer 67

bacillus and clostridum (gram pos rod)

Question 68

what are two drugs that enhibit cell wall syntheiss

Answer 68

beta lactams and glycopeptides

Question 69

drugs that inhibit protein synthesis

Answer 69

aminoglycosides, tetraclycines, chloramphenicol and macrolides

Question 70

________ and _______are inhibitors of nucleic acid synthesis

Answer 70

quinolones, and rifamycins

Question 71

___________are antimetabolites

Answer 71

sulfonamides and trimethoprim