Microbiology and Immunology

Question 1

how are bacterial classified?

Answer 1

their morphological and metabolic/biochemical differences

Question 2

allows to determine shape or organism, necessary because most bacteria are colorless and invisible to light

Answer 2

staining

Question 3

most useful microbiological staining technique

Answer 3

gram stain

Question 4

this type of bacteria stains blue

Answer 4

gram +

Question 5

this type of bacteria stains red

Answer 5

gram -

Question 6

different gram stains are a result of differences in what?

Answer 6

cell walls

Question 7

what type of bacteria cell wall? very thick, contains teichoic acid, doesn’t block diffusion of antibiotics (vulnerable to penicillin and lysozyme), has 2 layers, low lipid content, no endotoxin, no space/porin channel.

Answer 7

gram positive cell wall

Question 8

thin, cell wall has murrain lipoprotein, 3 layers, high lipid content, has periplasmic space and porin channel, outer cell membrane contains endotoxin (lipid A), blocks diffusion of things that attack walls (penicillins and lysozyme)

Answer 8

gram negative cell wall

Question 9

are all organisms susceptible to gram staining?

Answer 9

no - require other accomodations

Question 10

require dark field microscopy, can’t do gram stain

Answer 10

spirochetes

Question 11

require acid fast staining, can’t do gram stain

Answer 11

mycobacteria

Question 12

most disease causing organisms are what kind of bacteria?

Answer 12

gram neg rods or gram neg pleomorphic bacteria

Question 13

do not form spores, non mobile

Answer 13

gram pos cocci

Question 14

“spreading factor”, needed for invading tissue during spreading infection

Answer 14

hyaluronidase

Question 15

spherical gram pos cocci, usually arranged in chains or pairs, all are catalase negative, divided into 3 groups based on their ability to homeless red blood cells

Answer 15

streptococcus

Question 16

completely lyse RBCs, arranged in groups a-u, group a are among the most important human pathogens, many strains are anti-phagocytic, production of hemolysins, ability to adhere to pharyngeal epithelium

Answer 16

beta-hemolytic streptococcus

Question 17

group A streptococci are causative for?

Answer 17

pyogenic infections, streptococcal pharyngitis, tonsillitis, scarlet fever/rhuematic fever

Question 18

inflammatory disease that may develop after an infection with streptococcus bacteria can involve heart, joints, brain, skin

Answer 18

rheumatic fever

Question 19

not bile soluble, most of these are alpha-hemolytic, normal inhabitants of nasopharynx sf gingival crevices, group of streptococcus

Answer 19

viridans group of streptococcus

Question 20

part of viridans group, bind to teeth by producing dextran polysaccharides in presence of sucrose, not associated with period disease!

Answer 20

S. mutans

Question 21

metabolize sucrose to lactic acid which creates an acidic environment

Answer 21

s. mutans

Question 22

used by s. mutants to produce dextran

Answer 22

sucrose

Question 23

can be digested by S. mutants but the end product is lactic acid

Answer 23

glucose, lactose, fructose

Question 24

S. intermedius and S. anginosus (normal inhabitants of GI tract) are associated with what?

Answer 24

dental, brain, abdominal abscesses

Question 25

spherical, gram + bacteria, associated with tongue, colonize in mouth and URT of humans hours after birth

Answer 25

streptococcus salivarius

Question 26

most common aerobic organisms implicated in facial cellulitis

Answer 26

viridans streptococcus

Question 27

can be encapsulated with polysaccharide layer, resistant/destructive

Answer 27

streptococcus pneumoniae

Question 28

generally harmless component of normal flora, penicillin G resistant, non mobile, non spore forming, arranged in grape like clusters, facultative anaerobe, typical for access formation

Answer 28

staphylococcus

Question 29

most resistant disease causing organism that vancomycin and bactrim are often used 1st to tx

Answer 29

MRSA

Question 30

major producer of leukocidins, significant exotoxins- coagulase, hyaluronidase (degrades hyaluronic acid - ground substance of subcutaneous tissue), produces pigmented compounds called carotenoids

Answer 30

staphylococcus aureus

Question 31

bacillus (cause for anthrax and food poisoning) clostriudum (tetanus, botulism, gangrene, food poisoning, AB resistant pseudo colitis), corynebacterium (diptheria), listeria (endotoxins that cause meningitis and sepsis)

Answer 31

gram pos rods

Question 32

causes lock jaw or tetanus, spores generally dust born

Answer 32

clostridium tetani

Question 33

causative organism for meningitis and gonorrhea

Answer 33

neisseria, gram neg cocci

Question 34

spirochetes (cause for syph**, terponemtosies, lyme disease, leptospirosis), found in associated with NUG/NUP

Answer 34

gram neg spiral shaped organisms

Question 35

creates an acidic environment "aciduric", doesn't produce dextrans but produces a different extra-polysaccharide called lexan, associated with advanced caries in deep enamel

Answer 35

lactobacillus

Question 36

have been implicated in root caries, role in dental caries initiation and progression is unknown

Answer 36

actinomyces

Question 37

growth phase of bacteria. growth is slow at 1st as bacteria acclimate to environment, cellular metablic activity noy increased during this phase

Answer 37

lag phase

Question 38

growth phase of bacteria. phase that microorganisms are most prone to breakdown by antimicrobial agents

Answer 38

logarithmic "eponential" phase

Question 39

3 enzymes bacteria posses to break down oxygen products

Answer 39

catalase- breaks down hydrogen peroxide peroxidase- same superoxide dismutase- breaks down superoxide radical

Question 40

have all the enzymes, uses kreb's cycle and glycolysis, examples: neisseria,

Answer 40

obligate aerobes

Question 41

aerobic, can grow in absence of oxygen by using fermentation, ex: staphylococcus, listeria, actinomyces

Answer 41

facultative anaerobes

Question 42

"aerotolerant anaerobes", use fermentation, tolerate low amts of O2, ex: streptococcus, spirochetes, campylobacter (pregnancy gingivitis)

Answer 42

microaerophilic bacteria

Question 43

hate oxygen, ex: prevotella, porphymonas gingivalis

Answer 43

obligate anaerobes

Question 44

most often associated with hormonal "pregnancy" gingivitis, facial cellulitis, and NUP/NUG

Answer 44

prevotella

Question 45

produce collagenase, important pathogen for perio diseases

Answer 45

porphymonas gingivalis

Question 46

what are most fungi?

Answer 46

obligate aerobes

Question 47

most common fungus encountered in the dental setting, part of normal flora in digestive/respiratory/urogenital tracts

Answer 47

candidia albicans

Question 48

energy-less, must have host cell, composed of protein core (capsid) surrounding genetic material, may have outer lipid bilayer (envelope) or may be naked, small (.02-.03 microns)

Answer 48

viruses

Question 49

refers to the different kinds of organisms a virus can infect

Answer 49

host range

Question 50

referes to specific kinds of cells a virus can infect and is determined mainly by whether a virus can attach to a cell

Answer 50

specificity

Question 51

a complete virus particle (including its envelope if it has one)

Answer 51

virion

Question 52

4 possible outcomes once a host cell has been infected by a virus

Answer 52

death, transformation, latent infection, chronic slow infections

Question 53

what is the classification of viruses based on?

Answer 53

type and structure of viral nucleic acids (RNA or DNA- never both)

Question 54

role of _____ is to move the info contained in the DNA to the cell's cytoplasm where protein synthesis and viral replication takes place

Answer 54

mRNA

Question 55

primary function of mRNA

Answer 55

translation

Question 56

transcription is what to what?

Answer 56

DNA to RNA

Question 57

RNA genome can be similar to mRNA is known as what?

Answer 57

positive strand RNA

Question 58

RNA genome is a template for production is known as what?

Answer 58

negative strand RNA

Question 59

examples of RNA viruses?

Answer 59

HIV, Hep A, rhino virus, influenza virus, mumps, measles, rabies

Question 60

virus that has both positive and negative strands, cannot be translated into proteins until it is transcribed into mRNA

Answer 60

DNA viruses

Question 61

examples of DNA viruses

Answer 61

HPV, HSV I and II, VZV, CMV, EBV, small pox

Question 62

spreads via nasopharyngeal secretions, can cross placental barrier, has Koplik's spots

Answer 62

measles

Question 63

small, red-based lesions with blue center in mouth, seen in measles

Answer 63

Koplik's spots

Question 64

causative organism for herpangina

Answer 64

coxsackie virus

Question 65

causes chickenpox and shingles upon reactivation of the dormant virus

Answer 65

VZV

Question 66

DNA hepatitis virus

Answer 66

hep B

Question 67

RNA hepatitis virus

Answer 67

hep a, c, d, e

Question 68

hep b vaccine is an example of what type of immunity?

Answer 68

artificial acquired active immunity

Question 69

gamma globulin is an example of what type of immunity?

Answer 69

passive

Question 70

protection of body is provided by what 2 systems?

Answer 70

cell mediated immunity and antibody mediated "humoral" immunity

Question 71

what type of immunity? t-cell, defense against infection (esp mycobacterium tb, viral and fungal), allergic response, graft and tumor rejection, regulation of antibody response

Answer 71

cell mediated immunity

Question 72

what type of immunity? b cells, defense against infection (opsonizes bacteria, neutralizes toxins, and viruses), allergic response, autoimmunity

Answer 72

antibody mediated "humoral" immunity

Question 73

what type of immunity? non specific, not acquired from previous antigen exposure, doesn't improve after exposure, have no memory, includes skin/mucous membranes, natural killer cells, phagocytosis, inflammation, complement proteins

Answer 73

natural immunity

Question 74

group of proteins that circulate in the blood and serve to assist other defense mechanisms

Answer 74

complement systems

Question 75

2 complement pathways

Answer 75

classical- antibody dependent | alternative- spontaneous

Question 76

what type of immunity? occurs after exposure, improves with repeated exposures, mediated by antibodies and t cells, long term memory, passive or active

Answer 76

acquired immunity

Question 77

cells of immune systems made where

Answer 77

bone marrow

Question 78

cells of immune systmes

Answer 78

leukocytes- granulocytes, lymphocytes, monocytes, dendritic cells

Question 79

types of t cells

Answer 79

t-cytoxic cells, helper cells "CD4 cell"

Question 80

only T cels that can directly attack and kill diseased cells, including cancer cells

Answer 80

cytoxic t cells

Question 81

produce cytokines that stimulate macrophages, NK cells, dendritic cells, and other t cells

Answer 81

t helper cells

Question 82

what type of cell? differentiate into plasma cells and produce antibodies, antigen presenting cells, can form memory cells, involved in humoral immune response

Answer 82

b cells

Question 83

what do plasma cells come from?

Answer 83

antibodies

Question 84

functions of this cell- phagocytosis, antigen transportation/processing/presentation, cytokine production

Answer 84

macrophages

Question 85

kill virus and tumor infected cells, active w/ out prior exposure to antigen, non specific, a lymphocyte, kill with out antibody

Answer 85

Natural killer (NK) cells

Question 86

most numerous WBC, capable of phagocytosis, migrate in response to chemotactic factors (diapedesis), 1st line of defense

Answer 86

Polymorphonuclear neutrophils (PMNs)

Question 87

key regulator of the immune system, antigen presenting cell capable of activating T and B cells

Answer 87

dendritic cells

Question 88

immunoglobulins that react specifically with antigen, 5 classes- IgG, IgM, IgA, IgD, IgE

Answer 88

antibodies

Question 89

immunoglobulin class, predominant in secondary response, opsonizes, capable of activating the classical (antibody) complement pathway

Answer 89

IgG

Question 90

immunoglobulin class, produced in primary response, most efficient in agglutination "clumping", 10 binding sites, largest antibody, capable of activating the classical "antibody" complement pathway

Answer 90

IgM

Question 91

immunoglobulin class, main immunoglobulin in secretions, has J chain and secretory component, prevents attachment of antigen to mucous membranes

Answer 91

IgA

Question 92

immunoglobulin class, no known function in body, present in small amounts in serum

Answer 92

IgD

Question 93

immunoglobulin class, mediates anaphylactic hypersensitivity by binding to mast cells and basophils, targets certain parasites

Answer 93

IgE

Question 94

hypersensitivity reaction- IgE antibody is induced by antigen "allergen", binds to mast cells and basophils, release of mediators such as histamine, requires previous exposure to allergen

Answer 94

Type I- anaphylactic (immediate)

Question 95

what cells release histamine?

Answer 95

mast cells

Question 96

pallor is or is not a sign of histamine release?

Answer 96

is not

Question 97

hypersensitivity reaction- antigens on a cell surface combine with antibody leads to complement mediated lysis, ex: Rh and transfusion reactions, primary antibody- IgG

Answer 97

Type II- cytotoxic

Question 98

hypersensitivity reaction- release of lysosomal enzymes cause tissue destruction, complement is activated, PMNs called in, IgG primary antibody

Answer 98

Type III- Immune Complex

Question 99

hypersensitivity reaction- helped T cells are sensitized by antigens, *cell versus antibody mediated, induces inflammation and activation of macrophages which release mediators, ex: Tb skin test

Answer 99

Type Iv- delayed

Question 100

autoimmune diseases more common in male or female?

Answer 100

female

Question 101

autoimmune disorder, associated with Raynaud's phenomenon and generalized widening of the periodontal ligament space

Answer 101

scleroderma

Question 102

what makes up protein?

Answer 102

amino acids

Question 103

smallest unit of protein

Answer 103

amino acids

Question 104

buffer in saliva

Answer 104

sodium bicarbonate

Question 105

primary cell in the PDL

Answer 105

fibroblasts

Question 106

movement of cells to the site of inflammation

Answer 106

chemotaxis