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340 Cards in this Set
- Front
- Back
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True/False:
Staphylococcus Aureus is coagulase negative whereas other Staphylococci are coagulase positive |
False: Aureus is positive and other staph. is negative
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How does staphylococcus invade the body?
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From traumatic inoculation
(Cn't invade through intact skin and mucous membranse) |
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What does the cell wall of Streptococcus Aureus contain?
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Ribitol phosphate teichoic acid
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S. Aureus usually produces what?
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Abscess formation
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What does S. Aureus most commonly cause?
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Scalded skin syndrome
Toxic Shock Syndrome Osteomyelitis Infections of burns/surgery Resp tract infections Septicemia Bacterial endocarditis Staph food poisoning |
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What are the coagulase negative staphylococci?
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S. epidermis
S. saprophyticus |
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What is the most frequent cause of infections associated with medical devices?
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Staphylococcus Epidermis
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What is the frequent culprit of acute urinary tract infections in young women?
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Staphylococcus Saprophyticus
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What kind of Anaerobes are Staphylococci?
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Facultative Anaerobes
(Aerobic but also can ferment) |
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What does the Staphyloccoci bacteria yeild?
They are _____ positive and _____ negative enzymatically. |
Lactic Acid
Catalase, Oxidase |
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S. Aureus can grow at a temp. range of _____ degrees and at _____ concentrations as high as _____
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15-45
NaCI 15% |
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What enzyme does nearly all strains of S. Aureus produce?
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Enzyme coagulase
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What are the major virulence factors of S. Aureus?
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Protein A
beta-lactamase enterotoxin hyaluroni-hyaluronidase staphylokinase |
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what are the virulence factors for streptococcus pyrogens?
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M Protein
DNAse B (streptodornase) Pyrogenic toxin (erythrogenic) Streptolysin O & S Streptokinase Hyaluronidase Exotoxin A (SPE A) ExotoxinB (SPE B) |
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What are considered the super antigens of the Strep pyrogens?
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Exotoxin A & B
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What is the action of the Strep M. Protein?
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Resistance to phagocytosis
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What is the action of the Step DNAse B?
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Cleaves DNA
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What is the action of the Step pyrogenic toxin?
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Causes Scarlet Fever Rash
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What is the action of the Step Streptolysin O & S?
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Lysis of Red and White blood cells
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What is the action of the Step Streptokinase?
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Dissolves fibrin in blood clots
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What is the action of the Step Hyaluronidase?
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Breaks down hyaluronic acid
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What is the action of the Step Exotoxin A (SPE A)?
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Streptococcal toxic shock syndrome
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What is the action of the Step Exotoxin B (SPE B)?
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Rapidly destroys tissue
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Wha are the major virulence factors of Staph. Aureus?
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Protein A
Coagulase Staphylokinase Hyaluronidase (spreading factor) Bet-lactaminase (penicillinase) Enterotoxin Exfoliation toxin TSST (toxic shock syndrome toxin) |
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What is the action of the S. Aureus protein A?
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Inhibits complement fixation by binding to the Fc portion of IgG
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What is the action of the S. Aureus Coagulase?
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Clots blood
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What is the action of the S. Aureus Staphylokinase?
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Dissolves Blood clots
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What is the action of the S. Aureus Hyaluronidase (spreading factor)?
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Breaks down Hyaluronic acid
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What is the action of the S. Aureus Beta-lactamase (penicillinase)?
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Inactivates penicillin
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What is the action of the S. Aureus Enterotoxin?
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Causes Food Poisoning
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What is the action of the S. Aureus Exfoliatin toxin?
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Causes scalded skin syndrome
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What is the action of the S. Aureus TSST (Toxic shock syndrome toxin)?
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Causes toxic shock syndrome
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What is the major virulence factor for Clostridium botulinum?
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Botulinum neurotoxin
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What is the most potent toxin known to man?
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Botulinum neurotoxin
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What does botulinum neurotoxin cause ?
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Muscle and nerve paralysis (botulism)
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What is the virulence factor for Clostridium perfringens?
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alpha toxin (a lecithinase)
- Potent exotoxin |
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What does the alpha toxin do?
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Destroys integrity of cell membrane; breaks down fibrous tissue
(Gas Gangrene) |
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What is the virulence factor for Clostridium tetani?
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Tetanus toxin (tetanospasm)
- Neurotoxin |
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What is the action of Tetanus toxin?
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Interfreres with motor neurons
(tetanus or lockjaw) |
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What is the virulence factor fro Corynebacterium dipthereriae?
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Diptheria toxin
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What is the action of the diptheria toxin?
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Blocks elongation factor-2 during translation, inhibiting protein synthesis
(Diphtheria) |
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What is the virulence factor for Shigella species bacteria?
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Exotoxins and Endotoxins
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What are the actions of the Exo- and Endo-toxins of the shigella species?
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Enterocolitis
Bacterial dysentary (Shigellosis) |
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What is the predominante type of bacteria on the skin?
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Staphylococci and Corynebacteria
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What are the predominant bacteria on the conjunctiva?
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Sparse gram negative cocci and gram positive rods
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What are the bacteria that are predominantly on the teeth?
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Streptococci, and lactobacillis
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What are the bacteria that are predominant on the mucous membranes?
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Streptococci and lactic acid bacteria
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What are the bacteria that are predominant in the nares (nasal membrane)?
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Staphylococci and corynebacteria
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What are the bacteria that are predominant on the pharynx (throat)?
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Streptococci, neisseria, gram-neg. rods and cocci
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What are the bacteria that are predominant on the lower respiratory tract?
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None
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What are the bacteria that are predominant in the stomach?
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Helicobacter pylori (up to 50%)
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What are the bacteria that are predominant in the small intestine?
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Lactics, enterics, enterococci, bifidobacteria
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What are the bacteria that are predominant in the colon?
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Bacteroides, lactics, enterics, enterococci, clostridia
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What are the bacteria that are predominant Anterior urethra?
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Sparse: staphylococci, corynebacteria, enterics
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What are the bacteria that are predominant in the vagina?
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Lactic acid bacteria during child-bearing years; otherwise mixed
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On blood agar plates what do alpha hemolytic streptococci do?
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Cause incomplete lysis of red blood cells
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Some species of streptococcus produce these toxins that cause lysis of erythrocytes.
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Hemolysins
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Produce a zone of incomplete hemolysis and green discoloration adjacent to the strep colony.
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Alpha-hemolytic streptococci
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Produces a clear zone of hemolysis around the step colony.
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Beta-hemolytic streptococci
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Produces no hemolysis in the strep colony?
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Gamma streptococci
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How are the Beta-hemolytic forms of strep classified?
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Into lancefeild groups (A thru U) according to C carbohydrate composition of cell wall
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Pathogenic for humans. Further subdivided by Arabic numerals into specific antigen types based on cell wall M Protein.
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Group A strains of Beta-hemolytic forms of Strep.
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What causes rheumatic fecer, scarlet fever, and sore throat?
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The pyrotype S. pyrogens of group A strain beta-hemolytic strep
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What streptococcus pyrogens are associated with severe infections characterized by rash, hypotension, multiorgan failure and high mortality rate.
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Superantigens
S. enterotoxin A & B |
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Oral Strep is usually...
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Alpha hemolytic
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What are the oral strep alpha hemolytic bacteria?
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S. viridans, S. mutans, S. sanguinis, S. Salivarius
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The oral Strep alpha hemolytic bacteria most commonly cause what?
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Subacute endocarditis
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The bacterial growth curve reflects what?
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Dynamics in a population of bacteria over a period of time.
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When a bacteria is placed in a fresh nutrient-rich medium, they exhibit how many phases of growth?
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4
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What phase occurs when cells are metabolically active but not dividing? This is a period when cells are resynthesizing enzymes, coenzymes, ect. necessary for growth and division.
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Lag Phase
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What is known as the exponential growth phase? bacteria are growing and dividing at an exponential rate. this is a period of fastest growth where gen. time is maximal and constant.
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Log Phase
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Which phase is best to stain bacteria culture for study and where most cidal bacteria work best?
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Log Phase
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At tis phase the medium is becoming depleted in some nutrients, and toxic quantities of waste materials may be accumulating. The number of new cells produced is offset by the number of cells that are dying so total number of cells remains constant.
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Stationary phase
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Phase in which conditions are becoming less and less conducive to cell growth. Cells are dying more rapidly than new ones being made, resulting in a logarithmic decrease in cell number.
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Death phase
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Endotoxins are part of the outer membrane of the cell wall of what type of bacteria?
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Gram-negative bacteria
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The biological activity of endotoxin is associated with ...
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Lipopolysaccharide
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What is the toxicity of an endotoxin associated with?
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Lipid component (Lipid A)
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What is the immunogenicity of an endotoxin associated with?
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Polysaccharide components
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Lipopolysaccharides are associated with what on endotoxins?
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- Cell wall antigen (O antigens) are LPS
- LPS elicits variety of inflammatory responses - LPS activates complement by alternative (properdin) pathway |
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What are endotoxic organisms?
exotoxic? |
gram-neg
gram neg. and gram pos. |
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What is the chemical nature of endotoxins?
Exotoxins? |
Lipopolysaccharide
Protein |
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What is the relationship to the cell of endotoxins?
Exotoxins? |
Part of outer membrane
Extracellular, diffusible |
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Are endotoxins denatured while boiling?
Exotoxins? |
no
Usually |
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Are endotoxins antigenic?
Exotoxins? |
Yes
Yes |
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Do endotoxins form toxoid?
Exotoxins? |
No
Yes |
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What is the potency of endotoxins?
Exotoxins? |
Relatively low
Relatively high |
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What is the specificity of endotoxins?
Exotoxins? |
Low degree
High degree |
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Does endotoxin have enzymatic activity?
Exotoxins? |
No
Often |
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Does endotoxin have pyrogenicity?
Exotoxins? |
Yes
Occasionally |
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Are endotoxins released by organisms?
Exotoxins? |
No
Yes |
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What is essential to the function of the outer membrane of gram-negative bacteria?
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Lipopolysaccharide (LPS)
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What is the function of the outer membrane of gram negative bacteria?
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Acts as a protective permeability barrier
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How is endotoxin released into the hosts bloodstream?
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Cell must die and and outer membrane broken down in order to release endotoxin
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Minute ammounts of endotoxin in the oral mucosa causes what?
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Inflammation and resorption of adjacent bone.
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Endotoxin has a chemotactic effect on what?
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Neutrophilic granulocytes which induces phagocytosis
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In addition to endotoxin what enzymes does bacterial plaque also produce to initiate periodontitis?
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Hyaluronidase
Collagenase Chondroitin Sulfatase Elastase Proteases |
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What kind of endotoxin is present in dental plaque and in inflamed gingiva?
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Free endotoxin
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What is the most likely source of bacteria found in diseased periodontal tissue?
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Subgingival plaque
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Protease which degrades collagen
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Collagenase
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Collagenase has been demonstrated in to be part of the component system in what bacteria?
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Porphyromonas Species
Clostridium Species Bacteriosides Species AA |
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What is the lipopolysaccharide component of an endotoxin composed of?
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A lipid "A" core polysaccharide and an "O" antigenic side chain
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_____ can be activated by endotoxin in the absence of preceding activation of _____, _____, and _____. As a result the various complement components (_____, _____) are consumed and then their activity disappears or is reduced from serum.
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C3
C1, 4, 2 C3, 5-9 |
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The genus neisseria contains what two important human pathogens?
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N. gomorrhoeae and N. meningitidis
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What does N. gonorrhoeae cause?
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gonorrhea
- High prevalence, low mortality |
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What does N. Meningitidis cause?
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Meningococcal meningitis
- Low prevalence, high mortality |
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A gram-negative facultative rod-shaped bacterium in the same proteobacterial amily as Escherichia coli, the family Enterobacteriaceae, trivally known as " enteric" bacteria.
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Salmonella
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Salmonella causes what two disease in humans?
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Salmonellosis
Acute Gastroenteritis |
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Enteric fever (typhoid), resulting from bacterial invasion of the bloodstream
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Salmonellosis
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Results from a foodborne infection/intoxication
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Acute gastroenteritis
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What specific type of strep bacteria causes Pneumonia?
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S. pneumoniae
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What type of Strep bacteria causes Rheumatic fever?
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S. pyrogens
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What type of Strep bacteria causes heart valve infections?
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S. viridans
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What are the three enzymes that cleave plasminogen and thus produce plasmin which causes liquifaction of fibrin and is use clinically in the removal of blood clots
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Staphylokinase (S. Aureus)
Streptokinase (Hemolytic streptococci) Urokinase |
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What invasin is associated with Streptococci, staphylococci and clostridia and degrades hyaluronic acid of connective tissue
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Hyaluronidase
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What invasin is associated with the clostridium bacteria and dissolves collagen frame work of muscles?
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Collagenase
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What invasin is associated with Vibrio cholerae and shigella dysenteriae and degrades neuraminic acid of intestinal mucosa?
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Neuraminidase
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What invasin is associated with Staphylococcus aureus and disrupts neutrophil membranes and causes dischargeof lysosomal granules
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Leukocidin
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What invasin is associated with Staphylococcus Aureus and converts fibrinogen to fibrin which causes clotting
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Coagulase
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What invasin is associated with Staphylococci and streptococci bacteria and converts plasminogen to plasma which digests fibrin
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Kinases
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What invasin is associated with streptococcus pyrogens and repels phagocytes and disrupts phgocyte membrane and causes discharge of lysosomal granules?
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Streptolysin
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What invasin is associated with streptococci, staphylococci, and clostridia and phospholipases or lecithinases that destroy red blood cells (and other cells) by lysis?
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Hemolysins
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What invasin is associated with clostridium perfringens and destroys lecithin in in cell membranes?
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Lecithinases
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What invasin is associated with clostridium perfringens and destroys phospholipids in cell membranes?
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Phospholipases
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What invasin is associated with bacillus Anthracis and one component (EF) is an adenylate cyclase which causes increased levels of intracellular cyclic AMP?
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Anthrax EF
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What invasin is associated with bordetella pertussis and; one toxin component is an adenylate cyclase that acts locally producing an increase in intracellular cyclic AMP
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Pertussis AC
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Mycobacterium species, along with members of a related genus Nocardia, are classified as what?
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Acid-fast bacteria
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Why is mycobacterium not characterized as either a gram neg. or gram pos. bacteria?
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Contains neither, but does have peptidoglycan (murein) in the cell wall
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Fairlt large non-motile rod-shaped, acid fast, niacin-producing bacterium. Produces neither exotoxin or endotoxin and many non-pathogenic forms are part of the normal flora of of humans found in mostly dry and oily locales.
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Mycobacterium tuberculosis
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Why is it that Mycobacterium tuberculosis is always found in the well aerated upper lobes of the lungs?
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They are obligate aerobes
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The Mycobacterium tuberculosis is a facultative intracellular parasite, usually of _____, and has a slow generation time of _____, a physiological characteristic that may contribute to its _____.
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Macrophages
15-20 hours virulence |
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One of the methods used to diagnose active tuberculosis. Method of staining used in bacteriology in which a smear on a slide is flooded with _____-_____ stain, decolorized with acid alcohol, and counterstained with methylene blue. These specific organisms resist decolorization and appear _____ against a _____ background when viewed under amicroscope.
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Acid-fast staining
carbol-fuchsin Red Blue |
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The property of being acid-fast is attributable to...
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The presence of lipids and waxes (mycolic acids) in the cell wall of certain bacteria
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Alternate method of testing for tuberculosis that may indicate an infection, but not whether the infection is active. A purified protein derivative (PPD) extract from mycobacterium tuberculosis is injected subcutaneously, and the area near the injection is observed for evidence of _____ _____ _____.
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Classic Skin Test (PPD skin test)
Delayed hypersensitivity reaction |
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What are the common acid-fast bacteria that are of medical importance?
|
Mycobacterium tuberculosis
Mycobacterium leprae Mycobacterium avium-intracellulare complees |
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In addition to peptidoglycan, the acid-fast cell wall of Mycobacterium contains a large amount of glycolipids, especially _____ that make up approximately _____ of the acid-fast cell wall.
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Mycolic Acids
60% |
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Where are the mycolic acids of Mycobacterium located?
How do they adhere to this surface? |
Inner leaflet of mycobacterial cell wall
Covalently bound or loosely associated with arabino-galactan polymers |
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What prevents osmotic lysis on the acid-fast cell wall?
|
Peptidoglycan
|
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What impedes the entry of chemicals causing the organisms to grow slowly and be more resistant to chemical agents and lysosomal components of phagocytes on the acid-fast cell wall?
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Mycolic acids and other glycolipids
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What carries out a variety of activities including enzyme function and serving as adhesins on the acid-fast cell wall?
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Surface proteins
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Enables the bacterium to adhere intimately to host cells and other surfaces in order to colonize and resist flushing
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Adhesins
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What contains enzymes for nutrient breakdown as well as periplasmic binding proteins to facilitate the transfer of nutrients across the cytoplasmic membrane on the acid-fast cell wall?
|
Periplasm
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What inhibits mycolic acid biosynthesis and is an efficient antimycobacterial agent?
|
Isoniazid
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A small, rounded nodule produced by infection with M. Tuberculosis. it is the primary lesion of the lung with pulmonary TB
|
Tubercle or Ghon focus
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A gelatinous coat which surrounds the cell wall of certain bacteria and is especially important in protecting these cells against phagocytic attack from eukaryotic cells
|
Capsule
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The presence of a capsule can be a major factor in determining the _____ of a bacterium.
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Pathogenicity
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Besides determining pathogenicity a capsule is important in ...
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Adherence of cells to surfaces
Identification purposes |
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What causes capsules to swell and thus allow them to be identifyed?
|
Treatment of antiserum
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What bacteria have their virulence enhanced by the presence of a capsule coating?
|
S. Pneumoniae
Haemophilus influenzae Klebsiella pneumoniae Cryptococcus neoformans |
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Selectively permeable membrane that is involved in energy transformations and bordered externally by the cell wall in most bacteria
|
Cell membrane
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Surrounds the plasma membrane and serves to protect the cell from changes in osmotic pressure. Then it also anchors flagella, maintains cell shape, and control the transport of molecules into and out of the cell.
|
Cell Wall
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A dynamic, selectively permeable membrane enclosing the cytoplasm. It is located between the cell wall and the cytoplasm, and it regulates the movement of substances, including water, into and out of the cell.
|
Plasma Membrane
|
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What are teichoic acids unique to?
|
Gram-positive bacterial cell wall
|
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How thick is the gram-positive cell wall?
|
15-80 NM thick
|
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What is the layer which makes up approximately 90% of the gram positive bacterial cell wall?
|
Thick Murein layer
|
|
|
Polysaccharides which serve as attachment sites for bacteriophages on gram-positive bacteria
|
Teichoic acids
|
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How thick is the cell wall of Gram-negative bacteria?
|
10 NM thin
|
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What are the layers of the gram-negative cell wall?
|
Thin murein (10%)
Lipoproteins (Integral part) Lipopolysaccharides (LPS or endotox) Phospholipids Proteins |
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What layers of the cell wall of gram-negative bacteria make up the cell envelope and protects the cell from antibiotics and enzymes?
|
Lipopolysaccharide layer
Protein layer Phospholipid layer |
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What is a unique type of peptidoglycan which contains N-acetylmuramic acid which is it's definitive component?
|
Murein
|
|
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A polymer of sugars cross-linked by short chains of amino acids.
|
Peptidoglycan
|
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What feature distinguishes bacteria from archaea?
|
The presence of Murein is unique to bacteria
|
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What characteristics describes the lactic acid bacteria well?
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Gram-negative usually non-motile, non-sporeforming rods and cocci
|
|
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What gives lactobacillus its name?
|
Ferments glucose to lactose
|
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What is the most common application of lactobacillus?
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Industrial, esp. Dairy
|
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Several bacteria from the lactobacillus genus make up a natural flora of the human _____
|
Vigina
|
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What kind of environment does the lactobaccilus species create in the vagina?
What can this lead to? |
Acidic Environment
Can lead to urogenital infections |
|
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In what way are lactobacilli associated with dental caries?
|
Low numbers in oral cavity
probably secondary microbial invader |
|
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What is added to commercial milk products to assist lactose intolerant individuals in ingesting lactose sugars?
How is this done? |
Lactobacillus acidophilus
Enzymes produced by these bacteria convert milk sugars to products that are not harmful to the GI |
|
|
What are the two lactic acid bacteria?
|
Lactobacillus and streptococcus
|
|
|
These bacteria use the lactic acid fermentation pathway to reduce pyruvate to lactic acid.
|
Lactic acid bacteria
|
|
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What are two specific characteristics of lactobacillus and streptococcus?
|
Aciduric (tolerates acid environment)
Acidogenic (acid forming) |
|
|
Generally harmless bacteria to humans, rarely inciting harmful infections or diseases. Treatment of this vancomycin-resistant microbe usually consists of high doses of penicillin in combination with gentamicin.
|
Lactobacillus
|
|
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What bacteria is the main culprit in dental caries (esp. smooth surface caries)?
|
Steptococcus mutans
|
|
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What bacteria has been found to be a causative agent of root surface caries
|
Actinomyces
|
|
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Which two organisms are most commonly associated with the etiology of localized aggressive periodontitis (formerly called juvenile periodontitis)?
|
Actinobacillus actinomycetemcomitans
Capnocytophaga ochraceus |
|
|
What was aggressive periodontitis formerly called?
How many forms does it have? |
Juvenile periodontitis
2 forms: - Generalized - Localized |
|
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What is the generalized form of aggressive periodontitis formerly called?
|
Rapidly progressive periodontitis
|
|
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What bacteria predominates in the generalized form of aggressive periodontitis?
What are the age ranges? |
Prevotella intermedia and Eikenella corrodens
Ages 12-25 |
|
|
Characterized by rapid, severe periodontal destruction around most teeth. Characterized by episodic, rapid, severe attachment loss.
|
Generalized form of aggressive periodontitis
|
|
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What bacteria predominates in the localized form of aggressive periodontitis?
What are the age ranges? |
Actinobacillus actinomycetemcomitans
capnocytophaga ochraceus To a smaller extent:Prevotella intermedia and Eikenella corrodens Adolescents ages 12-19 |
|
|
Characterized by rapid and severe attachment loss confined to the incisors and first molars. The outstanding negative feature is the relative absence of local factors (plaque) to explain the severe periodontal destruction which is present.
|
Localized form of aggressive periodontitis
|
|
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What are the etiological factors of localized aggressive periodontitis?
|
Genetic predisposition
Dysfunction of Neutrophils |
|
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What are Aa and Capnocytophaga species also associated with systemically?
|
Juvenile Diabetes causing periodontal disease
|
|
|
Microorganisms which grow at an optimum pH well below neutrality (7.0)
|
Acidophiles
|
|
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What are the three cardinal points at which an organism grows?
|
Minimum pH: below where the organism grows
Maximum pH: above where the organism grows Optimum pH: range the organism best grows |
|
|
What are the bacteria which grow at neutral pH (7.0)?
|
Neutrophiles
Most bacteria |
|
|
What are some examples of neurtophiles?
|
Pseudomonas aeruginosa
Clostridium sporogenes Proteus species |
|
|
What are some examples of acidophiles?
|
Obligate acidophiles:
- Thiobacillus species |
|
|
Bacteria which grows at an alkaline condition.
|
Alkaliphiles
|
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|
What are some examples of alkaliphiles?
|
Nitrobacter species
Streptococcus pneumoniae |
|
|
What are the primary acidogenic organisms in the oral cavity?
|
Streptococcus
|
|
|
What is the main cause of enamel decalcification?
|
Lactic Acid
|
|
|
E. coli is in the bacterial family Enterobacteriaceae, which is made up of what?
|
Gram negative, non-spore-forming, rod-shaped bacteria that are often motile by means of flagella
|
|
|
These bacteria live in the intestinal tract of of humans and other animals.
What are some examples? |
Enteric bacteria
E. Coli Salmonella - agent of typhoid fever Shigella - Bacterial cause of dysentery |
|
|
Is Escherichia coli considered pathogenic?
What is it responsible for in humans? |
No
UTI, Neonatal meningitis, Intestinal diseases |
|
|
What is gram-negative, nonmotile, non-spore-forming coccus that occurs in chains or in pairs of cells. A facultative anaerobe and cosists of hyaluronic acid capsule and exhibit clear hemolysis on blood agar.
|
Streptococcus Pyogens (Group A Streptococcus)
|
|
|
What is one of the most frequent pathogens in humans?
|
Streptococcus Pyogens
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|
What is phagocytosis mediated by?
|
Macrophages and polymorphonuclear leukocytes
|
|
|
What are fixed macrophages?
|
Don't circulate
Fixed macros and cells of the reticuloendothelial system |
|
|
What are free macrophages?
|
Circulate in bloodstream
Includes leukocytes and free macros |
|
|
What is step one in phagocytosis?
|
Chemotaxis and adherence of microbe to phagocyte
|
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|
What is step 2 in phagocytosis?
|
Ingestion of microbe by phagocyte
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What is step 3 in phagocytosis?
|
Formation of phagosome
|
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|
What is step 4 in phagocytosis?
|
Fusion of phagosome with lysosome forming phagolysosome
|
|
|
What is step five in phagocytosis?
|
Digestion of ingested microbe by enzymes
|
|
|
What is step 6 in phagocytosis?
|
Formation of residual body containing indigestible material
|
|
|
What is step 7 in phagocytosis?
|
Discharge of waste materials
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|
What is the process in which DNA is transferred from a bacterial donor cell to a recipient cell by cell-to-cell contact?
|
Conjunction
|
|
|
Form of Sexual reproduction in which DNA is transferred from one live bacterium to another through direct contact. This contact is established through the presence of pili.
|
Conjunction
|
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|
The ability to transfer DNA by conjunction is dependent on the presence of what?
|
Fertility Factor (F)
|
|
|
Small circular DNA element that acts like a minichromosome and is labeled + if it is present or - if it is absent
|
Fertility Factor (F)
|
|
|
Self-replicating extrachromosomal DNA molecules
|
Plasmids
|
|
|
What is the process in which the greatest amount of genetic information is transferred?
|
Conjunction
|
|
|
What occurs more frequently?
Conjunction/Transformation |
Conjunction
|
|
|
What can potentially be transferred in conjunction?
|
Antibiotic resistance for bacteria
Bacterial potential for pathogenicity F Factors |
|
|
An F plasmid incorporated into the chromosome
|
Hfr (high frequency of recombination)
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|
Portions of DNA that move from one site on a chromosome to another (or to a plasmid) do so through what?
|
Transposons
|
|
|
Where does transcription occur?
|
Cytoplasm of prokaryotes, while it occurs in the nucleus of eukaryotes.
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|
|
The transfer of the genetic information from the archival copy of DNA to the short-lived messenger RNA
|
Transcription
|
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|
What is the enzyme that binds to a particular region of DNA and starts to make a strand of mRNA with a base sequence complementary to the DNA template that is downstream of the binding site
|
RNA Polymerase
|
|
|
What is a newly generated mRNA used as a template for?
|
Translation
|
|
|
What is the first step in transcription?
|
DNA unzips by DNA gyrase and RNA Polymerase binds to one strand of DNA
|
|
|
What is the second step in transcription?
|
RNA polymerase makes an elongating chain of RNA nucleotides, each one complementary to the DNA nucleotide H bonded to it.
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|
|
What is the third step in transcription?
|
Completed mRNA molecule released from RNA polymerase-DNA complex and can begin translation
|
|
|
The process wherein information in the form of nitrogenous bases along an mRNA is translated into the amino acid sequence of a protein
|
Translation
|
|
|
The transfer of DNA via a phage particle and does not require cell-to-cell contact
|
Transduction
|
|
|
The formation of DNA from an RNA template
|
Reverse transcription
|
|
|
Viruses that are enveloped and contain a linear, single-stranded, positive-sense RNA genome. They use their RNA genome as a template for an RNA-directed DNA polymerase
|
Retroviruses
|
|
|
The attachment of microbes and other foreign cells to phagocytes by antibody molecules such as IgG and complement proteins such as C3b is called what?
|
Opsonization or enhanced attachment
|
|
|
What antibody molecules and complement proteins are involved in attaching antigens during opsonization that results in a more efficient phagocytosis.
|
IgG or IgM
C3b and C4b |
|
|
How does the process of opsonization begin?
|
- IgG is made against a surface antigen of organism to be phagocytized
|
|
|
What part of the IgG in opsonization reacts with epitopes of the antigen?
|
Fab portion
|
|
|
What part of IgG binds to neutrophils/macrophages sticking antigen to phagocyte in opsonization?
|
Fc portion
|
|
|
What activate the phagocyte in Opsonization
|
Binding of IgG to Fc receptor
|
|
|
what does attachment promote in opsonization?
|
Destruction of the antigen
|
|
|
When is opsonization especially important?
|
Against microorganisms with antiphagocytic structures such as capsules
|
|
|
What are the two major opsonins?
|
IgG and C3b
|
|
|
What is an oxygen stable virulence factor of S. pyogenes?
|
Streptolysin S
|
|
|
What is an oxygen labile virulence factor of S. pyogenes?
|
Streptolysin O
|
|
|
What does S. pyogenes owe its major success as a pathogen to?
|
Ability to colonize rapidly, multiply and spread in its host while evading phagocytosis and confusing immune system
|
|
|
What are the antigenic components of the S. pyogenes cell surface that accounts for the bacteriums determinant to virulence?
|
- Capsular polysaccharide
- Cell wall peptidoglycan and lipoteichoic acid (LTA) - M Protein - Fimbrial proteins - Fibronectin binding proteins - Cell bound streptokinase |
|
|
What are the two principal bacteria associated with acute necrotizing ulcerative gingivitis (ANUG)?
|
Prevotella intermedia and Spirochetes
|
|
|
Acute recurring gingival infection of complex etiology, characterized by necrosis of papillae, spontaneous bleeding and pain
|
ANUG
|
|
|
What is NUG formerly known as?
|
Vincent's infection or trench mouth
|
|
|
What are the signs and symptoms of NUG?
|
- Interproximal gingival necrosis
- Marginal gingival pseudomembrane formation - Pain - No attachment loss - Fetid oris - Gingiva bleeds easily - Metallic taste - Low-grade fever, lymphadenopathy |
|
|
What are the subgingival bacteria that are associated with gingival health?
|
- S. mitis and sanguis
- Actinomyces viscosus & naeslundii - Rothia dentocariosus - Staphylococcus epidermidis - Small spirochetes |
|
|
What is the immunoglobin that is found in the highest concentration in serum samples from patients with periodontal disease?
|
IgG
|
|
|
What classification contains organelles and have larger ribosomes?
Eukaryotes/Prokaryotes |
Eukaryotes
|
|
|
What classification contains a rigid cell wall that contains peptidoglycan?
Eukaryotes/Prokaryotes |
Prokaryotes
|
|
|
What classification replicates by mitosis?
Eukaryotes/Prokaryotes |
Eukaryotes
|
|
|
What classification replicates by binary fission?
Eukaryotes/Prokaryotes |
Prokaryotes
|
|
|
What classification contains sterols in its membrane?
Eukaryotes/Prokaryotes |
Eukaryotes
Only prokaryote with sterol is mycoplasma |
|
|
What classification has a nucleus absent?
Eukaryotes/Prokaryotes |
Prokaryotes
|
|
|
What classification contains a nuclear membrane?
Eukaryotes/Prokaryotes |
Eukaryotes
|
|
|
What classification contains DNA in single, closed loop chromosome?
Eukaryotes/Prokaryotes |
Prokaryotes
|
|
|
What classification contains proteins in the chromosomes?
Eukaryotes/Prokaryotes |
Eukaryotes
|
|
|
What are examples of Eukaryotes?
|
- Protazoa
- Fungi - Plants - Animals - Humans |
|
|
Aerobic respiration is _____ at extracting chemical energy than is fermentation.
|
Much more efficient
|
|
|
Respiration refers to the method of obtaining metabolic energy that involves an _____ _____.
|
Oxidative phosphorylation
|
|
|
Respiration involves the formation of _____ during electron transfer.
|
ATP
|
|
|
What defines aerobic respiration?
|
Molecular oxygen is the terminal hydrogen acceptor
|
|
|
What defines anaerobic respiration?
|
Nitrate or sulfate as the terminal hydrogen acceptor
|
|
|
Aerobic respiration involves a cell membrane respiratory _____ _____ chain.
|
Electron transport
|
|
|
Where is the electron transport chain located?
|
Inner mitochondrial membrane
|
|
|
What are the four stages of Aerobic respiration?
|
1. Glycolysis
2. Formation of acetyl coenzyme A 3. The citric acid cycle 4. Electron transport chain and chemiosmosis |
|
|
Energy weilding process whereby organic molecules serve as both electron donors and acceptors. The molecule being metabolized does not have all its potential energy extracted from it. Not completely oxidized
|
Fermentation
|
|
|
What are the key points of fermentation?
|
- NAD+ is almost always reduced to NADH
- Results in an excess NADH - Pyruvate is often an important intermediate - Oxygen is not involved - Energy yields are low - Energy is derived from substrate-level phosphylation |
|
|
What are typical substrates for fermentation?
|
Sugars like glucose and amino acids
|
|
|
What are the typical products of fermentation?
|
Varies on the substrate but can include organic acids, alcohols, ketones, and gases
|
|
|
Generally speaking bacteria associated with periodontal health are characterized as ...
|
Gram-positive, nonmotile, facultative anaerobes
|
|
|
In a healthy mouth how many of species of organisms are there?
Periodontal infection is linked to what percentage of them? |
350 species
5% |
|
|
Good periodontal health is characterized by the presence of what bacteria?
|
Gram positive bacteria:
S. Sanguis S. Mitis Actinomyces viscosus Actinomyces naeslundii Some gram negative: Veillonella parvula Capnocytophaga ochracea |
|
|
What happens to the oral flora in periodontal disease?
|
Shifts from gram positive to gram negative
|
|
|
What bacteria is associated with chronic and aggressive periodontitis?
|
Porphyromonas gingivalis
|
|
|
What bacteria is formerly known as Bacteroides forsythus and is strongly linked to periodontal disease?
|
Tanerella forsythensus
|
|
|
What bacteria is associated with deep periodontal pockets, chronic periodontitis and ANUG?
|
Treponema denticola, sokranskii
Prevotella intermedia |
|
|
Obligate anaerobes are...
|
Superoxide dismutase (-), Catalase (-), and peroxidase (-)
|
|
|
What two toxic molecules arise as a byproduct of aerobic respiration?
|
Hydrogen peroxide
Free superoxide radicals |
|
|
What do cells possess to destroy the toxic molecules made from aerobic metabolism?
|
Enzymes Catalase and Superoxide dismutase
|
|
|
Enzyme which catalyzes the decomposition of free superoxide radicals into water and hydrogen peroxide.
|
Superoxide dismutase
|
|
|
Enzyme which catalyzes the decomposition of hydrogen peroxide to water and oxygen
|
Catalase
|
|
|
Enzyme which catalyzes the oxidation of various substances by peroxides.
|
Peroxidase
|
|
|
Require O2 for growth; they use O2 as a final electron acceptor in aerobic respiration
|
Obligate aerobes
|
|
|
Do not need or use O2 as a nutrient. in fact, O2 is a toxic substance, which either kills or inhibits their growth.
|
Obligate anaerobes
|
|
|
In what ways can obligate anaerobes live?
|
Fermentation
Anaerobic respiration Bacterial photosynthesis Novel process of methanogenesis |
|
|
Organisms that can switch between aerobic and anaerobic type metabolism. Under anaerobic conditions they grow by fermentation, but in the presence of O2 they switch to aerobic respiration
|
Facultative Anaerobes
|
|
|
Bacteria with an exclusively anaerobic type of metabolism but they are insensitive to the presence of O2. They live by fermentation alone.
|
Aerotolerant anaerobes
|
|
|
Obligate aerobes and most facultative anaerobes are...
|
Superoxide dismutase (+), Catalase (+), Peroxidase (-)
|
|
|
Most aerotolerant anaerobes are ...
|
Superoxide dismutase (+), catalase (-), peroxidase (+)
|
|
|
Endospores are formed by which two genera of bacteria?
|
Bacillus and Clostridium
|
|
|
What are the most resistant biological form known to exist?
|
Spores or endospores
|
|
|
Only gram-_____ form spores specifically of the genera _____ and _____
|
Positive
Bacillus Clostridium |
|
|
How are spores formed?
|
By bacteria that survive during periods of deprivation, like loss of food and water supply.
|
|
|
A structure that contains the absolute minimum of genetic information and associated materials required to produce the vegetative form once times become good.
|
Spores
|
|
|
Heat resistant spore formed within the cell. A complex multilayered structure containing peptidoglycan within its complex spore coat and calcium dipicolinate within its core.
|
Bacterial endospore
|
|
|
Are bacterial endospores hard to kill?
What must you do to kill it? |
Yes
Autoclaved at 121 C for 20 min. |
|
|
Spores contain _____ _____ and other components imparting high resistance.
|
Dipicolinic Acid
|
|
|
Process by which spores are able to grow into new organisms without uniting with another reproductive cell.
|
Asexual reproduction
|
|
|
_____ spores have thin cell walls; _____ spores have thick, strong cell walls.
|
Active
Dormant |
|
|
_____ is caused by bacillus anthracis
|
Anthrax
|
|
|
What diseases are caused by clostridium botulinum, C.perfringens, and C. tetani?
|
Botulism, gas gangene, tetanus
|
|
|
What produces an enterotoxin that can be detected using the ELISA assay?
|
Escherichia Coli (E. Coli)
|
|
|
What does ELISA stand for?
|
enzyme-linked immunosorbant assay
|
|
|
A technique that promotes the binding of the target antigen or antibody to a substrate, followed by the binding of an enzyme-linked molecule to the bound antigen or antibody. Presence of the antibody or antigen is revealed by color development in a reaction that is catalyzed by the enzyme which is bound to the antigen or antibody.
|
ELISA assay
|
|
|
What are the applications of the ELISA procedure?
|
Provides qualitative (yes/no) and quantitative (how much) information on myriad of pro- and eu-karyotic antibodies
|
|
|
What has ELISA proven to be useful in testing the presence of antibodies in?
|
Human immunodeficiency virus (HIV)
|
|
|
What bacteria can be used to produce enterotoxin that can be detected by ELISA assay?
|
S. Aureus
Vibrio cholerae |
|
|
What are the most potent poisons known which has a potency that is paralleled by their efficiency as antigens?
|
Bacterial toxins
|
|
|
Where is DNA in the bacterial cell generally confined to?
|
Nucleoid
|
|
|
What is the function of the ribosomes in a bacterial cell structure?
|
Site of translation
|
|
|
What is the function of the inclusion (storage granules) in a bacterial cell structure?
|
Storage of reserves of nutrients
|
|
|
What is the function of the capsule in a bacterial cell structure?
|
Layer of polysaccharides
Attachment to surfaces Protection against phagocytosis |
|
|
What is the function of the cell wall in gram positive bacterial cell structure?
|
Prevents osmotic lysis of cell protoplast and confers rigidity and shape to cells
|
|
|
What is the function of the cell wall in gram negative bacterial cell structure?
|
Peptidoglycan prevents osmotic lysis and confers rigidity and shape
Outer membrane is permeability barrier; associated LPS (endotoxin) and proteins have various functions |
|
|
What is the function of the plasma membrane in a bacterial cell structure?
|
Permeability barrier; transport of solutes; energy generation; location of numerous enzyme systems
|
|
|
What is the function of the chromosomes in a bacterial cell structure?
|
Genetic material of the cell
|
|
|
What is the function of the plasmid in a bacterial cell structure?
|
Extrachromosomal genetic material
|
|
|
What is the function of the Flagella in a bacterial cell structure?
|
Motility (swimming movement)
|
|
|
What is the function of the sex pilus in a bacterial cell structure?
|
Mediates DNA transfer during conjunction
|
|
|
What is the function of the common pili or fimbriae in a bacterial cell structure?
|
Attachment to surfaces; protection against phagocytosis
|
|
|
What is the most primitive of mechanisms for gene transfer among bacteria? It occurs naturally among some bacteria and there is no requirement for cell-to-cell contact
|
Transformation
|
|
|
The DNA that is picked up by the recipient cell in transformation must be _____-_____.
|
Double-stranded
|
|
|
What degrades one of the strands of DNA as it enters a cell in Transformation?
|
Intracellular DNAse (endonuclease)
|
|
|
What does the degradation of one of the strands of DNA do in the process of transformation?
|
hydrolysis provides the energy to pull the rest of the DNA into the cell
|
|
|
What is uptake dependent on in the process of transformation?
|
Competence factor
|
|
|
Where does the single stranded DNA insert into once inside the cell in Transformation?
|
Homologous regions of the recipient's chromosomes
|
|
|
Why are Transformation, transduction, and conjunction all significant?
|
They bring about an increase in the amount of genetic variation within a population.
|
|
|
What is the process which allows DNA to become integrated in a host cell chromosome?
|
Recombination
|
|
|
Genetic transfer mediated by F- prime cells
|
Sexduction
|
|
|
The transfer of genetic material from one bacterial cell to another by viral infection
|
Transduction
|
|
|
What produces two extracellular protein toxins, exoenzyme S and exotoxin A?
|
Pseudomonas aeruginosa
|
|
|
Gram-negative, aerobic rod belonging to the bacterial family pseudomonadaceae, and most strains are obligate anaerobes
|
Pseudomonas aeruginosa
|
|
|
Pseudomonas aeruginosa is an _____ _____, meaning that it exploits some break in the host defenses to initiate an infection.
|
Opportunistic pathogen
|
|
|
What can Pseudomonas cause?
|
UTI
Respiratory infection Dermatitis Soft tissue infection Bacteremia Bone/joint infection GI infection Systemic infections from: - Burns - Cancer - AIDS patients who are immunosuppressed |
|
|
Pseudomonas aeruginosa infection is a serious problem in patients hospitalized with ...
|
Cancer, Cystic fibrosis, and burns
|
|
|
P. aeruginosa strains produce _____ _____ contained in metachromatic granules. Wounds infected with P. aeruginosa, therefore, display a _____-_____ color
|
Fluorescent pigment
Bluish-green |
|
|
What is P. Aeruginosa notorius for which makes it a particularly dangerous and dreaded pathogen?
|
Resistance to antibiotics
|
|
|
What are the few antibiotics that can be effective in treating P. aeruginosa?
What disease are these antibiotics most futile in trying to prevent and/or cure? |
Fluoroquinolones
gentamicin imipenem Cystic Fibrosis |
|
|
This may act to impair the function of phagocytic cells in the bloodstream and internal organs to prepare for invasion by P. aeruginosa.
|
Exoenzyme S
|
|
|
Has exactly the same mechanism of action as the diphtheria toxin; causes the ADP ribosylation of eukaryotic elongation factor 2.
|
Exotoxin A
|
