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Pathogenic bacteria are _____________.
chemoheterotrophs
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Source of energy for photoheterotroph and photoautotroph growth.
light
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Source of carbon for growth of autotrophs.
CO2
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Source of carbon for the growth of heterotrophs.
organic compounds
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Source of energy for growth of chemoautotrophs.
oxidation of inorganic compounds
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Source of energy for the growth of chemoheterotrophs.
oxidation of organic compounds
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_____________ require oxygen for growth and have a respiratory metabolism.
obligate aerobes
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__________ require oxygen-free conditions for growth and have a fermentative metabolism.
Obligate anaerobes
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Mycobacterium and bordatella are ____________.
obligate aerobes
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Give 2 examples of an obligate anaerobe.
clostridium, bacteroides
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Oxygen is ________ because it becomes ____________.
toxic; superoxide
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Grow either aerobically, using oxidative phosphorylation, or anaerobically by fermentation.
facultative anaerobe
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Bacteria that require oxygen for growth but prefer a reduced oxygen concentration of 3-15%.
microaerophilic
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Bacteria that prefer a carbon dioxide concentration and b/ 3 and 20 percent.
capnophilic
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Process by which large quantities of ATP are formed by oxidative phosphorylation.
aerobic electron transport (aerobes)
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Process by which small amount of ATP are formed, NADH is used to reduce pyruvate.
fermentation (anaerobes or facultative anaerobes)
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The hub of fermentation.
pyruvate
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Under anaerobic conditions the electron transport systems may be coupled to electron acceptors other than oxygen.
anaerobic electron transport (facultative anaerobes, anaerobes)
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What are the 4 types of alterations in the nucleotide sequences of DNA?
base pair substitution, deletions, insertions, large deletions
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the substitution of a purine for a pyrimidine and vice versa.
tranversion
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the substitution of purine for purine or pyrimidine for pyrimidine.
transition
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Occur as a result of base pair substitution which may result in missense, nonsense, or neutral mutation.
point mutation
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2 types of physical mutagens.
ultraviolet light, high-energy ionizing radiation
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Physical mutagens cause formation of _________.
thymine dimers
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Agents that alter the pyrimidines or purines to cause errors in base pairing to labilize the base to spontaneous chemical modification.
chemical mutagens, ethylene sulfate or nitrogen and sulfur mustards
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Agents which interact with DNA and its secondary structure, producing local distortions in the helix, and therefore, promoting replication and recombination errors.
chemical mutagens, acrydine orange
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Transformation occurs with ________.
naked DNA
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Conjugation occurs with ___________ and require _________.
cell-to-cell contact; plasmid
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Transduction is a mechanism of ____________.
phage infection
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Process when DNA binds irreversibly to recipient bacteria, traverses the membrane with concomitant hydrolysis of one of the strands resulting in a single-stranded molecule gaining entrance to the cell; DNA single strand synapses with homologous regions of the endogenote; and recombination occurs.
transformation
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Powerful mechanism of adaptation of pathogens.
conjugation
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A nonessential extrachromosomal double stranded circular DNA capable of autonomous replication; required for conjugation.
plasmid
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A plasmid capable of replication either autonomously or as in integrated part of the host chromosome.
episome
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The transfer of genetic material by direct contact b/w donor and recipient; plasmid is essential.
conjugation
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converts F- to F+ cells
F factor
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tip able to attach to surface of an F- cell
F pilus
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specific receptor site for F pilus attachment
F- cell
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With F-mediated conjugation, the first step is _______ attachment; then, it retracts, allowing __________; both donor and recipient become __________.
pilus; direct contact of donor and recipient; F+ cells
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Process by which both plasmid and host chromosome are transferred to the recipient by conjugation mediated by the episome.
Hfr transfer
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With Hfr transfer, the _______ is the donor cell.
Hfr cell
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The Hfr cell has a ________ integrated with the host chromosome, which initiates conjugation with the _______ cell to transfer ________.
F factor; F- cell; host chromosome
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Plasmids carrying genes that confer the resistance to normally toxic substances.
R factors
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Bacteriophage capable of entering a lysogenic cycle.
temperate phage
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Bacteriophage capable of producing new viruses and lyses the bacteria.
virulent phage
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Inactivated phage genome which replicates synchronously with the host genome that produces repressor, which inhibit productive replication and maturation of phage particles.
prophage
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The repressor is produced by the _________ and inhibits productive replication and maturation of the _________.
prophage; phage particles
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Prophage is integrated into the host chromosome and replicates as part of the host genome.
λ-type lysogeny
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Prophage attaches to the cell membrane as independent entity, replicating in synchrony w/ host genome
P1-type lysogeny
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What are the 3 steps of the lysogenic cycle?
repression ---> synchronous replication ---> derepression
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Transduction that results from defective prophage excision, involving a λ-type prophage and only bacterial genes near the sites of prophage attachment; aberrant excision.
Specialized (restricted) transduction
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Transduction that result from packaging error during maturation, involving a P1-type prophage and any portion of the bacterial genome.
generalized transduction
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What 3 things can be spread by gene transfer that are of public health significance?
antibiotic resistance R factors, toxins, and virulence factor
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What are 2 types of ingress (do not cross epithelial barrier), which bacteria use to enter the body?
inhalation, ingestion
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What are 4 types of penetration (cross epithelial barrier) that bacteria can sue to enter the body?
insect bite, cutes/wounds, organ transplant, blood transfusion
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Cell lysis, apoptosis, pharmacological alterations of metabolism, and damage due to host responses (inflammation) are examples of what stage of disease-causing by bacteria?
damage
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The immune response provides ______ and _______ defense.
constitutive; induced
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What are the 2 types of pathogenic bacteria?
obligate pathogens, opportunistic pathogens
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Opportunistic pathogens affect __________ or have an ____________.
immunocompromised hosts; unusual port of access
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What is an antiphagocytic factor of bacteria that allows them to cause disease?
capsules
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Gram-positive bacteria have what unique antiphagocytic factor?
M protein
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Pili, M protein, and cytoplasmic membrane are _____________ factors.
adherence/colonization
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Haemophilus influenzae has a ________________ that helps it to invade the meninges.
type b capsular polysaccharide
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Bacteria utilize ____________ to avoid immune recognition and destruction.
intracellular parasitism
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Intracellular parasites induce internalization and avoid _______________.
lysosomal enzyme action
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3 facultative intracellular bacteria that multiply in the membrane-bound inclusion of macrophages by inhibiting lysosomal fusion with the phagosome.
Brucella, Salmonella, Mycobacterium
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Facultative intracellular bacteria that multiply in the phagolysosome.
Yersinia pestis
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Facultative intracellular bacteria that multiply in the cytoplasm.
L. monocytogenes
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Obligate intracellular bacteria that escape from the phagosome to the cytoplasm to multiply in the cytoplasm.
Rickettsia
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Obligate intracellular bacteria that multiply in the exocytic compartment.
Chlamydia
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Neisseria gonorrhoeae and Moraxella bovis achieve genotypic variation of cell surface Ag by variation in _______.
pillin
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Bacteria achieve genotypic variation in cell surface Ag by _______________.
DNA rearrangement and recombination
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Give examples of phenotypic variation of cell surface Ag. (3)
smooth vs rough, temperature dependent virulence, surface lipoproteins
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When gram (-) bacteria cross an epithelial barrier, __________ acts on macrophages, which then release ___(5)___ in large quantities, causing...(4)
endotoxin; TNF, prostaglandins, IL-1, nitric oxide, reactive oxygen intermediates; fever, intravascular coagulation, shock, and death.
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Exotoxins that act from the outside have what affect on the cell?
they kill the cells
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Exotoxins which act from the inside have hat affect on the cell?
they deregulate the cells
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Exotoxins that lyse erythrocytes (sometimes phagocytic cells as well).
hemolysins
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Which s. aureus hemolysin(s) that produce zones of complete hemolysis on sheep blood agar.
alpha, gamma, delta
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Which s. aureus hemolysin(s) produce a zone of incomplete hemolysis on sheep blood agar?
beta
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S. aureus beta toxin hemolysin degrades ___________ of the ___________.
sphingomyeline; erythrocyte membrane
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S. aureus delta toxin hemolysin lyses erythrocytes by a _______________.
detergent-like activity
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Oxygen-labile hemolysin of group A streptococci which binds cholesterol in the membrane.
Streptolysin O
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Toxins that kill and lyse phagocytic cells.
leukotoxins
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S. aureus leukocidin has to components that interact __________ and interrupt ___________ of the ____________ membrane.
synergistically; phospholipids;; phagocyte (neutrophils and macrophages of rabbits and man)
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Diphtheria toxin inhibits ____________ by catalyzing the inactivation of _____.
polypeptide chain elongation; EF-2
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Diphtheria toxin has two fragments; ___________ binds to the cell membrane, facilitating the entry of ________ into the cell; it inactivates EF-2 by coupling it with ______________.
fragment B; fragment A; adenosine diphosphate ribose
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___________ of Pseudomonas aeruginosa mode of action is similar to that of Diphtheria toxin.
Exotoxin A
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Multicomponent protein complex that inhibits eukaryotic cytoplasmic protein biosynthesis by inactivating the 60S ribosomal subunits ina catalytic manner.
Shigella cytotoxins (Shiga toxin)
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Choleragen of vibrio cholerae is a(n) ___________ that activates __________, which enzymatically degrades ATP, leading to increased intracellular levels of _________, stimulating hypersecretion of _____ and ______.
enterotoxin; adenylate cyclase; cAMP; electrolytes; water
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Heat-labile enterotoxin of E. coli stimulates ___________.
cAMP
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Heat-stable enterotoxin of E. coli activates __________, which enzymatically degrades GTP, causing a subsequent increase in ___________.
guanylate cyclase; cGMP
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Botulism toxins of C. botulinum inhibits the release of _________ from __________, resulting in ___________.
acetylcholine; cholinergic motor nerve endings; flaccid paralysis
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Tetanus toxin of C. tetani blocks ________________ in the CNS, resulting in ____________ and _____________.
presynaptic and post-synaptic inhibition; hyperflexia; spasms of skeletal muscles
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Extracellular enzyme that cleaves specific molecules and is known as "spreading factor."
hyaluronidase
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Extracellular enzymes that degrade membranes, resulting in tissue necrosis and exhibits several toxic effects, which include hemolytic, dermonecrotic, and lethal.
lipase, alpha toxin of C. perfringens
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B. bronchiseptica produces and releases _______________, which is an extracellular enzyme enters eukaryotic cells and causes whooping cough.
calmodulin-sensitive adenylcyclase
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Small, iron-chelating molecules; examples include aerobactin and enterobatin of E. coli and mycobactrin of M. tuberculosis.
siderophore/ siderochromes
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Ag that bind MHC of APC and stimulate large numbers of T cell nonspecifically, causing derangement of the immune response.
super antigens
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Exotoxin is released by ________ parent organisms.
gram + or -
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Endotoxin is produced by _________ parent organisms.
gram - only
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Exotoxins are ________ in chemical nature.
proteins
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Endotoxins are _________ in chemical nature.
lipid A (LPS)
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Exotoxins are ________ at 100°C.
labile
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Endotoxins are _________ at 100°C.
stable
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Exotoxins are ________ in formaldehyde.
labile
-
Endotoxins are _________ in formaldehyde.
stable
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Neutralization of exotoxins by Ab is _________.
complete
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Neutralization of endotoxins by Ab is _________.
partial
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Biologic activity os exotoxin is __________, whereas biologic activity of endotoxin is __________.
variable; always the same
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Exotoxins have ________ toxicity than endotoxin.
higher
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Many gram (-) bacteria use __________- and _________ secretion systems for subverting the normal cellular functions of their target eukaryotic cells.
type III and type IV
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Type III and type IV secretion systems evolved from ___________ and ___________, respectively, which function like a syringe to inject proteins through an external needle into a target cell's membrane and cytosol.
bacterial flagella (type III); sex pili (type IV)
-
A family of signal sensor (histidine autokinase), transduction, and response regulatory systems that allows bacteria to sense wide varieties of environmental signals and respond rapidly to changes in their environment.
Two-component regulatory system (2CRS)
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