MicrobiologyExcelsior Exam (ISM) Question
Answer
Who observed cells in plant material?
Hooke
Who proved that microorganisms caused disease?
Koch
Viruses cannot reproduce outside of a _____ ____
host cell
What finding was essential for Jenner's vaccination process?
A weakened microorganism may produce immunity
Recombinant DNA technology can be used to make what? human hormones, vaccines, drugs You are observing a cell through a microscope and note that it has no apparent nucleus. You conclude that it most likely has a...........
peptidoglycan cell wall.
A nucleated, green cell that moves by means of flagella is....
an algae
An agent that reproduces in cells but is not composed of cells and contain RNA as its genetic material is a....
virus
A multicellular organism that has a mouth and lives in an animal host is a
helminth
In the name Escherichia coli, coli is the specific.....
epithet
You are looking at a white cottony growth on a culture medium. Microscopic examination reveals it is multicellular. You can conclude that the organism......
- has DNA enclosed in a nucleus -has cell walls absorbs organic nutrients -is eukaryotic
Members of what groups contain DNA?
-bacteria -helminths -fungi -protozoa
What groups have cell walls?
-bacteria -fungi -plantae
You are observing a cell through a microscope and note that it has no apparent nucleus. You conclude that it most likely has a...........
peptidoglycan cell wall.
What is true about enzymes?
- lover activation energy of reaction- are not used up in a reaction- are made of proteins
What type of bond is between molecules of water in a beaker of water?
Hydrogen bond
What type of bond holds hydrogen and oxygen atoms in a molecule of H2O?
covalent bond
What type of molecule contains the alcohol glycerol?
lipids
What type of molecule is composed of CH2O units?
carbohydrates
Structurally, ATP is most like what type of molecule?
nucleic acids
What molecule has chemicals in genes?
nucleic acid
Which molecule is composed of a chain of amino acids?
proteins
What are the primary molecules making up plasma
lipids
membranes in cells? Starch, dextran, glycogen, and cellulose are polymers of...
glucose
What structure does light pass through after leaving the condenser in a compound light microscope?
specimen
What are the steps of the Gram Stain?
1. Alcohol-acetane -2. Crystal violet -3. Safranin 4.Iodine
The counterstain in the acid-fast stain is a basic...
dye
The purpose of a mordant in the Gram stain is to prevent the..
crystal violet from leaving the cells
The best uses of a negative stain is to determine...
cell size and shape
Simple staining is often necessary to improve contrast in what microscope?
electron microscope
What microscope is used to see internal structures of cells in a natural state?
phase-contrast microscope
What microscope achieves the highest magnification and greatest resolution?
electron microscope
The light that hits the specimen is scattered and does not come directly from the light source in what microscope?
darkfield microscope
What microscope takes advantage of differences in the refractive indexes of cell structure?
phase-contrast microscope
What is the appearance of gram-positive bacteria after addition of the first dye in the Gram stain?
purple
What is the appearance of gram-negative bacteria after addition of the decolorizing agent in the Gram stain?
colorless
What is the total magnification of a chloroplast viewed with a 10X ocular lens and a 45X objective lens?
450X
You suspect a 100 nm structure is present in a cell. What provides the lowest magnification that you can use to see this structure?
scanning electron microscope
Assume you stain Bacillus by applying malachite green with heat then counterstaining with safranin. Through the microscope, the green structures are...
endospores
(51)You find colorless areas in cells in a Gram-stained smear. What should you do next?
an endospore stain
What Gram reaction do you expect from acid-fast bacteria? Gram-positive Bacteria smears are fixed before staining to...
kill the bacteria and affix the cells to the slide
The purpose of the ocular lens is to magnify the image from the....
objective lens
What is true about gram-positive cell walls?
-maintains shape -sensitive to lysozyme -contains teichoic acids
What happens when a bacterial cell is placed in a solution containing 5% NaCl?
water will move out of the cell
Force of which a solvent moves across a semi-permeable membrane from a higher to a lower concentration is....
osmotic pressure
By what mechanism can a cell transport a substance from a active transport lower to a higher concentration? Characteristic of the plasma membrane:
1.selectively permeable -2. site of cell wall formation -3.compoed of phospholipid bilayer 4.contains proteins
The mitochondrion most closely resembles what type of cell?
prokaryotic
What is true of prokaryotic cells?
1.motile by means of flagella -2.reproduce by binary fission -3.have a semirigid cell wall
What are some structures found in prokaryotic cells?
1.axial filament -2.peritrichous flagella -3.flagella 4.Pili
What are some parts of the active transport process?
1.transports protein -2.ATP -3.plasma membrane 4.fungi
What Gram reaction do you expect from acid-fast bacteria? Gram-positive Bacteria smears are fixed before staining to...
kill the bacteria and affix the cells to the slide
The purpose of the ocular lens is to magnify the image from the....
objective lens
What is true about gram-positive cell walls?
-maintains shape -sensitive to lysozyme -contains teichoic acids
What happens when a bacterial cell is placed in a solution containing 5% NaCl?
water will move out of the cell
In bacteria, photosynthetic pigments are found in...
chromatophores
The difference between simple diffusion and facilitated diffusion is that facilitated diffusion requires
transporter proteins
(67)What cell structure has a role in the initiation of disease?
Fimbria
Fimbria and pili differ in that pili are used to transfer...
DNA
Where are phospholipids most likely found in a prokaryotic cell?
plasma membrane
What is found in mitochondria and prokaryotes?
-the circular chromosome -the ATP generating mechanism -70S ribosomes
What is found in Archaea?
Pseudomurein
What is found in mycoplasmas?
Sterol-rich cell membranes
(73) What will happen if a bacterial cell is placed in distilled water with lysozyme?
the cell will undergo osmotic lysis
What will happen if a bacterial cell is placed in 10% NaCl the cell will plasmolyze
with penicillin? What are some energy reserves?
-sulfur granules -lipid inclusions -metachromatic granules -polysaccharide granules
The bacteria on the outside of termite protozoa..
propel the protozoan
What compounds are enzymes?
-dehydrogenase -cellulase -B galactosidase
How many molecules of ATP can be generated from the complex oxidation of glucose to CO2 and H2O?
38
What is true about anaerobic respiration?
1.involves the Krebs cycle -2.requires cytochromes -3.involves the reduction of nitrate -4.generates ATP
What is the fate of pyruvic acid in an organism that uses aerobic respiration?
it is oxidized in the Krebs cycle
Fatty acids are catabolized in the...
Krebs cycle
According to the chemiosmotic mechanism, ATP is generated when...
protons are moved across a membrane
What are some end products of fermentation?
-glycerol -acetone -ethyl alcohol -lactic acid
A strictly fermentative bacterium produces energy by...
glycolysis only
What percent of the total ATP produced from the complete 89% catabolism of glucose is produced by aerobic respiration? What is true about beta oxidation?
1.it is the method of catabolizing fatty acids2.involves the formation of acetyl CoA- 3.involves the formation of 2 carbon units
The oxidation of glucose with organic molecules serving as electron acceptors is...
fermentation
Aerobic respiration differs from anaerobic respiration in what respect?
the final electron acceptors are different
In green and purple bacteria, electrons to reduce CO2 come from...
CO2
What uses CO2 for carbon and H2 for energy?
Chemoautotroph
What uses glucose for carbon and energy?
Chemoheterotroph
What has bacteriochlorophylls and uses alcohols for carbon?
Photoheterotroph
Cyanobacteria are an example of what?
Photoautotroph
An enzyme, citrate synthase, in the Krebs cycle is inhibited -noncompetitive inhibition-feedback inhibitionby ATP; this is an example of what types of inhibitions? allosteric inhibition A bacterial culture grown in a glucose-peptide medium causes the pH to increase. The bacteria are most likely
using the peptides
When oxygen is unavailable, Halobacterium produce ATP photophosphorylation by The addition of what to a culture medium will neutralize
buffers
acids? Salts and sugars work to preserve foods by creating a
hypertonic environment
The term facultative anaerobe refers to an organism that uses
oxygen or grows without oxygen
What are some disadvantages of the standard plate count?
-cells may form aggregates -chemical and physical requirements are determined by media and incubation -requires incubation time
What are some disadvantages of the direct microscopic count?
-no incubation time -enumerate dead cells -large number of cells is required -some organisms are motile
What is used to determine metabolic activity?
-decreased dissolved oxygen -NO2 produced from the electron transport chain -CO2 produced from the Krebs cycle -acid production from fermentation
Thirty-six colonies grew in nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample?
36
Most bacteria grow best at pH of
7
A culture medium on which only gram-positive organisms grow and a yellow halo surrounds Staphylococcus aureus selective medium and a differential medium colonies is called a... A culture medium consisting of agar, human blood, and beef heart is a __________ medium
complex
During which growth phase will gram-positive bacteria be log phase most susceptible to penicillin? The length of time it takes for a cell to divide is
generation time
What group of microorganisms is most likely to spoil a freshwater trout preserved with salt?
Halophiles
Name an organic growth factor.
NAD+
What is an example of a metabolic activity that could be used to measure microbial growth?
Glucose consumption
An experiment began with 4 cells and ended with 128 cells. How many generations did the cell go through?
5
The source of nutrients in nutrient agar is
peptone and beef extract
Producers in the hydrothermal vents on the ocean floor use sulfide CO2 for their carbon source and what for energy? What best describes the pattern of microbial growth?
The cells in a population die at a constant rate
What is a substance that can sterilize?
Ethylene oxide
What is used for surgical hand scrubs?
Chlorhexidine
Name some heavy metals.
-silver nitrate -Merthiolate -Mercurochrome
Phenolics differ from phenol in that phenolics are ...
-relatively odorless -more effective antibacterial
agents -nonirritating (126) What substances achieve sterilization?
-Ethylene oxide -autoclave -formaldehyde -dry heat
What is a limitation of the autoclave?
Use with heat-labile materials
What is a direct result of heat?
-breaking sulfhydryl bonds -breaking hydrogen bonds -denaturing enzymes
What substance is the least effective antimicrobial agent?
soap
What are effective against nonenveloped viruses?
-Ethylene oxide -Chlorine -Ozone
Which concentration of ethyl alcohol is the most effective bactericide?
70%
What could be used to sterilize plastic Petri plates in a plastic wrapper?
Gamma radiation
(136) Foods are preserved with...
-potassium sorbate -sodium propionate -sodium nitrate
What is the most useful for disinfecting medical instruments?
Quats
What is most resistant to chemical biocides?
Mycobacteria
A sequence of nucleotides in DNA that codes for a functional product is a
Gene
The lagging strand of DNA is started by an ______ primer. RNA The leading strand of DNA is made.....
continuously
Multiple replication forks are possible on a bacterial ____________
chromosome
________ joins nucleotides in one direction only.
DNA polymerase
What are some products of transcription?
mRNA, rRNA, tRNA, rDNA
What is true about bacteriocins?
-Bacteria that produce bacteriocins are resistant to their own bacteriocins -the genes coding for them are on plasmids -Nisin is a bacteriocin used as a food preservative
An enzyme produced in response to the presence of a substrate is called
an inducible enzyme
Transformation is the transfer of DNA from a donor to a recipient cell
by a bacteriophage
The initial effect of ionizing radiation on a cell is that it causes the formation of...
highly reactive ions
According to the operon model, for the synthesis of an inducible enzyme to occur, the _______ must bind to the __________
substrate; repressor
Synthesis of a repressible enzyme is stopped by the ______________ binding to the operator
corepressor-repressor
Conjugation differs from reproduction because conjugation transfers __________horizontally to cells in the same DNA; generation _________ The necessary ingredients for DNA synthesis can be mixed together in a test tube. The DNA polymerase is from human DNA Thermus aquaticus and the template is from a human cell. The DNA synthesized would be most similar to What is the mechanism by which the presence of glucose inhibits the arabinose operon?
catabolic repression
An enzyme that covalently bonds nucleotide sequences in DNA is..
DNA ligase
An enzyme that copies DNA to make a molecule of RNA is...
RNA polymerase
An enzyme that cuts double stranded DNA at specific nucleotide sequences is
the restriction enzyme
An enzyme that cuts and seals DNA is
transposase
In transcription, ______ is copied to ______
DNA; RNA
A cell that cannot make _______, cannot make _______
tRNA; proteins
If you have inserted a gene in the Ti, the next step in genetic engineering is inserting Ti into___________
Agrobacterium
What is a "hit or miss" method of making rDNA?
protoblast fusion
Pieces of DNA stored in yeast cells are called a ....
Library
A population of cells carrying a desired plasmid is called a.....
clone
Self-replicating DNA used to transmit a gene from one organism to another is a ...
vector
A technique used to identify bacteria carrying a specific gene is called a....
Southern blot
What technique is used to alter one amino acid in protein?
site-direct mutagenesis
(169) What organism naturally possesses the Ti plasmid?
Agrobacterium tumefaciens
What organism degrades PCB's and has been engineered to Pseudomonas produce BT toxin? An example of gene therapy is insertion of the _______gene in a diabetic person's _________ cells
insulin; pancreas
The use of antibiotic resistance gene on a plasmid used in genetic engineering makes ____ ______ possible
direct selection
A specific gene can be inserted into a cell by what means?
1.a gene gun -2.electroporation -3.microinjection 4.agrobacterium
PCR can be used to identify an unknown bacterium because the...
RNA primer is specific
Foreign DNA can be inserted into cells by what means.
-electroporation, -transformation, -a gene gun, protoplast fusion
What is true of Archaea?
-they lack peptidoglycan in their cell walls, -they are prokaryotes, -some produce methane from carbon dioxide and hydrogen, -some are thermoacidophiles, -others are extreme halophiles
What characterizes Domain Bacteria?
Prokaryotic cells; ester linkages in phospholipids
The outstanding characteristic of the Kingdom Fungi is....
absorption of dissolved organic matter
What is true about members of the Kingdom Plantae?
-can photosynthesize, -are multicellular, -use inorganic energy sources, -have eukaryotic cells
What is true about the Kingdom Animalia?
-use organic carbon sources, -are multicellular, have eukaryotic cells, -use organic energy sources
A taxon comprised of one or more species and below family is a....
genus
The phylogenetic classification of bacteria is based on ____ sequences
rRNA
In the scientific name Enterobacter aerogenes, Enterobacter is the....
genus
Bacteria and Archaea are similar in which of the following Possess prokaryotic cells ways? A group of cells all derived from a single parent is a....
strain
Serological testing is based on the fact that _______ react specifically with an ________
antibodies; antigen
Phage typing is based on the fact that _______viruses attack specific ________
bacterial; cells
Genetically identical cells derived from a single cell is a.... clone Into which group would you place a photosynthetic cell that lacks a nucleus?
Bacteria
Into which group would you place a multicellular heterotroph with chitin cell walls?
Fungi
You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in which Archaea group? Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan Proteobacteria (Gram-negative bacteria) wall surrounded by an outer membrane? What indicates that two organisms are closely related?
their DNA can hybridize
What is found primarily in the intestines of humans?
facultatively anaerobic gram-negative rods
What is most resistant to high temperatures?
Bacillus subtilis
You discovered a unicellular organism that lacks a nucleus Archaea and peptidoglycan. You suspect the organism is in which
group? Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan Proteobacteria (Gram-negative bacteria) wall surrounded by an outer membrane? What indicates that two organisms are closely related?
their DNA can hybridize
What is found primarily in the intestines of humans?
facultatively anaerobic gram-negative rods
What is most resistant to high temperatures?
Bacillus subtilis
You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in which Archaea group? Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan Proteobacteria (Gram-negative bacteria) wall surrounded by an outer membrane? What indicates that two organisms are closely related?
their DNA can hybridize
What is found primarily in the intestines of humans?
facultatively anaerobic gram-negative rods
What is most resistant to high temperatures?
Bacillus subtilis
You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in which Archaea group? Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan Proteobacteria (Gram-negative bacteria) wall surrounded by an outer membrane? What indicates that two organisms are closely related?
their DNA can hybridize
What is found primarily in the intestines of humans?
facultatively anaerobic gram-negative rods
What is most resistant to high temperatures?
Bacillus subtilis
You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in which Archaea group? Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan Proteobacteria (Gram-negative bacteria) wall surrounded by an outer membrane? What indicates that two organisms are closely related?
their DNA can hybridize
What is found primarily in the intestines of humans?
facultatively anaerobic gram-negative rods
What is most resistant to high temperatures?
Bacillus subtilis
What are some characteristics of spirochetes?
-difficult to culture in vitro, -helical shape, -possess an axial filament, -gram negative
You have isolated a bacterium that grows in a medium containing an organic substrate and nitrate in the absence of oxygen. The nitrate is reduced to nitrogen gas. This bacterium is using _________ _________
anaerobic respiration
What lacks a cell wall?
Mycoplasma
What forms conidiospores?
Actinomycetes and related organisms
Requirements for X and V factors are used to identify
Haemophilus
You have isolated a bacterium that grows in a medium containing only inorganic nutrients. Ammonia is oxidized to nitrate ion. This bacterium is a ____________
chemoautotroph
Escherichia coli belongs to the....
proteobacteria
What is true about the causative agent of Rocky Mountain -gram negative, -transmitted by ticks, -in the genus Spotted Fever? Rickettsia, -an intracellular parasite The bacteria responsible for more infections and more different kinds of infections are....
Streptococcus
The nonsulfur photosynthetic bacteria use organic compound as...
electron donors to reduce CO2
What is the best reason to classify Streptococcus in the Lactobacillales?
rRNA sequences
Salmonella, Shigella, Yersinia, and Serratia are all .....
gram negative facultatively anaerobic rods
You have isolated a prokaryotic cell. The first step in identification is a...
gram stain
Actinomycetes differ from fungi because Actinomycetes laca a...
membrane bounded nucleus
Caulobacter are different from most bacteria because they have ______
stalks
What should you do if you suspect a patient has tuberculosis?
Do an acid-fast stain
What is true about fungi?
-are heterotrophic, -have eukaryotic cells, -few are pathogenic to humans, -most are aerobic
What is true about helminths?
-some have male and female reproductive organs in one animal, -have eukaryotic cells, -are heterotrophic, -are multicellular
What is true about protozoa?
-may have flagella or cilia, -may reproduce sexually, -have eukaryotic cells, -are unicellular
A lichen doesn't exist if the ______ and ______ partners are separated.
fungal; algal
In lichen, the fungus provides the _________
holdfast
In lichen, the alga produce_______
carbohydrates
Lichens are important to ________ producers
soil
Transmission of helminthic diseases to humans is usually by...
the gastrointestinal route
What characteristics of parasitic Platyhelminthes?
-dorsoventrally flattened, -divided into flukes and tapeworms, -are hermaphroditic
Cercariae, metacercaria, miracidia, and rediae are stages in nematodes the life cycle of... What arthropods transmit diseases while sucking blood from a human?
-lice, -fleas, -kissing bugs, -mosquitos
What is true about algae?
-some are capable of sexual reproduction, -use CO2 as their carbon source, -use light as their energy source, -produce oxygen from hydrolysis of water
A definitive host harbors which stage of a parasite?
adult
The microspora and archaezoa are unusual eukaryotes because they lack...
mitochondria
What is the most effective control for malaria?
vaccination
What multinucleated amoebalike cells produce fungus-like Plasmodial slime mold spores? What organism can grow photoautotrophically in the light and chemoheterotrophically in the dark?
Euglena
The cells of plasmodial slime molds can grow to several centimeters in diameter because they distribute nutrients by...
cytoplasmic streaming
If larvae of Echinococcus granulosus is found in humans, humans are the....
intermediate host
Yeast infections are caused by...
Candida albicans
Leishmania is an euglenozoa. What is true about this organism?
-is flagellated, -is transmitted by sandflies, -a human parasite
What way does viruses differ from bacteria?
viruses are not composed of cells
What provides the most significant support for the idea that viruses are nonliving chemicals?
They cannot reproduce themselves outside of a host
What is true about spikes?
-only found on enveloped viruses, -used for absorption, -may cause hemagglutination
What is the criterion to classify viruses?
-morphology, -size, -Nucleic acid, -number of capsomeres
Phage DNA is incorporated into host cell DNA is
lysogeny
A naked infectious piece of RNA is a...
viroid
A clear area against a confluent "lawn" of bacteria is called plaque a... Lysogeny can result in..
-acquisition of new characteristics by the host cell, -transduction of specific genes, -immunity to reinfection by the same phage
An infection protein is a
prion
An envelope is acquired during which of the following steps?
release
An example of a latent viral infection is
cold sores
The most common route of accidental AIDS transmission to health care workers is...
needle stick
To which group does a small, nonenveloped single stranded RNA virus most likely belong?
Picornavirus
Bacteriophages derive what from the host cell?
-nucleotides, -amino acids, -tRNA
Generally, in DNA-containing virus infection, the host animal cell supplies..
-tRNA, -RNA polymerase, -nucleotides
Viruses that have reverse transcriptase are in _______ and Hepadnaviridae; Retroviridae _______ What is true of viruses?
contain a protein coat, -use the anabolic machinery of the cell, -contain DNA or RNA but never both
To which group does a small, nonenveloped single stranded RNA virus most likely belong?
Picornavirus
Bacteriophages derive what from the host cell?
-nucleotides, -amino acids, -tRNA
Generally, in DNA-containing virus infection, the host animal cell supplies..
-tRNA, -RNA polymerase, -nucleotides
Viruses that have reverse transcriptase are in _______ and Hepadnaviridae; Retroviridae _______ What is true of viruses?
contain a protein coat, -use the anabolic machinery of the cell, -contain DNA or RNA but never both
Nontoxic strains of Vibrio cholerae can become toxic when they are in the human intestine with toxic strains of bacteria. This suggest that the toxin genes are acquired by
transduction
An oncogenic RNA virus must have what enzyme?
reverse transcriptase
Most RNA viruses carry what enzyme?
RNA-dependent RNA polymerase
A commensal bacterium may be an
opportunistic pathogen
_____ refers to different organisms living together
Symbiosis
A nosocomial infection is acquired during the course of
hospitalization
Koch's postulates don't apply to disease because all diseases aren't caused by..
microorganisms
What are some diseases that spread by droplet infection?
Diphtheria, -tuberculosis, -common cold, -measles
Mechanical transmission differs from biological transmission in that mechanical transmission doesn't
involve specific diseases
What infection can cause septicemia?
focal infection
Transient microbiota differ from normal microbiota because transient microbiota are
present for a relatively short time
One effect of washing regularly with antibacterial agents is increased susceptibility to disease the removal of normal microbiota. This can result in ..
What is a fomite?
A hypodermic needle
What is true of biological transmission?
the pathogen may require the vector as a host, pathogens may be injected by the bite of the vector, -pathogen may enter the host in the vector's feces, the pathogen reproduces in the vector
A disease that develops slowly and last for months is
chronic
A initial illness is a
primary infection
A short lasting primary infection is
acute
Infection characteristic of a carrier state is
inapparent
The science that deals with the point in time when diseases epidemiology occur and how they are transmitted is called... A cold transmitted by facial tissue is an example of...
vehicle transmission
Influenza transmitted by an unprotected sneeze is an example of...
droplet transmission
A sexually transmitted disease is an example of
direct contact
Gastroenteritis acquired from roast beef is an example of
vehicle transmission
A needle stick is an example of a
fomite
The yeast Candida albicans does not usually cause disease antagonist bacteria because of What contributes to the incidence of nosocomial infections?
lapse in aseptic techniques, -lack of insect control, lack of hand washing, -formation of biofilms
The most frequently used portal of entry for pathogens is the
mucous membranes of the respiratory tract
What diseases are usually contracted by the respiratory route?
measles, -tuberculosis, -pneumonia
How do most pathogens gain access through the skin?
enter through hair follicles and sweat glands
Kinase destroys
fibrin clots
________ breaks down substances between cells.
Hyaluronidase
________ destroys neutrophils
Leukocidins
_______ lyse red blood cells
Hemolysins
What is true of exotoxins?
have specific methods of action, -composed of proteins, -more potent than endotoxins, -produced by gram positive bacteria
Cytopathic effects are changes in host cells due to
viral infections
What contributes to symptoms of fungal disease?
allergic response to the host, -toxins, -capsules
Methods of avoiding host antibodies
Invasims, -IgA protease, -antigenic change
Siderophores are bacterial proteins that compete with animal
transferrin
Botulism is caused by an exotoxin; therefore, it could easily be prevented by
boiling food prior to consumption
(298) What organisms can produce exotoxin?
Staphylococcus aureus, -Corynebacterium diphtheriae, -Clostridium tetani, -Clostridium botulinum
The symptoms of tetanus are due to the exotoxin produced Clostridium tetani by What is true of staphylococcal enterotoxin?
causes vomiting, -diarrhea, -is an exotoxin
Septic shock due to gram positive bacteria is caused by
superantigens
A needle stick is an example of what portal of entry?
parenteral route
The mechanism by which gram negative bacteria can cross inducing TNF the blood brain barrier is by Injectable drugs are tested for endotoxins by the
Limulus amoebocyte lysate test
Endotoxins in injectable drugs could cause
nerve damage
Antibiotics can lead to septic shock if used to treat...
gram negative bacterial infections
The body's defenses against any kind of pathogen is
innate immunity
What are some physical factors to protect the skin and mucous membranes from infection?
tears, -saliva, -layers of cells
Removing microorganisms from the lower respiratory tract ciliary escalator is the function of the What are some characteristics of inflammation?
pain, -swelling, -redness, -local heat
The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway C3 beginning with the activation of_____ Adherence of phagocytes to the lining of blood vessels is
margination
What is normally found in serum?
complement
What is an effect of complement activation?
increased blood vessel permeability, -opsonization, -bacterial cell lysis, -increased phagocytic activity
Defensive cells such as T cells identify pathogens by binding
toll like receptors
What are some effects of histamine?
redness, -pain, -vasodilation, -swelling
A _____ is a sign the body temperature is rising
chill
Complement fixation results in
activation of C3b, -cell lysis, -opsonization, immune adherence
Neutrophils with defective lysosomes are unable to produce
toxic oxygen products
Activation of C5-C9 results in
leakage of cell contents
What is involved in adaptive immunity?
lymphocyte
What is involved in resistance to parasitic helminths?
Eosinophil
Macrophages arise from what?
monocyte
Bacteria have siderophores that capture iron; humans counter this by
transferrins
What are some effects of fever?
increases production of T cells, -increases interferon activity, -increases transferrin production
Bacterial enzymes such as a catalase and superoxide dismutase can protect bacteria from
phagocytic digestion
A type of immunity resulting from vaccination is
artificially acquired active immunity
The type of immunity resulting from transfer of antibodies from one individual to a susceptible individual by means artificially acquired passive immunity of injection is Immunity resulting from recovery from mumps is
naturally acquired active immunity
Newborns immunity due to the transfer of antibodies across the placenta is
naturally acquired passive immunity
T-cells are activated by
interaction between CD$ and MHC II
The specificity of an antibody is due to
the variable portions of the H and L chains
Characteristics of cellular immunity
--it can inhibit the immune response, --the cells originate in bone marrow,--cells are processed in the thymus gland
Plasma cells are activated by
an antigen
The antibodies that can bind to large parasites are
IgE
In addition to IgG, the antibodies that can fix complement are
IgM
Definition of antigen
A chemical that elicits an antibody response and can combine with these antibodies
Definition of antibody
a protein made in response to an antigen that can combine with that antigen
(346) Patients with an inherited type of colon cancer called familial adenomatous polyposis have a mutation in the apoptosis gene that codes for Chemical signals sent between leukocytes are
interleukins
Natural killer cells
destroy tumor cells--destroy virus infected cells-destroy cells lacking MHC-I
Antigens coated with antibodies are susceptible to
phagocytosis
Cell death caused by perforin and granzymes is caused by
cytotoxic T lymphocytes
Antigen-antibody binding may result in
complement activation-- opsonization of the antigen--agglutination of the antigens-neutralization of the antigen
What are normally used in vaccinations?
Parts of bacterial cells, inactivated viruses, toxoid, live attenuated bacteria
If a patient shows the presence of antibodies against diphtheria toxin, this indicates
The patient may have been vaccinated, or a recent transfusion may have passively introduced the antibodies, or the patient may have had the disease and has recovered, or the patient may have the disease
Antibodies for serological testing can be obtained from
Vaccinated humans, monoclonal antibodies, vaccinated animals
A reaction between an antibody and soluble antigenforming lattices is called
precipitation reaction
A reaction between antibody and particulate antigen is called
an agglutination reaction
An indirect version of what test using antihuman globulin may be used to detect patient's antibodies against Treponema pallidum?
Immunofluorescence
Toxoid vaccines such as the vaccines against diphtheria and tetanus elicit
an antibody response against these bacterial toxins
What type of vaccine involves host synthesis of viral antigens?
Nucleic acid vaccine
Purified protein from B. pertussis is a
subunit vaccine
What type of vaccine is live measles virus?
Attenuated whole agent vaccine
A test used to identify Streptococcus pyogenes in a patient direct fluorescent antibody test is the What is a pregnancy test used to find the fetal hormone HCG in a woman's uterine using anti HCG and latex spheres?
Passive agglutination reaction
What is a test to determine patient's blood type by mixing patient's red blood cells with antisera?
direct agglutination reaction
What is a test to determine the presence of soluble antigens precipitation reaction in patient's saliva? Inactivated tetanus toxin is a
toxoid vaccine
To detect botulinum toxin in food, the suspect food is injected into two guinea pigs. The guinea pig that was vaccinated against botulism survives, while the one that was not vaccinated dies. This is an example of
neutralization
Dead Bordetella pertussis can be used in
an inactivated whole agent vaccine
What is the third step in a direct ELISA test?
Antihuman immune serum
(372) What uses red blood cells as the indicator?
complement fixation
The circumsporozite antigen of Plasmodium can be used to
produce monoclonal antibodies, decrease recurring infections, vaccinate healthy people
Hypersensitivity is due to
an altered immune response
The chemical mediators of anaphylaxis are
found in basophils and mast cells
What may result from systemic anaphylaxis?
shock
Graft versus host disease will most likely be a complication of
a bone marrow transplant
Cancer cells may escape the immune system because
tumor cells shed their specific antigens
Autoimmunity is due to
IgG and IgM antibodies
Immunotoxins can be used to treat cancer because they
poison cells
Worldwide, the primary method of transmission of HIV is heterosexual intercourse A hypersensitivity reaction occurs
on a second or subsequent exposure to an antigen
Type IV hypersensitivities
The symptoms occur within a few days after exposure to an antigen, they contribute to the symptoms of certain diseases, they are cell mediated, the symptoms are due to lymphokines
Reactions of antigens with IgE antibodies attached to mast release of chemical mediators cells causes Hay fever is an example of
Type I hypersensitivity
Transfusion reactions are an example of
Type II hypersensitivity
What is true of HIV
Bone marrow can be a reservoir for future infection, HIV can be transmitted by cell to cell contact, the T cell response triggers viral multiplication, viral infection of T-h cells results in signs elsewhere in the patient
Likely vaccines against HIV
Glycoprotein, protein core, subunit, antibodies against streptococcus
What causes damage to kidney cells in glomerulonephritis?
complement fixation
HIV is transmitted by
Human milk, homosexual activity, heterosexual activity, hypodermic needles
Drugs such as AZT and ddC that are currently used to treat stopping DNA synthesis AIDS act by What describes a cytotoxic autoimmune reaction?
antibodies react to cell surface antigens
Clinical AIDS is diagnosed when
the CD4 T cell count is <200
MMR vaccine contains hydrolyzed gelatin. A person receiving this vaccine could develop an anaphylactic reaction if the person has
antibodies against gelatin
Penicillin was considered a "miracle drug" because
It inhibits gram positive cell wall synthesis, it doesn't affect eukaryotic cells, has selective toxicity
The first antibiotic discovered was
penicillin
Most of the available antimicrobial agents are effective against
bacteria
What antibiotics are bactericidal?
Cephalosporins, penicillin, aminoglycosides, rifampin
What antimicrobial agent has the fewest side effects?
penicillin
Act by competitive inhibition
Ethambutol, Isoniazid, Sulfonamide
What method of action would be bacteriostatic?
inhibition of RNA synthesis
What antimicrobial agent is recommended for used against Amphotericin B fungal infections? More than half of our antibiotics are produced by
bacteria
Flucytosine would be most useful to treat
candidiasis
Antibiotics that interfere with cell wall synthesis
semisynthetic penicillins, cephalosporins, natural penicillins, vancomycin
The antimicrobial drugs with the broadest spectrum of activity are
tetracylines
Acyclovir inhibits
DNA synthesis
Amantadine inhibits release of
viral nucleic acid
Fluoroquinolone inhibits
DNA synthesis
Protozoans and helminths diseases are difficulty to treat because
their cells are structurally and functionally similar to human cells
What causes drug resistance?
May be due to increased uptake of a drug, may be transferred from one bacterium to another during conjugation, may be carrier on a plasmid
Advantages of using two antibiotics together
Lessening the toxicity of individual drugs, providing treatment prior to diagnosis, prevention of drug resistance
Drug resistance occurs when antibiotics are used
indiscriminately
What would be selective against the tubercle bacillus?
Ethambutol because it inhibits mycolic acid synthesis
In the presence of penicillin, a cell dies because it undergoes
osmotic lysis
Niclosamide prevents ATP generation in mitochondria. You would expect this drug to be effective against
helminths
What are some bactericidals?
Semisynthetic penicillin, bacitracin, streptomycin, natural penicillin
Mebendazole is used to treat cestode infections. It interferes with microtubule formation; therefore it would not affect
bacteria------(does affect protozoa, human cells, fungi, helminths)
The antibiotic actinomycin D binds between adjacent G-C transcription pairs, thus interfering with Use of antibiotics in animal feed leads to antibiotic resistant bacteria because
the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and
their progeny repopulate the host animal What are normal microbiota of the skin?
Pityrosporum, Staphylococcus, Corynebacterium, Propionibacterium
The etiologic agents of warts is
papovavirus
What are transported by respiratory route?
smallpox, chicken pox, German measles
What are causes by herpesvirus?
keratoconjunctivitis, chicken pox, shingles
Thrush and vaginitis are caused by
Candida albicans
The greatest single cause of blindness in the world is
trachoma
What causes ringworm?
Trichophyton, microsporum, epidermophyton
What is sensitive to penicillin?
streptococcus
What infections are caused by S. Aureus?
Sty, Carbuncle, furuncle, pimples
What are some causative agents of conjunctivitis?
herpes simplex, adenovirus, Haemophilus aegyptii, Chlamydia trachomatis
Congenital rubella syndrome-
it is contracted in utero, may result in deafness, blindness, and mental retardation, may be fatal
The etiologic agent of fever blisters is
herpes simplex
Trifluridine is used to treat
epidemic herpetic keratitis
What is used to treat sporotrichosis?
fungicide
Scabies is a skin disease caused by a
mite
A patient has pus filled vesicles and scabs on her face, throat, and lower back. She most likely has
chicken pox
Herpes gladiatorium is transmitted by
direct contact
(438) A 17 year old male pus filled cysts on his face and upper back. Microscopic examination reveals gram positive rods. This infection is
acne
Encephalitis and meningitis are difficult to treat because
antibiotics cannot penetrate the blood-brain barrier
Leprosy is
rarely fatal, diagnosis may be based on the lepromin test, it is transmitted by direct contact
Rabies
hydrophobia is an early symptom, it is not fatal in bats, caused by Rhabdovirus, diagnosis is based on immunofluorescent techniques
The symptoms of tetanus are due to
clostridial neurotoxin
The treatment for tetanus is
antibodies
The most effective control of a vectorborne diseases is
elimination of the vector
Treatment for tetanus in an unimmunized person is
tetanus immune globulin
Treatment for tetanus in an immunized person is
tetanus toxoid
The most common route of central nervous system invasion by pathogens is through
the circulatory system
The most common cause of meningitis in children is
Haemophilus influenzae
A 30 yo female was hospitalized after she experienced convulsions. One examination, she was alert and oriented and complained of a fever, headache, and stiff neck. What Gram stain of cerebrospinal fluid is most likely to provide rapid identification of the cause of her symptoms? What are caused by prions
sheep scrapie, kuru, transmissible mink encephalopathy, Creutzfeldt Jakob disease
(452) A diagnosis of rabies is confirmed by a direct
fluorescent antibody test
Streptococcal pneumonia is treated with
antibiotics
Microscopic examination of cerebrospinal fluid reveals amoeba. What is the organism?
Naegleria
Microscopic examination of cerebrospinal fluid reveals gram-positive rods. What is the organism?
Listeria
A vaccine is available for
tetanus, neisseria meningitis, Haemophilus meningitis, rabies
What are acquired by ingestion?
Poliomyelitis, listeriosis, botulism
Septicemia
Symptoms are due to bacterial endotoxin, symptoms include fever and decreased blood pressure, it may be aggravated by antibiotics, lymphangitis may occur
What are treated with penicillin?
pericarditis, anthrax, listeriosis
What is a symptom of brucellosis?
Undulant fever
What are transmitted in raw milk?
Brucellosis, listeriosis, anthrax
Characteristics of Bacillus anthracis
found in soil, forms endospores, gram positive
Symptoms of gangrene are due to
proteolytic enzymes, necrotizing exotoxins, hyaluronidase, microbial fermentation
High incidence of what diseases is increased by unsanitary endemic murine typhus, epidemic typhus, plague, and crowded conditions? relapsing fever (466) Toxoplasmosis
can be congenital, caused by protozoan, the reservoir is cats, is transmitted by the gastrointestinal route
Caused by bacterium
plague, epidemic typhus, relapsing fever, tickborne typhus
Septicemia may result from
contamination through the parenteral route, pneumonia, a focal infection, a nosocomial infection
Schistosomiasis
the intermediate host is an aquatic snail, a parasite of birds causes swimmers itch in humans, the cercariae penetrate human skin, it is caused by a flatworm
Human to human transmission of plague is usually by
respiratory route
A characteristic symptom of plague is
bruises on the skin
A predisposing factor for infection by Clostridium perfreinges is
gangrene
Arthropods can serve as a reservoir for
Brucellosis
Diseases transmitted to humans from domestic cats
Bartonella, Toxoplasmosis, plague
What can be treated with antibiotics
Lyme disease, Tularemia, plague
A patient complains of fever, severe muscle and joint pain and a rash. The patient reports returning from a Caribbean Dengue vacation one week ago. What do you expect? What is evidence that the arthritis afflicting children in Lyme, Connecticut, was due to bacterial infection?
Treatable with penicillin
What is the usual cause of septic shock?
Endotoxin
What is true about Group B streptococci
they cause gram positive sepsis, they are present in healthy carriers, they cause neonatal sepsis
A patient persents with inflammation of the heart valves, fever, malaise, and subcutaneous nodules at the joints; the recommended treatment is
anti inflammatory drugs
What is true about otitis media?
caused by Staphylococcus aureus, caused by streptococcus pyogens, transmitted by swimming pool water, a complication of tonsillitis
A diagnosis of strep throat is confirmed by
serological test, gram stain, hemolytic reaction, bacitracin inhibition
Penicillin is used to treat
scarlet fever, streptococcal sore throat, diptheria, pneumococcal pneumonia
What microorganism causes symptoms most like tuberculosis?
histoplasma
A person can have a positive tuberculin skin test because
she has been vaccinated, she has tuberculosis, she is immune to tuberculosis, she has had tuberculosis
What causes an infection of the respiratory system that is transmitted by the gastrointestinal route?
Mycobacterium tuberculosis
What is the reservoir for Psittacosis?
parakeets
What is the reservoir for Tuberculosis?
cattle
What is the reservoir for Histoplasmosis?
soil
What is the reservoir for Pneumocystis?
humans
What produces exotoxin?
streptococcus pyogenes, Corynebacterium diptheriae, bordetella pertussis
What produces the most potent exotoxin?
Corynebacterium diptheriae
The recurrence of influenza epidemics is due to
antigenic shift
What etiologic agents results in the formation of abscesses?
Blastomyces
Infection by what is often confused with viral pneumonia? Mycoplasma What causes a disease characterized by a red rash?
Streptococcus
Inahalation of arthroconidia is responsible for infection by Coccidioides what? Legionella is transmitted by
airborne transmission
Infection that begins in the lungs and spreads to the skin
Blastomyces
Microscopic examination of a lung biopsy shows thick walled cysts. What is the etiology?
Pneumocystis
A patient has a paroxysmal cough and mucus accumulation. What is the etiology of the symptoms?
Bordetella
What respiratory infection can be contracted by ingestion? Tuberculosis What produces small "fried egg" colonies on a medium containing horse serum yeast extract?
Mycoplasma
What is required for tooth decay?
acid producing bacteria, capsule forming bacteria, sucrose
What is true of salmonellosis?
it requires a large infective dose, a healthy carrier state exists, it is a bacterial infection, it is often associated with poultry products
What disease of the gastrointestinal system is transmitted by the respiratory route?
Mumps
The symptoms of trichinellosis are due to the
encystement of larval Trichinella in muscles
Poultry products are a likely source of infection by
Salmonella enterica
What feeds on red blood cells?
Entamoeba histolytica
What is true of staphylococcal food poisoning?
suspect foods are those not cooked before eating, it can be prevented by refrigeration, it is treated by replacing water and electrolytes, it is characterized by rapid onset and short duration of symptoms
The most common cause of traveler's diarrhea is probably
Escherichia coli
Thorough cooking of food will prevent
salmonellas, beef tapeworm, trichinellosis
Most of the normal microbiota of the digestive system are found in
the large intestine
What organisms is likely to be transmitted via contaminated shrimp?
vibrio
What organism is likely to be transmitted via contaminated Trichinella pork? What are transmitted by water?
Cryptosporidium, Hepatitis A virus, Salmonella, Cyclospora
"Rice water stools" are characteristic of
cholera
Most gastrointestinal infections are treated with
water and electrolytes
Vibrio parahaemolyticus gastroenteritis is treated with
tetracycline
The most common mode of HAV transmission is
contamination of food during preparation
The easiest way to prevent outbreaks of gram negative gastroenteritis is to
cook food thoroughly
Microscopic examination of a patient's fecal culture shows Campylobacter spiral bacteria. The bacteria probably belong to the genus Feces from a patient with diarrhea lasting for weeks with frequent, watery stools should be examined for
Cyclospora
Helicobacter can grow in the stomach because it
makes NH-3
Eukaryotes that cause gastroenteritis
Entamoeba, Giardia, Cryptosporidium, Cyclos pora
Hepatitis C
--diagnosed by PCR--incubation of 4 to 22 weeks-transmitted by the parenteral route--it is a flavivirus
Delicatessen meats
Listeria
Milk
Campylobacter
Oysters
Vibrio
Beef
E.Coli
(528)Predisposing factors to urinary tract infections
diabetes mellitus, toxemia, tumors, kidney stones
Pyelonephritis may result from
cystitis, ureteritis, urethritis, systemic infections
Cystitis is most often caused by
gram negative rods
The reservoir for leptospirosis is
domestic dogs
Trichomoniasis is primarily a
sexually transmitted disease
Syphillis is treated with
penicillin
What can cause congenital infections or infections of the newborn?
genital herpes, gonorrhea, nongonococcal urethritis, syphilis
(535)Genital warts recurs at the
initial site of infection
Nongonococcal urethritis can be caused by
Trichomonas vaginalis, Mycoplasma homini, streptococci, Candida albicans
Candidiasis can be caused by an
opportunistic infection
Most nosocomial infections of the urinary tract are caused by
E. coli
Glomerulonephritis is
an immune complex disease
The most common reportable disease in the United States is
gonorrhea
What is the most difficulty to treat with chemotherapeutic agents?
Genital herpes
Leukocytes at the infected site is a symptom of
trichomoniasis
What is caused by Chlamydia?
Lymphogranuloma venereum
What forms lesions similar to those of tuberculosis?
Syphilis
What disease causes a skin rash, hair loss, malaise, and fever?
Syphilis
Staphylococcus saprophyticus causes
cystitis
Nongonococcal urethritis can be caused by
ureaplasma, mycoplasma, chlamydia
A patient is experiencing profuse greenish yellow foul smelling discharge form her vagina; she is complaining of itching and irritation. What is the most likely treatment?
Metronidazole
A 25 year old male presents with fever, malaise, and a rash Rickettsia, Borrelia, Streptococcus, Treponema on his chest, arms, and feet. The etiology could be A 25 year old male presented with fever, malaise, and rash on his chest, arms, and feet. Diagnosis was made based on serological testing. The patient then reported that he had an penicillin ulcer on his penis tow months earlier. This disease can be treated with A pelvic examination of a 23 year old female showed vesicles and ulcerated lesions on her labia. Cultures were Genital herpes negative for Neiseeria and Chlamydia; the VDRL test was negative. What is probable? (552)Whare are some habitats for extremophiles?
inside rocks, 100 degree water, salt evaporating pond, acid mine wash
What animal would you expect to find a specialized organ termite that holds cellulose degrading bacteria and fungi? The addition of untreated sewage to a freshwater lake would cause the biochemical oxygen demand to
increase
Sludge digestion takes place under
anaerobic conditions
When does primary sewage treatment take place?
the amount of oxygen doesn't make any difference
Eighty one percent of microorganisms in the soil are
bacteria
Most of the microorganisms in the soil are found at a depth between 3 and 8 of Nitrosomonas and Nitrobacter are capable of
nitrification
What process is done by Rhizobium and certain cyanobacteria?
Nitrogen fixation
What wastewater treatment process is responsible for removal of most of the BOD in sewage?
Secondary sewage treatment
Residual chlorine must be maintained in
water treatment
Sedimentation of sludge occurs in
primary sewage treatment
The product of what process contains the highest BOD?
Primary sewage treatment
Zoogloea form flocculent masses in
secondary sewage treatment
Anaerobic respiration occurs in
anaerobic sludge digestion
Filtration to remove protozoa occurs in
water treatment
Bacteria can increase the Earth's temperature by
producing CH4, which is a greenhouse gas
The bacteria contributing most of the bacterial biomass to soil are
actinomycetes
The bacteria that grow first in the microbial succession in a anaerobic mesophiles compost pile are The release of phosphate containing detergents into a river increase algal growth would What is true about releasing untreated sewage into a river?
it decreases the dissolved oxygen, it is a health hazard, it increases BOD
Spoilage due to can leakage after processing is
spoilage by mesophile bacteria
Spoilage of canned foods stored at high temperatures, accompanied by gas production is
thermophilic anaerobic spoilage
Spoilage of canned foods due to inadequate processing NOT accompanied by gas production is
flat sour spoilage
What alternative fuels (energy source) is produced by bacteria?
methyl alcohol, hydrogen, ethyl alcohol, methane
What food additives are produced by microorganisms?
Citric acid, amylase, protease, Glutamic acid
Wine is made from fruit juices by
anaerobic fungal growth
Commercial sterilization differs from true sterilization in that commercial sterilization may result in
the survival of thermophiles
Microbial products can be improved by
modifying culture conditions, mutating existing strains, isolating new strains, genetically engineering strains
Cellulase attached to a membrane filter will
degrade cellulose
What are produced using microbial fermentation?
yogurt, sour cream, blue cheese
Methane made from biomass is produced by
anaerobic respiration
Ethanol for automobile fuel is produced from corn by
fermentation
As cheese ages it gets more
acidic
Your friend says he had stored a semisoft cheese (blue cheese) in his refrigerator for three weeks. He asks you why the outer "skin" of the cheese is so much thicker than it was when he originally purchased the cheese. You tell him that
fungi have been growing
You are growing Bacillus subtilis in a bioreactor and notice that the growth rate slowed and the pH has decreased. What could you do?
Add oxygen
Radiation is used for
killing Trichinella, killing insects eggs and larva, for foods that cannot be heated, preventing
sprouting Canning preserves food by
heating
Canning works to preserve foods because of
anaerobic environment and heat
Radiation works to preserve foods because of
lethal mutations
Fermentation works to preserve foods because of
pH
Created by:
Christy L. Duval on 2008-10-01
