ULL Bio 261 Test 3
Identify the major symptoms of localized inflammation and of septic shock
(septic shock)-fever usually higher than 101˚F (38˚C) -low body temperature (hypothermia) -fast heart rate -rapid breathing, or more than 20 breaths per minute (inflammation) considerable damage to healthy tissue, particularly in key organs, such as lungs and brain tissue.
Describe host tissue specificity for pathogens?
-Different pathogens invade different tissues. -Routes of infection are crucial (e.g., tetanus is in wounds, while Salmonella is ingested, not vice versa).
Describe the inflammation reaction. What are some causes of inflammation?
-Effective inflammatory response isolates and limits tissue damage, destroying damaged cells and pathogens. -. Caused by non-degradable pathogens that cause persistent inflammation, infection with some types of viruses, persistent foreign bodies, overactive immune system reactions
List the immunizations recommended for children in the United States. For which of these have you been immunized? List the diseases for which you may have acquired naturally.
-Hib -Neisseria menngitides -streptococcus pneumoniae -tetanus, diphtheria, pertussis -Hepatitis B and A -HPV -Influenza virus -Inactivate polio (IPV) -measles, mumps, rubella (MMR) -Chicken pox
Identify physical and chemical barriers to pathogens. How might these barriers be compromised?
-Mucosal membranes are coated with a thick layer of mucus. -Stomach acid inhibits bacterial growth. -Skin is salty and acidic, limiting bacterial growth. -The immune system comprises both innate and adaptive immune responses
Where do all blood cells originate? What determines what they differentiate into?
-all blood cells originate from a single type of unspecialized cell called a stem cell. -A multipotent stem cell has the potential to differentiate into different types of cells within a given cell lineage or small number of lineages, such as a red blood cell or white blood cell.
Describe the process of phagocytosis. What types of cells are phagocytic?
-certain living cells called phagocytes ingest or engulf other cells or particles. The phagocyte may be a free-living one-celled organism, such as an amoeba, or one of the body cells, such as a white blood cell. - white blood cells (such as neutrophils, monocytes, macrophages, mast cells, and dendritic cells).
Describe the circulation of a leukocyte from the blood to the lymph and back to the blood.
-drains lymph fluid from extravascular tissues -Blood is pumped through arteries and capillaries and returns from the body through veins -In capillary beds, leukocytes and solutes pass from blood into the lymphatic system
Distinguish between infection and disease?
-infection=when a pathogen has invaded your body and is multiplying in host cells and tissues -disease=occurs if the body's defenses can't be mobilized fast enough to prevent the infection from messing w normal bodily functions
Under what conditions are interferons produced, and how do they limit the transmission of viruses from one host cell to another?
-produced by virally infected cells -Interferons serve as a warning system and prevent viral replication by stimulating the production of antiviral proteins in uninfected cells once they receive the interferon signal from infected cells.
Identify and compare the targets and the recognition mechanisms used by T-cytotoxic cells and NK cells.
-recognize cells that do not display Major Histocompatibility Complex I (MHC I) proteins, as all normal host cells should have MHC I. -If a cell lacks MHC I and displays a stress protein, an NK cell will activate to destroy the target, which is likely a virally infected or cancerous host cell.
Summarize antibody production starting with pathogen interaction with an APC.
-uptake and degradation of pathogen -presentation of processed antigen to Th2 cell -cytokine activation of b cell -proliferate and differentiate into plasma and memory cells -plasma cells produce antibodies
What is MRSA and how could you isolate and identify this organism? Why is it a problem? What are possible alternative treatments? What type of disease would or could it cause?
1. MRSA is methicililin-resistant staphylococcus aureus and detected by chromogenic agar media or nucleic acid-based test. 2. because methicillin treats staphylococcus aureus. 3. requires a non b-lactam antibiotic such as vancomycin, tetracycline, or sulfa drugs. 4. Food poisoning, toxic shock, common in skin or wound infections.
What steps in the viral maturation process are inhibited by nucleoside analogs? By protease inhibitors? By interferons?
1. inhibiting elongation of viral nucleic acid chain by nucleic acid polymerase. 2. disrupt viral replication by binding the active site of HIV protease, preventing this enzyme form processing large viral polyproteins. 3.prevent viral multiplication by stimulating antiviral proteins in unaffected cells
Only particles smaller than ________ μm in diameter reach the lungs.
10
A laboratory in which Ebola virus is studied would be classified as a BSL-________ laboratory.
4
Diptheria toxin is a
AB toxin
Explain how diphtheria toxin work
AB toxin that blocks protein synthesis in eukaryotic cells, the B subunit of the toxin to bind with a receptor protein allowing the A subuint to enter the cell and block protein synthesis
How do super antigens cause disease?
Activate more T cells than normal. They are capable of eliciting a strong immune response
What event is required but not sufficient to cause an infectious disease?
Adherence is the enhanced ability of microbes to attach to host tissues. It is required to initiate disease but is not sufficient because the host has many innate defenses that can thwart infection.
Which of the following is TRUE about research on the human microbiome?
Advanced nucleic acid sequencing techniques were needed before a good understanding of its microbial abundance and diversity could be developed.
What causes immunodeficiency and what is the result of this condition?
B and T cell deficiencies resulting in either increased susceptibility to cancers (T cell) or bacterial infections (B cells)
Laboratories that work with extremely low risk pathogens are classified as
BSL-1
Common probiotics include
Bifidobacterium species
What is opsonization, and how does opsonization help fight bacterial infections?
C3b coating a target makes it easier for the phagocytes to engulf it;
TH cells express a ________ protein coreceptor.
CD4
TC (cytotoxic) cells express a(n) ________ protein co-receptor.
CD8
explain how cholera toxin works
Cholera toxins affect the small intestines and cause massive secretion of fluid into the lumen resulting in vomiting and diarrhea
what does Clostridium difficult cause? What are the basic characteristics of this organism that help it cause disease?
Clostridium difficult causes diarrhea, severe abdominal pain, and fever, inflammatory lesions, and bowel perforations. It is a spore-former and antibiotic resistant bacteria, infections most often occur following an antibiotic treatment, it is an opportunistic infection caused by low counts of E. coli.
New vaccine strategies resulting from progress in biochemistry and molecular biology include the production of
DNA, recombinant vector, and synthetic peptide vaccines.
What is TRUE about stomach microbiota?
Despite the acidic of the stomach, diverse phylotypes of resident microbes thrive in the stomach.
What causes UTIs? Are men or women more susceptible to UTIs and why?
E coli and P mirabilis infiltrating the urethra and infecting the bladder, women are more susceptible because when they wipe, if done improperly can cause bacteria to reach the urethra
Which bacterium shows a characteristic metallic green sheen when grown on eosin-methylene blue (EMB) agar?
Escherichia coli
An important intestinal pathogen generally acquired from contaminated food or water is
Escherichia coli O157:H7.
What types of organisms make antibiotics and give examples of each.
Fungi > Penicillium makes penicillin Bacteria > soil bacterium Streptomyces platensis produces platensimycin
Why are there fewer clinically effective antifungal and antiparasitic agents than antibacterial agents?
Fungi are eukaryotic so antifungals must be topical to avoid damaging host cells
________ are cytotoxins produced by T cells that cause apoptosis.
Granzymes
Which of these microorganisms is most likely to be found in the human stomach?
Helicobacter pylori
Which of the following is NOT an immunoglobin? IgD IgG IgC IgA
IgC
Type I hypersensitivity is caused by the release of vasoactive products from mast cells coated with
IgE
What are the different classes of antibody and where are they found? What is unique about each?
IgG- most common found circulating body (long term immunization) IgA- secretory found in tears, saliva, and breast milk IgM- aggregate of five immunoglobulin molecules attached by j chain c IgE- antibody that binds to eosinophils found in serum IgD- found in serum function unknown
Which antibodies bind complement?
IgM
In class switching during the secondary antibody response, the most common antibody switch is from
IgM to IgG
Which of the following is a benefit of studying the human microbiome?
It may allow for the development of personalized medical treatments, allow for more finely targeted probiotics, and allow for increased recognition of disease biomarkers.
GOOD
LUCK
What causes lactose intolerance and its symptoms? What other things do fecal bacteria do?
Lactose intolerance is caused when the cells lining the small intestines do not have the enzyme acts. The lactose then ferments causing gasses that cause symptoms. Symptoms: abdominal craps, bloating, and diarrhea They break down sugars and such to their simplest forms
Compare and contrast live attenuated vaccines, inactivated vaccines, and toxoids. Which of these has the greatest potential to cause active disease in the recipient?
Live vaccines- use a weakened (or attenuated) form of the germ that causes a disease. because these vaccines are so similar to the natural infection that they help prevent, they create a strong and long-lasting immune response. Inactivated vaccines- use the killed version of the germ that causes a disease. Inactivated vaccines usually don't provide immunity (protection) that's as strong as live vaccines. So you may need several doses over time (booster shots) in order to get ongoing immunity against diseases. Toxoid vaccines- use a toxin (harmful product) made by the germ that causes a disease. They create immunity to the parts of the germ that cause a disease instead of the germ itself. That means the immune response is targeted to the toxin instead of the whole germ. toxoid vaccines are the worst for you
which of the following is NOT a subunit of lipopolysaccharide (LPS)? Which of the following is NOT a subunit of lipopolysaccharide (LPS)? O-specific polysaccharide core polysaccharide M protein lipid A
M protein
Streptococcus pyogenes produces proteins called ________, which alter(s) the surface of the pathogen and inhibits phagocytosis
M proteins
Identify the cells that display MHC class I and MHC class II proteins on their surfaces.
MCH I are found on all nucleated cells MCH II are found on antigen-presenting cells, such as dendritic cells, macrophages, and b cells
What are MHCs and why are they important?
MHC( Major Histocompatibility Complex) molecules are important components of the immune system because they allow T lymphocytes to detect cells, such as macrophages, that have ingested infectious microorganisms.
Describe the molecules or structures that facilitate pathogen adherence to host tissues?
Molecules: Adhesions are glycoproteins or lipoproteins found on the pathogens surface that enable it to bind to a host cell Structures: Capsules( form a thick coating outside the plasma membrane and cell wall and serves two important functions in bacterial pathogenicity Fimbriae and Pili(are cell surface protein structures that functions in attachment) Flagella( bacterial cell surface protein structure that functions in attachment
A gram-negative, oxidase-positive diplococcus growing on chocolate agar likely belongs to the genus
Neisseria.
explain how botulism toxin work
Neurological exotoxins (AB), the most potent biological substance known, the major one is protein that forms complexes with nontoxic botulism proteins to yield a bioactive protein complexes that bind to block the release of ACH causing flaccid paralysis
What advantage(s) does nucleic acid amplification have over standard culture methods for identification of microorganisms? What are the disadvantages?
Nucleic acid hybridization: methods identify specific pathogens in patient samples by using unique nucleic acid probes to detect pathogen DNA; Presence of amplified gene segment confirms presence of pathogen; Almost immediate results
What is an opportunistic pathogen?What steps can a person take to help avoid opportunistic infections
Opportunistic infection is an organism that causes disease only in the absence of normal host resistance. The steps a person can take to avoid opportunistic infections are not using intravenous drugs, no tobacco, or excessive alcohol
How is the bivalence of antibodies significant for a precipitation reaction, and under what conditions does precipitation occur maximally?
Precipitation is the interaction of a soluble antibody and soluble antigen to form an insoluble complex. Only occurs when they are in equal concentrations. SOLUBLE ANTIGENS; Antigens that have more than one antibody-binding epitope can cross-link the bivalent antibodies that recognize them, causing a precipitate to develop from the aggregated antibody-antigen complexes
Based upon microbiome projects, the dominant microbial species on the skin is
Propionibacterium species.
Why are secondary or booster reimmunizations given?
Secondary reimmunizations produce a secondary immune response and boost antibody titers.
Explain the concept of selective toxicity in terms of antimicrobial therapy.
Selective toxicity are antibiotics that target Bacterial ribosomes so they kill the Bacteria without damaging any host cells; They inhibit or kill the pathogen without adversely affecting the host
Which is a more serious condition, bacteremia, or septicemia, and why?
Septicemia is more serious than bacteria because septicemia is when bacteria are present in the blood and ,multiply while they are there and the initial focus produces toxins or other poisonous substances. septicemia usually begins as an infection in a specific organ such as the intestines, kidneys, or lung and then spreads rapidly throughout the body from there. symptoms include massive inflammation, culminating in septic shock(sepsis), and death
Shiga toxin is an enterotoxin that is produced by
Shigella dysenteriae
Why do certain pathogens only infect specific hosts?
Some pathogens only infect specific hosts because that host has the necessary molecules needed for the interaction of the host tissues and pathogen
What are the common genera of bacteria found on the skin, in the throat and in the intestines?
Staphylococcus, Propionibacterium, and Corynebacterium are common on the skin. Lactobacillus, Leuconostoc, and Streptococcus are common in the throat. Firmicutes, Bacteroidetes, and Actinobacteria are common in the intestines
Which genus produces hyaluronidase?
Streptococcus
T cells recognize antigens with their
T cell receptors
antigen-presenting cells present antigens to
T lymphocytes
What major class of immune cells mediates an innate immune response? What additional type of immune cells is required for an adaptive immune response?
T lymphocytes; B cells or Lymphocytes
Which of the following is TRUE about cytokines? They are carbohydrates. They play a role in the growth of stem cells, but are not important in immunity. They are proteins that play an important role in immunity and the growth of stem cells. They play an important role in immunity, but do not affect stem cell growth.
They are proteins that play an important role in immunity and the growth of stem cells.
What is the drawback of live attenuated vaccines?
They can cause disease in some immunocompromised individuals.
What is the role of fecal transplants in medicine?
They can provide a healthy microbiota to help treat Clostridium difficle infections.
What major virulence factors are produced by Salmonella?
Type 1 fimbriae to facilitate attachment of cells to gastrointestinal tissues. several different classes of exotoxins. antiphagocytic proteins that block engulfment of bacterial cells by host phagocytes. proteins that promote survival if the bacterium does not get phagocytosis. siderophores organic molecules that bind iron tightly and in pathogenic bacteria, allows bacteria to outcompete host sequestration systems for iron. endotoxins
Explain how blood is typed and what does it mean? What types of blood are each able to give and receive and why?
Typed by agglutination (reaction between antibody and particle-bound antigen resulting in visible clumping of the particles) to classify the antigen on the surface of RBC
Which is an example of acquisition of natural passive immunity?
a fetus protected from disease by its mothers antibodies
What is a nosocomial infection?
a hospital acquired infection (HAI), is an infection whose development is favored by a hospital environment, such as one acquired by a patient during a hospital visit or one developing among hospital staff.
Identify host factors that limit or accelerate infection of a microorganism at selected local sites
accelerate infection- high virlulence of pathogen, lifestyle choices ( choosing to use drugs, smoke, or drink) and immunodeficiency disease (HIV) limit infection- low virulence of pathogen and choosing not to drink, smoke, or use drugs
Which of the following environmental and host factors influence the composition of the resident microbiota on the skin? age weather personal hygiene age, personal hygiene, and weather
age, personal hygiene, and weather
What is the advantages and disadvantages of agglutination tests versus fluorescent antibody assays? How are the later used to identify specific cells in complex mixtures, such as blood?
agglutination tests are used to ID blood group antigens and many pathogens, fluorescent antibodies are chemically modified to help ID atigens on intact cells. depending on the type of dye used on cells microbiologists can determine the type of cell based on the color they fluoresce
Which of the following can be used in creating a vaccine? inactivated viruses recombinant proteins attenuated bacteria all of the above
all of the above
Which of the following are proteins that interact directly with antigens during the adaptive immune response? major histocompatibility complex T cell receptors (receptors on T cells) immunoglobins all of these
all of these
Identify culture methods and conditions used for blood, wound, urine, fecal, and genital specimens. Of what importance are selective and differential growth media in pathogen detection, and what special conditions must be maintained for the isolation of anaerobic pathogens?
all of these specimens can be grown on either general-purpose or enriched media. selective media allow some not all organisms to grow while differential media allows for ID of organisms based on their growth and appearance special conditions for anaerobic pathogens grown in maintained anoxic conditions during collection and transport
Which of the following would be useful for treating Candida? a macrolide a fusion inhibitor a nucleoside reverse transcriptase inhibitor an azole
an azole
What is an IgAse and why would a bacterial pathogen produce one?
an enzyme that bacteria produce to counter that secretory antibodies isA which helps prevent pathogen adherence to host tissues. Once ida is countered by IgAse to hose defense is useless
Which of the following is NOT an autoimmune disease? systemic lupus erythematosus type 1 diabetes multiple sclerosis anaphylaxis
anaphylaxis
The life-threatening condition that may develop during a type I hypersensitivity reaction is called
anaphylaxis.
Indirect EIA is used to detect
antibodies
immunoglobulins are produced by B cells and are also known as
antibodies
Where does the antibody bind to an antigen? What part of the antibody binds?
antibodies bind antigens at the antigenic determinant or epitope
Explain the reasons for changes in antibody titer for a single infectious agent, from the acute phase through the convalescent phase of infection.
antibodies move from the blood to the feces because the body has almost removed all the infectious bacteria and is not removing the last of it as waste
What term is used to describe the unique molecules found on the surface of different pathogens?
antigens
A serum containing antigen-specific antibodies is called an
antiserum
Another name for "programmed cell death" is
apoptosis
The disk-diffusion test is used for
assessing antimicrobial activity.
How can the spread of HAIs be controlled?
assessing potential risks and applying basic aseptic techniques
The decrease or loss of virulence of a pathogen is referred to as
attenuation
Which of the following diseases is/are associated with organ-specific autoimmune disease? autoimmune hypothyroidism and juvenile (type I) diabetes autoimmune hypothyroidism juvenile (type I) diabetes systemic lupus erythematosus (SLE)
autoimmune hypothyroidism and juvenile (type I) diabetes
Name some pathogens that produce exotoxins and what is their mode of action?
bacillis antracits- produce lethal factor with protective antigen (AB) to kill cell vibrio cholera- produces cholera (AB) to cause diarrhea/vomiting staph aureus- produces toxic shock toxin (SA) causes hemolysis and cell death
The condition that results when some bacteria are shed in the bloodstream and distributed to distant parts of the body but do not reproduce in the blood is called
bacteremia.
The measurable strength of the binding of an antibody to antigen is called
binding affinity.
Which of the treatments listed below would be most effective for a patient with a genetic defect that causes severe combined immunodeficiency (SCID), a condition in which there is a severe deficiency in B and T lymphocytes? bone marrow transplant repeated doses of antisera multiple immunizations intravenous antibiotics
bone marrow transplant
How are T cells similar and different?
both Th1 & Th2 cells initiate other functions, Th1 cells will secrete cytokines to activate macrophages to kill intracellular bacteria, Th2 will play a crucial role in b cell activation and antibody production
MacConkey agar and eosin-methylene blue (EMB) agar are ________ media.
both selective and differential
Why do botulisms and tetanus show such apposing symptoms?
botulism toxin blocks the release of acetylcholine causing the muscles to stay relaxed. tetanus toxin blocks the release of glycine, which is an inhibitory neurotransmitter, causing acetylcholine to constantly be released inhibiting muscles from relaxing
What parts of the body do not have normal flora bacteria?
brain, the circulatory system, the lungs, and the urinary bladder
Dimers of IgA are present in
breast milk colostrum, saliva, and tears.
How does the activity of each antibiotic class lead to control of the affected pathogens?
broad Spectrum: general effective against both gram negative and positive pathogens. Narrow Spectrum: used against generally resistant gram positive pathogens; useful against certain pathogens that don't respond to broad spectrum
an outer coat consisting of a dense, well-defined polymer layer surrounding a cell and used in attachment is called a
capsule
The pouch at the beginning of the large intestine is called the
cecum
How does placque form in the teeth? What type of bacteria cause dental caries? Are they aerobic or anaerobic organisms? What would you see if you did a gram stain of dental plaque?
cells form a biofilm containing streptococcus and other fermenting bacteria, they create an anaerobic environment, dental plaque stains purple (GP) and is rod shaped
Which of the following are found on the surfaces of all nucleated cells? M proteins G proteins Class II MHC proteins Class I MHC proteins
class I MHC proteins
Distinguish between clonal deletion and clonal selection.
clonal deletion is the killing of cells that recognize host antigens rather than foreign antigens. clonal selection is the retaining of cells that can recognize foreign antigens
staphylococcus aureus produces ________, leading to fibrin clots that protect them from attack by host cells.s
coagulase
Describe the basic structure of an antibody.
constant, and variable sites. variable sites vary depending on specific antigen
Eukaryotic intestinal parasites, such as Giardia, can be identified by observing stool samples for the presence of
cysts
Communication between cells of the immune system is accomplished in many cases through
cytokineses
Which of the following is a category of exotoxin?
cytolytic toxin
The damaged areas of teeth caused by organic acids produced by dental plaque are called
dental caries
Extensive microbial growth in a thick bacterial layer on the teeth is called
dental plaque
Which type of medium allows a variety of microbes to grow but often changes color in the right conditions, such as when fermentation causes a pH change?
differential but not selective
Compare a direct and indirect ELISA with respect to their ability to identify infection with a particular pathogen.
direct EIA= detects antigen indirect EIA= detects antibody
Describe the disc diffusion test and the E test for antimicrobial susceptibility. For an individual organisms and an antimicrobial agent, what do the results signify?
disc diffusion test- a test of the antibiotic sensitivity of bacteria. It uses antibiotic discs to test the extent to which bacteria are affected by those antibiotics. Inhibition zones means antibiotic is working E test-used to determine whether or not a specific strain of bacterium or fungus is susceptible to the action of a specific antimicrobial.
________ is a damage or injury to a host organism that impairs its function.
disease
The human oral microbiota consists of
diverse aerobic and anaerobic microorganisms.
Describe the properties of microorganisms that grow well on the skin. What determines whether or not an organism will colonize a body site?
dry, moist, and sebaceous skin are the three microenvironments microorganisms like
The use of special culture media and incubation conditions to isolate microorganisms from samples is known as a(n)
enrichment culture
The part of the antigen recognized by the antibody or TCR is called the
epitope.
Which major body sites are heavily colonized by microbes? Are you born with these microbes?
exposed skin, oral cavity, and gastrointestinal tract. you are not born with any microbes you are exposed to them over time.
Antibody-mediated immunity is particularly effective against
extracellular pathogens
A recombinant-vector virus would still be effective if the vaccinia virus is unable to express the cloned gene as an antigenic protein.
false
A toxoid is an attenuated form of a toxin that retains both its antigenicity and toxicity.
false
All antigens are immunogens.
false
All microorganisms that live in the human body are harmful.
false
Hyaluronidase worsens infection by causing damage to red blood cells.
false
Interferons promote viral replication.
false
Normal microbiota is usually found in the blood, lymph, and nervous systems of the body.
false
Which of the following immunological tests would allow the specific identification of a microorganism directly in infected tissues? fluorescent antibody (FA) enzyme-linked immunosorbent assay (EIA) agglutination radioimmunoassay (RIA)
fluorescent antibody (FA)
Clostridium difficile infections most often occur
following antibiotic treatment
Blood agar is an example of a medium that supports the growth of many microbes. Medium that supports a wide variety of growth is called ________ medium.
general-purpose
Methylene blue in EMB agar slightly inhibits
gram positives
EMB agar preferentially selects for the growth of ________ bacteria.
gram-negative bacteria
An attenuated strain of a pathogen
has lost its virulence, but may be used to create a vaccine.
The component that enriches chocolate agar is
heat-lysed blood cells.
Although technically not part of the immune system, nonpathogenic normal microbiota plays a major role in preventing disease. Describe this role.
helps host resist pathogens, particularly on the skin and in the gut (competitive exclusion).
The basis for blood typing is referred to as
hemagglutination
In the United States, every clinical and research institution requires that workers be protected from ________, a pathogen that is contracted almost exclusively from handling patient specimens (rather than from known exposure or accidents).
hepatitis B
What are the primary chemical mediators released from mast cells during a type I hypersensitivity reaction?
histamine and serotonin
The major histocompatibility complex in humans is also called the
human leukocyte antigen (HLA).
The rapid increase in adaptive immunity after a second antigen exposure is called
immune memory
The ability of humans to resist a disease is called
immunity
The purposeful artificial stimulation of active immunity to a particular infectious disease is known as
immunization.
Substances that induce an immune response are known as
immunogens.
Which of the following is a cause of drug-specific resistance in disease-causing organisms? indiscriminate nonmedical use of antimicrobials poor immunity nosocomial infection inappropriate hygiene
indiscriminate nonmedical use of antimicrobials
The bodys non-inducible, preexisting ability to recognize and destroy a variety of pathogens or their products is called
innate immunity
Some of the cytokines produced by lymphocytes are called
interleukins.
Which of the following is NOT a function of the human gut microbiome? production of essential amino acids and vitamins production of volatile fatty acids from polysaccharides iron and trace metal absorption maturation of the gastrointestinal tract
iorn and trace metal absorption
What does it mean on a label that says "contains active culture"?
it contains a live and active bacteria culture within it. It is a probiotic
Why does eating a high sugar diet contribute to dental caries?
it is food for the bacteria to grow, these fermenters produce acid, which wear down the tooth enamel.
What circumstances can contribute to attenuation of a pathogen?
keeping pathogens in a lab culture=decreases virulence and attenuation is the decrease of loss of virulence
Decalcification of the tooth enamel is caused by
lactic acid
The most heavily colonized human organ by bacteria is the ________, containing 10111012 bacterial cells per gram. mouth small intestine large intestine skin
large intestine
Intracellular pathogens sometimes produce ________ that can kill phagocytes.
leukocidins
Which of the following immunogens is most effective as a vaccine?
live virus
What are examples of lymphoid tissue?
lymph nodes, spleen, tonsils, adenoids and the thymus (an organ in the chest that is particularly large during infancy).
The first defense cells that interact with a pathogen in the body are
macrophages
Antibodies are found in
milk, mucosal secretions, and serum.
What advantages do monoclonal antibodies have compared to polyclonal antibodies? How are mAbs produced?
monoclonal antibodies are inexpensive to create and are used typically in pregnancy tests. mAbs are made by identical immune cells that are all clones of a unique parent cell.
Give an example for each: natural and artificial active immunity and natural and artificial passive immunity.
natural active- getting a disease and recovering natural passive- passing antibodies from host to host (breastfeeding) artificial active- receiving vaccination and developing immunity (booster shot) artificial passive- receiving pre-formed antibodies (antivenom)
The process by which antibodies block interactions between pathogens or their products and host cells is termed
neutralization
It is thought that attenuation occurs especially in a laboratory setting because
nonvirulent or weakly virulent mutants grow faster in laboratory media when there is no selective advantage to virulence
What is autoimmunity and give examples of autoimmune diseases. Explain the mechanism associated with each disease.
occurs when T and B cells are activated to produce immune reactions against self proteins, example type 1 diabetes (loss of tolerance)
Pathogenicity is the ability
of the pathogen to inflict damage on the host.
MHC I proteins are found
on all nucleated cells
Enhanced phagocytosis of antibody-sensitized cells is known as
opsonization.
Identify the basic mechanisms of antibiotic resistance in bacteria and describe what practices encourage their dissemination.
organism is impermeable to antibiotic. organism can inactivate antibiotic. organism may modify target of antibiotic. organism may develop resistant biochemical pathway. organism may be able to pump out the antibiotic (efflux) overuse of antibiotics make bacteria more resistant
The human microbiome contains all
organisms present in and on the body
the best term to describe the general process by which microorganisms cause diseases is known as
pathogenesis
At what body sites do pathogens typically attach and colonize?
pathogens typically attach and colonize at sites in the mucous membranes. They secrete mucus which retains moisture and naturally inhibits microbial attachment.
Natural killer cells like Tc cells use ________ and granzymes to kill their targets without prior exposure or contact with the foreign cells.
perforin
The first cell type active in the innate response is usually a(n)
phagocyte
Some activated B cells are transformed into ________ cells that secrete antibodies, and others remain as ________ cells.
plasma / memory B
Obligately anaerobic normal flora are found in ________, which is/are an anoxic habitat(s) of the body.
portions of the oral cavity
Normal microbiota helps to ________ colonization of pathogenic organisms.
prevent
After the first exposure to an antigen, a ________ stimulates growth and multiplication of antigen-reaction cells.
primary adaptive immune response
Describe primary and secondary antibody responses in serum.
primary- produces short-lived plasma cells that live for less than a week, mostly IgM secondary- memory cells don't need T cell help, antibody response is quicker, produces 10-100x more antibodies (IgG)
Following antibiotic therapy, patients are often administered ________ to facilitate recolonizaton of normal microbiota in the intestines.
probiotics
What is a probiotic? How does it differ from a prebiotic? Give an example of a probiotic. What are the name of some of the genera found in a probiotic?
probiotics are living organisms that confer a health benefit to the host, they take up nutrients used by pathogens, and prebiotics provide nutrition for pathogens
The used of personal protective equipment (PPE) is required for clinical laboratory technicians. What protective apparel does PPE include?
protective eye wear, face wear, lab coat, gloves
Which of the following are NOT found in the gastrointestinal tract of healthy humans? Clostridium Bacteroides Escherichia coli protists
protists
Organisms such as Streptococcus pyogenes and Staphylococcus aureus that produce leukocidins and are associated with pus are called ________ pathogens.
pyogenic
Which of the following prevents supercoiling of bacterial DNA? penicillins cephalosporins macrolides quinolones
quinolones
influenza virus targets
respiratory epithelium
Some antibiotics inhibit protein synthesis by disruption of translation through interactions with the
ribosomes
explain how tetanus toxin works
same as botulism toxin except they bind to inhibitory neuron so the muscle never relaxed and is constantly flooded with ACH
one microenvironment of the skin is an area where glands produce an oily substance called
sebum
The spread of pathogens through the blood and lymph systems that results in a bloodborne systemic infection is called
septicemia
The study of antigen-antibody reactions is known as
serology
What are complement and the complement pathway?
set of circulating, inactive proteins that are sequentially activated in response to a pathogen.
Distinguish between immune specificity, memory, and tolerance.
specificity- antibody reaction is dependent on lymphocyte cell receptor interacting with pathogen memory- subsequent exposure to the same antigen results in rapid production of large quantities of Tcells or antibodies tolerance- acquired inability to make an adaptive immune response to one's own antigens
What are the key points necessary for proper collection of clinical specimens, and why is it important that diagnostic test for these specimens are both highly specific and sensitive?
specimen should be obtained aseptically and must have a large enough sample size. testing is pathogen specific and there needs to be enough pathogen for the test to perceive it
A mechanism for penicillin resistance in bacteria is
splitting the β-lactam ring of the antibiotic.
How do streptokinase and coagulase promote bacterial infection and invasion?
streptokinase- produced by streptococcus pyroxenes an dissolves fibrin lets allowing bacteria to spread by making the host produce plasmin coagulase- produced by staphylococcus aureus and induces fibrin clotting which allows bacterial cells to remain at the site of infection ( prevents access to pathogens by cells of the immune response)
Staphylococcus aureus and Streptococcus pyogenes strains can produce ________ that cause the severe and sometimes life-threatening symptoms of toxic shock syndrome.
superantigen toxins
All the following can cause contact dermatitis EXCEPT latex gloves. superantigens. jewelry. poison ivy.
superantigens
What are the most common types of HAIs and the pathogens associated with them?
surgical site infection 21.8% respiratory tract infection 21.8% gastrointestinal tract infection 17.1% other 16.4% urinary tract infections 12.9% blood stream infection 10%
Explain the rationale for periodic revaccination in children and adults.
that certain strains of pathogens develop immunity or resistance to vaccines through mutation. example: flu season
Describe the method, time frame, and rationale for the tuberculin skin test. What component of the immune response does this test detect?
the TB skin test is administered through the patients skin and results start to show after a 3 day period it affects it produces a delayed hypersensitivity reaction which affects your Th cells
Adaptive immunity occurs when
the innate immune response fails to eliminate pathogens in the body and virulent infections persist after the initial innate defense response.
Why is the lower respiratory tract typically microbe-free?
the lungs like to remain sterile
An Etest® is a clinical tool used for the determination of
the minimum inhibitory concentration (MIC) value of an antimicrobial agent.
Describe the relative importance of innate immunity compared to adaptive immunity. Is one more important than the other? Can we survive in a normal environment without immunity?
the noninducible ability to recognize and destroy an individual pathogen or its products; the acquired ability to recognize and destroy a particular pathogen or its products; no; no
What is the value of antimicrobial drug susceptibility testing for the microbiologist, the physician and the patient?
the value is high is high for all three as microbiologists can mas produce drugs that physicians can prescribe to patients which can make them healthier
Identify and discuss the standard safety procedures adopted by microbiology laboratories. Under what biosafety level do most clinical laboratories operate? Where are most BSL-4 laboratories located?
there are 6 safety standards restrict access practice good hygiene use PPE vaccinate handle specimens safely decontaminate most laboratories opperate under BSL-1 36% of BSL-4 labs are on college campuses
Superantigens produce a harmful immune response because
they activate too many T cells, causing excessive inflammation and cell damage.
How do products like beano work
they are enzyme based dietary supplements that reduce gas in the digestive tract. Beano contains the enzyme alpha-galactosidase that breaks down oligosaccharides. Oligosaccharides can only be partially digested and are a major contribute to the fermentation of gas in the digestive tract.
Why are patients in healthcare facilities especially susceptible to pathogens?
they are there because they are sick (immunocompromised) or they require surgery which opens the body to easy pathogen entry
Why are beta-lactam antibiotics generally more effective against gram-positive bacteria than gram negative bacteria?
they inhibit cell wall synthesis with beta-lactam ring
In Hashimotoss disease, auto-antibodies are made against ________, a product of the thyroid gland.
thyroglobulin
Describe several reasons why phagocytes are not always effective at removing pathogens from the body.
to accomplish ingestion, the phagocyte must first adhere to the particle
________ is the acquired inability to mount an adaptive immune response against self.
tolerance
All positive HIV-EIA tests must be confirmed by another independent test, usually the HIV Western blot.
true
An individual can receive injections of an antiserum or purified antibodies derived from an immune individual.
true
Antihistamines are used to treat some allergic symptoms because they neutralize the histamine mediators that cause rapid dilation of blood vessels and contraction of smooth muscles that initiate the symptoms of systemic anaphylaxis.
true
Clostridium botulinum are endospore-forming bacteria normally found in the soil.
true
Dead phagocytes make up much of the material of pus
true
Gram stain smears of urethral exudates for the detection of Neisseria gonorrhoeae are highly specific.
true
HIV infection causes immunosuppression because it causes the destruction of CD4 lymphocytes.
true
HLAs are responsible for immune-mediated organ transplant rejection.
true
In cases of suspected foodborne or waterborne infections, fecal samples should be inoculated into a variety of selective media.
true
In the EIA test for HIV infection, the microtiter plate is coated with disrupted HIV particles.
true
Nucleic acid probes are used to detect the presence of particular sequences of DNA.
true
Pathogenicity islands are clusters of genes for virulence factors that are located together on the bacterial chromosome.
true
Protists are NOT normally found in the gastrointestinal tract of healthy individuals.
true
Streptococcus mutans produces dextran to aid in attachment to tooth surfaces.
true
Superantigens activate more T cells than a normal immune response.
true
The causal agents of urinary tract diseases are often members of the normal flora.
true
The use of antivenom to treat snakebite is an example of artificial passive immunity.
true
localized infections by pyogenic bacteria often form boils or abscesses.
true
virulence genes may be located on mobile genetic elements.
true
Compare and contrast the four types of hypersensitivity. Which ones are mediated by antibody?
type 1- immediate response IgE sensitization of mast cells histamine production (allergies) type 2- cytotoxic IgG interacts with cell surface antigen usually takes a few hours typically drug allergies type 3- immune complex IgG interacts with circulating antigen takes a few hours occurrence depends on where antigens settle type 4- delayed Th1 inflammatory activation of macrophages example poison ivy reaction
Which of these is often used as a prophylactic measure to protect a person against future attack by a pathogen? vaccination artificial passive immunity antiserum injection None of these are correct.
vaccination
What is the importance of vaginal Lactobacillus in healthy adult women?
vaginal lactobacillus acidophilus is important because it ferments glycogen which creates lactic acid. The lactic acid produced maintains the slight acidic ph(-5) which is needed for protection purposes.
What are the virulence factors? How can the LD50 test be used to define virulence of a pathogen?
virulence factors are substances or strategies of a pathogen that indirectly or directly enhance invasiveness and host damage by facilitating and promoting infection. The LD50(lethal dose 50) is a test designed to test the cells of a pathogen that kills 50% of the animals in a test group.Highly virulent pathogens show little difference in the number of cells required to kill 100% of the population as compared to 50% of the population.
The following compounds are all produced by intestinal microbiota EXCEPT vitamin B12. thymine. vitamin C. vitamin K.
vitamin c
What other factors may control the outcome of an infectious disease?
water supply sanitation facilities food climate.
The vagina of an adult female is
weakly acidic
