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Test 2
MB 411 Test 2
130
Microbiology
03/25/2012

Additional Microbiology Flashcards

 


 

Cards

Term
Which of the following archaea are opportunistic pathogens of humans?
Definition
no archaea are pathogens (at least none that of which we know)
Term
Which of the following act as barrier defenses against the entry of pathogens into the body?
Definition
Skin, mucus, ciliated epithelial cells, and stomach acid are all examples of barrier defenses that act to prevent the entry of pathogens into the body.
Term
Cholera toxin is an example of a cytotonic enterotoxin. What is a cytotonic enterotoxin?
Definition
a toxin that acts in the gastrointestinal (GI) tract , a toxin that alters host cells without killing them (entero in GI tract, -tonic alters activity vs -lytic which kills)
Term
Certain organisms, for example Salmonella Typhi, are able to establish a state of chronic
carriage in some individuals. What does chronic carriage mean?
Definition
the organism colonizes or establishes inapparent infection in those individuals
Term
Which of the following is/are clinical signs of disease?
Definition
Fever (stuff you can measure)
Term
The Gram-positive bacterium, Clostridium difficile, an obligate anaerobe, can give rise to endogenous infections that result in antibiotic-associated gastrointestinal disease. Which of the following statements about C. difficile is/are correct?
Definition
-presence will always cause disease
-grow best at low oxygen levels
-it's endogenous: meaning it is normally in our intestines but doesn't cause disease until normal bacteria is wiped out by antibiotics

Can colonize healthy people
Term
What happens when a pathogen infects a dead-end host?
Definition
The pathogen cannot be transmitted to a new host
Term
Diphtheria toxin is an example of a cytolytic toxin. What is a cytolytic toxin?
Definition
a toxin that causes cell death
Term
What class of microbial pathogens causes most endogenous infections of humans?
Definition
Bacteria
Term
Which of the following is/are characteristics of organisms that establish exogenous infections in humans?
Definition
They don't colonize humans before infecting them
Term
Which of the following are characteristics of a facultative intracellular pathogen?
Definition
it can grow inside host cells and also outside host cells
Term
Excessive cytokine production causes which of the following immunopathologies?
Definition
Toxic shcok syndrome, Delayed Type hypersensitivity (DTH) reactions, chronic inflammation. (all of the above)
Term
The Gram-negative bacterium, Campylobacter jejuni is generally considered to have a low
infective dose in humans. What does it mean to have a low infective dose?
Definition
only a few organisms are necessary to cause disease
Term
Which of the following mechanisms for local invasion of tissues potentially could be
employed by an obligate extracellular pathogen?
Definition
cytolytic exotoxins are produced by the invading pathogen, hyaluronidase is produced by the invading pathogen
Term
Which of the following types of clinical specimens would not normally contain microorganisms (specimens come from normally sterile sites)?
Definition
blood, cerebral spinal fluid
Term
The Gram-positive, spore-forming bacterium Bacillus anthracis is an obligate pathogen of
humans. What is an obligate pathogen?
Definition
an organism that always causes disease when in a host
Term
In the context of medical microbiology, the term ?Parasite? refers specifically to which of the following?
Definition
any eukaryotic pathogen that is not a fungus
Term
Which of the following may be consequences of a failure by the immune system to resolve an infection?
Definition
death of host, persistent infection of the host
Term
Which of the following are virulence factors commonly found among protozoan parasites?
Definition
adhesins, secreted phos
Term
Which of the following are possible outcomes of viral interaction with a cell?
Definition
infection without cell death, failed infection, latent infection, cell death (all of the above)
Term
Which of the following are routes by which pathogens potentially can disseminate within the body?
Definition
systemic spread of microbe after local invasion at or near PoE, loaclized infection or systemic disease
Term
Which of the following factors determine whether an opportunistic pathogen will cause disease?
Definition
whether the host is immunodeficient, virulence factors, inoculum load of pathogen is high
Term
Among viruses that commonly cause human disease, which of the following virus?host
interactions result in active replication and production of new virus particles?
Definition
infection without cell death
Term
Which of the following are cell?mediated effectors of the adaptive immune system?
Definition
TH1 T cell, cytotoxic T-lymphocyte
Term
Which of the following statements is/are true of the adaptive immune system in humans?
Definition
adapts to microbes/pathogens you're exposed to during life, specifically recognizes molecules, requires times initiated by innate immune system
Term
Which of the following are beneficial effects of local, short?term inflammation?
Definition
immune system effector molecules and cells are delivered to sites of infection
increases drainage of tissue fluid into lymph
generates physical barrier to spread of infection
repair of injured tissue promoted
Term
Which of the following are effector functions of complement small fragments?
Definition
local pro-inflammatory activity, chemoattractant for neutrophils
Term
Which of the following myeloid cell types are granulocytes?
Definition
neutrophils, basophilsm eosinophils
Term
Which of the following strategies is/are used by Coxiella burnetii, the causative agent of Q fever, to prevent it from being killed after uptake into host cells by phagocytosis?
Definition
resistant to environmental changes by  phagolysosomes, low infectious dose, uses type IV secretion system
Term
Which of the following strategies is/are used by Mycobacterium tuberculosis, the causative agent of tuberculosis, to prevent it from being killed after uptake into host cells by phagocytosis?
Definition
prevents formation of phagolysosome
Term
Which of the following strategies is/are used by Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, to prevent it from being killed after uptake into host cells by phagocytosis?
Definition
Bacteria rupture the phagosome membrane and escape into the cytoplasm of the host cell.
Term
Which of the following humoral and/or cellular effectors of the innate immune system
contribute most to the control of infections caused by extracellular bacteria?
Definition
complement
Term
Which of the following humoral and/or cellular effectors of the innate immune system
contribute most to the control of infections caused by viruses?
Definition
none (extracellular)
Term
Which of the following are humoral effectors of the innate immune system?
Definition
complement
Term
Which of the following statements is/are true of the innate immune system in humans?
Definition
Preformed components, early induced, has physical barriers, checkpoints, recognizes limited repertoire of pathogen-specific molecules
Term
Which of the following cell types are leukocytes?
Definition
neutrophils, WBC
Term
Which of the following events occur during a local inflammatory response?
Definition
synthesis of acute phase proteins, influx of phagocytic cells to site of infection
Term
Which of the following cell types of the lymphoid lineage are phagocytic?
Definition
none
Term
Which of the following are effector functions of macrophages?
Definition
phagocytosis and digestion of cellular pathogens and debris
release pro-inflammatory cytokines
release chemokines to attract neutrophils, macrophages, monocytes, lymphocytes
activiate NK cells
Term
Macrophages are a differentiated form of which of the following types of cells?
Definition
monocyte, myeloid lineage
Term
Which of the following molecules can act as opsonins?
Definition
complement large fragments, specific antibodies, acute phase proteins,
Term
Which of the following behaviors may be induced in innate immune system cells upon
detection of pathogen?specific molecules or structures?
Definition
influx of phagocytic cells to site of infection
local inflammation
synthesis of acute phase proteins
Term
Which of the following types of bactericidal molecules are made from scratch in the
phagolysosome of macrophages?
Definition
hydrogen peroxide, superoxide anion, nitric oxide
Term
?/??interferons have which of the following functions?
Definition
antiviral activity, suppress infection
Term
Tumor necrosis factor ? has which of the following functions?
Definition
causes cellular and physiological changes for inflammation, release pro-inflammatory cytokine, activates endothelial cells and causes increased vasuclar permeability
Term
Which of the following signs and symptoms of localized inflammation are caused by
vasodilation?
Definition
heat and redness
Term
Which of the following do the mechanisms of cell killing used by phagocytes and cytotoxic Tlymphocytes have in common?
Definition
cell-mediated immunity
Term
Which of the following kinds of antigens can be recognized by B-cell receptors?
Definition
Proteins
Peptides (small protein fragments)
Polysaccharides (carbs)
Haptens (small molecules of any kind)
Term
Staphylococcus aureus is an encapsulated, extracellular bacterial pathogen that can cause a variety of diseases. Which of the following humoral and/or cellular effectors of the immune system would be most important for clearing S. aureus infections?
Definition
Antibody and Neutrophils
Term
Following vaccination with MMR, which of these humoral and/or cellular effectors of the
immune system would be most important for clearing the virus infections?
Definition
CTLS and Neutralizing Antibodies
Term
Which of the following cell types can present antigens to naïve CD8+ T-cells?
Definition
Plasmacytoid dendritic cells
Term
L. pneumophila is a bacterium that is taken up by macrophages by
phagocytosis. L. pneumophila blocks phagolysosome fusion and grows in the phagosome.Which of the following humoral and/or cellular effectors of the immune system would be most important for clearing L. pneumophila infections?
Definition
    TH1 T cells and activated macrophages
Term
Which of the following vaccines, identified by their abbreviations, are polysaccharide-conjugates?
Definition
Hib, MCV, PCV
Term
Why are conjugate vaccines needed in infants to confer immunity to encapsulated bacteria?
Definition
T-independent antibody responses are not fully developed in infants.
Bacterial capsular polysaccharide antigens require an unusual form of T cell help to genrate a anitbody response. This form of T cell help is not present in infants until age 2
Term
Human immunodeficiency virus (HIV) infects CD4+ T-cells and ultimately kills them. Untreated HIV infection results in the acquired immune deficiency syndrome (AIDS). Which of the following immune system defects in AIDS patients is/are directly caused by the loss of CD4+ Tcells?
Definition
Activation of macrophages by TH1 T cells
phagocytosis of extracellular bacteria by neutrophils
extravasation of monocytes
killing of infected host cells by cytotoxic t lymphocytes
Term
Which of the following statements is/are true of herd immunity?
Definition
It can protect a population against pathogens when not every individual is immune.
It can apply to populations of any kind of organisms
Is not applicable to pathogens that cannot be transmitted horizontally
The specific fraction of the population must be immune for herd immunity to operate varies depending on the shedding and transmission characteristic of the pathogen.
Term
Human papillomavirus type 18 (HPV-18) is sexually transmitted and can establish persistent infections of mucosal epithelia. Following vaccination, which of the following humoral and/or cellular effectors of the immune system would be most important for protecting against HPV-18 infection?
Definition
neutralizing antibodies
Term
Which of the following vaccines, identified by their abbreviations, are polysaccharideconjugates?
Definition
MCV4 and Hib
Term
Which of the following cell types contribute to the maintenance of serum antibody levels after resolution of an infection?
Definition
Long term producer B Cells, Plasma Cells, T Cells
Term
Which of the following applications of epidemiology typically would be used to monitor an ongoing immunization program?
Definition
Data collection
Data analysis
Determine frequency with which disease is observed vs expected in each sement of population
Data from medical records or surveys
Term
Which of the following statements is/are true of immunological memory?
Definition
It is conferred in part by pools of antigen specific memory T cells
Memory B cells do not secrete antibody
Activation of naïve b cells are suppressed during second exposure to antigen
Term
Why does the number of microbes present in the body keep increasing during the early phase of a typical adaptive immune response?
Definition
The innate immune system has failed to control the infection
Time is required for clonal expansion of lymphocytes to take place
Humoral and cell mediated effectors of the adaptive system have not yet been produced in sufficient numbers.
Term
Which of the following are features of the immune response to a secondary antigenic
challenge?
Definition
Memory B cells reactivated
IgG is produced before IgM
Antigen specific memory T-cells will be reactivated
Secondary response occurs faster than primary
Term
Against which of the following vaccine-preventable diseases is/are the U.S. general public immunized routinely?
Definition
Hib
PCV
HPV
IPV
DtaP
Hep A
Hep B
Rv
Influenza
MCV4
MMR
Varicella
Term
Which of the following vaccines, identified by their abbreviations, contain infectious (live)
viruses?
Definition
Varicella Zoster
Term
Which of the following diseases is the Tdap vaccine intended to prevent?
Definition
Diphtheria, tetanus, pertussis
Term
Which of the following immune responses is/are defective in patients who have AIDS?
Definition
no TH1 or TH2
Term
Which of the following humoral and/or cellular effectors of the immune system would be most important for clearing L. pneumophila infections?
Definition
TH1, CTL, NK
Term
Which of the following is/are characteristics of an inapparent infection?
Definition
Fever, Inflammation, flu like symptoms
Term
Which of the following are possible outcomes of infection with hepatitis B  virus?
Definition
Cirrhosis of the liver and hepatocellular carcinoma associated with chronic infection by hepatitis B virus. ( develop long-term sequelae/ persistent infection)
Term
Which of the following is/are characteristic of organisms that establish endogenous infections in humans? 
Definition
a. Endogenous infections are caused by microbes that normally colonize the host.

b. Amoung the four classes of pathogens, only bacteria and fungi normally colonize humans, and bacteria are by far the most common to cause endogenous infections.
Term
The Gram-negative bacterium, Vibrio cholerae generally is considered to have a high infective dose in humans. What does it mean to have a high infective dose?
Definition
A lot of bacteria have to be ingested in order to cause disease
Term
Which of the following factors contribute to pathogenesis (disease causation) for all types of microbial pathogens (bacteria, viruses, fungi, and parasites)?
Definition
virulence factors


inflammation

cytotoxins

antigenic variation

interference (e.g reduces expression of MHC 1 on infected viruses)

stealth (hiding from immune system )

misdirection of immune responses
Term
Which of the following cell types is/are involved only in antigen-spcific immune responses?
Definition
a.
T-lymphocytes and B-lymphocytes
Term
People with liver damages have reduced capacity to control infection by a number of bacteria and fungi. Which of the following immune systemcomponets would you expect to be affected directly by liver damage?
Definition
a. Macrophages activated in the liver and spleen screte TNF-a into the bloodstreem; this induces a local protective effect. Macrophages release TNF-a. Systemic infection with gram-neg bacteria: sepsis.
Term
After encontering a pathogen in perifperal tissues, plasmacytoid dendritic cells do which of the following?
Definition
a. They are lymphoid lineage

Although not part of the phagocytic effector response of the immune system, plasmacytoid dendritic cells, in common with myeloid dendritic cells, use phagocytosis to sample antigens from pathogens. Peptides generated inside the vacuolar compartment are displayed by MHC II molecules on the surface of the dendritic cell. These peptide antigens are then presented to CD4 + T-cells to initiate adaptive immune responses.

None of the other lymphoid cell types is phagocytic.
Term
Which of the following cell types can activate macrophages?
Definition
T-lymphocytes (TH1 Cell)
Term
What two types of signaling molecules are secreted by macrophages when they detect bacteria?
Definition
a. cytokines and chemokines.
Term
What is the purpose of clonal deletion during lymphocyte development?
Definition
a. developing lymphocytes that are poteintally self-reactive are removed before they can mature.
Term
What is the purpose of clonal expansion during an adaptive immune response?
Definition
a. in Activated immunity the proliferatoino and differentiation of activated specific lymphoyes to form a clone of effector cells ; effector cells eliminate antigens.
Term
If a person is exposed to rabies virus via a bite wond, what class (es) of antibody directed against the virus would be most likely to prevent systematic spread of the infection?
Definition
a. IgG and IgA
Term
Vibrio Cholerae O1 is an extracellular pathogen that causes disease without invading tissues. What class (es) of antibody directed against V. cholerae O1, or its exotoxin, would be able to protect against infection by the bacterium?
Definition
a.  IgG, IgA
Term
Which of the following are factors that might predispose an affected person to

Chromobacterium violaceum infection?
Definition
host immune system weakened

microbe gains access to normally sterile sites

large inoculum size

microbe has virulence factors
Term
Which of the following strategies may be used by intracellular pathogens to avoid being killed following phagocytosis into macrophages?
Definition
polysaccharide capsule

enzymes capable of lysing phagocytic cells

blocking phagolysosome fusion
Term
Which of the following are effector functions of complement large fragments?
Definition
Get cross linked onto target cell membrane (limits diffusion), prevents collateral damage, opsonize bacteria (makes them susceptible to bacteria).
Term
Which of the following are characteristics of a pathogen-associated molecular pattern?
Definition
receptors of PAMPS are invariant

are signatures of broad classes of pathogen

are detected by binding to host cell receptors or to secreted molecules.

are souble (diffusible) molescules like fMLF and LPS
are part of pathogen surfaces repeating mannose-fucose units in bacterial cell walls.
Term
Which of the following types of leukocytes may undergo extravasation at a site of local inflammation?
Definition
a. neutrophils  and macrophages are the principal inflammatory cells.
Term
Which of the following important molecules of the innate immune system are involved in attracting leukocytes to sites of infections?
Definition
a.
Dendrtic cells
Term
Which of the following are among the microbial cell killing mechanisms used by phagocytes?
Definition
engulfment of microbe in a phagosome

phagosome acidifies and fuses with lysosome

acidification

formation of toxic oxygen

formation of toxic nitrogen oxides

antimicrobial peptides

enzymes

competitors
Term
  Which of the following cell types can present antigens to CD8+ T-Cells?
Definition
a. MHC class I, dendritic cells
Term
Mycobacterium tuberculosis is an intracellular pathogen that infects macrophages. Which of the following humoral and/or cellular effectors of the immune system would be most important for combating infection by M. tuberculosis ?
Definition
Natural Killer Cells
Term
Clostridium tetani is an extracellular pathogen that can cause systemic disease, even though it does not invade tissues. What class(es) of antibody directed against C. tetani , or its exotoxin, would be important for preventing tetanus?
Definition
IgA
Term
Which of the following cell types can activate B cells to produce antibody? 
Definition
a. Professional antigen presenting cell. pg. 343/Native B Cells
Term
Unlike Vibrio cholerae, the related extracellular bacterium Vibrio vulnificus can cause invasive disease (septicemia). What isotype(s) of antibody generated in response to infection would contribute to the control of V. vulnificus invasive disease, but not to the control of V. cholerae infection?
Definition
IgM and IgG
Term
Where in the body would activated dendritic cells most commonly be found?
Definition
peripheral tissue
Term
After encountering a pathogen in peripheral tissues, myeloid dendritic cells do which of the following?
Definition
Bind and phagocytose any pathogen molecules (antigens), migrate to afferent lymphatics, and then go to the nearest lymph nodes
Term
In which of the following places in the body would macrophages be found?
Definition
Peripheral Tissue
Term
In which of the following places in the body would naïve lymphocytes be found?
Definition
Efferent lymphatics, blood, lymph node
Term
Which of the following drug-resistance mechanisms is/are found only in bacteria?
Definition
Drug Inactivation
Term
In which of the following classes of pathogen does antimicrobial drug resistance occur by enzymatic inactivation of the drug?
Definition
Bacteria
Term
In which of the following classes of pathogen does antimicrobial drug resistance occur through mutations in target enzymes that prevent drug binding?
Definition
Fungi, Parasites, Bacteria, and Viruses (all of them)
Term
Which are examples of immediate actions that might be taken by public health authorities in response to case of a reportable disease?
Definition
Isolation, Restriction, Emerging Pathogen Surveillance, PEP of Case Contacts Needed, and             Contact Tracing
Term
Which of the following diseases should be reported immediately to the local
health department if they are suspected by a physician in North Carolina?
Definition
Anthrax, Botulism, Plague, Smallpox, Tulgaremia, Novel Influenza, and Hemorrhagic Fever Virus
Term
A pos. PPD skin test for tuberculosis involves which of the following humoral and/or cellular effectors of the adaptive immune system?
Definition
Cytokines
Term
For which of the following types of infectious disease would supportive care alone be an appropriate treatment?
Definition
For diseases where treatment doesn't improve outcome or noncurative diseases such as Ebola/Hemorrhagic Fever and HUS
Term
What type of infections is combination therapy with antimicrobial agents intended to treat?
Definition
Persistent Infection
Term
Which of the following potentially could be a curative treatment for an infectious disease?
Definition
Antimicrobial agents or Surgical Treatment
Term
Which of the following types of test results might help a clinician to refine a differential
diagnosis?
Definition
Blood work, acid fast test, gram stains, culture, serology (ELISA), PCR, PPD, or Chest X-Rays
Term
In which of the following places in the body would naïve lymphocytes encounter their antigen for the first time?
Definition
Lymph nodes
Term
Which of the following types of intracellular pathogens would be expected to enter cells by phagocytosis?
Definition
Bacteria, fungi, or parasites
Term
Which of the following types of intracellular pathogens would be expected to enter cells by endocytosis?
Definition
viruses
Term
Which of the following are effector functions of terminal complement components?
Definition
Signal for help, pro-inflammatory signal, and enhances phagocytosis
Term
Which of the following are effector functions of neutrophils?
Definition
Act as phagocytes
Term
Which of the following are effector functions of natural killer cells?
Definition
kill any abnormal host cells
Term
Which of the following are similarities between the cell killing mechanism utilized by the complement system and that of natural killer cells?
Definition
Both create pores in target cell's cell membrane
Term
In which of the following places in the body would monocytes be found?
Definition
Peripheral tissues
Term
Which of the following are potential targets of antimicrobial drugs?
Definition
growth and actual microbe
Term
Which of the following mechanisms can lead to drug resistances in viruses?
Definition
target alterations
Term
Which of the following are components of cough etiquette (respiratory hygiene)?
Definition
Cover mouth and nose when you sneeze
cough into tissue, sleeve, but not hand
discard used tissues into waste container
washing hands with soap and running water
practice hand hygiene afterwards
Term
Which of the following pathogens are transmitted by the airborne route?
Definition
    ?  Measles virus
  ?  Tuberculosis
  ?  Varicella Zoster
Term
Against which of the following diseases could herd immunity help to protect a human
population?
Definition
Whopping cough, pertussis
Term
Which of the following are considered to be vertical routes of pathogen transmission?
Definition
Spread of infection from mothers to newborns
This can occur across the placenta during pregnancy (placental fetal)
during process of giving birth (maternal parturition)
after birth when pathogen is passed from mother to newborn (maternal neonatal)
Term
Which of the following is/are characteristics of most pathogens that are maintained in humans?
Definition
Infect only humans,
Term
In public health, which of the following is/are control measures that would be implemented only in response to an outbreak of disease?
Definition
Recall of contaminated food
Isolation orders and quarantine orders
Post exposure prophylaxis
Term
Which of the following may be vectors for human pathogens?
Definition
Ticks, Fleas, Mosquitoes
Term
Which of the following statements is/are true of zoonotic infections?
Definition
They are always caused by pathogens that have animal reservoirs
Infections that are transmitted to humans from a vertbrate, non-human reservoir
can occur with direct or indirect contact
unable to be transmitted from human to another human
Term
Use of disinfectant would be appropriate for which of the following?
Definition
Reducing microbial contamination of surfaces
Term
Which of the following types of pathogens are most likely to be transmitted vertically by the maternal-parturition route?
Definition
Pathogens transmitted horizontally by urogenital sexual route
Term
Which of the following constitute active surveillance for disease outbreaks?
Definition
Real time monitoring by public health agencies of hospital admission data and sentinel sites
Term
Which of the following characteristics would enable a pathogen to be transmitted efficiently to naïve hosts?
Definition
It becomes airborne in respiratory droplet nuclei