microbiology unit 3 Exam
The antibody-secreting progeny cells of a B-cell clone are called
plasma cells.
The circulating substances that affect the hypothalamus and initiate fever are
pyrogens.
class 2 MHC genes code for
receptors located primarily on macrophages and B cells
Allergies run in families because
relative production of IgE is inherited
The adaptive immune response differs from the innate response in that
the adaptive immune response targets specific immunogens and remembers them, mounting an even stronger response on subsequent encounters, whereas innate response is nonspecific and has no memory
In order for B cells to produce antibodies and cytotoxic T cells to attack infected host cells, they must first
undergo maturation, encounter their specific antigen target, and then become activated through citokines
You have received the first hepatitis A vaccine. It was required for your mission trip to Nicaragua in Central America, where hepatitis A is common. However, you never went back for the booster shot of the vaccine, which should have been received within 6 months of the initial vaccination. What statement accurately reflects your present immunity to this pathogen?
you are at risk to get hepatitis A since your immune system status is only partial. Not enough immune memory cells were produced sincr you received kne dosage of vaccine, so you are likely to get the disease when exposed to the virus.
Not all phagocytic cells are antigen-presenting cells. B cells, macrophages, and dendritic cells differ from neutrophils in that they synthesize
MHC II receptors
A urine specimen obtained from a patient went to the microbiology lab for a bacterial culture and antibiotic sensitivity testing. The specimen sat out on the processing counter for a couple of hours before being cultured. Twenty four hours later, the lab report goes into the computer-over 100,000 bacterial cells per milliliter of urine. Which statement is an accurate assessment of these results?
The bacterial count is not accurate since the culture sat without refrigeration.
an example of epigenetic change is
a microbe that can induce changes in host DNA, resulting in suppression of defenses or weakening of individual cells
As an adult who never developed chickenpox infection as a child, you elect to receive the protective vaccine against this pathogen at the age of 35. This vaccine will stimulate:
a primary immune response
Live, attenuated vaccines -include the sabin polio vaccine -include the measles, mumps. rubella vaccine (MMR) -contain viable microbes that can multiply in the person -require smaller doses and few boosters compared to inactivated vaccines -all of the choices are correct
all of the choices are correct
resident biota are found in/on -skin -mouth -nasal passages -large intestines -all of the choices are correct
all of the choices are correct
The primary advantage of genotypic analysis for identification is that
culturing of the organism is not required.
A laboratory technologist splashed a blood specimen onto his face, eyes, nose, and mouth. This specimen was from an HIV positive patient. If this blood exposure leads to HIV infection in the technologist, the transmission route is
direct
If you were a bacterial cell, which of the following would be the most beneficial for you to have or be able to make for the survival of your species?
endospores
all of the following can result in acquired immune deficiency except
enzyme deficiency
which of the following is not a normal portal of an infectious disease? -coughing and sneezing -skin -all of these choices are normal exit portals -removal of blood -urogenital tract and feces
All of these are normal exit portals.
What may result when grafted tissue such as bone marrow contains passenger lymphocytes?
Graft versus host disease
Which of the following is not true of type 3 hypersensitivity? -the Arthus reaction is a local response -it involves an immune complex reaction -it involves production of IgE antibodies -Serum sickness is a systematic response -Antigen-antibody complexes are deposited in the basement membrane of epithelial tissues
It involves production of IgE antibodies
a patient enters your clinic with a suspected helminth infection. in support of this diagnosis, you suspect elevated levels of which antibody in the patient's serum?
IgE
Which is incorrect about the Fc region of an immunoglobulin?
It forms the antigen binding sites.
The infectious doses for various bacterial infections are listed in the table below. which of these bacteria would likely have the greatest virulence? *bacterium-infectious does *Mycobacterium tuberculosis-10 *Neisseria gonorrhea-1,000 *Vibrio Cholerae-1,000,000,000 *Salmonella enterica-10,000
Mycobacterium tuberculosis
A patient's vaginal specimen is sent from the walk-in clinic to thr microbiology laboratory. There it is cultired on bacteriological media and then placed into an ambient air incubator set at 22% oxygen and 37 degrees Celcius. The patient is strongly suspected of having gonorrhea. She had sexual contact with a partner recently diagnosed with gonorrhea, and now she is displaying the typical symptoms of a vaginal exudate or fluid. Neisseria gonorrhea is a microaerophillic gram-negative coccus-shaped bacterium. Seventy-teo hours later, the culture has still not grown Neisseria gonorrhea so the lab reports the results back as negative. Interpret this result.
The culture was placed into the wrong environment for Neisseria gonorrhoeae.
Which of the following is not true regarding healthcare-associated infections? -Eschecheria coli and staphylocci are common infectious agents -Medical and surgical asepsis help lower their occurrence -these infections often involve the patient's urinary tract and surgical incisions -the patient's resident biota can be the infectious agent -these infections are only transmitted by medical personnel
These infections are only transmitted by medical personnel.
Which of the following statements does not represent the role of a cell marker in the third line of defense?
They serve as transcription factors to initiate antibody production.
When would Koch's postulates be utilized?
To determine the cause of a new disease in a microbiology research lab
an example of natural passive immunity would be
a fetus acquiring maternal IgG to the chickenpox virus across the placenta.
SCID is defined by a lack of funtional B and T vells which eliminates protection by humorap and cell- mediated immunity. Which of the following is true? -a genetic mutation renders the individual incapable of removing a toxic DNA metabolite from lymphocytes, which ultimately destroys them -genes that code for interleukin receptors are mutated so the individual's B and T cells do not receive the activation signals, rendering them useless -all of the choices describe cases of SCID -Genes coding for B and T cell receptors are mutated so the cells are incapable of binding antigens -a genetic defect disrupts the development of the lymphocytic cell lines
all of the choices describe cases of SCID
The Centers for Disease Control and Prevention mandates that some diseases must be reported, while it is not necessary for others. This is so that -statistics may be gathered for certain diseases -.the incidence and prevalence for diseases of public health importance can be tracked -.disease trends and areas of outbreak can be monitored for certain diseases. -high-risk epidemics can be identified and dealt with as quickly as possible. -all of these choices validate why it is important to report certain diseases to the CDC
all of thede choices validate why it is important to report certain diseases to the CDC
antigen presenting cells -includes macrophages -includes dendritic cells -engulf and modify anrigen to be more immunogenic -hold and present processed antigen on their cell surface -all of these choices are correct
all of these choices are correct
lymphocytes -gain tolerance to self by destruction of lymphocytes that could react against self -develop into clones of B and T cells with extreme variations of specificity -have membrane receptors that recognize foreign antigens -possess MHC antigens for recognizing self -all of these choices are correct
all of these choices are correct
The serum of a person with blood type A and Rh- will have the ability to make which of the following antibodies?
anti-B and anti-Rh
You cut your finger dicing chicken for dinner. Which of thr following is not a source of chemicals that stimulate the inflammatory response that results from the injury?
antibody-producing plasma cells
Exotoxins
are secreted by pathogenic organisms
based on new information from thr Human Microbiome Project, the human body typically begins to be colonized by its normal biota
before birth; in utero
What will be the immediate action of an allergen when it enters the body for a second time?
binding of allergen to adjacent IgE binding sites on mast cells and basophils
Which type/s of hypersensitivities is IgG involved with?
both antibody mediated and immune complex mediated
Due to efforts by the federal government and healthcare facilities from 2008-2013, the number of HAIs has decreased in all areas except which of the following?
catheter-associated UTIs
which of the following is not a chief function of inflammation? -destroy microbes -cause a fever -start tissue repair -block further Invasion -mobilize and attract immube components to injurt site
cause a fever
an example of natural active immunity would be
chickenpox infection followed by lifelong immunity.
an example of artificial active immunity would be
chickenpox vaccine triggers extended immunity to chickenpox.
John Snow famously traced a London outbreak of chloera to a pump on Broad Street. This cholera outbreak was an example of a _________ epidemic.
common-source
The mononuclear phagocyte (MPS) is an intricate network throughout the body that comprises
connective tissue fibers and phagocytic white blood cells.
the potential for hemolytic disease of the newborn occurs when
fetal Rh+ cells enter an Rh- mother
depending on the organism, direct examination of a specimen is often the most rapid diagnostic tool used in the clinical microbiology lab. you have a sample of pus from a patient's penis. what will be the easiest test to confirm that the patienr has gonorrhea?
gram-stain
Which of the following pair's is mismatched? -transfusion reaction-Type II hypersensitivity -hay fever-Type IV hypersensitivity -serum sickness-Type III hypersensitivity -Food allergy-Type I hypersensitivity -Poison Ivy dermatitis-Type IV hypersensitivity
hay fever - type IV hypersensitivity
John, a Peace corps worker in the country of Mali in Africa, was in a car accident while traveling through a rural area. He was treated at a tiny rural hospital, and due to his loss of blood. he required a transfusion. John has B- blood type and has never received a transfusion before. Which statement is correct regarding this scenario?
he can safely receive O- blood even though he makes anti-A antibodies
Diseases can re-emerge for a variety of reasons. Evaluate the following statements and choose the one that does not provide for a re-emergence.
humans have avoided animal habitats
edward jenners work involved
immunization using a related, less pathogenic organism to give protection against a more pathogenic one.
Mycobacterium tuberculosis has traditionally been identified in patient samples using biochemical tests, and more recently through DNA probe analysis. In vivo testing can also be completed using the tuberculin skin test. A more recent test that seems to be surpassing the others is Quantia-FERON-TB gold test. Blood samples are mixed with protein antigsns of M. tuberculosis. After 16 to 24 hours of incubation, the amount of cytokine interferon produced by the patient's cells is measured. If the patient is infected with M. tuberculosis, their WBCc will release interferon in response to contact with the tuberculosis protein antigens. This test falls under which category of identification tests?
immunologic test
Histamine causes all of the following except
increased sensitivity to pain
An endotoxin is
indicative of gram-negative bacterial infection
Local edema, swollen lymph nodes, fever, soreness, and abscesses are indications of
inflammation
What is the first step in the major events of the inflammatory process?
injury and mast cells releasing chemical mediators
During presentation of APC-bound antigen, macrophages and dendritic cells secrete the cytokine _________, which activates T helper cells.
interleukin-1
Bacterial toxins are chemical products made by bacteria. A person ingests some honey containing Clostridium botulinum. The C. botulinum is actively growing and releases toxin in the honey. The person becomes ill from ingesting the toxin. This is an example of a/an
intoxication
all of the following pertain to interferon except -it inhibits capillary permeability and vasodilation -it is produced by certain white blood cells and tissue cells -it is a protein -it includes alpha, beta, and gamma types it inhibits viruses, tumors, and cancer gene expression
it increases capillary permeability and vasodilation.
Which of the following is incorrect about complement? -it involves a classical pathway -it is composed of at least 20 blood proteins -it involves an alternate pathway -it acts in a cascade reaction -it only appears in the blood during a response to a pathogen
it only appear in the blood during a response to a pathogen
phenotypic testing is often beneficial in identifying infectious agents from patient samples; however, some disadvantages include
lengthy culturing times and the inability to grow some bacteria in vitro
which of the following statements below represents the correct order of events in the adaptive immune response?
lymphocyte development, antigen presentation, lymphocyte challenge, lymphocyte response
When monocytes migrate from the blood out to the tissues, they are transformed by inflammatory mediators to develop into
macrophages
Your patient has a rash, a fever, and a very high white blood count. Blood specimens are taken, put into culture bottles, and sent down to the microbiology lab for incubation and analysis. Select the statement that vest reflects why microbial analysis of blood is an important step in patient diagnosis.
microbial growth in blood samples may indicate sepsis
After loading wood into a fireplace, you realize you have gotten a splinter in your finger. Within a short period of time, your finger is painful, red, and swollen, and is warm to the touch. Yhis is an example of
nonspecific resistance
Which statement about clinical identification tests are true?
not all diseases are identified by clinical tests.
the difference between the terms pathogenicity and virulence is that
pathogens cause disease and virulence describes the degree of pathogenicity
Cytotoxic T cells
secrete granzymes and perforins that damage target cells.
Class 1 MHC gene codes for
self receptors recognized T lymphocytes
the initial encounter with an allergen is called the _______ dose.
sensitizing dose
You would like to identify as many bacterial species as possible in the human mouth. Why is biochemical testing not the most efficient and accurate method of completing this task?
since you do not know the growth characteristics and metabolic properties of the bacteria in the mouth, you cannot determine all varieties of media to use for isolation and culture
A patient visits your clinic with recurrent respiratory infections. Based upon their medical history. it appears they have been an active smoker for over 40 years. select the statement that most accurately reflects how this information may reveal why the patient is highly susceptible to respiratory pathogens.
smoking can paralyze the ciliary escalator.
which of the following is not a factor that weakened host defenses against infections? -physical and mental stress -chemotherapy -strong, healthy body -genetic defects in immunity -old age
strong, healthy body
you have dermatitis triggered by a particular material in your socks. your feet are covered with a really itchy rash. which has developed blisters over the last day or so. you had first worn them two or three days ago, and you did not launder them after buying them at the store. Finding some antihistamine medication in your bathroom cabinet. you decide to take it to relieve the itching rash. Which statement is true?
the anti-histamine will have no effect on the rash because histamine is not ghe chemical mediator in this hypersensitivity.
one of the major differences between the first and second line of defense is that
the first line defenses are anatomical barriers whereas the second line defenses are mechanisms.
In systematic lupus erythematosis (called lupus), complexes of antibody and antigen form, and these immune complexes insert themselves into small blood vessels, joints, heart, and kidney, causing damage to the organ tissue. The course of the disease is unpredictable, with periods of illness alternating with remissions. How is lupus, a type 3 autoimmune disease. similar to the tuberculin reaction, a type 4 hypersensitivity reaction?
the mechanism of both lupus and the tuberculin reaction involve large amounts of inflammatory chemicals released into tissue
Which of the following is incorrect about blood cells? -they include leukocytes that are either granulocytes or agranulocytes -they include glial cells -after birth, they are produced in red bone marrow sites -they develop from undifferentiated stem cells -they include erythrocytes that, when mature, lose their nuclei
they include glial cells
You are studying a newly identified infectious disease within a population. Think of the typical graph of the course of infection--incubation period through to convalescent period. The new disease reveals a course of infection characterized by fluctuating symptoms, with intermittent periods of invasion (acute period) between prodromal periods. The whole course of infection occurs over a period of months or even years. Based upon the information presented, select the statement that most accurately reflects this new infectious disease.
this infectious disease exhibits latency
you do not really want to get your 3 children vaccinated. Your view is why do it when others around you will get the vaccine and end up protecting you and your children. Which is an accurate statement that your physician may provide to you in response to your challenge to vaccination?
this is not a smart choice. if enough people choose not to get vaccinated, the susceptible population grows to a large size, breaking the protective effect of herd immunity