Among the virulence factors produced by staphylococcus aureus are hemolysin, coagulase, hyaluronidase, and enterotoxin. Which of these factors contributes to the ability of S. aureus to invade the body?
What feature of the skin creates a physical barrier to microbial invasion?
The outer layers are dead cells, lightly linked together,man dare frequently shed
A small amount of antigen is injected under the skin of a patient. After 30 minutes there is no apparent change at the injection site, but 36 hours later the patient reports that the area is red and swollen. This type of response is due to
Type lV hypersensitivity
Which complement protein is the key to activating the alternative pathway of complement activation?
Which of the following molecules would contain T-independent antigens?
The syndrome known as AIDS is characterized by
One or more opportunistic diseases and the presence of HIV
A person comes to the clinic complaining of aching joints and muscles, swelling, and a decrease in urine output. The clinicians also notes a rash on the skin of the face. A probable diagnosis is
Systemic lupus erythematosus
Toxoid vaccines are commonly used when?
Immunity to the toxins produced by a pathogen is sufficient to prevent disease
First line of defense may be described as?
Intact skin, mucous membranes, sebum,tears and so forth
What type of immunity is produced by the body when a person contracts a disease?
Naturally acquired active immunity
After an initial exposure to a pathogen, the phenomenon of ______ produces a faster, more effective response to subsequent exposures.
Phagocytes are brought to a site of infection by?
Detection of chemokines and complement factor gradients
The close contact between newborns and family members allows them to become _____ with microbes that become established as their macrobiota.
Which of the following pairing of microbe and disease was disproven using Koch's postulates?
Haemophilus influenza and the flu
Which of the following pairs of lymphocyte and glycoprotein is mismatched?
An agricultural worker experiences difficulty breathing, which becomes progressively worse. Tests show inflammation and damage of the lung tissue, but IgE antibodies and granulocytes are in the normal ranges. With which disorder of the immune system are these signs and symptoms consistent?
Type III ( immune complex-mediated) hypersensitivity
Which of the following statements regarding the demonstration of the etiology of disease is FALSE?
The suspect agent must be the only potential pathogen present in disease cases
Variolation was first used?
To immunize the Chinese against smallpox
A new virus is discovered that causes cells to clump together. Which of the following types of assay would be useful for diagnosing infection with this virus?
Which of the following types of epidemiology applies Koch's postulates to study a disease?
A person is exposed to desert air containing fungus spores and develops valley fever as a result. Valley fever is an example of a ______ disease.
Which of the following combinations of pathogen and virulence factor is correct?
Streptococcus pyogenes and protein M
Viral neutralization testing is based on the fact that
Viruses introduced into appropriate cell cultures have a cytopathic effect
Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders?
The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.
Primary immunodeficiency diseases
Are detectable close to birth
The Fc portion of an antibody is formed by
Portions of both of the heavy chains only
Which of the following iron-binding proteins is NOT part of the body's iron storage and transport system?
How is the development of autoimmunity normally prevented?
Colonal deletion of T cells, lack of necessary cytokine signals, and regulatory T cell suppression prevent activation of autoreactive T cells.
Serologic tests for diagnoses of disease may detect
Either antigens or antibodies specific for certain antigens
The components of the second line of defense against microbes may be characterized as
Responders to invasion
Anti- human antibodies (specific for human IgG antibodies) with fluorescent molecules covalently attached are used for
Both indirect ELISA and indirect fluorescent antibody tests
Graft rejection can be reduced by
Preventing T cell proliferation
Leukocytes migrate to a site of infection in response to
Which of the following components of antigen processing is mismatched?
Endogenous antigen: MHC ll
Which of the following statements regarding inactivated vaccine is correct?
It is safer than attenuated vaccines
Protection from infection known as species resistance is a result of
Both the absence of necessary receptors and lack of suitable environment in the body.
Which of the following statements is TRUE of eosinophils?
They secrete toxins onto the surface of helminth parasites
Vomiting is a common sign of food poisoning. The corresponding symptoms would be
The name systemic lupus erythematosus refers in part to the distinctive rash resulting from
Antibody-antigen complexes accumulating in the skin
Which of the following is NOT an example of symbiosis?
Microbes passing across the placenta to the fetus
Phagocytic cells in the epidermis known as _____ contribute to its ability to prevent microbial invasion.
Which of the following characteristics is shared by the skin and mucus membranes?
They are both constantly shedding and replacing cells
The taxonomic approach to classifying disease is based on the
Type of microbe that causes the disease
Type 1 helper T(Th1) cells produce ______ to stimulate increased phagocytosis,
Gamma interferon (INF-y)
A young woman comes into the clinic complaining of itchy, red skin and swelling on her arms and legs. She had not been in any parks of wooded areas recently, but she had been shopping. A blood sample reveals elevated levels of granulocytes. What treatment is the physician likely to prescribe at this point?
Subjective characteristics of a decease that only the patient can feel
Which of the following statements concerning rheumatoid arthritis (ra) is True?
Accumulations of antibody complexes lead to inflammation in and destruction of the joints
Which of the following is the key difference in the roles of the classical and alternative pathways of the complement system?
The range of microbes types that can be targeted
What is the function of NK cells?
They identify and poison virus- infected cells
The incidence of tuberculosis in the year 2000 in the United States was 12.43/100,000 cases. This means
There were 12.43 new cases of tuberculosis for every 100,000 people in the United States in the year 2000
An infectious disease researchers isolates the pathogen responsible for an emerging disease. The microbe is grown in the lab for many generations. A preparation of the laboratory- grown microbe is treated with ionizing radiation and then tested for its potential as a vaccine. What type of vaccine is this?
During a visit to a hospital, a child receives the oral polio vaccine. He then returns to his distant village. Sometime later a polio outbreak occurs in the village, but the child and his siblings, who had not had the vaccine, are spread. What is the explanation for this event?
Fever is beneficial during viral infections because the higher temperature?
Increases the effectiveness of interferons
Tissue samples can be tested for pathogen using _______ assays.
Direct fluorescent antibody
How is hemolytic disease of the newborn prevented?
Administering anti-Rh IgG late in pregnancy and after pregnancy ends
When immunization levels in a population are high, ________ provides protection from infection for at-risk persons who cannot be immunized.
Several days after a walk in the woods, Cheryl develops a localized rash. It is not painful and soon fades so she thinks nothing of it. Several months later she experiences increasing fatigue, low-grade fever, and a pain in the joints. These symptoms persist for months before she seeks medical attention. This description is most consistent with an ______ infection.
Which of the following is transmitted by the parental route?
Which of the following is the best definition of "microbial antagonism"?
The presence of normal macrobiota that protect the body by competing with pathogens in a variety of ways to prevent pathogens from invading the body
Diseases that are induced by modern medical procedures are referred to as _______ infections.
Treatment with high doses of antibiotics may lead to which types of health care associated infection?
Titration is a serological procedure that
Determines the amount of an antibody in the blood
Organisms that are resident microbiota are best described as
Microorganisms that remain with the person throughout life