GTC MICROBIOLOGY COMPREHENSIVE EXAM UPDATED
QUESTIONS AND ANSWERS GRADED A+
✔✔What does it mean that the disease ofter is "subclinical?" - ✔✔The disease may go
unnoticed because of the absence of symptoms, even though clinical tests reveal signs
of disease.
✔✔Name the causative agent in plague: - ✔✔Yersinia pestis
✔✔What is a buboe? - ✔✔Buboes are smooth, enlarged, reddened, and painfully
inflamed lymph nodes.
✔✔How does transmission occur? - ✔✔Fleas are the vectors for the spread of the
bacteria. Infected fleas that have left their normal animal hosts can spread plague to
humans.
✔✔What type of plague has the highest mortality? - ✔✔pneumonic plague: spread to
lungs (or through inhalation)
✔✔Can plague be treated? - ✔✔Yes, streptomycin and tetracycline are effective
against Yersinia.
✔✔Name the bacteria that cause Lyme disease? - ✔✔Borrelia burdorferi (gram - rod)
✔✔How is it transmitted? - ✔✔ticks (biological vector)
✔✔Is a bull's eye rash always seen? What is that? - ✔✔No, 80% of patients have the
bull's eye rash at the site of infection. It is erythema migrans.
✔✔Can it be treated? - ✔✔Yes, penicillins, tetracyclines, or cephalosporins are effective
in the first phase, later phases are difficult to treat.
✔✔What are some late manifestations of the disease? - ✔✔headache, fatigue, in small
% nervous (CNS) and cardiovascular symptoms, eventually chronic arthritis
✔✔How is Rocky Mountain spotted fever transmitted? - ✔✔ticks (biological vectors)
✔✔Which bacterium causes the disease? - ✔✔Rickettsia
✔✔What type of rash is seen? - ✔✔subcuaneous hemorrhages known as petechiae
✔✔What are other symptoms? - ✔✔fever, headache, chills, muscle pain, nausea and
vomitting
,✔✔How serious is the disease? - ✔✔Early diagnosis is crucial because prompt
treatment often makes the difference between recovery and death. It is impossible to
eliminate the ticks in the wild, in part because they can survive without feeding for more
than four years.
✔✔What is the cause of "mono?" - ✔✔Bacteria = Epstein Barr Virus; "Mono" is a result
of a patient's cellular immune system with an infected WBC.
✔✔Which cells are involved? - ✔✔After initially infecting epithelial cells of the throat and
salivary glands, Epstein-Barr virus enters the blood, where it invades B lymphocytes
(WBC).
✔✔Characterize the virus that causes this disease: - ✔✔EBV is an enveloped, double-
stranded DNA virus that replicates in a host's cell's nucleus.
✔✔Why is this called a "persistent" infection? - ✔✔virus can invade many organs (liver,
myocarditis, glomerulonephritis)
✔✔How is it transmitted? - ✔✔Transmission of Epstein-Barr virus usually occurs via
saliva, often during the sharing of drinking glasses or while kissing. Infectious
mononucleosis is commonly known as the "kissing disease".
✔✔What is the cause of Burkitt's Lymphoma? - ✔✔EBV suppresses apoptosis
(programmed cell death) of B lymphocytes, causing infected cells to become immortal.
In combination with a suppressed immune system, such infected B cells are one source
of cancers, like Burkitt's lymphoma, a cancer of the jaw.
✔✔What are the signs? - ✔✔1) sore throat, fever, enlarged lymph nodes, many other
varied symptoms
2) "persistent" infection: virus can invade many organs like the liver, heart (myocarditis),
and kidney (glomerulonephritis)
✔✔Who is most at risk for CMV infections? - ✔✔Fetuses (teratogenic) and
immunocompromised patients are susceptible to severe complications of CMV infection.
Newborns may develope hepatomegaly, splenomegaly, hearing\visual problems, and
CNS involvement. Immunosuppressed adults may develope pneumonia or systemic
diseases.
✔✔What does CMV stand for? - ✔✔Cytomegalovirus
✔✔What does it mean that this disease is often "subclinical?" - ✔✔"Subclinical" refers
to the fact that CMV, while remaining in a latent state, does not have clinical symptoms
until the immune system is compromised.
✔✔Name three viral hemorrhagic fever: - ✔✔1) Dengue fever
, 2) yellow fever
3) Ebola hemorrhagic fever
✔✔Name the agent that causes malaria: - ✔✔Plasmodium (severity of disease depends
on species)
✔✔How is it transmitted? - ✔✔Anopheles mosquito. Complex life cycle: bite (protozoan
--> liver and divides - also may remain dormant there) liver --> RBC. Mosquito takes up
a form of protozoan that will reproduce in the mosquito and can infect next human.
✔✔What types of symptoms and signs are seen? - ✔✔As protozoa are released from
RBCs the patien has intervals of high fever, anemia, fatigue, jaundice. These bouts
occur in cycles every few days.
✔✔Is there treatment? What is it? - ✔✔Yes, chloroquine (resistance). People travelling
to malarial region take chloroquine as prophylaxis (prevention of disease). Currently
trying to develope vaccine.
✔✔What is the concern in infections with Toxoplasma? - ✔✔Toxoplasma can be
transferred across placenta and cause birth defects (teratogenic) like microcephaly
(abnormally small head), blindness and retardation.
✔✔Where do these infections come from? - ✔✔Feces from cats --> soil --> plants -->
animals --> humans (eating meat not fully cooked) or direct inhalation from cat feces
(litterbox), less likely.
✔✔Name all of the teratogenic agents signified by the acronym "TORCH:" - ✔✔TO:
Toxoplasma, Hepatitis B, Varicellovirus
R: Rubella
C: Cytomegaly
H: Herpes
✔✔Name a helminth that causes granulomas to form in multi-organ systems: -
✔✔Schistosomiasis
✔✔How do "trench mouth" and "thrush mouth" differ? - ✔✔Acute necrotizing gingivitis,
"trench mouth", is an overgrowth of certain bacteria resulting with bleeding gums,
ulceration, fever, and pain. "Thrush" is an infection of the oral mucous membrane by the
fungus Candida albicans.
✔✔Name the common cause of dental caries: - ✔✔Streptococcus mutans (normal
mouth flora). These bacteria make a polysaccharide (glucan) to help other bacteria stick
--> biofilm (dental plaque).
QUESTIONS AND ANSWERS GRADED A+
✔✔What does it mean that the disease ofter is "subclinical?" - ✔✔The disease may go
unnoticed because of the absence of symptoms, even though clinical tests reveal signs
of disease.
✔✔Name the causative agent in plague: - ✔✔Yersinia pestis
✔✔What is a buboe? - ✔✔Buboes are smooth, enlarged, reddened, and painfully
inflamed lymph nodes.
✔✔How does transmission occur? - ✔✔Fleas are the vectors for the spread of the
bacteria. Infected fleas that have left their normal animal hosts can spread plague to
humans.
✔✔What type of plague has the highest mortality? - ✔✔pneumonic plague: spread to
lungs (or through inhalation)
✔✔Can plague be treated? - ✔✔Yes, streptomycin and tetracycline are effective
against Yersinia.
✔✔Name the bacteria that cause Lyme disease? - ✔✔Borrelia burdorferi (gram - rod)
✔✔How is it transmitted? - ✔✔ticks (biological vector)
✔✔Is a bull's eye rash always seen? What is that? - ✔✔No, 80% of patients have the
bull's eye rash at the site of infection. It is erythema migrans.
✔✔Can it be treated? - ✔✔Yes, penicillins, tetracyclines, or cephalosporins are effective
in the first phase, later phases are difficult to treat.
✔✔What are some late manifestations of the disease? - ✔✔headache, fatigue, in small
% nervous (CNS) and cardiovascular symptoms, eventually chronic arthritis
✔✔How is Rocky Mountain spotted fever transmitted? - ✔✔ticks (biological vectors)
✔✔Which bacterium causes the disease? - ✔✔Rickettsia
✔✔What type of rash is seen? - ✔✔subcuaneous hemorrhages known as petechiae
✔✔What are other symptoms? - ✔✔fever, headache, chills, muscle pain, nausea and
vomitting
,✔✔How serious is the disease? - ✔✔Early diagnosis is crucial because prompt
treatment often makes the difference between recovery and death. It is impossible to
eliminate the ticks in the wild, in part because they can survive without feeding for more
than four years.
✔✔What is the cause of "mono?" - ✔✔Bacteria = Epstein Barr Virus; "Mono" is a result
of a patient's cellular immune system with an infected WBC.
✔✔Which cells are involved? - ✔✔After initially infecting epithelial cells of the throat and
salivary glands, Epstein-Barr virus enters the blood, where it invades B lymphocytes
(WBC).
✔✔Characterize the virus that causes this disease: - ✔✔EBV is an enveloped, double-
stranded DNA virus that replicates in a host's cell's nucleus.
✔✔Why is this called a "persistent" infection? - ✔✔virus can invade many organs (liver,
myocarditis, glomerulonephritis)
✔✔How is it transmitted? - ✔✔Transmission of Epstein-Barr virus usually occurs via
saliva, often during the sharing of drinking glasses or while kissing. Infectious
mononucleosis is commonly known as the "kissing disease".
✔✔What is the cause of Burkitt's Lymphoma? - ✔✔EBV suppresses apoptosis
(programmed cell death) of B lymphocytes, causing infected cells to become immortal.
In combination with a suppressed immune system, such infected B cells are one source
of cancers, like Burkitt's lymphoma, a cancer of the jaw.
✔✔What are the signs? - ✔✔1) sore throat, fever, enlarged lymph nodes, many other
varied symptoms
2) "persistent" infection: virus can invade many organs like the liver, heart (myocarditis),
and kidney (glomerulonephritis)
✔✔Who is most at risk for CMV infections? - ✔✔Fetuses (teratogenic) and
immunocompromised patients are susceptible to severe complications of CMV infection.
Newborns may develope hepatomegaly, splenomegaly, hearing\visual problems, and
CNS involvement. Immunosuppressed adults may develope pneumonia or systemic
diseases.
✔✔What does CMV stand for? - ✔✔Cytomegalovirus
✔✔What does it mean that this disease is often "subclinical?" - ✔✔"Subclinical" refers
to the fact that CMV, while remaining in a latent state, does not have clinical symptoms
until the immune system is compromised.
✔✔Name three viral hemorrhagic fever: - ✔✔1) Dengue fever
, 2) yellow fever
3) Ebola hemorrhagic fever
✔✔Name the agent that causes malaria: - ✔✔Plasmodium (severity of disease depends
on species)
✔✔How is it transmitted? - ✔✔Anopheles mosquito. Complex life cycle: bite (protozoan
--> liver and divides - also may remain dormant there) liver --> RBC. Mosquito takes up
a form of protozoan that will reproduce in the mosquito and can infect next human.
✔✔What types of symptoms and signs are seen? - ✔✔As protozoa are released from
RBCs the patien has intervals of high fever, anemia, fatigue, jaundice. These bouts
occur in cycles every few days.
✔✔Is there treatment? What is it? - ✔✔Yes, chloroquine (resistance). People travelling
to malarial region take chloroquine as prophylaxis (prevention of disease). Currently
trying to develope vaccine.
✔✔What is the concern in infections with Toxoplasma? - ✔✔Toxoplasma can be
transferred across placenta and cause birth defects (teratogenic) like microcephaly
(abnormally small head), blindness and retardation.
✔✔Where do these infections come from? - ✔✔Feces from cats --> soil --> plants -->
animals --> humans (eating meat not fully cooked) or direct inhalation from cat feces
(litterbox), less likely.
✔✔Name all of the teratogenic agents signified by the acronym "TORCH:" - ✔✔TO:
Toxoplasma, Hepatitis B, Varicellovirus
R: Rubella
C: Cytomegaly
H: Herpes
✔✔Name a helminth that causes granulomas to form in multi-organ systems: -
✔✔Schistosomiasis
✔✔How do "trench mouth" and "thrush mouth" differ? - ✔✔Acute necrotizing gingivitis,
"trench mouth", is an overgrowth of certain bacteria resulting with bleeding gums,
ulceration, fever, and pain. "Thrush" is an infection of the oral mucous membrane by the
fungus Candida albicans.
✔✔Name the common cause of dental caries: - ✔✔Streptococcus mutans (normal
mouth flora). These bacteria make a polysaccharide (glucan) to help other bacteria stick
--> biofilm (dental plaque).
