Final (Past Exams) Flashcards
Give an example where post-exposure vaccination is recommended?
after being bitten by an animal suspected to be infected with the rabies virus.
Which vaccine protects solely or principally by induction of serum antibodies?
Hep A Vaccine
Passive immunization is used for all of the following except
to elicit production of secretory antibodies
What drug inhibits the function of influenza A virus M2 protein? 1/1
Rimantidine
Which class of anti-HIV drug is also effective against hepatitis B virus?
Anti-reverse transcriptase
Which drug blocks release of influenza A virus from an infected cell?
TAMIFLU
What virus does not create “giant cells” during the course of an infection?
Norovirus
Name a hepatitis virus for which hepatocyte death is mainly due to killing by cytotoxic T lymphocytes.
Hep B
During hepatitis B virus infection, infectious viral particles are released from cells. What is a property of these particles?
42 nm diameter particles containing HBs Antigen
Name a hepatitis virus that mainly infects via a fecal-oral mode of transmission.
Hep A
Which hepatitis virus causes a high incidence of persistent infections (70% of infections becoming persistent in otherwise healthy adults)?
HCV
Which of the following is diagnostic for infection with herpes simplex virus type 1
Cowdry type A inclusion Bodies
Which of the following is not a property shared by the different herpes viruses?
genome is directly translated into protein upon entry into the cell.
Infection with which herpesvirus is commonly diagnosed by agglutination of red blood cells from horses?
Epstien Barr Virus
Which of the following is a property shared by the different herpes viruses?
Encode a large arrary of enzyme involved in nucleic acid metabolism
assemble viral capsids in the host cell nucleus
production of virus results in destrruction of the infected cell.
able to exsist in a latent state
Name a type of human papillomavirus strongly associated with cervical carcinoma.
HPV 18
What is role of the human papillomavirus E6 protein during infection?
binds p53 and promotes p53 degradation
Which of the following is diagnostic for infection with human papilloma virus?
Koliocytic cells
What viral protein sequesters the retinoblastoma protein (Rb) and prevents it from controlling E2f transcription factor?
adenovirus E1a protein
Specific variants of which types of virus cause life threatening acute respiratory infections and are the target of vaccination of new military recruits in the US?
Adenovirus
What virus primes the synthesis of its genomic DNA with the serine residue of a viral protein?
adenovirus
In a study that I described in class, blood samples were taken monthly over a 39 month period from patients infected with HIV to follow the virus replicating in the patients’ systems and the patients’ antibody response. The patients became infected with HIV in month 0. What is a valid conclusion from the study?
month 12 plasma has anti-HIV antibodies that react strongly to month 0 virus
HIV mutates rapidly during an infection due to errors by which enzyme?
viral reverse transcriptase
What is a role of the HIV gp120 protein?
bind to CD4 receptors and/or CCr5/CXCR4 coreceptors (depending on the cell type)
What is the main reason that HIV positive individuals are able to transmit the virus many years after their initial infection?
viral DNA integrated in the host genome is transcribed by host cell RNA polymerase II
Which virus is the most common agent of gastroenteritis in children?
rotovirus
Which influenza virus protein mediates adsorption of the virus onto a host epithelial cell surface?
hemagluttinen
xWhat is an example of a cellular function supplied by a viral genome integrated into the human cell genome?
syncytin-1 for placental fusion
Regarding chemical agents used in microbial control, what compound class is hexachlorophene a member of? 1/1
Phenolics
Regarding the use of heat to control microbial pathogens, what is the time required to kill 90% of the microbes in a sample at a specific temperature?
1/1
he decimal reduction time
What is the term for inhibition or elimination of microbes on living tissue? 1/1
antisepsis
What is the term for treating all patients are as though they are a source of infectious pathogens? Answer:__1__ 1/1
universal precautions
What is the Spaulding Classification category of a dental implant?
critical
Pasteurization of milk serves to control potential epidemics by 1/1
breaking the connection between the source of pathogens and susceptible individuals
What is true about biologic transmission with respect to vector-borne pathogens? 1/1
he pathogen is carried internally within the body of the vector and undergoes a key life cycle step during this time
In airborne disease transmission, what is a property of droplet nuclei?
4 micrometers or less in diameter
What is true about a propagated epidemic?
the number of cases begins to fall once the number of susceptible individuals falls below the threshold density
What is an index case with respect to an epidemic?
he first case of the epidemic
What is an example of a disease that is typically sporadic and does not occur in epidemics?
histoplasmosis
What the mortality rate for a disease?
number of deaths from a disease per number of cases of the disease
What is true about the rRT-PCR diagnostic test for Zika virus? (rRT-PCR = real-time Reverse Transcription PCR test
to have the best chance of detecting virus the test must be conducted within 2 weeks after onset of symptoms associated with Zika virus infection
What is the order of components for an ELISA test that uses a blood serum sample to measure a patient’s anitbody response to an infection? The order reads left to right in the answer choices. Step K= enzyme substrate added; step M= patient serum added; step X= enzyme conjugated antibody added.
aboratory produced antigen bound to well surface; Step M; Step X; Step K
What antigen is best suited for detection with a latex agglutination assay?
capsular polysaccharide
Urea broth is an example of which type of culture medium used for diagnosis of a bacterial infection?
characteristic medium
What bacterial cell staining method involves the use of fuschin as the staining agent combined with carbolic acid as a mordant?
Ziehl-Neelson method
The “sensitivity” of a diagnostic test measures the percentage of
true positive test results among the total of true positives plus false negatives
What is the “specificity” of a diagnostic test for a pathogen that gives a true negative test result 990 out of 1000 times (i.e. when the pathogen is actually absent), with a false positive result occurring 10 out of 1000 times? Express you answer as a percentage.
0.99
Which protozoan survives and differentiates in macrophages, aided by expressing a superoxide dismutase enzyme?
Leishmania species
What protozoan is chlorine-resistant, making it easy to transmit in public swimming pools?
cryptosporidium parvus
The reduviid bug is the vector for which disease?
Chagas disease
The anaerobic metabolism of some protozoal pathogens makes them susceptible to which drug?
metronidazole
What is the term for the host in which a parasite’s sexual reproduction phase occurs?
definitive host
What protozoal disease agent is transmitted in the feces of infected domestic cats?
oxoplasma gondii
What disease agent causes periodic attacks of chills and fever that coincide with massive lysis of red blood cells?
Plasmodium falciparum
Infection by which organism is most likely to be initiated by breathing it into the lungs?
Blastomyces dermatitidis
Which fungal staining method involves a fluorescent probe for chitin?
calcofluor white treatment
What is an anti-fungal drug that binds ergosterol in fungal membranes and alters membrane permeability?
amphotericin B
How does the anti-fungal itraconazole work?
inhibits cytochrome P450-dependent 14-alpha-lanosterol demethylation
Infection by which organism is usually not associated with the formation of granulomas in the lung?
Candida albicans
Infection by which organism is usually not associated with the formation of granulomas in the lung?
Candida albicans
Fungi of which genus are particularly sensitive to anti-fungal agents that inhibit synthesis of beta-(1,3)-D-glucan. (Name one genus)
candida
Which fungus lacks ergosterol?
Pneumocystis jiroveci
Which disease agent causes a superficial mycosis known as a tinea?
Malassezia furfur
Which pathogenic fungus only grows in a mold form (lacks a yeast form)?
Aspergillus fumigatus
Which is a characteristic component of most fungal cell walls?
polymer of N-acetyl-glucosamine
Which fungus is neurotropic and produces melanin in its cell wall?
cryptococcus neoformans
Which of the following is true about Creuzfeldt-Jakob disease (CJD)?
Caused by accumulation of PrP(Sc)
Which of the following is true about Fatal Familial Insomnia (FFI)?
is a human prion disease
What disease is caused by accumulation of a protein in amyloid fibrils?
Bovine spongiform encephalopathy
What is a possible role for the gut bacteriophage community, as presented in class?
bacteriophage may limit bacteria in the gut, killing off cells when they reach a high concentration
What is an example of a host cell trait supplied by an viral genome integrated into the host cell genome?
botulinum toxin for Clostridium botulinum
When performing controlled viral infections in tissue culture, which of the following best describes what is
occurring during the eclipse phase of an infection?
Viruses are attached to receptors on host cell surfaces
Which Adenovirus protein binds and inactivates p53, preventing p21 activation in response to DNA damage?
E1b
Which adenovirus serotypes cause life threatening acute respiratory infections and are the target of vaccination?
serotypes 4 and 7
In a study that I described in class, blood samples were taken monthly over a 39 month period from patients
infected with HIV to follow the virus replicating in the patients’ systems and the patients’ antibody response. The patients became infected with HIV in month 0. What is a valid conclusion from the study?
month 0 plasma does not have significant levels of anti-HIV antibodies
What is the role of the HIV gp120 protein?
binding to the host cell CD4 receptor and either the CCR5 OR CXCR4 coreceptor, depending on the cell type
For which RNA virus, initially encountered in the gastrointestinal tract, is a vaccine not available?
norovirus
The Human Papilloma Virus E7 protein plays a role most similar to the role of what other viral protein?
Adenovirus E1a protein
What viral protein sequesters Rb and prevents it from controlling E2f transcription factor?
Adenovirus E1a protein
Passive immunization is used for all of the following except
to elicit production of secretory antibodies
An adjuvant is used to
boost the immunogenicity of a killed (inactivated) virus vaccine
Which drug blocks release of influenza A virus from an infected cell?
tamiflu
Which class of anti-HIV drug is also effective against hepatitis B virus?
reverse transcriptase inhibitors
The anti-herpes simplex virus drug acyclovir
is phosphorylated by the viral thymidine kinase enzyme
Which hepatitis virus causes a high incidence of persistent infections (70% of infections becoming persistent in otherwise healthy adults)?
HCV
A individual who had a prior acute infection with HBV that completely resolved would display which of the follow
serological properties?
presence of anti-HBs antibodies combined with lack of detectable HBs and HBe antigens
Which hepatitis virus(es) mainly infect via a fecal-oral mode of transmission?
HAV and HEV
Which Human Herpes Viruses fails to establish a true latency, but down-regulates to a low level of viral
production when not causing active disease?
CMV
What is the cause of shingles?
varicella zoster virus reactivation
Conjunctivitis can be caused by
adenovirus
What is the role of the HIV gp41 protein?
fusion of viral and cellular membranes during viral entry
What is a naked capsid virus composed of?
only nucleocapsid
What is a property of the anti-cytomegalovirus drug ganciclovir?
is more toxic than acyclovir because it is more readily used by cellular thymidine kinase
What is role of the human papillomavirus E6 protein during infection?
binds p53 and promotes p53 degradation
What is the main reason that HIV positive individuals are able to transmit the virus many years after their initial
infection?
viral DNA integrated in the host genome is transcribed by host cell RNA polymerase II
What virus does not create ³giant cells´during the course of an infection?
hepatitis A virus
Which of the following is diagnostic for infection with human papilloma virus?
Koilocytic cells
During hepatitis B virus infection, non-infectious viral particles are released from cells. What is a property of
these particles?
22 nm diameter particles containing mainly HBs antigen
Which is a characteristic component of most fungal cell walls?
polymer of N-AQcetyl-glucosamine
Which fungus lacks a yeast form?
aspergillus fumigatus
which disease agent causes a superficial infection of skin surfaces?
malassezia furfur
infection by which organism is not associated with the formation of granulomas in the lung?
sporothrix schenkii
Which fungal staining method involves flurosecnt detection of chitin
clacofluor white
how does echinocandins work as anti-funal drgus?
inhibiting synthesis of beta (1,2) d glucan
what is the human body’s primary mechanism for fighting fungi?
neutrophil phagocyteosis and T cell mediated immunity
Which fungus causes cutaneous lesions and can be identifed upon histopathological examination as a thick walled yeast with a single broad-based bud?
blastomyces dermatididis
What agent of “desert rehumatism” can cause chronic meningitis that is fatal without lifelong treatment?
coccidioides immitis
infection by which organism is not associated with the formation of granulomas in the lung?
sporothrix schenkii
Which diesease agent causes a superficial infection of skin surfaces?
malassezia fufur
Which fungus lacks a yeast form, only exhibiting a mold form?
aspergillus fumigatus
Which form of candidiasis is associated with high incidences of oral cancer?
plaquelike/nodular
fungi of which genus are notable as a cause of life-threatening infections of diabetes pts.
rhizopus
Which anti-fungal class binds ergosterol in fungal memebranes and alters memebrane permeability?
polyenes
infection by which organism is associated with the formation of granulomas in the lung?
histoplasma capsulatum
For fungi, to what does the term dimorphism refer?
capability to grow as a yeast or a mold
Which of the following is the most correct description of chitin?
polymer of NAG
WHich is a true statement about babesia , a malaeria-like illness that is endemic to the US?
it is transmitted by ixodes ticks
What protozoan is the most common causes of epidemic waterbourne diarrheal diease?
giardia lamblia
What is meant by a definiitive host when referring to a parasitic organism?
the host in which the parasite’s sexual reproduction phase occurs
Which disease agent produces cysts in the brains of infected indiviudals and raises dopamine level?
toxoplasma gondii
WHat protozoal disease agent is transmitted by Anopheles mosquitos and results in the destruction of red blood calls?
plasmodium falciparum
Chagas disease (American trypanosomiasis) is transmitted by which vector organism?
reduvid bug
Which genus contains the most commonly sexually transimitted protozoan disease agent?
trichomonas
the anaerobic metabolism of some protzoal pathogens makes them susceptible to which drug?
metronidazole
what protozoan is chlorine-resistant, making it easy to transmit in public swimming pools?
cryptosporidium parvum
What is true about a prozone reaction in a latex agglutination test for detecting microbial antigens?
it is an example of a false negative test result
eosin methylene blue (EMB) agar is an example of which type of culture medium used for diagnosis of a bacterial infection?
differential medium
What is true about the rRt-PCR diagnostic test for zika virus? (rRT-PCR= real time reverse transcription PCR test)
to have the best chance of detecting virus the test must be conducted within 2 weeks after onset of symptoms associated with zika virus infection
What are the basic components of a PCR assay used for diagnostic purposes?
pathogen DNA, a pair of pathogen-specific DNA primers, dNTPs, and a thermostable DNA polymersase
What is the sensitivity of a diagnostic test for a pathogen that gives a postive test result 499 out of 500 times that the pathogen is actually present?
99.8%
What is the basis for calling an ELISA test for microbial antigen detection a “sandwhich” assay?
the antigen being detected in the patient’s serum is “sandwhiched” between a specfic antibody boundto the solid support and another antibody to the antigen that is added during the test
Which type of medium permits growth of one group of bacteria while inhibiting growth of some other groups?
selective medium
What is meant by “specificity” in regards to a diagnostic test?
the percentage of true-negative results out of the total true-negatives and false positives
What is true about harborage transmission with respect to vector-borne pathogens?
the pathogen is carried internally within the body of the vector but does not undergo changes during this time
What is an index case with respect to an epidemic
the first case of the epidemic
When considering a propagated epidemic of an infectious disease, what does the threshold density represent?
the miniumum number of susceptible individuals necessary to continue propagating the diease
What is the mrobidity rate for a disease?
number of new cases in a specific time perioud per unit of population
in disease transmission, particles of 4 micrometers or less in diameter that can remain airbourne for hours are called what?
droplet nuclei
What is an example of a class of compounds that are commonly used lab and hospital disinfections that are tuberculocidal but have a disagreeable odor and can cause skin irritation?
lysol
What is the Spaulding Classification caterogry of a dental implant?
critical
What is the decimal reduction time in the heat-killing of microorganisms
time required to kill 90% of microbes in a sample at a specific temperature
What is the Spaulding Classification Category of a dental instrument that touches bone?
critical
