Week 8 Flashcards
Most DNA viruses which infect humans have this type of capsid.
Icosahedral
What is the difference between positive and negative sense RNA viruses?
negative-sense single stranded RNA viruses need to carry RNA dependent RNA polymerase in the virion in order to infect
All DNA viruses replicate in the nucleus with exception of this virus family.
Poxvirus
Which positive-sense RNA virus uses a unique virion-associated polymerase?
Retrovirus; uses RNA dependent DNA polymerase
This virus type has a naked nucleocapsid with three icosahedral capsid shells and a segmented genome.
Double stranded RNA viruses
Which protein on the surface of virus envelope aids in attachment and fusion?
F protein
What is the significance of the M protein in viruses?
aids in viral structure
Which viruses burst from host cells as opposed to budding from the cell surface?
unenveloped viruses
Which virus type is more sensitive to inactivation?
enveloped
This virus has long pleomorphic enveloped helical nucelocapsids containing -SSRNA. It causes acute hemorrhagic fevers in man and monkeys.
Filoviridae
Is Filoviridae segmented?
No
What two viruses are most common in Filoviridae family?
Ebola virus and Marburg virus
This virus is enveloped nucleocapsid, helical symmetry, segmented -SSRNA.
Bunyaviridae
La Crosse virus is part of this family of viruses.
Arthropod borne bunyaviruses (caused by mosquito)
Crimean-Congo hemorrhagic fever is caused by a tick is part of this family of viruses.
Arthropod borne bunyaviruses (caused by tick)
Rodent borne bunyaviruses include
Hantavirus and Sin nombre virus
Arenaviridae are a -SSRNA genome which is segmented or non-segmented?
2 segments
Lymphocytic choriomeningitis virus is part of this family of viruses.
Arenaviridae
Which bacteria is responsible for causing 80% of UTIs?
E. coli
It destroys beta lactam antibiotics
Symptoms of this protozoa include Steatorrhea (excessive fat in feces) and malabsorption with flattening of the villi
Water, “greasy”, foul-smelling diarrhea
giardia
What type of diagnostic test can you do for giardia?
Fecal O&P exam. Zinc concentrate
Treatment for giardia
Metronidazole
Giardiasis can lead to deficiencies of which vitamins?
Fat soluble vitamins (D,E,A,K)
Which staining method is commonly used to visualize Cryptosporidium protozoa?
acid-fast
Which medication is commonly used for the treatment of cryptosporidiosis in immunocompromised patients?
Spiramycin (macrolide) is an antibiotic that has shown efficacy in the treatment of cryptosporidiosis, particularly in immunocompromised patients. It is often used as an alternative therapy when other antiparasitic medications are not available or not well-tolerated.
Which of the following is used for the treatment of Cryptosporidium?
Nitazoxanide is an antiprotozoal medication used for the treatment of Cryptosporidium.
Cryptosporidium is most commonly identified in which patient population?
Immunocompromised patients
What is a characteristic finding in the diagnosis of Leishmaniasis?
Amastigotes, which are a form of Leishmania found inside macrophages, are a characteristic finding for the diagnosis of Leishmaniasis. This is often identified through aspirates from marrow, spleen, lymph nodes, or skin lesions.
What are the three primary avenues through which Toxoplasma gondii is commonly transmitted to humans?
cat feces, transplacental, undercooked meat
For which population is Toxoplasma gondii particularly concerning?
immunocompromised
How is active infection of Toxoplasma gondii typically treated?
Active Toxoplasma gondii infection is typically treated with the combination of sulfadiazine and pyrimethamine.
Which trematode has eggs with large lateral spines?
Schistosoma mansoni
Schistosoma mansoni is characterized by a large lateral spine on its eggs, a notable morphological feature that can be observed on stool examination. Schistosoma haematobium eggs are oval with a terminal spine, while Schistosoma japonicum eggs have a minute subterminal spine or no spine, making them appear more rounded.
What is the most effective treatment for trematode infections?
Praziquantel
What is the primary treatment for cestode infections?
Praziquantel
What cestode is associated with megaloblastic anemia due to vitamin B12 deficiency?
Diphyllobothrium latum, or the fish tapeworm, can cause a vitamin B12 deficiency leading to megaloblastic anemia. This uncommon complication is due to the worm’s ability to absorb vitamin B12 in the intestine.
Necator americanus and Ancylostoma duodenale are hookworms which are treated with which medication?
Albendazole and Mebendazole
What type of bladder cancer is caused by Schistosoma haematobium?
squamous cell carcinoma
Which intestinal nematode is most likely to cause severe iron-deficiency anemia?
Hookworms (e.g., Ancylostoma duodenale and Necator americanus) are known to cause severe iron-deficiency anemia. This is because they attach to the gut wall and feed from the capillaries in the intestinal villi.
Which medication can be used against most intestinal nematodes?
Bendazoles like albendazole can be used to treat all of the intestinal nematode infections mentioned in this lesson (e.g., Enterobius vermicularis, Ancylostoma duodenale, Necator americanus, Ascaris lumbricoides, Strongyloides stercoralis and Trichinella spiralis) as they lead to microtubule dysfunction in these worms.
Which bacteria causes atypical pneumonia?
mycoplasma pneumoniae
What is a common early symptom of infection of Ebola virus and Marburg virus infections?
A common early symptom of infection from Ebola virus and Marburg virus is hemorrhagic fever. It is characterized by high fever, headache, muscle pain, fatigue, and often leads to severe bleeding, both internally and externally.
Which animals are known to harbor Marburg and Ebola virus?
monkeys and bats
What family do Ebola virus and Marburg virus belong to?
The Ebola and Marburg viruses belong to the Filoviridae family, also known as filoviruses.
What is the primary mode of transmission for hantavirus?
Hantaviruses are primarily transmitted to humans through contact with infected rodents and their urine, droppings, or saliva. In particular, the virus can be transmitted when humans come into contact with dust particles that contain dried rodent excreta, which can be inhaled and lead to infection.
How many RNA segments does the genome of bunyaviruses consist of?
3
How many RNA segments are typically found in the genome of arenaviruses?
2
The lymphocytic choriomeningitis virus primarily manifests in humans with symptoms indicative of:
meningoencephalitis
Arenaviruses are primarily spread to humans by:
rodents
Which virus is the most common cause of viral encephalitis in the US?
La Crosse virus (arthropod borne bunyaviruses) transmitted by mosquitoes
Cutaneous infections by fungi are caused by _____.
dermatophytes
Which of the following regions is Histoplasma capsulatum endemic to?
Ohio and Mississippi River valley
What is the primary mode of transmission for Histoplasma capsulatum?
bird and bat droppings
Histoplasma capsulatum is characterized as being ___morphic
dimorphic
dimorphic, replicates in spherules as endospores, San Joaquin Valley
Coccidioides immits
What is the method of transmission for Coccidioides immitis?
Inhalation of spores
What is the geographical distribution of Coccidioides immitis?
San Joaquin Valley
monomorphic yeast, capsule, pigeons, opportunistic, India Ink
Cryptococcus neoformans
opportunistic, dimorphic, pseudohyphae
Candida albicans
macrophages, ohio, mississippi, dimorphic fungus, TB, bird bat droppings
Histoplasma capsulatum
____ affects the lipid bilayer and denatures protein.
Alcohols (ethyl or isopropyl alcohol)
Can alcohols kill spores?
No. They don’t and thus aren’t used on medical equipment
Which isopropyl alcohol is stronger/better at killing bacteria, 70% or 100%?
70% bc it requires presence of water to denature the proteins
____ affect the lipid bilayer and alter membrane permeability.
surfactant/detergents
Can surfactant/detergents kill spores?
No
Can chlorine compounds kill spores (a sterilant)?
Yes
Can H2O2 kill spores?
Yes
Can iodine kill spores?
No
____ modify proteins and interfere w/ the ETC
Iodine
____ denature proteins and damage DNA
Aldehydes
_____ gas is a high level sterilant that kills spores
ethylene oxide
What type of heat is more effective at killing spores?
moist
Can UV irradiation kill spores?
No
How often should you re-screen for diabetes if the patient is negative or when the risk factors change?
q3 years
What is the minimum A1c level to diagnose diabetes?
6.5
What is the minimum fasting plasma glucose level to diagnose diabetes?
126 on TWO different occasions
2-hour plasma glucose ___ mg/dL or higher on TWO different occasions
200
A random plasma glucose over ___ w/ symptoms can dx diabetes
200
How do you calculate eAG from A1c?
30 x A1c - 46 = eAG
Classic PKU is due to mutation in which gene?
phenylalanine hydroxylase (<1% enzyme activity)
In patients with elevated Phe levels and not responsive to low Phe diet suggests defects in what other substrate?
tetrahydroBIOPTERIN biosynthesis or regeneration
What is Kuvan?
synthetic BH4 given to patients with PKU
Early decelerations in FHR tracing is typically caused by what? And what type of curve would you expect to see?
head compression; U shaped
Variable decelerations are due to what? What type of curve?
umbilical cord compression; V-shaped
What are the ACOG guidelines for pap test>
cytology alone q3 years for 21-29; 30-65 cytology q3 years + HPV screen q5 years
The fungal cell wall is made of ____.
chitin, mannoproteins, and glucan
Dysbiosis can occur w/ increased # of anaerobes present in the preputial space in uncircumcised men. This can correlate with increased risk of what infection?
HIV
Which bacteria causes trench fever?
Bartonella quintana
Which bacteria causes cat-scratch fever?
Bartonella henselae
What is Brill-Zinsser disease? What bacteria can cause this?
relapsing form of epidemic typhus fever; Rickettsia prowazekii
Which type of agar based medium is used for mycoplasmas?
Eaton’s agar
On Eaton’s agar what do most mycoplasmas resemble?
fried egg
On Eaton’s agar what does Mycoplasma pneumoniae resemble?
mulberries
On Eaton’s agar what does Ureaplasma urealyticum resemble?
tiny T colonies