93. Microbiology p194-206
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- Medically important helminths
- p194
- Which Cestode (tapeworm) can cause brain cysts and seizures?
- Taenia solium
- Echinococcus granulosus (a cestode) can cause cysts in the ____when ingested in dog feces; and _____ if antigens are released from cysts
- liver, anaphylaxis
- What is the standard treatment for trematodes (flukes)?
- Praziquantel
- Which fluke penetrates human skin, forming granulomas, fibrosis, and inflammation of the spleen & liver?
- Schistosoma
- Larvae of the nematode (roundworm) ___ are known to penetrate skin of feet & cause anemia if infect intestine.
- Ancylostoma duodenale (hookworm)
- Echinococcus granulosus (a cestode) can cause cysts in the ____when ingested in dog feces; and _____ if antigens are released from cysts.
- liver, anaphylaxis
- Which nematode causes anal pruritis?
- Enterobius vermicularis (pinworm)
- Lavae of the nematode ___ are found in the soil, penetrate the skin, and cause intestinal infection.
- Strongyloides stercoralis
- Trichinella spiralis (a nematode) is usually found in what food?
- undercooked meat, usually pork
- Which nematode can be seen crawling in the conjunctiva?
- Loa loa
- Treatment for river blindness, caused by onchocerca volvulus, is ___
- Ivermectin
- Wuchereria bancrofti cause blockage of lymphatic vessels in a condition known as:
- elephantiasis
- Three nematodes treated with Diethylcarbamazine:
- Loa loa, Toxocara canis, and Wucheria bancrofti
- Parasite hints
- p195
- Perianal pruritis caused by:
- Enterobius
- Microcytic anemia a result of infection with
- Ancylostoma, Necator
- Schistosoma mansoni is known to result in
- portal hypertension
- Schistosoma haematobium can cause ___ cancer and hematuria
- bladder
- A trematode that causes hemoptysis is:
- Paragonimus westernani
- Clonorchis sinensis causes disease in the:
- biliary tract
- Virology
- p195
- All DNA viruses are dsDNA except:
- parvoviridae
- All DNA viruses are linear except these two:
- papoviruses, hepadnavirus (circular)
- All RNA viruses are ssRNA except
- Reoviridae ("repeato-virus" (reovirus) is dsRNA)
- Do hepadnavirus, herpesviruses, and poxvirus have an envelope?
- Yes
- Which virus is often responsible for "pink eye" (conjunctivitis)?
- adenovirus
- Which SS-linear(-) DNA virus is responsible for "slapped cheeks" rash?
- Parvovirus
- Which is the smallest DNA virus?
- Parvovirus
- Which DNA virus can cause aplastic crises in sickle cell disease?
- Parvovirus (B19 virus)
- Name 3 "naked" DNA virsuses (no envelope)
- Parvo, Adeno, and Papovirus (you have to be naked for a PAP smearÂ…)
- The largest DNA virus, one which can cause "milkmaid's blisters" or molluscum contagiosum (and could be used in germ warfare), is:
- poxvirus
- DNA virus characteristics
- p196
- Papovirus is not linear, but rather ____
- circular, supercoiled
- The only DNA virus that is not icosahedral is
- Pox (complex)
- All DNA viruses replicate in the nuclear except
- Pox (carries own DNA-dependent RNA polymerase)
- RNA viruses
- p197
- Poliovirus, Echovirus,Rhinovirus, Coxsackievirus, and HAV are all members of which viral family?
- Picornaviruses ("PERCH")
- Picorna-, Calci-, Flavi-, Toga-, Retro-, and Coronaviruses all share which RNA structure?
- SS + linear
- Which SS-linear, nonsegmented RNA virus family is responsible for measles, mumps, and croup?
- PaRaMyxovirus (Parainfluenza-croups; RSV-bronchiolitis in babies; Measles, Mumps)
- Hantavirus, Sanfly/Rift Valley fevers, and California encephalitis are all part of this SS-circular RNA viral family.
- Bunyaviruses
- Orthomyxoviruses include which ubiquitous virus?
- Influenza virus
- HIV and HTLV are both ____ with ____capsid symmetry.
- retroviruses; icosahedral
- What is the #1 cause of fatal diarrhea in children?
- Rotavirus (a reovirus)
- Rabies is caused by this viral family.
- Rhabdoviruses
- Virus family credited with the "common cold"
- Coronaviruses
- Ebola/Marburg hemorrhagic fever are caused by which viral family?
- Filoviruses
- More virology
- p198
- Three naked (nonenveloped) RNA viruses are:
- Calcivirus, Picornavirus, Reovirus (Naked CPR)
- From where to herpesviruses aquire their envelopes?
- nuclear membrane
- From where do enveloped viruses usually acquire their envelopes?
- plasma membranes
- This is the only virus that is not haploid:
- retrovirus (which has 2 identical ssRNA molecules, so considered diploid)
- The only DNA viruses that does not replicate in the nucleus is:
- poxvirus
- The two RNA viruses which do not replicate in the cytoplasm are:
- Influenza virus and retroviruses
- Viral Vaccines
- p198
- Live attenuated vaccines induce humoral and cell-mediated immunity, while killed viruses induce only ____ immunity.
- humoral
- Are MMR (measles, mumps, rubella) vaccines live or killed?
- Live attenuated
- Rabies, influenza, HAV, and Salk polio vaccines are of which type (live or killed)?
- Killed (SalK=killed)
- A recombinant viral vaccine exists for which virus?
- HBV (antigen=HBsAg)
- Worldwide pandemics of influenza virus are in part attributable to which type of viral genetics?
- Reassortment (viruses with segmented genomes exchange segments)
- Viral Pathogens
- p199
- What structural similarity is shared by herpesviruses, HBV, and smallpox virus?
- They are DNA enveloped viruses.
- RNA nucleocapsid enteroviruses include which pathogens?
- poliovirus, coxsackievirus, echovirus, HAV
- The viral pathogens adenovirus, papillomaviruses, and parvoviruses are all what type of viral pathogens?
- DNA nucleocapsid viruses
- Bunyaviruses, Orthomyxoviruses (influenza viruses), Arenaviruses, and Reoviruses are all what type of RNA virus?
- segmented (BOAR)
- Aseptic (viral) meningitis can be caused by which small RNA viruses?
- poliovirus, coxsackievirus, echovirus (and not by two other picoRNAviruses, rhinovirus and HIV)
- Reovirus considered the most important global cause of infantile gastroenteritis
- Rotavirus (ROTA=Right Out The Anus)
- All paramyxoviruses have 1 serotype with this exception:
- parainfluenza virus (4 serotypes)
- Parotitis can be caused by this paramyxovirus:
- mumps virus ("mumps gives you bumps")
- Triad of mumps symptoms are:
- asceptic Meningitis, Orchitis, and Parotitis (MOP)
- Measles virus
- p. 200
- What virus type causes measles?
- paramyxovirus
- What bluish-gray spots on the buccal mucosa are diagnostic of measles
- Koplik spots
- 3 Cs of measles
- Cough, Coryza, Conjunctivitis
- 3 possible sequellae
- SSPE, encephalitis, giant cell pneumonia. SSPE = subacute sclerosing panencephalitis
- Influenza viruses
- p. 200
- Five facts about Influenza: enveloped/nonenveloped, nuclear material, antigens, infection --> what risk?, protection.
- 1. Enveloped 2. ssRNA with segmented genome 3. Hemagglutinin and neuraminidase antigens 4. Risk of fatal bacterial superinfection 5. Protection = killed viral vaccine
- Treatment for influenza A?
- Amantadine, rimantadine, zanamivir, and oseltamivir
- Treatment for influenza B?
- Zanavir and oseltamivir (neuraminidase inhibitors)
- Rabies virus
- p. 200
- Rabies -- _______ (cytoplasmic inclusion) in _______(cell type)
- Negri bodies in neurons
- Rabies -- incubation period
- weeks to 3 months
- Rabies -- most common sources in US
- bat, raccoon, skunk (>dog)
- Rabies travels to the CNS byÂ…
- retrograde migration up nerve axons
- Arboviruses
- p. 200
- Arbovirus -- mode of transmission
- Transmitted by arthropods (mosquitoes, ticks)
- Arbovirus -- classic illnesses
- Dengue fever (in SE Asia = hemorrhagic shock syndrome) and yellow fever
- Arbovirus -- members of the family
- flavivirus, togavirus, bunyavirus
- Yellow fever
- p. 200
- Yellow fever is transmitted by ____________
- the Aedes mosquito
- Symptoms of yellow fever
- high fever, black vomitus, and jaundice.
- Yellow fever -- histology
- Liver: councilman bodies (acidophilic inclusions)
- Herpesviruses
- p. 201
- Name the diseases caused by the following Herpesviridae:
- HSV-1
- respiratory secretions and saliva
- HSV-2
- sexual contact, perinatal
- VSV
- respiratory secretions
- EBV
- respiratory secretions, saliva
- CMV
- congenital, transfusion, sexual contact, saliva, urine, transplant
- HHV-8
- sexual contact
- Name the routes of transmission for the following Herpesviridae:
- Mononucleosis
- p.201
- Mononucleosis is caused by _______
- EBV
- symptoms of mono
- fever, hepatosplenomegaly, pharyngitis, and lymphadenopathy (esp posterior auricular nodes)
- how do you test for mono?
- heterophil antibody test
- what do you see in the peripheral blood (mono)?
- atypical lymphocytes (cytotoxic T cells)
- Tzank test
- p.201
- What's a Tzanck test?
- A smear of an opened skin vesicle to detect multinucleated giant cells (seen in HSV-1, HSV-2, VSV)
- Hepatitis transmission
- p.201
- Name the type of nucleic acid and the virus type for the following hepatitis viruses:
- Hepatitis A
- fecal-oral
- Hepatitis B
- parenteral, sexual, maternal-fetal
- Hepatitis C
- blood (IV drug users)
- Hepatitis D
- coinfection with HBV!
- Hepatitis E
- enterically; water-borne epidemics
- Name the mode of transmission for the following hepatitis viruses
- which Hepatitis virus causes a high mortality rate in pregnant women?
- E
- which hepatitis virus has a short incubation period?
- A (3 weeks)
- which Hep virus has a long incubation period?
- B (3 months)
- which Hep virus has a DNA-dependent DNA polymerase?
- B; reverse transcription also occurs
- which pairs of viruses are similar in course, severity, and incubation?
- HAV & HEV; HBV & HCV
- Which virus type infection leads to chronic-carrier-status?
- B, C, and D
- Hepatitis serologic markers
- p. 202
- If I got a Hepatitis B vaccine (no infection), for what Ab would I have a positive serology?
- HBsAb
- If I recently had a Hepatitis B infection, for what Ab would I have a positive serology
- HBsAb and HBcAb (positive during window period)
- What test tells you either that I have a current infection or that I am a chronic Hep B carrier?
- HBsAg
- What test demands that you(the doctor) to tell me to stop having sex with my spouse lest I give them Hep B?
- HBeAg
- What test tells you(the doctor) that I can resume sex with my spouse because I'm not likely to give them Hep B?
- HBeAb (indicates low transmissibility)
- What is the "window period"?
- after the actue infection is cleared and before the humoral response produces lots and lots of Ab (HBsAg AND anti-HBs negative; HBcAb positive)
- How big is the Hep B virus
- 42 nm
- When can I detect HBV particles by DNA polymerase?
- during the incubation period and the acute disease period
- How can I distniguish between complete recovery from Hep B infection and the chronic carrier state?
- Complete recovery: HBsAg-neg, HBsAb-pos; Chronic carrier: HBsAb-neg. HBsAb-pos; HBcAb is positive in BOTH states
- HIV
- p. 203
- HIV has a ________ genome with __<#>__ molecules of __<nucleic acid>____
- HIV has a diploid genome with 2 molecules of RNA
- HIV: name the "rectangular nucleocapsid protein"
- p24
- HIV: name the envelope proteins
- gp41 and gp120
- HIV: name the matrix protein
- p17
- HIV: what other important protein hangs out inside the nucleocapsid?
- reverse transcriptase
- Does HIV integrate into the host genome?
- YES. HIV syntehsizes dsDNA from RNA and integrates the dsDNA into the host genome
- HIV diagnosis
- p. 203
- How do I make a diagnosis of HIV?
- ELISA --> confirmed by Western blot
- T or F: HIV testing is always positive 1-2 weeks after infection
- FALSE. ELISA/Western blot look for viral PROTEINS and can be falsely negative for the first 1-2 months of HIV infection
- How can I monitor the effect of HIV drug therapy?
- HIV PCR/viral load
- HIV immunity
- p. 203
- Who is immune to HIV?
- homozygous for CCR5 mutation
- What % of US caucasians have a slower course of HIV infection because of heterozygosity for the above allele?
- 20%
- Persons with ______________ have a rapid progression to AIDS
- CXCR1 mutation
- Time course of HIV infection
- p. 203
- HIV become symptomatic _____ after infection
- 3-10 years
- Anti-p24 and anti-gp120 increase between _______ after initial infection; after the onset of immunodeficiency, they ___________(increase or decrease)
- 1-2 months; decrease
- Opportunistic infections in AIDS
- p. 204
- Name the opportunistic infections seen in the following categories: (for AIDS patients)
- bacterial
- TB, Mycobacterium avium-intercellulare complex
- viral
- HSV, VAV, CMV, PML (JC virus)
- fungal
- Thrush (Candida albicans), cryptococcosis (cryptococcal meningitis), histoplasmosis, Pneumocystis pneumonia
- protozoan
- toxoplasmosis, cryptosporidiosis
- Prions
- p. 204
- Multiple choice: Prions are -- 1) infectious proteins ONLY 2) infectious RNA 3) infectious DNA 4) infectious proteins occasionally mixed with nucleic acids
- 1) infectious proteins
- Name examples of prion diseases
- CJD, kuru, scrapie, "mad cow"
- Jeopardy style: pathologic prions take on this conformation
- What is beta-pleated sheet
- Prions are associated with ___________ encephalopathy
- spongiform
- Microbiology -- systems
- p.204-205
- Normal flora: dominant
- p. 204
- Name the dominant normal flora in each of these areas:
- skin
- Staph epidermidis
- nose
- Staph aureus
- oropharynx
- Strep viridans
- dental plaque
- Strep mutans
- colon
- Bacteroides fragilis > E. coli
- vagina
- Lactobacillus, colonized by E. coli and group B strep
- Common causes of pneumonia
- p. 204
- Name the common causes of pneumonia in the following age groups:
- Children (6 weeks to 18 yrs)
- Virus (RSV), Mycoplasma, Chlamydia pneumoniae, Strep pneumoniae
- Adults (18-40 yrs)
- Mycoplasma, Chlamydia pneumoniae, Strep pneumoniae
- Adults (40-65 yrs)
- Strep pneumoniae, H. influenze, Anaerobes, Viruses, Mycoplasma
- Elderly
- Strep pneumoniae, viruses, anerobes, H. Influenzae, Gram-negative rods
- An AIDS patient comes into your office with symptoms of pneumonia. What organisms are you considering?
- Staphylococcus, gram-negative rods, fungi, viruses, Pneumocystis carinii
- A patient in the CCU gets pneumonia. What organisms are you thinking?
- Nosocomial infections are usually Staphylococcus and gram-negative rods
- The same patient also aspirated some peas prior to getting sick. What organisms do you add to your list?
- Anaerobes
- His domineering wife of this same patient is mad because he also had a viral infection last week. What infectious agents would you now consider?
- add H. influenzae; another common postviral pneumonia bug is Staph
- The wife is so distressed she goes into labor and gives birth to a 10 lb baby girl, who also gets pneumonia. Does she have the same bug as her dad in the CCU?
- Neonatal pneumonia is usually due to Group B streptococci or E. coli -- the dad could have the latter.
- Of course, the wife get sick too, but her pneumonia is classified as "atypical." What might she have?
- Mycoplasma, Legionella, Chlamydia
- Cause of meningitis
- p. 205
- Name the causes of meningitis in the following age groups:
- Newborn (0-6 months)
- Group B strep, E. coli, Listeria
- Children (6 mo to 6 years)
- Strep pneumoniae, Neisseria meningitidis, Haemophilus influenze type B, Enteroviruses
- 6-60 years
- N. meningitidis, Enteroviruses, S. pneumoniae, HSV
- 60+ years
- Gram-negative rods, Listeria
- An AIDS patient comes to you with high fevers, stiff neck, and mental status changes. What organisms might be causing his meningitis?
- Cryptococcus, CMV, toxoplasmosis (brain abscess), JC virus (PML)
- CSF findings in meningitis
- p. 205
- You do a spinal tap on your patient. The CSF pressure appears to be increased. What type of infectious agent have you eliminated?
- none. It could be bacterial, TB, fungal, or viral (in viral, CSF pressure is normal to increased)
- You do a quick smear of the spinal tap under the microscope and see increased polys. What type of infectious agent does this suggest?
- bacterial. In fungal, TB, and viral, you see increased lymphocytes.
- The lab tests show an increase in protein and a decrease in sugar in the CSF. Does that confirm your previous guess or confuse you?
- Confirms. These findings are seen in bacterial, fungal, and TB infections. In viral infections the protein and sugar concentrations of the CSF are normal.
- Osteomyelitis
- p. 205
- What population is most likely to get osteomyelitis?
- children
- What lab test is elevated in osteomyelitis?
- ESR
- For each of the following groups of persons, name the organism that is most likely to cause osteomyelitis
- Most people (nonspecific)
- S aureus -- assume S aureus if no other information
- sexually active
- Neisseria gonorrhea (rare -- septic arthritis is more common)
- drug addicts
- Pseudomonas aeruginosa
- Sickle cell Px
- Salmonella
- Prosthetic replacement
- S. aureus and S. epidermidis
- Vertebral
- Mycobacterium tuberculosis
- Urinary tract infections
- p. 205
- What 2 groups of males are likely to get UTIs?
- old men with enlarged prostates and baby boys with congenital defects
- What are symptoms of pyelonephritis?
- fever, chills, flank pain, CVA tenderness?
- What are symptoms of a UTI?
- dysuria, frequency, urgency, suprapubic pain
- The 2nd most common cause of UTI in young, ambulatory women is __________________
- Staphylococcus saprophyticus
- Your patient gets a UTI while in the hospital. What organisms do you want to make sure his antibiotics cover while his urine culture is growing?
- E. coli, Proteus, Klebsiella, Serratia, Pseudomonas
- What are predisposing factors for UTIs?
- female gender (10:1; short urethra colonized by fecal flora), flow obstruction, kidney surgery, catheterization, gynecologic abnormalities, diabetes, pregnancy
- UTI Bugs
- p. 206 "SSEEK PP"
- Has a blue-green pigment and fruity odor
- Pseudomonas aeruginosa
- Two UTI bugs that are nosocomial and drug resistant
- Pseudomonas aeruginosa and Serratia marcescens
- Leading cause of UTIs
- Escherichia coli
- What does Proteus mirabilis produce?
- Urease
- Serratia marcescens produce what color pigment?
- red
- Large mucoid capsule and viscous colonies
- Klebsiella pneumoniae
- What do E. coli colonies show on EMB agar?
- metallic sheen
- 2nd leading cause of UTIs in sexually active women
- Staphylococcus saprophyticus
- Associated with struvite stones and swarming on agar
- Proteus mirabilis