08a: Micro Flashcards

1
Q

Which part of cell wall structure is unique to gram positive bacteria?

A

Lipoteichoic acid

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2
Q

Mycobacteria doesn’t gram stain well because:

A

Cell wall has high lipid content

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3
Q

Chlamydia doesn’t gram stain well because:

A
  1. Intracellular

2. Low muramic acid in cell wall

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4
Q

Ziehl-Neelsen stain (carbol fuchsin) is used to stain (X). What are the steps that go into staining?

A

X = acid-fast bacteria (Mycobacteria, Nocardia) and protozoa (Cryptosporidium)

  1. Carbol fuchsin (red) dye
  2. Acid-alcohol wash
  3. Methylene blue counterstain
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5
Q

(X) bacteria is cultured on (Y) agar, which contains potato extract

A
X = Bordetella pertussis
Y = Bordet-Gengou 

(Bordet for Bordetella)

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6
Q

Dark black, slightly luminous colonies on cysteine tellurite agar

A

C. diptheriae

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7
Q

Legionella grown in which agar?

A

Charcoal yeast extract agar, buffered with Cys and iron

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8
Q

Fungi grown on which agar?

A

Sabouraud

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9
Q

(X) antibiotics are ineffective against anaerobes because they require oxygen to enter cell

A

X = aminoglycosides

“AminO2glycosides require O2”

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10
Q

List bacteria that are obligate intracellular. They must be in cells because they rely on (X)

A
  1. Rickettsia
  2. Chlamydia
  3. Coxiella

X = host ATP

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11
Q

T/F: H. pylori is catalase positive

A

True (also urease and oxidase positive)

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12
Q

Bacteria that produce urease (increase/decrease) pH of environment

A

Increase (hydrolyze urea into ammonia and CO2)

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13
Q

Bacteria bind and import short pieces of environmental, naked chromosomal DNA from another bacterial cell lysis

A

Transformation

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14
Q

F(+/-) contains genes required for (X). When “mating bridge” is formed, what’s being transferred?

A

F+
X = sex pilus and conjugation (with F- cell)

Single strand of plasmid DNA to F- cell, making it an F+ cell

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15
Q

F+ plasmid becomes incorporated into bacterial chromosomal DNA, making F+ cell a(n) (X) cell. If it comes in contact with F- cell, what can occur?

A

X = Hfr (high-frequency recombination)

Conjugation with F- cell allows Hfr cell to transfer/replicate part of chromosome (F- cell becomes “recombinant F- cell”)

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16
Q

List the 5 bacterial toxins encoded in lysogenic phage

A

“ABCD’S”

  1. group A strep erythrogenic toxin
  2. Botulinum toxin
  3. Cholera toxin
  4. Diphtheria toxin
  5. Shiga toxin
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17
Q

Recent traveller to Latin America, Asia, or Africa presents with fever, HA, watery diarrhea that has become bloody. Hepatosplenomegaly and faint, erythematous maculopapular lesions on chest/abdomen. Dx?

A

Typhoid fever

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18
Q

Kidney transplant patient with low-grade fever and pneumonia symptoms. Small, round organisms staining red with mucicarmine stain of bronchoalveolar fluid. Dx?

A

Cryptococcus neoformans lung disease

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19
Q

Pseudohyphae with blastoconidia

A

Candida

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20
Q

(X) bacteria produces (Y) factor, which enlarges area of hemolysis formed by S. aureus

A
X = Group B strep (agalactiae)
Y = CAMP
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21
Q

Gram positive, Catalase negative, PYR positive, gamma hemolytic

A

Enterococcus

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22
Q

(X) assay can be used to test for TB in patients with BCG vaccine due to fewer false (pos/neg)

A

X = Interferon gamma release assay

False pos

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23
Q

AIDs patient with CD4 count recently dropped under 50: what’s a key bacterium that he should now receive prophylactic Rx for?

A

Mycobacterium avium (with Azithromycin)

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24
Q

Penicillins/cephalosporins work by binding (X). Vancomycin works by binding (Y).

A
X = Penicillin-binding proteins (ex: transpeptidases)
Y = glycoproteins
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25
Q

Prevention of neonatal tetanus involves efforts focused on:

A

Vaccination of pregnant women and those of child-bearing age (with inactivated tetanus toxoid)

Also cord hygiene

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26
Q

Cat bite resulting in cellulitis. Most likely infectious cause:

A
Pasteurella multocida (#1) 
Could also be Bartonella
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27
Q

Pasteurella multocida can cause which two key presentations/diseases?

A

Osteomyelitis and cellulitis

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28
Q

Patient presents with infected calf injury that has mouse-like odor

A

Pasteurella multocida infection

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29
Q

T/F: Bacterial vaginosis can be prevented via condom use

A

False - not a sexually transmitted disease

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30
Q

(X) are mulberry-like inclusions in cytoplasm of either monocytes or granulocytes. Which disease(s)?

A

X = morulae

  1. Ehrlichiosis (in monocytes)
  2. Anaplasmosis (in granulocytes)

“MEGA berry = Monocytes Ehrlichiosis, Granulocytes Anaplasmosis”

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31
Q

Chlamydia serotypes L1, L2, L3 cause:

A

Lymphogranuloma venereum (small painless ulcers on genitals with swollen painful inguinal lymph nodes that ulcerate)

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32
Q

(Acetylated/deacetylated) histones allow chromosome transcription

A

Acetylated (via HAT)

“you put a HAT on to go to work”

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33
Q

Restrictive cardiomyopathy with amyloid deposition is typically (primary/secondary) amyloidosis

A

Primary (ex: MM)

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34
Q

Transmission of Giardia lamblia is via (X) in water. Diagnosis is via (Y)

A
X = cysts (fecal-oral route)
Y = trophozoites/cysts in stool or antigen detection
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35
Q

Abscess with “Anchovy paste” exudate

A

Amebiasis (entamoeba histolytica); liver abscess

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36
Q

Transmission of Entamoeba histolytica is via (X) in water. What are the methods of diagnosis?

A

X = cysts (fecal-oral route)

  1. Trophozoites with engulfed RBCs; cysts with up to 4 nuclei in stool
  2. Ag detection
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37
Q

Flask-shaped ulcers formed on intestinal biopsy

A

Entamoeba histolytica

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38
Q

Which drugs used to eliminate E. histolyctica cysts from intestinal lumen?

A

Paromomycin or Iodoquinol

Otherwise, general Rx is metronidazole

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39
Q

Severe diarrhea in AIDs patient caused by protozoa

A

Cryptosporidium

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40
Q

Rx for cryptosporidium

A

Immunocompetent: Nitazoxanide
Immunocompromised: Spiramycin

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41
Q

Toxoplasma: (X) are transmitted in cat feces. What’s the treatment?

A

X = oocyts

Sulfadiazine and pyrimethamine

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42
Q

Toxoplasmosis (X) brain lesions can be mistaken for (Y) and the two can be differentiated via which method?

A
X = ring-enhancing (calcified)
Y = CNS lymphoma (usually solitary lesion)

Biopsy

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43
Q

Rapidly fatal meningoencephalitis from swimming in freshwater lake

A

Naegleria fowleri (enters via cribiform plate)

44
Q

Naegeria fowleri diagnosis via (X) and Rx is (Y)

A
X = amoebas in spinal fluid
Y = Amphotericin B (linked to few survivors)
45
Q

Patient presents with cervical/axillary lymphadenopathy, somnolence, and recurring fevers. Reports recent bug bite that was very painful

A
African sleeping sickenss via:
Trypanosoma brucei (CNS protozoa) - transmitted by Tsetse fly
46
Q

Trypanosoma brucei diagnosed via (X) and treated with (Y)

A
X = trypomastigotes in blood smear
Y = Suramin (for blood disease), Melarsoprol (for CNS penetration)
47
Q

Test for G6PD deficiency before administering which anti-malarial drugs?

A
  1. Primaquine

2. Artesunate

48
Q

Severe, irregular fever patterns and cerebral malaria

A

P. falciparum

49
Q

(X) drug is used to treat both malaria and babesia

A

X = atovaquone

50
Q

Malaria: mosquitos are carrying (X) form of protozoan. Enters human and matures to (Y) form in (blood/liver).

A

X = sporozoite
Y = merozoite (contained in schizont)
Liver

51
Q

Malaria: (X) form of protozoan enters/infects RBCs.

A

X = merozoite

52
Q

T/F: All merozoites in malaria come from liver

A

False - after initial infection of RBCs, life cycle (trophozoite to schizont to merozoite) continues in RBCs

53
Q

Fever, respiratory distress (crackles, infiltrates), hemolytic anemia. Severe disease in asplenic patients. Which protozoan?

A

Babesia

54
Q

Chagas disease caused by (X) and treated with (Y)

A
X = Trypanosoma cruzi
Y = Benznidazole or nifurtimox
55
Q

Leishmania donovani transmitted via (X) and diagnosed via (Y)

A
X = sandfly
Y = presence of amastigotes in macrophages
56
Q

Black fever, aka kala-azar, is caused by (X) and presents with which symptoms?

A

X = Leishmania donovani (visceral leishmaniasis)

Spiking fevers, hepatosplenomegaly, pancytopenia (fatal if left untreated)

57
Q

Leishmaniasis treatment:

A

Stibogluconate (cutaneous; ulcers) or amphotericin B (visceral)

58
Q

(X) nematode can auto-infect host by ability to produce which larvae form?

A

X = Strongyloides stercoralis (threadworm)

Rhabditiform (non-infectious; seen in host feces) lay eggs in intestine that hatch Filariform larvae (infectious; penetrate mucosa and re-enter blood)

59
Q

Visceral larva migrans caused by which organism?

A

Toxocara canis

60
Q

Skin changes, due to loss of (X), and river blindness caused by which organism?

A

X = elastic fibers

Onchocerca volvulus

61
Q

Worm crawling across eyeball

A

Loa loa

62
Q

Liver cystic mass with eggshell calcifications

A

Echinococcus granulosus

63
Q

Fluke egg with lateral spine

A

Schistosoma mansoni

64
Q

Fluke egg with terminal spine

A

Schistosoma haematobium

65
Q

Schistosoma transmitted via (X) and Clonorchis sinensis transmitted via (Y)

A
X = contact with fresh water snails
Y = eating undercooked fish
66
Q

(X) fluke/trematode causes (Y) type of gallstone

A
X = Clonorchis sinensis
Y = pigmented (brown; injured hepatocytes release beta-glucoronidase which hydrolyzes BRDG so high levels of unconjugated BR)
67
Q

Klebsiella is lactose (fermenter/non-fermenter)

A

Fermenter

68
Q

IgA proteinase role is to allow bacteria to:

A

Adhere to mucosa (via cleaving IgA at hinge region and reducing effectiveness)

69
Q

1 yo child with 3-5 days high fever, febrile seizures followed by maculopapular rash on trunk

A

Roseola infantum (by HHV-6)

70
Q

Viral particle with envelope highly similar to that of nuclear cell membrane

A

Herpesviruses (acquire envelope via budding from nucleus)

71
Q

T/F: Cryptococcus is a budding yeast

A

True

72
Q

HIV patient with pain and itching in peri-rectal area. Single, hard mass with superficial ulceration. No hemorrhoids, no lymphadenopathy. Dx?

A

Squamous cell cancer (anus); linked to HPV infection

73
Q

All RNA virus genomes are single stranded except:

A

Reovirus (dsRNA)

74
Q

All DNA viruses replicate in (nucleus/cytoplasm) except:

A

Nucleus

Pox (“Pox out of the box”)

75
Q

All RNA viruses replicate in (nucleus/cytoplasm) except:

A

Cytoplasm

Influenza and Retrovirus (HIV, HTLV)

76
Q

Which DNA virus has a reverse transcriptase?

A

Hepadna (HBV)

77
Q

Parvovirus is highly tropic for (X) cells and enters via (Y) receptor

A
X = erythroid precursors
Y = P antigen (aka Globoside)
78
Q

Number one cause of aseptic meningitis

A

Enteroviruses (picornavirus family)

79
Q

Zika is part of which virus family?

A

Flaviviruses

80
Q

Nearly all positive sense RNA viruses have (helical/icosahedral) capsids except:

A

Icosahedral

Coronavirus (helicall) and HIV (complex, conical)

81
Q

Nearly all negative sense RNA viruses have (helical/icosahedral) capsids except:

A

Helical; Delta virus (uncertain)

82
Q

1 rabies carrier in US

A

Bats

83
Q

Eosinophilic negri bodies in neural tissue on microscopy

A

Rabies

84
Q

Ebola is what type of virus?

A

Filovirus (neg sense RNA)

85
Q

Ambisense virus

A

Arenavirus (both pos and neg sense RNA)

86
Q

(Pos/neg) strand RNA viruses must always carry their own (X) polymerase

A

Neg

X = RNA-dep RNA pol (to make pos strand)

87
Q

List the segmented RNA viruses

A

All neg-sense

“BOAR” (Bunyavirus, Orthomyxovirus, Arenavirus, Reovirus)

88
Q

High fever, black vomit, and jaundice after mosquito bite

A

Yellow fever (flavivirus; aedes mosquito)

89
Q

Most important global cause of infantile gastroenteritis is (X). Prevention via:

A

X = rotavirus

Live vaccine (recommended by CDC for all infants)

90
Q

(X) change in genome causes genetic shift. (Y) causes genetic drift.

A
X = reassortment (cause pandemics)
Y = random mutations (cause epidemics)
91
Q

Mumps symptoms

A

Parotids and testes as big as “POM-Poms”

  1. Parotitis
  2. Orchitis (can cause sterility)
  3. Meningitis
  4. Pancreatitis
92
Q

Bullet-shaped virus; capsule studded with (X) spikes

A

X = glycoprotein

Rabies

93
Q

HIV: ELISA/Western blot tests are often false (pos/neg) on newborns born to infected mothers. What should be used to detect viral load in infant?

A

False positive (anti-gp120 Ab cross placenta)

PCR

94
Q

Viral hepatitis liver biopsy: granular eosinophilic “ground glass” appearance with cytotoxic T cells

A

HBV infection (note: cytotoxic T cells, NOT HBV, mediate damage)

95
Q

Viral hepatitis liver biopsy: ballooning degeneration, spotty necrosis, monocyte infiltration, (X) bodies

A

X = councilman

HAV infection

96
Q

Prions are normally (PrPC) predominantly (alpha-helical/beta-pleated) proteins.

A

Alpha-helical

PrPSC transformation higher in beta-pleated sheets

97
Q

Just about any healthy patient over 6 months old presenting with septic meningitis most likely has infection with (X). Which age group is the exception within this age range?

A

X = S. pneumo

Teens (N. meningitidis is #1)

98
Q

Pneumonia in an otherwise healthy neonate: top two infectious causes. What about for septic meningitis in a neonate?

A
  1. Group B step
  2. E. coli

Same pathogens for meningitis!

99
Q

Kids and teens presenting with pneumonia symptoms are most likely infected with:

A

Virus (RSV)

100
Q

Adults (up until age of 40) presenting with pneumonia symptoms are most likely infected with:

A

Mycoplasma

101
Q

Patients over 40 presenting with pneumonia symptoms are most likely infected with:

A

S. pneumo

102
Q

Painless, beefy red genital ulcer that bleeds easily on contact

A

Granuloma inguinale (Klebsiella granulomatis; uncommon in US)

103
Q

Which antibiotics inhibit 30S ribosome? And 50S?

A

“buy AT 30, CCEL (sell) at 50”

30S: Aminoglycosides, Tetracyclines
50S: Chloramphenicol, Clindamycin, Erythromycin, Linezolid

104
Q

Aminoglycosides: bacteria mechanism of resistance to drug

A
  1. Transferase enzyme (on cytoplasmic surface) catalyze transfer or acetyl, methyl, or other groups to drug (inactive it)
  2. Efflux pumps
105
Q

Aminoglycosides are absolutely contraindicated in patients with (X) disease

A

X = Myasthenia gravis (can cause neuromuscular blockade)

106
Q

Dapsone mechanism of action

A

(Like sulfonamides) inhibits Dihydropteroate synthase (blocks PABA to DHF conversion in folate synthesis)

107
Q

(X) antimicrobial drug has same target as methotrexate

A

X = Trimethoprim (inhibits dihydrofolate reductase)