Sketchy Micro Flashcards
1
Q
Associate bird or bat droppings with what fungus?
A
Histoplasma
also spelunking
2
Q
Where is histoplasma endemic to?
A
Midwestern US
3
Q
How is histoplasma transmitted?
A
Spores, airborne
4
Q
How big is histoplasma as compared with RBCs?
A
Smaller
Many histo spores (ovoid bodies) can be found within macrophages
5
Q
What kind of fungus is histoplasma?
A
Dimorphic
Mold in the cold, yeast in the heat
6
Q
What is the treatment for histoplasma?
A
Itraconazole
7
Q
The calcified granulomas of histoplasma resemble what infection
A
TB
8
Q
Where is blastomycosis endemic to?
A
Great lakes, Ohio River Valley, Southern US
9
Q
Is blastomycosis dimorphic?
A
Yes
Mold in the cold, yeast in the heat
10
Q
How is blastomycosis transmitted?
A
Inhalation of spores
11
Q
How big is blastomycosis w/r/t RBCs?
A
Almost the same size as RBCs
12
Q
How would a CXR look of a person with a blastomycosis infection?
A
Hazy, with patchy alveolar infiltrate
13
Q
Disseminated infection with blastomycosis, as with an immunocompromised patient, presents with
A
Skin and bone issues such as osteomyelitis
14
Q
T/F: Infection with blastomycosis can be either acute or chronic.
A
True
15
Q
How is blastomycosis diagnosed?
A
KOH wet mount;
Culture;
Urine antigen test
16
Q
How is blastomycosis treated?
A
azoles for local infection, ie itraconazole
amphotericin B for disseminated infection
17
Q
How does blastomycosis appear under the microscope?
A
Broad based budding (looks like balls)
18
Q
Where is coccidiodes endemic to?
A
Southwestern US
19
Q
How is coccidiodes transmitted?
A
Inhalation
Earthquakes are a risk factor bc of dust.
20
Q
What kind of organism is coccidiodes?
A
Dimorph
Mold in the cold
Spherules of endospores in the heat
21
Q
How big is coccidiodes w/r/t RBCs?
A
Bigger than RBCs
22
Q
What is the presentation of coccidiodes infection in a healthy person?
A
Asymptomatic subclinical - pneumonia-like with coughing and arthralgia
23
Q
What does the CXR of a patient with coccidiodes infection look like?
A
CXR can show cavities or nodules
24
Q
Seeing erythema nodosum on a patient with coccidiodes indicates what clinical scenario?
A
It indicates that the patient is having a robust immune response
25
Infection of coccidiodes in an immunocomprimised patient would show what?
Skin and bone involvement, as well as meningitis
26
How is coccidiodes diagnosed?
KOH
Culture
Serology for IgM
27
What is the treatment for coccidiodes?
Local lung infection, can use azole drugs;
| Systemic infection, use amphotericin B
28
What is the regional distribution of paracoccidiodes?
South America
29
How does paracoccidiodes appear?
Captain's wheel - multiple buds from one single center
30
What fungal form does paracoccidiodes assume in the lung?
Yeast in the lung;
| Mold in the environment
31
What size is paracoccidiodes w/r/t RBCs?
Paracoccidiodes is larger than RBCs
32
What is the mode of transmission for paracoccidiodes?
Respiratory droplets
33
What are the symptoms of infection with paracoccidiodes?
Coughing
Cervical lymphadenopathy
Granulomas in lungs
Mucocutaneous lesions
34
How is infection with paracoccidiodes treated?
Itraconazole for mild infection;
| Amphotericin B for severe infection
35
What is a unique feature of cryptococcus neoformans?
cryptococcus neoformans is heavily encapsulated
**Has a repeating polysaccharide capsular antigen which lends itself to being tested with the latex agglutination test
36
Where is cryptococcus neoformans found?
Soil
Pidgeon droppings
Can stay infectious for a LONG time
37
What is the mode of transmission of cryptococcus neoformans?
Inhalation
| Primary focus of infection is the lungs
38
Is cryptococcus neoformans urease (+) or (-)?
Urease (+)
39
What population is most at risk for infection from cryptococcus neoformans?
The immunocomprimised, particularly HIV patients
40
How does infection with cryptococcus neoformans present?
Cryptococcal pneumonia, fever, cough, dyspnea
41
What is a severe presentation of cryptococcus neoformans infection?
Meningitis, often results in neurological deficits
42
How is cryptococcus neoformans grown in culture?
Sabauraud's agar
silver stain = methanamine
red stain = mucicarmine
43
Under the microscope, what feature does cryptococcus neoformans have?
Wide capsular halo
44
On gross pathology, what distinctive features does cryptococcus neoformans have?
Soap bubble lesions on gray matter of brain
45
What is the treatment for infection with cryptococcus neoformans?
Amphotericin B and flucytozine (and fluconazole) - joint
46
What populations are particularly susceptible to infection with mucormycosis?
Leukemics
Diabetics
Neutropenics
(immunocompromised)
47
How is mucormycosis (or rhizopus) transmitted?
Spore inhalation
| **DKA (excess ketones, as with unmanaged diabetes, is a major risk factor)
48
How does mucormycosis appear?
Wide angle branching rods, nonseptate
49
Where does mucormycosis like to profilerate?
Blood vessels
50
Where does mucormycosis like to go when it infects?
It like to cross the cribiform plate and go to the brain, it creates gigantic lesions ie rhinocerebral mucormycosis, results in eschars (abscesses) on the face
51
How is infection with mucormycosis treated?
Surgical debridement of necrotic tissue
Amphotericin B
this baby is a killer**
52
What bacterial infection is often fatal in burn patients?
Pseudomonas
53
```
Pseudomonas is:
Gram ___
Shape:
Oxidase ___
Catalase ___
Capsule or no capsule?
```
```
Gram (-) encapsulated bacillus
Oxidase +
Catalase + (associated with chronic granulomatous disease)
Obligate aerobe
enterobacteriaciae
```
54
What is the #1 cause of nosocomial pneumonia?
Pseudomonas;
| common cause of respiratory failure in CF patients
55
Pseudomonas can progress to what infection in diabetics and IV drug users?
Osteomyelitis
56
Erythema gangrenosum are black skin lesions caused by sepsis induced by what organism?
Pseudomonas
57
Exotoxin A is a virulence factor of what bacterium?
Pseudomonas
58
How is pseudomonas treated?
Pipercillin/tazobactam;
Aminoglycosides in combination in beta lactams;
Fluroquinolones for UTI (indwelling catheter patients)
59
Psuedomonas can cause what pruritic papulopustular infection?
Hot tub folliculitis - underchlorination of hot tubs
60
Legionella causes what 2 presentations?
1. Legionnaire's disease - atypical pneumonia seen in smokers;
2. Pontiac fever - self-limiting
61
What stain should legionella be visualized with?
Silver stain
Legionella is a gram (-) bacillus but can't use H&E
Oxidase (+)
62
How is legionella transmitted?
From the source, not contagious person to person
63
How is legionella grown?
Special agar - buffered charcoal yeast extract w/ cysteine and iron
64
What is seen on CXR of a patient with Legionnaire's diseasE?
Patchy infiltrate with consolidation of 1 lobe
65
```
A patient has the following symptoms:
Hyponatremia;
Neurologic symptoms - HA, confusion;
Diarrhea;
High fever;
Pneumonia-like symptoms
What is the likely pathogen?
```
Legionella
66
How is legionella diagnosed?
Culture respiratory sputum
Special agar - buffered charcoal yeast extract w/ cysteine and iron
Visualize with silver stain OR
Rapid urine antigen test
67
What is the treatment for legionella?
Macrolides
| Fluoroquinolones
68
What is the taxonomy of Coxielle Burnetti?
Gram (-)
| Obligate intracellular
69
Q Fever is caused by what pathogen?
Coxielle Burnetti
70
How is Coxiella Burnetti transmitted?
Kicked up in dirt and farm animal droppings - aerosol transmission;
Or vets that deal in the birth of farm animals (placental secretions)
71
What are the symptoms of Q fever?
```
Caused by Coxielle Burnetti:
Pneumonia
HA
fever
HEPATITIS***
usually self-limiting
```
72
What is a rare complication of Q fever (Coxiella Burnetti) that can be seen in immunocompromised patients?
Endocarditis
73
The wheal seen in a + PPD is what type of hypersensitivity reaction?
Type IV
74
What virulence factors prevent TB from being destroyed?
Cord factor - serpentine shape - prevents mycobacterium from destruction;
Sulfatides allow TB to survive in macrophages and prevent formation of the phagolysosome
75
What is the taxonomy of Mycobacteerium tuberculosis?
Acid-fast
| Obligate aerobe
76
What is a tuberculoma?
Cavitary lesion in the brain caused by TB infection
77
What is the acronym for TB treatment?
RIPE
| Rifampin - Isoniazid - Pyrazinamide - Ethambutol
78
The tuberculoid form of M. leprae infection is what kind of immune response?
Th1 - cell-mediated immunity - body can contain infection within macrophages
presents with well-demarcated, hairless plaque on skin
79
The lepromatous form of M. leprae infection is what kind of immune response?
Th2 - humoral response - body cannot contain infection within macrophages - reason for neuropathy and lesions on extensor surfaces, leonine facies
80
Is there human to human transmission of M. leprae?
Yes, esp where lepromatous form predominates
81
What is the reservoir for M. Leprae in the U.S.?
Armadillo
82
Name the virus:
Naked
DNA virus
#1 cause of tonsillitis
Adenovirus
| common cause of conjunctivitis also
83
What populations are at risk for getting adenovirus?
Military recruits (can receive a live vaccine);
People who swim in public pools;
Children
84
What virus is responsible for the complication of hemorrhagic cystitis?
Adenovirus
85
Aspergillus fumigatus is a conidia that shares what feature with bacteria?
It's catalase +
86
Aflatoxins that cause hepatocellular carcinomas are what kind of aspergillus?
Aspergillus FLAVUS
87
How does aspergillus appear under the microscope?
Acute angles (
88
How is aspergillus transmitted?
Inhalation
89
Aspergillus causes what kinds of infections?
THREE:
1. Allergic bronchopulmonary aspergillosis (ABPA) -
2. Aspergillomas - balls of fungus in the lungs
3. Angioinvasive Aspergillosis - WORST
90
Allergic bronchopulmonary aspergillosis (ABPA) is what kind of hypersensitivity reaction?
Type 1
Wheezing, fever, **migratory pulmonary infiltrate, increased IgE
can be seen in CF patients
91
What patient populations are at risk for developing aspergillomas?
TB, Klebsiella patients
92
What patients are at risk for Angioinvasive Aspergillosis?
Immunocomprimised
Kidney failure, ring-enhancing lesions on brain, Endocarditis, necrosis around nose due to spread to paranasal sinuses
Treat with ampho B, surgical debridement as necessary
93
Aspergillosis, except for the most severe form, is treated with:
"conazoles" ie Voriconazole
94
Orthomyxovirus is responsible for what disease?
Influenza BITCHES
3 strains - A, B, C
8 segments --> relates to how the virus can mutate
95
What is the taxonomy or orthomyxovirus?
RNA
(-) sense
Enveloped
96
What is unique about orthomyxovirus as an RNA virus?
It's the only RNA virus that replicates in the nucleus
97
Influenza A is responsible for what kinds of outbreaks?
PANdemics and epidemics
Pandemics - antigenic SHIFT - changes in Hs and Ns on surface antigens to form new viruses (reassortment)
Epidemics - antigenic DRIFT - point mutations
98
Influenza B is responsible for what kinds of outbreaks?
Just epidemics
| Epidemics - antigenic DRIFT - point mutations
99
How does Tamiflu work?
NA inhibitor
Prevents NA from breaking viral babies free from sialic acid;
must give early in the course of the disease
100
How is influenza (orthomyxovirus) transmitted?
Respiratory droplets
101
What vaccines are available for influenza (orthomyxovirus)
Trivalent - 2A and 1B strains
Quadrivalent - 2A and 2B strains
can receive >6 months of age
102
What is the major complication of influenza (orthomyxovirus)?
Pneumonia, often by Staph aureus or Strep pneumo;
| Guillain-Barre syndrome (high protein, low WBC in CSF)
103
What is the taxonomy of Paramyxovirus?
Single strand
RNA virus
(-) sense
Replicates in the cytoplasm
104
Why is the MMR vaccine not indicated for pregnant patients?
It's live-attenuated
105
Associate the 4 C's: Cough, Coryza, Koplick spots and Conjunctivitis, with what viral illness?
Measles (Rubeola)
caused by Paramyxovirus
4 days of that stuff, followed by a maculopapular rash that becomes confluent and is itchy, Starts on face and moves down the body
106
What are the complications of measles (rubeola)?
Pneumonia
| SSPE - subacute sclerosing panencephalitis - can happen years later, no tx for it
107
What virulence factors does paramyxovirus-rubeola have?
Hemagglutinin
Fusion proteon --> multinucleated giant cells --> syncytia
**Vitamin A admin reduces virulence factors and complications
108
Mumps is caused by what kind of virus?
Paramyxovirus
109
RSV is caused by what kind of virus?
Paramyxovirus
110
Croup is caused by what kind of virus?
Paramyxovirus
111
Hemagglutinin, Fusion Protein and Neuraminidase are virulence factors of what paramyxovirus?
Mumps
112
Where does mumps replicate?
Parotid glands
Can cause orchitis and meningitis
113
What is the most common cause of pneumonia and bronchiolitis in infants?
RSV
| Infiltrates on CXR
114
What is the only virulence factor of RSV?
Fusion protein (syncytia formation)
115
Seal bark and inspiratory stridor are characteristic of what paramyxoviral infection?
Croup aka laryngotracheobronchitis
116
A pediatric patient with Croup would likely have a CXR showing:
Steeple sign - narrowing of subglottal region
117
Croup has what virulence factors?
Croup is a paramyxovirus - parainfluenza:
| HA, NA, fusion protein
118
What is the gram (-) rod is responsible for causing whooping cough (100 days cough)?
Bordatella pertussis
| Highly contagious - transmission via respiratory droplets
119
Bloodwork of a patient with whooping cough would show what abnormality?
Leukocytosis
120
How does the bordatella pilus work to infect cells?
Filamentous hemagglutinin attaches, pertussis toxin exotoxin causes ciliary stasis and death of ciliated cells
121
Which bordatella vaccine is used in the U.S.?
Acellular (DTaP), has a shorter window of effectiveness than the killed version (used abroad)
122
Bordatella pertussis is treated with:
Macrolides
123
Name the pathogen:
Gram (-)
Coccobacilliary
Grows on chocolate agar with factors V and X
Haemophilus influenzae
124
How is Haemophilus influenzae transmitted?
Aerosol
125
Pneumonia, Epiglottitis, Meningitis and Otitis media are three presentations of what gram (-) bacterium?
Haemophilus influenzae
126
What patient population is more at risk for Haemophilus influenzae infection?
Splenectomized patients (SCD) - can develop sepsis or septic arthritis
127
The Haemophilus influenzae vaccine covers what type?
Type B (the cause of meningitis, encapsulated)
128
What are the symptoms of epilglottitis caused by Haemophilus influenzae?
Inspiratory stridor;
"cherry red epiglottis;"
drooling
129
What is indicated for close contacts of a patient with Haemophilus influenzae?
Rifampin prophylaxis
