Microbiology Flashcards
(204 cards)
1
Q
What is Tellulrite agar used to detect?
A
C. diphtheriae
2
Q
What is Loeffler medium used to detect?
A
C. diphtheriae
3
Q
What is lowenstein-Jensen agar used to detect?
A
Mycobacterium TB
4
Q
How do you stain for H. pylori?
A
Silver Stain
5
Q
How do you stain for Legionella?
A
Silver Stain
6
Q
Where can you get listeria from?
A
Unpasteurized milk, deli meats or by vertical transmission/vaginal delivery
7
Q
What is carbol fuschin?
A
Acid fast stain
8
Q
What is the charcoal yeast extract with cysteine and iron?
A
Legionella
9
Q
What is MacConkey agar used for?
A
Lactose fermenting (such as E.coli); will form pink colonies
10
Q
What is EMB (eosin-methylene blue) agar used for?
A
E. coli (forms green metallic sheen)
11
Q
What are the aerobes?
A
Nocardia, Pseudomonas, Mycobacterium
12
Q
What are obligate intracellular pathogens?
A
Rickettsia, Chlamydia
13
Q
What are the catalase positive organisms?
A
S. aureus, E.coli, Candida, Serratia, Pseudomonas, Aspergillus, Listeria, Burkholderia, Nocardia
14
Q
How does Pertussis toxin work?
A
Increases cAMP b displaying Gi, impairing phagocytosis. Its an ADP-ribosylating toxin.
15
Q
How does C. perfringens toxin work?
A
It is a phospholipase (lecithinase) that degrades cell membranes
16
Q
Transformation vs Transduction?
A
Transformation: naked DNA transfer
Transduction: Generalized - lytic phage
Trasnduction: Specialized - lysogenic phage
17
Q
What does Protein A do and what pathogen is it a virulence factor of?
A
Virulence factor of S. aureus. Binds Fc portion of IgG inhibiting complement activation and phagocytosis
18
Q
If you get influenza infection, what pathogen can give you pneumonia after?
A
S. aureus (especially in elderly) or S. pneumo/Hib
19
Q
What produces dextrans from glucose?
A
S. sanguis (viridans strep)
20
Q
What are the toxins of S. pyogenes?
A
Exotoxin A and Streptolysin O
21
Q
What is PYR Test positive?
A
S. pyogenes
22
Q
What produces CAMP factor?
A
S. agalactiae
23
Q
What causes subacute endocarditis following GI/GU procedures?
A
Group D enterococci
24
Q
What encodes the diptheria toxin?
A
Beta-prophage
25
What else can diphtheria cause besides pharyngitis?
Myocarditis, arrhythmia, lymphadenopathy
26
What does Elek test do?
Tests for diphtheria toxin
27
What has metachromatic granules (blue and red)?
Diphtheria
28
What forms spores?
Bacillus (anthrax, cereus), clostridium, Coxiella burnetti
29
What else does C. perfringens cause besides gas gangrene?
Late onset food poisoning causing watery diarrhea; from undercooked meat
30
What looks like serpentine or medusa head?
Anthrax
31
What is the only gram positive bacteria to make endotoxin?
Listeria
32
Which bug causes spontaenous abortion?
Listeria
33
What cause vertebral osteomyelitis?
Myocbacterium TB (Pott's Disease)
34
What is the prophylactic treatment of MAC?
Azithromycin
35
What does cord factor do?
Inhibits macrophage maturation and induces release of TNF-alpha
36
What do sulfatides (in TB) do?
inhibit phagolysosomal fusion
37
What does Lepromin test show?
Positive for tuberculoid due to Th1 response but negative for lepromatous due to Th2 response (no cell immunity)
38
What presents as hypopigmented hairless plaques with focal decreased sensation?
Tuberculoid Leprosy
39
What strain of Hib causes conjunctivitis, otitis media, bronchitis?
Nontypable
40
How do you treat Hib meningitis?
Ceftriaxone
41
How do you treat Hib mucosal infections?
Amoxicillin +/- clavulanate?
42
What do labs show for for legionella?
Hyponatremia
43
What is a non lactose fermenting gram negative rod that produces H2S?
Salmonella
44
What is a non lactose fermenting gram negative rod that does not produce H2S?
Shigella
45
What is the diagnosis? Travel to endemic area, faint rose colored spots on the abdomen, fever, abdominal pain, intestinal perforation.
Salmonella Typhi
46
How does Salmonella typhi cause a carrier state?
Remain in gallbladder
47
What enteric infection do you get from puppies' feces?
Campylobacter of Yersinia
48
What is urease, oxidase, and catalase positive?
H. Pylori
49
Treatment for H. pylori?
PPI + clarithromycin + amoxicillin or metronidazole
50
What does leptospira cause?
Flu-like symptoms, jaundice, photophobia, conjunctival suffusion
51
Where do you get leptospira from?
Water contaminated with animal urine; seen among surfers and tropics?
52
What is Weil disease?
Severe form of Leptospirosis (jaundice, azotemia, fever, hemorrhage, anemia)
53
How do you treat Lyme Disease?
Doxycycline or Ceftriaxone
54
What causes Francisella?
Ticks, rabbits, deer fly
55
How do you treat Rickettsial disease (rocky mountain etc)
Doxycycline
56
What bug do you get from cattle placenta and tick feces?
Coxiella Burnetti (Q fever aka pneumonia)
57
What has cytoplasmic inclusions seen on Giemsa?
Chlamydia
58
What grows on Eaton agar?
Mycoplasma (cholesterol enriched media)
59
What is a disc shaped yeast on methenamine silver stain?
Pneumocystis Jirovecii
60
What is a cigar shaped budding yeast?
Sporothrix schenkii
61
What is the treatment for entaemoba histolytica?
Metronidazole; Iodoquinol for asymptomatic
62
What causes bloody diarrhea, liver abscess with anchovy paste exudate, RUQ pain?
Entamoeba Histolytica
63
What is the classic triad of congenital toxoplasmosis?
Intracranial calcifications, chorioretinitis, hydrocephalus
64
How do you treat toxoplasmosis?
Sulfadiazine, pyrimethamine
65
What is the treatment for African sleeping sickness?
Suramin for blood borne disease; Melasoprol for CNS penetration
66
What is the treatment for Babesia?
Atovaquone + azithromycin
67
Which bugs cause dilated cardiomyopathy?
Coxsackie B and T. cruzi (Chagas Disease)
68
What is the treatment for T. cruzi?
Benzinidazole or nifurtimox
69
What disease is it if you see macrophages with amastigotes?
Leishmniasis
70
What is Leishmaniasis
Spiking fevers, hepatosplenomegaly, pancytopenia
71
What is associated with a strawberry cervix?
Trichomonas vaginalis
72
What do you treat Trichomonas with?
Metronidazole (both bacterial vaginosis and this is metronidazole)
73
What is the treatment for Strongyloides?
Ivermectin or albendazole
74
How do you treat enterobius, ascaris, and ancytoplasma/necator?
Pyrantel pamoate or bendazole
75
What is it if you see rhabtidiform larvae in stool?
Strongyloides
76
What are the symptoms of strongyloides?
Pruritc streak (larva currens), GI sx (diarrhea, vomiting, epigastric pain - may resemble peptic ulcer)
77
What bug is a snail the host of?
Schistosoma
78
What forms hyatid cysts in the liver?
Echinococcus
79
Which hepatitis virus causes risk of fulminant hepatitis in pregnancy women?
HEV
80
What bug do you get from shellfish?
HAV
81
Which two viruses are exceptions to this rule: all dsDNA and + RNA are infectious?
HBV, Poxvirus
82
What virus is an exception to this rule: all enveloped viruses acquire their envelopes from plasma membrane?
Herpesvirus: acquires envelopefrom nuclear membrane
83
What are the polyomaviruses?
JC and BK viruses
84
Which DNA virus is partially double stranded?
Hepadnavirus
85
Where do you get norovirus from?
Cruise ships, nursing homes, schools
86
Who gets rotavirus?
Children. It is the #1 cause of fatal diarrhea in children
87
What is the reservoir for yellow fever?
Monkeys or humans
88
What are the symptoms of yellow fever?
Jaundice, black vomitus, high fever
89
What is Pavlizumab?
It is a monoclonal antibody against F protein that prevents pneumonia caused by RSV in premature infants
90
How do paramyxoviruses cause infection?
They express F protein (surface protein) causing respiratory epithelial cells to fuse and form and multinucleated cells?
91
Which receptor does HIV bind early?
CCR5
92
Which receptor does HIV bind late?
CXCR4
93
Antibody to which of the HIV proteins crosses the placenta and creates a false positive result in the baby?
GP120
94
What causes hairy leukoplakia in AIDS patients?
EBV
95
What causes acid fast cysts in the stool?
Cryptosporidium
96
How do you differentiate superficial vascular proliferations in HIV caused by HHV-8 (Kaposi) from Bartonella henslae (bacillary angiomatosis)?
HHV-8 has lymphocytic infiltrate
| B. henslae has neutrophilic infiltrate
97
What does P. jirovecii look like on imaging?
Ground glass appearance
98
How do you tell Haemophilus ducreyi and primary syphilis apart?
H. ducreyii you see a painFUL chancroid; primary syphilis you see a painLESS chancre.
99
What do you use for pneumocystis and pneumocystis plus toxoplasma (if severe) prophylaxis?
TMP- SMX
100
How does chloroquine work?
Blocks detoxification of heme into hemozoin
101
Which of the NRTI's is a nucleotide instead of a nucleoside?
Tenofovir
102
Which NRTI for general HIV prophylaxis and transmission to baby?
Zidovudine
103
What is the toxicity of cephalosporins?
Increases nephrotoxicity of aminoglycosides, vitamkin K deficiency, hypersensitivity reactions
104
What is lepromin test positive for?
Tuberculoid leprosy because of Th1 response (would see IFN-gamma and IL-2 in induration)
105
What do you give for acute diphtheria?
Antitoxin (passive immunization) then give erythromycin/penicillin, DPT vaccine
106
How does Daptomycin work?
Membrane depolarization, inactivated by surfactant. Associated with CKP increase and myopathy
107
What is unique about spores?
They are heat resistant so you must autoclave
108
What causes noninflammatory diarrhea?
Cholera, Giardia, ETEC, S. aureus, B. cereus
109
What would you see in the stool if you had cholera?
Mucus and epithelial cells in stool
110
How do Nystatin and Amphotericin B work?
Create pores in cell membrane
111
What is Amphotericin B's toxicity?
Arrhythmias (hypokalcemia, hypomagnesia), nephrotoxicity, anemia, IV phlebitis, fevers/chills
112
Is Aspergilloma colonizing or invasion?
Colonizing
113
How does Flyctosine work?
Inhibits DNA & RNA synthesis
114
How does Griseofulvin work?
Inhibits microtubule function
115
What does HCV progress to?
Chronic stable hepatitis
116
How does lyme disease present?
Facial nerve palsy, arthralgias, cardiac block, erythema migrans (annular rash with central clearing)
117
What organs does mumps cause inflammation in?
Pancreas, testes, parotid gland
118
What does anthrax look like on blood agar?
Nonhemolytic, rough gray colonies
119
What is the classic presentation of congenital syphilis?
Desquamating rash, cleft palate, rhinitis, RPR+
120
What else can ascaris cause besides intestinal infection?
Pneumonia; it posses one of the most potent allergens so cause type 1 hypersensitivity
121
What infections are CF patients most likely to get?
Pseudomonas
122
What is the diagnosis? Caseating granulomatous disease from ingestion of unpasteurized milk?
Brucella Abortis
123
What does Brucella abortis?
Abortions, endocarditis (aortic), mostly mild fevers
124
How does Fluconazole work?
Blocks lanosterol demethylase
125
What do you think of if you have HIV and see ring enhancing lesions?
Primary CNS lymphoma and to toxoplasma
126
What is the life cycle of strongyloides?
Get into feet from sand --> hematogenous spread to lungs --> coughed up and swallowed --> develop into adults --> lay eggs in intestinal mucosa --> hatch into rhabtidiform larvae --> excreted in stool
127
What is larva currens and what do you see it with?
It is pruritic, erythematos linear streaks on thighs and buttocks seen with strongyloides (due to larvae migrating away from perianal region)
128
How does diphtheria toxin work?
Inhibits protein synthesis via ADP ribosylation of EF-2
129
What virulence factor does E. coli use to cause meningitis and pneumonia?
K1 capsule
130
What virulence factor does E. coli use to cause pyelonephritis and cystitis?
Fimbriae
131
What does LPS endotoxin cause?
Septic shock
132
What part of LPS causes shock?
Lipid A
133
What do you give measles?
Vitamin A
134
What is a nonenterococcus group D bug?
S. bovis
135
What can you get enterococcus bacterial endocarditis?
GU instruments or cath
136
How does C. Diff toxin work?
Disrupts cytoskeleton via actin depolymerization
137
What is the MCC of infections associated with foreign bodies?
S. epidermis
138
What is the most likely organism if you have pneumonia, GI symptoms (diarrhea), high fever especially if neutrophisl but no bacteria?
Legionella
139
What do you get Legionella from?
Contaminated water exposure (cruise ships, recent travels, AC, hot tub)
140
What is ribavrin used for?
RSV and HCV
141
What should someone who develops septic shock or severe pulmonary disease from SW US be evaluated for?
Plague
142
Why is MRSA resistant to all beta lactams?
It has penicillin binding protein so drug can't find it easily
143
How does acyclovir work?
Inhibits viral DNA synthesis by incorporating into viral DNA
Needs to be phosphorylated first (only in infected cells so few adverse effects)
144
What is the major pathogenesis of Salmonella and Shigella?
Mucosal invasion
145
What is a small focus of fibrotic tissue in TB?
Ghon complex (calcification is immune system walling off granuloma)
146
What is a cavitary lesion in TB?
Latent TB
147
What makes a cholera infection more likely?
PPI
148
What kills latent malaria infection with vivax and ovale?
Primaquin
149
What type of medium is Thayer Martin?
Selective
150
What does env in HIV make?
Glycosylated to make gp41 (invading) and gp120 (attaching)
151
When does T helper cell response to TB occur?
2-4 weeks after infection
152
What presents with prodrome, then agitation, disorientation, hydrophobia, hypersalivation, progressing to death or coma?
Rabies
153
What do you get rabies from?
Bats, raccoon, skunk bites
154
What transmits campylobacter?
Cattle, sheep, dogs, chicken
155
What has granular eosinophilic appearance resembling ground glass?
HBV (HBsAg in hepatocellular cytoplasm)
156
What is the host for schistosoma?
Snail
157
What does parvovirus cause in adults?
RA like symptoms
158
What is the diagnosis? Dysphagia, diplopia, dysphonia.
Botulinum
159
Why does HDV need HBV?
For coating of viral particles
160
What does MAC grow at?
41deg and has more widespread involvement in body
161
How does HBV replicate?
Produces positive RNA template from DNA template but DNA progeny
162
What is the only DNA viruses in the hepatitis family?
HBV
163
Why is there no vaccine to HCV?
Huge antigenic variation
164
What is one way CMV be transmitted?
Blood transfusions
165
What is an indurated genital ulcer?
Gumma (from syphilis)
166
What type of hypersensitivity does TB damage through?
Type 4
167
How do you tell if someone has risk for chronic HepB
HbeAg and HbsAg positive
168
How doe shigella invade the GI tract?
By first gaining access to M cells
169
What do you use to treat most coagulase negative straph?
Vancomycin
170
What is this: progency has capsid of one and genome of another but no change in genome so next generation of virions revert back to normal.
Phenotyping mixing
171
What do gram negative organisms that ferment lactose look like on agar?
Pink on MacConkey
172
What are the segmented viruses?
BOAR: bunya, orthomyxo, arena, reo
173
What has one large polypeptide that is cleaved by proteases into functional viral proteins?
Picronavirus
174
How does tetanus toxin infect?
Wound --> motor neurons --> spinal cord
175
How do you prevent HSV reactivation?
Daily valaycyclovir. Acyclovir during 1st episode is just for that episode (it doesn't affect latent)
176
How does HCV have so much genetic variability?
3-5 exonuclease
177
What has cutaneous black eschar?
Antrhax
178
What has black eschar from the nose?
Mucormycosis
179
What is pustular skin lesions that form thick scabs?
Impetigo
180
If you do gastric biopsy and put in urea solution. If it turns pink then what does that mean?
Positive urea test indicative of H. pylori (urease converts urea to ammonia)
181
What would isoniazid monotherapy in TB result in?
Selective survival of bacterial cells secondary to gene mutation (either of catalase peroxidase enzyme or binding site of isoniazid)
182
What can be cultured at refrigeration temperatures and is beta hemolytic?
Listeria
183
What is most useful for making a tetanus diagnosis?
History and physical (there is no serum toxin assay)
184
What is the MC outcome of hepatitis infection?
Complete resolution
185
Which E. coli does not ferment sorbitol on MacConkey agar?
EHEC
186
What are the MCC of intraabdominal infections?
B. fragilis, E. coli
187
What causes abscess around appendix?
B. fragilis
188
How can HAV be killed?
Boiling, chlorination, bleach, formalin
189
What most likely happened if baby is born and gets oral thrush, interstitial pneumonia, and lymphopenia?
Mom transmitted HIV to baby
190
What do you treat Giardia with?
Metronidazole
191
What causes disulfiram like reaction with alcohol?
Metronidazole
192
What presents with intensely pruritic rash (excoriation with small crusted red papules) worse at night and on hands/palms?
Scabies
193
What is raltegavir?
Integrase inhibitor: prevents viral DNA integration and therefore inability to synthesize mRNA
194
Why do you use primaquine for vivax and ovale?
To kill hypnozoites (those inside hepatocytes)
195
Why do hepatocytes get destroyed when HBsAg present?
Viral antigens displayed on cell surface stimulate cytotoxic CTLs
196
What else besides BPH can also have difficulty starting a stream and maintaining?
Diabetic neuropathy leading to overflow incontinence
197
What causes liver abscess?
Echinococcus, Entameoba
198
What are councilman bodies a result of?
These eosinophilic globules are a result of hepatocyte apoptosis
199
What is reassortment?
When viruses with segmented genomes exchange segments. Responsible for influenza pandemics
200
What has trophozoites with phagocytosed RBC or cysts in stool?
Entamoeba histolytica
201
What is CMV colitis?
Common cause of colitis in immunocormpromised.
Reactivation of CMV after retinitis in HIV: GI sx, colonoscopy shows erythema, erosions, ulcerations.
Biopsy shows large cells with large ovioid nuclei containing basophilic depossits (intranuclear inclusions)
202
What would the HSV DNA of three different vesicular lesions look like?
The same!
203
What does Hep B infection lead to?
Most completely resolve
204
How do you kill anaerobic spores?
Autoclave (exposure to steam at 121 celsius for 15 minutes)
