Microbiology Basics Flashcards
USMLE Step 1 First Aid - Microbiology notes (360 cards)
0
Q
Gram-positives:structure
a. outside structure
b. function
c. composition
A
a. cell wall/ cell membrane
b. Major surface Antigen
c.
i. Peptidoglycan for support
ii. . Teichoic acid induces -TNF and IL-1.
1
Q
Bacterial Structures: Peptidoglycan-purpose
A
Gives rigid support, protects against osmotic pressure
2
Q
Gram-negatives-outside structure
A
Site of endotoxin-(lipopolysaccharide-LPS), major surface Antigen
3
Q
Bacterial Structures: Plasma membrane-function
A
Site of oxidative and transport enzymes; lipoprotein bilayer
4
Q
Bacterial Structures: Ribosome
A
Protein synthesis; 50S and 30S subunits
5
Q
Bacterial Structures: Periplasm-composition
A
hydrolytic enzymes, including beta-lactamases
6
Q
Bacterial Structures: Capsule -function, composition
A
Protects against phagocytosis; Polysaccharide
7
Q
Bacterial Structures: Pilus/fimbria
a. function
b. composition
A
Mediate adherence of bacteria to cell surface; sex pilus forms attachment between 2 bacteria during conjugation; glycoprotein
8
Q
Bacterial Structures: Flagellum
a. function
b. composition
A
Motility; Protein
9
Q
Bacterial Structures: Spore
a. function
b. composition
A
Provides resistance to dehydration, heat, and chemicals; Keratin-like coat, dipiclonic acid
10
Q
Bacterial Structures: Plasmid
a. function
b. composition
A
Contains a variety of genes for ABX resistance, enzymes, toxins; DNA
11
Q
Bacterial Structures: Glycocalyx
a. function
b. composition
c. clinical
A
Mediates adherence to surfaces, especially foreign surfaces (e.g. indwelling catheters); Polysaccharide; Staphylococcus epidermidis
12
Q
Structures unique to gram (+) organisms
A
Lipoteichoicacid (combination of lipids and teichoic acids)
13
Q
Features unique to G(-) organisms
A
Endotoxin/LPS (outer membrane), Periplasmic space (location of many beta-lactamases)
14
Q
Mycoplasma-composition
A
contain sterols and have no cell wall
15
Q
G(+) cocci
A
Staphylococcus Streptococcus
16
Q
G(-) cocci
A
Neisseria
17
Q
G(+) Rods
A
Clostridium Corynebacterium Bacillus Listeria Mycobacterium (acid fast) Gardnerella (gram variable)
18
Q
Mycobacteria-composition
A
mycolic acid-high lipid content
19
Q
Branching Filamentous bacteria-name, G?
A
-Actinomyces Nocardia; G+
20
Q
Pleomorphic (G-) bacteria-name, G
A
Rickettsia, Chlamydia, G-
21
Q
Spiral Spirochetes -name, G?
A
- Borrelia, Leptospira, Treponema
- (G-)
22
Q
Visualizing Treponemes
A
Darkfield microscopy and fluorescent Ab staining
23
Q
Visualizing Mycobacteria
A
Acid-fast stain
24
Visualizing Legionella
Silver stain
25
Giemsa's stain is used to visualize...?
Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium
26
PAS (periodic acid-Schiff) stain
stains glycogen, mucopolysaccharides-- diagnose Whipple's
27
Ziehl-Neelsen stain
Use to stain Acid-fast bacteria (Nocardia, Mycobacterium)
28
India ink
used to visualize Cryptococcus neoformans
29
Silver stain
used to visualize: fungi (pneumocystis), Legionella, H.Pylori
30
Media/Special culture requirements for: H. influenzae
Chocolate agar w/ factors V (NAD) and X (hematin)
31
Media/Special culture requirements for:
| N. gonorrheae/N. meningitidis
Thayer-Martin media
32
Thayer-Martin media-composition
Vancomycin, polymyxin, nystatin
33
Media/Special culture requirements for: B. pertussis
Bordet-Gengou (potato) agar
34
Media/Special culture requirements for: C. diphtheriae
Tellurite plate, Loffler's medium
35
Media/Special culture requirements for: M. tuberculosis
Lowenstein-Jensen agar
36
Media/Special culture requirements for: Eaton's agar requires
cholesterol
37
Media/Special culture requirements for: E. coli
Eosin-methylene Blue (EMB) agar (blue-black colonies w/ metallic sheen)
38
Media/Special culture requirements for: Lactose-fermenting enterics
Pink colonies on MacConkey's agar
39
Media/Special culture requirements for: Legionella
Charcoal yeast extract agar buffered w/ increased iron and cysteine
40
Media/Special culture requirements for: Fungi
Sabouraud's agar (Media used for isolation)
41
Obligate aerobes
Nocardia Pseudomonas Mycobacterium tuberculosis Bacillus
42
Obligate anerobes
Clostridium, Bacteroides, Actinomyces
43
Obligate intracellular bugs
a. name
b. indication
a. Rickettsia, Chlamydia
| b. can't make their own ATP
44
Facultatively intracellular bugs
Salmonella Neisseria Brucella Mycobacterium Listeria Francisella Legionella Yersinia
45
Encapsulated bacteria
S. pneumonia, H.influenze, N.meningitidis, E.coli, Salmonella,Klebsiella, group B Strep.
46
Capsule and vaccines-form
Polysaccharide capsule antigens + carrier protein
47
Quellung (+) Bacteria
S. pneumonia, H.influenze, N.meningitidis, E.coli, Salmonella,Klebsiella, group B Strep.
48
Urease (+) bugs
Proteus, Klebsiella, H. pylori, Ureaplasma, S. epidermidis, S.saphryticus, Nocardia+
49
Pigment-producing bacteria
1. Actinomyces israelii-yellow
2. S. aureus --> yellow pigment (Auerus is Latin for gold)
3. Pseudomonas aeruginosa --> blue-green pigment
4. Serratia marcescens --> red pigment (Think of red maraschino cherries)
50
protein A-function
disrupts opsonization and phagocytosis-binds Fc region of
51
IgA protease-who secretes?
S. pneumoniae, H. influenzae, and Neisseria to prevent phagocytosis
52
Group A streptococcus virulence factors
M protein: Helps prevent phagocytosis
53
Exotoxin: Typical diseases
Tetanus, botulism, diphtheria
54
Superantigens
Bind directly to MHCII and T-cell receptor simultaneously, activating large numbers of T-cells to stimulate release of IFN-gamma and IL-2
55
S. aureus-toxin
TSST-1
56
Exfoliatin
staphylococcal scalded skin syndrome in S. aurues
57
Staphylococcal scalded skin syndrome
Exfoliatin (S.aureus)
58
Toxins: Enterotoxins
food poisoning (S.aureus)
59
S. aureus-food poisoning
Enterotoxins
60
Scarlet fever-caused by
S. pyogenes
61
ADP ribosylating exotoxins: B component
binds to a receptor on the surface of the host cell, enabling endocytosis.
62
Corynebacterium diptheriae-toxin
Diptheria
63
Pseudomonas aeruginosa-toxin
Exotoxin A
64
Shigella-toxin
Shiga
65
E.Coli O157:H7-clinical
HUS-->cytokine release, but no host cell invasion
66
Toxins: Heat-labile toxin-function
stimulates Adenylyl cyclase-->cAMP
67
Toxins: Pertussis toxin (PT)-mechanism
disable Gi -->overactivates adenylate cyclase ( cAMP-increase -->phagocytosis impaired
68
C. botulinum-general mechanism
cleaves SNARE proteins needed for NT release
69
Clostridium perfringens-mechanism
alpha toxin-->gas gangrene Get double zone of hemolysis on blood agar
70
Toxins: Tetanus toxin (tetanospasmin)
Blocks the release of inhibitory neurotransmitters GABA and glycine Causes lockjaw
71
Toxins: Botulinum toxin (aka Botox)-direct mechanism
Blocks release of ACh Causes anticholinergic symptoms, CNS paralysis (especially cranial nerves) Spores found in canned food, honey (causes floppy baby)
72
C. botulinum-general mechanism
cleaves SNARE proteins needed for NT release
73
Toxins: Bacilus anthrax toxin
mimics adenylate cyclase
74
Toxin: E. coli O157:H7
inactivates 60S ribosome by removing adenine from rRNA
75
Toxins: Streptolysin O-mechanism
degrades cell membranes; B-hemolytic
76
Streptolysin O
S. pyogenes
77
Vibrio Cholerae toxin-mechanism
permanently activates Gs--> Overactivates adenylate cyclase
78
B. pertussis-toxin mechanism
permanently disables Gi
79
Endotoxin-chemistry
Lipopolysaccharide (structural part of bacteria; released when lysed)
80
Transformation-definition
ability to take up naked DNA( (from cell lysis) from environment. "competence"
81
F+-function
plasmid contains genes for conjugation process; plasmid is replicated and DNA transferred through pilus from the F+ cell.
82
Hfr-definition
F+ plasmid is incorporated into bacterial chromosomal DNA.
83
Generalized transduction-definition
Lytic phage infects bacterium, leading to cleavage of bacterial DNA. Parts of DNA may become packaged in viral capsid. Phage infects another bacterium, transferring these genes
84
Specialized transduction
Lysogenic phage infects bacterium; viral DNA incorporated into bacterial chromosome. When phage DNA is excised, flanking bacterial genes may be excised w/ it.
85
Transposition (transposons)-definition
Segment of DNA that can jump (excision and reincorporation) from one location to another, can transfer genes from plasmid to choromosome and vice versa.
86
5 bacterial toxins encoded in a lysogenic phage
ShigA -like toxin, Botulinum toxin, Cholera toxin, Diphtheria toxin, Erythrogenic toxin of Streptococcus pyogenes
87
alpha-hemolytic bacteria-definition
a. green ring around colonies on blood agar
88
Beta-hemolytic bacteria-definition
clear area of hemolysis on blood agar
89
Catalase
a. function
b. clinical
a. degrades H2O2, an antimicrobial product of PMNs. H2O2 is a substrate for myeloperoxidase.
b. chronic granulomatous disease-lack NADPH
90
Catalase (+)-name
Pseudomonas, Listeria, Aspergillus, Candida, E.coli, S.aurues, Serratia
91
TSST-mechanism
brings together MHCII and the TCR--IFN-gamma + IL-2 release --> shock
92
Dzs caused by Staphylococcus aureus
1. ) Inflammatory Dz - skin infxns, organ abcesses, pneumonia
2. ) Toxin-mediated dz - Toxic shock syndrome (TSST-1), scalded skin syndrome (exfoliative toxin), rapid-onset food poisoning (pre-formed enterotoxins)
3. ) MRSA (methicillin-resistant S. aureus) infxn: important cause of serious nosocomial and community-acquired infxns. Resistant to beta-lactams due to altered penicillin-binding proteins.
4. ) Misc. - acute bacterial endocarditis, osteomyelitis
93
Staphylococcus epidermidis
Infects prosthetic devices and catheters; contaminates blood cultures.
94
Streptococcus pneumoniae (the pneumococcus)
Meningitis, Otitis media (in children), Pneumonia, Sinusitis
95
Viridans group Streptococci
dental caries (S. mutans) and subacute bacterial endocarditis (S. sanguis).
96
Diseases caused by Streptococcus pyogenes (GAS)
1. ) Pyogenic - pharyngitis, cellulitis, impetigo
2. ) Toxigenic - Scarlet fever, toxic shock syndrome
3. ) Immunologic - rheumatic fever, acute glomerulonephritis
97
Streptococcus pyogenes --virulence factor
M protein
98
Streptococcus agalactiae (GBS)
Bacitracin resistant Beta-hemolytic Causes: Pneumonia meningitis Sepsis (mainly in babies) B is for Babies!
99
Enterococci
Enterococus faecalis and E. faecium
100
Lancefield group D
Includes enterococci and nonenterococcal group D streptococci. Lancefield grouping is based on differences in the C carbohydrate on the bacterial cell wall.
101
VRE
Vancomycin-resistant Enterococci: an important cause of nosocomial infxn.
102
Streptococcus bovis
Highly associated w/ colon cancer. One of the group D streptococci.
103
Bacterial spores
a. traits
b. composition
a. resistant to destruction by heat and chemicals; no metabolic activity.
b. dipiclonic acid in their core.
104
Anthrax
Caused by Bacillus anthracis: Gram (+), spore-forming rod that produces anthrax toxin. Only bacterium w/ a protein capsule (contains D-glutamate)
105
Anthrax infxn via contact
Malignant pustules (painless ulcer) Can progress to bacteremia and death Black skin lesions - vesicular papules covered by black eschar *[I think these only occur via contact route of infxn]
106
Anthrax via inhalation of spores
Flulike Sx that rapidly progress to fever, pulmonary hemorrhage, mediastinitis, and shock
107
Woolsorter's dz
Anthrax caused by inhalation of spores from contaminated wool
108
Listeria monocytogenes route of transmission
ingestion of unpasteurized milk/cheese and deli meats, or by vaginal transmission during birth.
109
Listeria monocytogenes motility
Form actin rockets by which they move from cell to cell; tumbling motility.
110
Listeria monocytogenes-clinical
neonatal meningitis
111
Actinomyces and Nocardia
Both are G(+) rods forming long branching filaments, resembling fungi
112
Actinomyces israelii
a. aerobic or anerobic
b. stain
c. location
d. clinical
e. tx
G(+)
a. anaerobe
b. not acid fast
c. oral flora
d. oral/facial abscesses that may drain thru sinus tracts in skin. Forms yellow sulfur granules in sinus tracts.
e. penicillin
113
Nocardia asteroides
a. aerobic or anerobic
b. stain
c. location
d. clinical
e. tx
G(+)
a. aerobic
b. weakly acid-fast aerobe
c. soil
d. pulmonary infxn in immunocompromised pts.
e. sulfonamides
114
Primary TB-clinical
Ghon complex: Hilar nodes, Ghon focus (granulomas)
115
Extrapulmonary TB
CNS (parenchymal tuberculoma or meningitis) Vertebral body (Pott's dz) Lymphadenitis Renal GI
116
Secondary TB-location
upper-lobe- Fibrocaseous cavitary lesion
117
PPD (+)
current infxn, past exposure, or BCG vaccinated sarcoidosis)
118
Mycobacterium tuberculosis-clinical
fever, night sweats, weight loss, and hemoptysis
119
Mycobacterium kansasii
pulmonary TB-like Sx
120
Mycobacterium avium-intracellulare
Often resistant to multiple drugs Causes disseminated dz in AIDS
121
Leprosy (Hansen's dz)-definition
acid-fast bacillus that likes cool temperatures
122
PPD (-)
no infxn or anergic (steroids, malnutrition, immunocompromise) sarcoidosis
123
Lactose fermenters:
a. fast
b. slow
a. Klebsiella, E. coli, Enterobacter
| b. Citrobacter, Serratia
124
Lactose-fermenting enteric bacteria
Grow pink colonies on MacConkey's agar
125
Neisseria: Fermenters
1. Glucose: Neisseria meningitidis & N. gonorrhoeae
| 2. Maltose: Neisseria meningitidis
126
Neisseria gonorrheae (Gonococci)
a. polysaccharide capsule
b. fermentation
c. vaccination
d. transmission
e. clinical
f. treatment
a. polysaccharide capsule- no
b. fermentation- glucose
c. vaccination- no due to rapid antigenic variation of pilus proteins
d. transmission- sex
e. clinical-sex (gonorrhea, neonatal conjunctivitis, PID-Fitz-Hugh Curtis syndrome) + septic arthritis
f. treatment-ceftriaxone + (azithromycin or doxycycline) for possible chlamydia coinfection
127
Neisseria meningitidis (Meningococci)
a. polysaccharide capsule
b. fermentation
c. vaccination
d. transmission
e. clinical
f. treatment
a. polysaccharide capsule- yes
b. fermentation-Maltose
c. vaccination- yes (none for type B)
d. transmission-respiratory and oral secretions
e. clinical- meningococcemia and meningitis, Waterhouse-Friderichsen syndrome
f. treatment- ceftriaxone or penicillin G
128
Haemophilus influenzae -clinical
Epiglottitis, Meningitis, Otitis media, and Pneumonia.
129
Tx for Haemophilus influenzae
Ceftriaxone. Rifampin prophylaxis in close contacts.
130
Haemophilus influenzae vaccine-why specific structure
promote T-cell activation, class switching
131
Legionella pneumophila-lab
hyponatremia
132
Legionella pneumophilia-trasmission
Aerosol transmission from environmental water souce habitat
133
Legionnaires' disease-clinicall
severe pneumonia, fever, GI and CNS symptoms
134
Pseudomonas aeruginosa - clinical
Pneumonia (CF) Sepsis (black lesions on skin), Exteral otitis (swimmer's ear), UTI, Drug use, Diabetic Osteomyelitis (+ hot tub folliculitis)
135
grapelike odor
Pseudomonas aeruginosa
136
Klebsiella: clinical
Aspiration pneumonia; Abscesse (lungs, liver), Alcoholics Diabetics; nosocomial UTIs
137
Yersinia enterocolitica-transmission
pet feces, contaminated milk, or pork
138
Helicobacter pylori
a. clinical
b. risk factor for
a. Gastritis, duodenal ulcers
| b. peptic ulcer, gastric adenocarcinoma, and lymphoma
139
Helicobacter pylori-
a. identification
b. shape
a. catalase (+), urease (+), oxidase (+)
| b. comma shaped
140
Helicobacter pylori Tx?
Proton pump inhibitor + clarithromycin + amoxicillin or metronidazole
141
Spirochetes
a. composition
b. visualization
a. axial filaments
b.
Borrelia-anilline dyes (write stain or Giemsa); Treponema-dark-field microscopy.
142
Leptospira interrogans-cause
water contaminated w/ animal urine
143
Syphilis-caused by
treponema pallidum
144
Primary syphilis
a. clinical
b. test
a. painless chancre (localized dz)
| b. VDRL/RPR; FTA-BS
145
Secondary syphilis-clinical
disseminated-rash on palms & soles;condylomata lata
146
Tertiary syphilis
gummas, aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis), Argyll Robertson pupil
147
Congenital syphilis
CN VIII deafness, Saber shins, Saddle nose, Hutchinson's teeth (smaller and more widely spaced)
148
Argyll Robertson Pupil
Constricts w/ accomodation but is not reactive to light--tertiary syphilis.
149
VDRL-definition
detects nonspecific antibody that reacts with beef cardiolipin.
150
VDRL False Positives
Viruses (mono, hepatitis); Drugs, Rheumatic fever, Lupus & Leprosy
151
Clue cells
bacterial vaginosis
152
Q fever
a. cause
b. source
c. clinical
a. Coxiella burnetii; no arthropod vector.
b. Tick feces and cattle placenta release spores that are
inhaled as aerosols
c. pneumonia.
153
Rocky Mountain Spotted Fever
a. cause
b. clinical
c. tx
a. Rickettsia rickettsii
b. HA, fever, rash (starts at wrists and ankles and then spreads to trunk, palms, and soles)
c. doxycycline.
154
Weil-Felix Reaction
Assays for anti-rickettsial Abs, which cross-react w/ Proteus Ag. Weil-Felix is usually positive for typhus and Rocky Mountain spotted fever, but negative for Q fever.
155
Chlamydiae-form
Elementary body & Reticulate body
156
Chlamydiae: Elementary body-function
Enters cells via endocytosis and transforms into the reticulate body
157
Chlamydiae: Reticulate body-function
Replicates in cell by fission; reorganizes into elementary bodies.
158
Chlamydia trachomatis-clinical
reactive arthritis (Reiter syndrome); follicular conjunctivitis; nongonococcal urethritis; PID
159
What can cause atypical pneumonia
C. pneumonia, C. psittaci
160
Chlamydiae: treatment
azithromycin* or doxycycline
161
Chlamydia trachomatis serotypes A, B, and C
Chronic infxn, follicular conjuctivits--> blindness (Africa)
162
Chlamydia trachomatis types D-K
Urethritis/PID, Ectopic pregnancy Neonatal- pneumonia (staccato cough), conjunctivitis
163
Chlamydia trachomatis serotypes L1, L2, and L3
Lymphogranuloma venerum -small, painless ulcers on genitals swollen, painful inguinal lymph nodes that ulcerate
164
Mycoplasma pneumoniae -clinical
atypical walking pneumonia
165
Mycoplasmal pneumonia-lab
cold agglutinins (IgM)
166
Important killed vaccines
Rabies, Influenza, Salk Polio (IV), and HAV
167
Important recombinant viral vaccines
HBV (Ag = recombinant HBsAg) HPV (types 6, 11, 16, and 18)
168
Cowdry A inclusions
Intranuclear inclusions shown in cells infected w/ HSV (would show up on Tzanck smear)
169
Influenza virus
a. category
b. composition
a. Orthomyxoviruses
| b. hemagglutinin & neuraminidase
170
A major mode of protection from influenza virus?
Killed viral vaccine vi reformulated vaccine
171
Genetic shift/Antigenic shift-mechanism
Reassortment of viral genome--viruses with segmented genomes exchange segments
172
Genetic Drift-mechanism
changes based on random mutation
173
Paramyxoviruses-clinical
parainfluenza, RSV(bronchiolitis, pneumonia infats), mumps & measles
174
Rubeola (measles) virus
a. category
b. physical
c. clinical
a. paramyxovirus that causes measles.
b. Koplik spots w /blue-white center, descending maculopapular
rash
c. cough, coryza, conjuctivitis
175
Image: Rubeola (measles) virus
.
176
Mumps virus-clinical
Parotitis , orchitis, aseptic meningitis
177
Image: Rabies virus-location
Purkinje cells: cerebellum, hippocampal neurons.
178
Rabies-tx
killed vaccine
179
Neoplasms associated w/ HIV
Kaposi's sarcoma, Invasive cervical carcinoma, Primary CNS lymphoma non-Hodgkin's lymphoma
180
Dominant normal flora of the: Skin
Staphylococcus epidermis
181
Dominant normal flora of the: Nose
S. epidermis; colonized by S. aureus
182
Dominant normal flora of the: Oropharynx
Viridans group streptococci
183
Dominant normal flora of the: Dental plaque
Streptococcus mutans
184
Dominant normal flora of the: Colon
Bacteroides fragilis > E. coli
185
Dominant normal flora of the: Vagina
Lactobacillus, colonized by E. coli and group B strep
186
Neonates and normal flora
Neonates delivered by cesarean section havve no flora, but are rapidly colonized after birth.
187
Food poisoning from: Vibrio parahemolyticus and V. vulnificus
Food: Contaminated seafood (V. vulnificus can also cause wound infxn from contact w/ contaminated water or shellfish)
188
Food poisoning from: Bacillus cereus
Food: reheated rice.
189
Food poisoning from: S. aureus
Food: Meats, mayonnaise, custard
190
Food poisoning from: Clostridium perfringens
Food: reheated meat dishes
191
Food poisoning from: Clostridium botulinum
Food: improperly canned foods (bulging cans)
192
Food poisoning from: E. coli O157:H7
Food: Undercooked meat
193
Food poisoning from: Salmonella
Food: poultry, meat, and eggs.
194
EIEC
a. mechanism
b. clinical
a. invades intestinal mucosa --> necrosis and inflammation.
| b. dysentery
195
ETEC
a. mechanism
b. clinical
a. Heat Labile & Heat Stable (enterotoxins)
| b. traveler's diarrhea (watery)
196
EPEC
a. mechanism
b. clinical
a. absorption reduced-adheres to apical surface, flattens villi,
b. Pediatric Diarrhea
197
Common causes of pneumonia in CF
Pseudomonas
198
Common causes of post-viral pneumonia
Staphylococcus H. influenzae
199
Common causes of atypical pneumonia
Mycoplasma Legionella Chlamydia
200
Common causes of meningitis in HIV
Cryptococcus CMV Toxoplasmosis (brain abscess) JC virus (PML)
201
CSF findings in meningitis: Bacterial
a. Pressure
b. Cell type
c. Protein
d. Sugars
a. Pressure = increased
b. Cell type = PMN
c. Protein = increased
d. Sugars = decreased
202
CSF findings in meningitis: Fungal/TB
a. Pressure
b. Cell type
c. Protein
d. Sugars
a. Pressure = increased
b. Cell type = lymphocytes
c. Protein = increased
d. Sugars = decreased
203
CSF findings in meningitis: Viral
a. Pressure
b. Cell type
c. Protein
d. Sugars
a. Pressure = normal/increased
b. Cell type = lymphocytes
c. Protein = normal/increased
d. Sugars = normal
204
Osteomyeltitis-Assume if no other information is available
Staph aureus
205
Osteomyelitis in sexually active pt
Neisseria gonorrhoeae (rare), Septic arthritis more common
206
Osteomyelitis in diabetics and drug addicts
Pseudomonas aeruginosa
207
Osteomyelitis in Sickle cell
Salmonella
208
Osteomyelitis in prosthetic replacement
S. aureus and S. epidermis
209
Osteomyelitis in vertebra
Mycobacterium tuberculosis (Pott's dz)
210
Osteomyelitis with cat and dog bites/scratches
Pasteurella multocida
211
Bug hints (if all else fails):Traumatic open wound What is the bug?
Clostridium perfringens
212
Bug hints (if all else fails):Surgical wound What is the bug?
S. aureus
213
Bug hints (if all else fails):Dog or cat bite What is the bug?
Pasteurella multocida
214
Bug hints (if all else fails):Currant jelly sputum What is the bug?
Klebsiella
215
Bug hints (if all else fails):Sepsis/meningitis in newborn What is the bug?
group B strep
216
Killed vaccines-mechanism
induce humoral immunity
217
gram-positive rods with metachromatic (blue and red) granules and Elek test for toxin.
Corynebacterium diphtheriae
218
Black colonies on cystine-tellurite agar
Corynebacterium diphtheriae
219
Cord factor
a. definition
b. condition
a. virulent strains inhibits macrophage maturation and induces release of TNF-a
b. TB
220
Sulfatides
a. definition
b. function
c. condition
a. surface glycolipids
b. inhibit phagolysosomal fusion
c. TB
221
Lepromatous-clinical
diffusely over the skin-lion-like facies
222
Tuberculoid-clinical
hairless skin plaques
223
Gram (-): Coccoid rods-name
Haemophilus influenzae
Pasteurella
Brucella
Bordetella
224
Pasteurella-cause
cellulitis, osteomyeitis
225
Brucella
a. category
b. cause
c. clinical
a. Gram (-) coccoid rod
b. unpasteurized dairy
c. remittent fever, weakness, headache, chills,
226
EHEC
a. strain
b. mechanism
c. clinical
a. O157:H7
b. Shiga-like toxin
c. HUS; Dysentery that causes Hemolytic-uremic
syndrome (triad of ). Also called STEC
(Shiga toxin-producing E. coli).
; microthrombi
consume platelets thrombocytopenia.
227
Hemolytic-uremic syndrome
a. clinical
b. pathology
c. cause
a. anemia, thrombocytopenia, ARF
b. toxin damages endothelium --> microthrombi formation:
1) hemolysis (shistocytes)--> renal blood flow decreased
2) thrombi consume platelets --> thrombocytopenia
c. EHEC- O157:H7
228
Salmonella:
a. motility
b. dissemination
c. reservoirs
d. hydrogen sulfide
e. Antibiotics
f. Immune response
g. clinical
h. lactose fermentation
a. motility- flagella
b. dissemination-disseminate hematogenously
c. reservoirs- many animal reservoirs
d. hydrogen sulfide- Produce hydrogen sulfide
e. Antibiotics- may prolong fecal excretion of
f. Immune response-monocytic response
g. clinical-Can cause bloody diarrhea
h. lactose fermentation- Does not ferment lactose
229
Shigella:
a. motility
b. dissemination
c. reservoirs
d. hydrogen sulfide
e. Antibiotics
f. Immune response
g. clinical
h. lactose fermentation
a. motility- No flagella
b. dissemination- Cell to cell transmission; no hematogenous
spread
c. reservoirs- humans and primates
d. hydrogen sulfide- Does not produce hydrogen sulfide
e. Antibiotics- Antibiotics shorten duration of fecal excretion of
organism
f. Immune response - PMN
g. clinical- Often causes bloody diarrhea
h. lactose fermentation- Does not ferment lactose
230
Salmonella typhi -mechanism
can remain in gallbladder and cause a carrier state.
231
What are the comma shaped bacteria?
Campylobacter jejuni, Vibrio cholera, H. pylori
232
E.Coli's virulence factors
fimbriae, K capsule, LPS endotoxin
233
fimbriae-clinical
cystitis, pyelonephritis
234
K capsule-clinical
pneumonia, neonatal meningitis
235
LPS endotoxin-clinical
septic shock
236
Ixodes-which diseases
Lyme disease, Babesia
237
Lyme disease-clinical
Facial nerve palsy (typically bilateral); Arthritis (migratory), Cardiac block (AV nodal); Erythema migrans
238
Lyme Disease symptom mneumonic
FAKE
239
Lyme disease-treatment
doxycycline, ceftriaxone
240
Tertiary syphillis- aortitis pathology
vasa vasorum destruction
241
Tertiary syphillis: signs
broad-based ataxia, Romberg (+), Charcot
| joint, stroke w/out hypertension
242
neurosyphillis: test
spinal fluid with VDRL or RPR
243
Jarisch-Herxheimer reaction
Flu-like syndrome after antibiotics are started—due to killed bacteria releasing pyrogens.
244
hemagglutinin-definition
promotes viral entry
245
neuraminidase -definition
promotes progeny virion release
246
pandemics-shift or drift?
Genetic shift / antigenic shifts
247
epidemics-cause
Genetic drift
248
F-protein-mechanism
F protein --> respiratory epithelial cells fuse and form multinucleated cells.
249
Palivizumab-mechanism
monoclonal antibody against F protein
250
Palivizumab-use
RSV prevention in premaure infants
251
Paramyxoviruses-mechanism
F-protein
252
Typhus
a. clinical
b. cause
a. rash starts centrally and spreads out, sparing palms and soles.
b. Rickettsiae typhi & Rickettsiae prowazekii
253
Rickettsiae typhi
Endemic (fleas)
254
Rickettsiae prowazekii
Epidemic (human body louse)
255
Rickettsia requires? Why?
CoA and NAD+ ; obligate intracellular organisms --> cannot synthesize ATP
256
Why is Q fever queer?
no rash or vector; causative organism can survive outside
| in its endospore form.
257
Why is Chlamydiae unusual
lacks muramic acid
258
Chlamydiae-lab diagnosis
cytoplasmic inclusions seen on Giemsa or fluorescent antibody-stained smear.
259
Rabies-mechanism
Travels to the CNS by migrating in a retrograde
| fashion up nerve axons.
260
Image: Rabies virus
.
261
Pseudomonas aeruginosa-assosciated with
wound and burn infxn;
262
cocci in pairs
Neisseria meningitidis
263
Grows in 42°C
Campylobacter jejuni
264
Grows in alkaline media
Vibrio cholerae
265
Produces urease
Helicobacter pylori
266
Tellurite plate
C. diphtheriae
267
Loffler's medium
C. diphtheriae
268
Endotoxin: Source
Outer cell membrane of most gram-negative bacteria
269
Endotoxin: Chemistry
Lipopolysaccharide (structural part of bacteria; released when lysed)
270
Endotoxin: Location of genes
Bacterial chromosome
271
Endotoxin: Clinical effects
Fever, shock (hypotension), DIC
272
Endotoxin: Typical Diseases
Meningococcemia; sepsis by gram-negative rods
273
Recombination-definition
Exchange of genes between 2 chromosomes by crossing over within regions of significant base sequence homology.
274
Reassortment-definition
viruses with segmented genomes (e.g., influenza virus) exchange segments.
275
Complementation-definition
When 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein. The nonmutated virus "complements" the mutated one by making a functional protein that serves both viruses
276
Phenotypic mixing-definition
coinfection of a host cell by 2 viral strains--> progeny virions contain nucleocapsid proteins from one strain and genome from other srain. No change in viral genomes(no exchange). Net generation reverts back to original
277
serpetine cords-indicate
cord factor
278
cord factor-mechanism
neutrophils inhibited, mitochondria destroyed, TNF released
279
meningitis in babies
Streptococcus agalactiae
280
pneumonia, meningitis, sepsis in babies
Streptococcus agalactiae
281
neonatal meningitis
Listeria monocytogenes
282
unpasteurized dairy products
Listeria monocytogenes
283
Listeria monocytogenes-treatment
ampicillin
284
skin infections
Staphylococcus aureus
285
pneumonia after influenza virus infection
Staphylococcus aureus
286
Pyrrolidonyl Arylamidase (+)
Streptococcus pyogenes
287
Transformation- which bugs
S. pneumoniae, H. influenzae type B, and Neisseria
288
Deoxyribonuclease & Transformation
naked DNA is degraded in medium --> no transformation
289
F-: definition
Bacteria w/o plasmid
290
Pelvic inflammatory disease-cause
Chlamydia trachomatis, Neisseria gonorrhoeae
291
Fitz- Hugh-Curtis syndrome-defintion
pelvic inflammatory disease leads to infection of the liver capsule and "violin string" adhesions of peritoneum to liver B
292
Pelvic inflammatory disease-clinical
purulent cervical discharge, cervical motion tenderness
293
PID may include...
salpingitis, endometritis, hydrosalpinx,tubo-ovarian abscess
294
Salpingitis- risk factor for
ectopic pregnancy,infertility, chronic pelvic pain, and adhesions
295
Pneumonia: neonates (< 4 WK)
Group B streptococci, E. Coli
296
Meningitis: newborn (0-6 MO )
Group B streptococci, E. coli, Listeria
297
Leading cause of UTI
E.coli
298
2nd leading cause of UTI in sexually active women
Staphylococcus saprophyticus
299
3rd leading cause of UTI.
Klebsiella pneumoniae
300
Pandemics-mechanism
reassortment
301
ADP ribosylating exotoxins: A component
attaches an ADP-ribosyl to a host cell protein (ADP ribosylation), altering protein function.
302
pnemonia- what organisms's virulence factor
K capsule
303
neonatal meningitis-what organisms's virulence factor
K capsule
304
Lepromatous-immunity
humoral Th2 response w/ low cell-mediated immunity
305
Tuberculoid-immunity
cell-mediated immunity with a largely Th1-
306
Vibrio Cholera-clinical
rice water diarrhea
307
Leprosy-clinical
infects hands and superficial nerves
308
Heat Stable-mechanism
stimulates Guanylate cyclase-->cGMP
309
Weil's disease-clinical
jaundice, hemmorrhage, photophobia azotemia from liver and kidney dysfxn
310
Leptospira interrogans-clinical
flu-like symptoms, photophobia w/conjuctival suffusion
311
Bacillus anthracis-composition
D-glutamate
312
Pseudomona aeruginosa-mechanism
ADP-ribosylation of EF-2 --> inhibits protein synthesis
313
Pseudomona aeruginosa-toxin consequence
host cell death
314
Lag phase: -definition
metabolic activity w/o division
315
Exponential Phase -definition
population doubles every 20 minutes
316
Stationary phase-definition
nutrient depletion slows growth. Spore formation in some bacteria.
317
Death Phase-definition
prolonged nutrient depletion and buildup of waste products leads to death.
318
Bacterial Growth Curve: A
Lag phase
319
Bacterial Growth Curve: C
Exponential Growth
320
Bacterial Growth Curve: D
Stationary Phase
321
Bacterial Growth Curve: B
Death Phase
322
Generalized transduction-result
phage infects another bacterium, transferring these genes.
323
Generalized transduction-composition
parts of bacterial chromosomal DNA may become packaged in viral capsid.
324
Legionelle Pneumonia-treatment
macrolide or quinolone
325
Klebsiella Pneumonia-structure
abundant polysaccharides capsules --> mucoid colonies
326
red "currant jelly" sputum
Klebsiella Pneumonia
327
Secondary TB-cause
re-infxn of partially immune hypersensitized host (usu. adult) or reactivation of dormant TB in the lungs
328
Primary TB-location
mid zone of lung
329
H. influenza-mechanism
IgA Protease
330
Salmonella Typhi-clinical
rose spots on the abdomen, fever,diarrhea
331
H.Influenza-transmission
Aerosol transmission
332
bloody diarrhea
Shigella
333
produces H2S
Salmonella
334
Corynebacterium diphtheriae-mechanism
ADP-ribosylation of EF-2 --> inhibits protein synthesis; encoded by B-prophage
335
Corynebacterium diphtheriae-clinical
pharyngitis w/pseudomembrane in throat
336
Shigella-mechanism
inactivate 60S ribosome by removing adenine from rRNA
337
Shigella-clinical
1. dysentery --> GI mucosal damage
| 2. HUS --> cytokine release
338
Bacillus Anthracis-mechanism
Mimics the adenylate cyclase enzyme (increases cAMP)
339
a-Hemolytic-name
streptococcus pneumoniae, viridans streptococci (catalase (-), optochin resistant)
340
B-Hemolytic-name
1. ) Staphylococcus aureus (catalase and coagulase positive)
2. ) Streptococcus pyogenes - GAS (catalase negative and bacitracin sensitive)
3. ) Streptococcus agalactiae - GBS (catalase negative and bacitracin resistant)
4. ) Listeria monocytogenes (tumbling motility, meningitis in newborns, unpasteurized milk)
341
Peptidoglycan-composition
Sugar backbone with peptide side chains crosslinked by transpeptidase.
342
Gram negative-antigens
surface antigen- endotoxin-(lipopolysaccharide-LPS); Lipid A (induces TNF and IL-1), O Polysaccharide is the antigen
343
H. Influenza vaccine: Composition
type B capsular polysaccharide (polyribosylribitol phosphate) conjugated to diphtheria toxoid or other protein.
344
(polyribosylribitol phosphate
type B capsular polysaccharide
345
Lancet-shaped, gram-positive diplococci
Streptococcus pneumoniae
346
gram-positive diplococci
Streptococcus pneumoniae
347
rusty sputum
Streptococcus pneumoniae
348
Endotoxin: Mode of Action
Induces TNF, IL-1, and IL-6
349
Streptococcus pyogenes: toxin
Exotoxin A, Steptolysin O
350
Exotoxin A
Streptococcus pyogenes
351
Alpha toxin
Clostridium Perfringens
352
S.aureus-virulence factor
Protein A
353
Hfr × F-definition
Replication of incoporated plasmid DNA may include some flanking chromosomal DNA. Transfer of plasmid and chromosomal genes.
354
Transposition (transposons)-example
antibiotic resistance genes on R plasmid
355
C. difficile- Toxin A-function
enterotoxin, binds to the brush border of the gut
356
C. difficile-Toxin B function
causes cytoskeletal disruption via actin depolymerization
357
pseudomembranous colitis
C. difficile
358
Hippurate test (+)
Streptococcus
| agalactiae
359
What are the toxicigenic infections of S.aglactiae
scarlet fever, toxic shock-like syndrome, necrotizing fasciitis
