BACTERIOLOGY Flashcards
(245 cards)
1
Q
o typhlitis (necrotizing enterocolitis)
o Shanghai fever (mild form of typhoid)
o peritonitis in patients undergoing peritoneal dialysis
A
Pseudomonas
2
Q
most common STD overall
A
CHLAMYDIA TRACHOMATIS
3
Q
endocarditis in patients who underwent GIT surgery
A
E. faecalis
4
Q
type b (polyribitol phosphate) = 95% of invasive disease
A
H. influenzae
5
Q
“snow shoe” / “tennis racket” terminal spores
A
C. tetani
6
Q
- gram-positive cocci in chains
- Catalase-negative
• Alpha-hemolytic
• Bile and optochin-resistant
A
VIRIDANS STREPTOCOCCI (S. MUTANS, S. SANGUIS)
7
Q
paroxysmal pattern of hacking coughs, accompanied by production of copious amounts of mucus, that end with an inspiratory “whoop”
A
Pertussis or Tuspirina
8
Q
Scarlet Fever
- postpharyngitic
- due to erythrogenic toxin, seen in lysogenized strains
- fever, strawberry tongue, centrifugal rash (sandpaper-like), Pastia lines, desquamation
A
S. pyogenes (GAS)
9
Q
Treatment of Lepromatous leprosy
A
o dapsone, rifampin, and clofazimine
10
Q
- types D–K
-
most common cause of STDs
- NGU in males; PID in females
- usual coinfection with gonorrhea
- birth complications
- neonatal conjunctivitis
- neonatal pneumonia
- associated with Reiter syndrome
A
• Genital Tract Infections sec to C. trachomatis
11
Q
Exotoxin A of _______ – inhibits elongation factor-2 (EF-2), resulting in decreased protein synthesis in gastrointestinal mucosal
A
Pseudomonas aeruginosa
12
Q
SPECTRUM OF DISEASE: LYME DISEASE
- Stage 1: erythema chronicum migrans
- Stage 2: myocarditis (AV block), meningitis, Bell palsy
- Stage 3: autoimmune migratory polyarthritis (onion skin lesions), acrodermatitis chronica atrophicans
A
BORRELIA BURGDORFERI
13
Q
Associated with gastric carcinoma and MALT lymphomas
A
H. pylori
14
Q
antibiotic-containing selective medium, is used for unsterile specimens (e.g. urethral, endocervical) suspected for N. gonorrhea inf.
A
Thayer-Martin agar,
15
Q
- gram-positive cocci in grape-like clusters
- b -hemolytic yellow or golden colonies on blood agar
- catalase-positive
- coagulase-positive
- salt-tolerant on mannitol salt agar (halotolerant)
- “Gold” color is due the pigment staphyloxanthin
A
STAPHYLOCOCCUS AUREUS
16
Q
ATYPICAL PNEUMONIA associated with atherosclerosis
A
CHLAMYDIA PNEUMONIAE
17
Q
meningococcal vaccine contains capsular polysaccharide of strains
A
A, C, Y, and W-135
18
Q
o 3-4 weeks (or longer)
o Diminished paroxysmal cough
o Development of secondary complications (pneumonia, seizure, encephalopathy) in pertussis
A
Convalescent stage
19
Q
increases intracellular cAMP in gastrointestinal mucosal cells, resulting in decreased absorption and increased secretion in the digestive tract
A
Cholera Toxin
20
Q
MESENTERIC ADENITIS (pseudoappendicitis)
A
YERSINIA ENTEROCOLITICA
21
Q
• weakly staining, gram-negative spirochetes
• largest medically-important bacteria
- stain well with aniline dyes (Giemsa or Wright stain)
- cultured on BSK medium
A
BORRELIA BURGDORFERI
22
Q
DOC for Lyme disease
A
doxycycline
23
Q
bullous impetigo
A
S. aureus
24
Q
STAPHYLOCOCCI
A
25
most common cause of osteomyelitis in an otherwise healthy patient is
Staphylococcus aureus.
26
**Gas Gangrene**
* **alpha toxin, a lecithinase** that cleaves cell membranes
* Gas produced by anaerobic metabolism
CLOSTRIDIUM PERFRINGENS
27
Phase of pertussis
o 1-2 weeks
o rhinorrhea, malaise, fever, sneezing, anorexia
**o Antibiotics most effective**
Catarrhal phase
28
promote adherence and invasion of N. gonorrhea into epithelial cells; expression results in opaque colonies
Opa proteins
29
• **comma-shaped gram**-negative rods
## Footnote
**• motile**
**• oxidase-positive**
**• cultured on thiosulfate citrate bile salts sucrose (TCBS) agar**
**• shooting star motility**
VIBRIO
30
influenza-like symptoms few hours after receiving penicillin, due to lysis of treponemes
Jarisch-Herxheimer reaction
31
classical detection using **Weil-Felix reaction** - cross-reaction with antigens of OX strains of Proteus vulgaris
RICKETTSIAE
32
VIRULENCE FACTORS OF S. AUREUS
33
• Culture: **Potassium tellurite: dark black colonies**
**• Loeffler’s medium**: after 12 hours of growth, stain with methylene blue.
C. diphtheriae
34
o 2-4 weeks
o ‘**Whoop**’ → burst of non-productive coughs
o Increased number of lymphocytes in blood smear
**o Antibiotics ineffective** during this stage of pertussis
• Paroxysmal phase
35
* Gram-positive **"lancet-shaped**" cocci in pairs or chains
* Catalase-negative
**• Alpha-hemolytic**
**• Bile and optochin-sensitive**
**• positive Quellung reaction**
STREPTOCOCCUS PNEUMONIAE
36
cell-wall component that prevents phagocytosis in group A streptococci (Streptococcus pyogenes).
Protein M
37
**VIRULENCE FACTORS OF E.COLI**
**• pili or fimbriae –** attachment, colonization factor, associated with UTI (cystitis, pyelonephritis)
**• flagellum (H)**
• **capsule (K) –** associated with pneumonia and neonatal meningitis (K1)
**• endotoxin (O)**
**• enterotoxins**
- **ST and LT cause** **watery diarrhea**, increase cAMP (similar to cholera toxin)
- **verotoxin (Shiga-like toxin) causes bloody diarrhea (HU**S), inhibits protein synthesis by inactivating the 60S subunit of eukaryotic cells (E. coli O157:H7, STEC, EHEC)
38
**Encapsulated Bacteria**
**Some Killers Have Pretty Nice and Shiny Bodies.**
**Streptococcus pneumoniae**
**Klebsiella pneumoniae**
**Haemophilus influenzae**
**Pseudomonas aeruginosa**
**Neisseria meningitidis**
**Salmonella typhi**
**B group streptococci**
39
• sinusitis, otitis media, pneumonia
**• meningitis**
• **epiglottitis** - most common cause; cherry red epiglottis; thumb sign
**• COPD exacerbations**
H. influenzae
40
most common cause of bacterial gastroenteritis
CAMPYLOBACTER JEJUNI
41
TRIAD OF BOTULISM
1. Symmetric descending flaccid paralysis (with prominent bulbar involvement)
2. Absence of fever
3. Intact sensorium
42
most common cause of meningitis among aged **2-18 yrs**
N. meningitidis
43
* gram-positive cocci in chains
* catalase-negative
**• beta-hemolytic**
**• bacitracin-sensitive**
**• Lancefield group A**
**• positive PYR test**
**STREPTOCOCCUS PYOGENES**
44
Vibrio species found in trauma to skin, especially in shellfish handlers, or by ingestion of raw shellfish
V. vulnificus
45
* anaerobe (normal oral flora)
* setting: local trauma (broken jaw or dental extraction)
* PE: hard, nontender swelling with **sinus tracts** draining **sulfur granules**
ACTINOMYCES ISRAELII
46
**Vibrio species contaminated with raw seafood**
**V. parahaemolyticus)**
47
DOC FOR LEGIONELLA PNEUMOPHILA
azithromycin or erythromycin
48
False Positive VDRL Results
**VDRL**
**Viruses (EBV, Hepatitis)**
**Drugs (marijuana)**
**Rheumatic fever, RA**
**Lupus, Leprosy**
49
Vector of Lyme disease
bite from deer ticks (Ixodes scapularis, Ixodes pacificus)
50
BACITRACIN SENSITIVITY
**B – BRAS**
Bacitracin
group B strep Resistant
group A strep Sensitive
51
PONTIAC FEVER
LEGIONELLA PNEUMOPHILA
52
CAT SCRATCH DISEASE
BARTONELLA HENSELAE
## Footnote
* gram-negative rod
* normal oral flora of cats
**• cat-scratch fever in immunocompetent individuals**
**• bacillary angiomatosis in immunocompromised**
• transmission: cat bite or scratch
53
Impetigo contagiosa
**S. PYOGENES (GAS)**
* perioral blistered lesions with honey-colored crust
* accumulation of neutrophils beneath stratum corneum
* complication: **poststrep GN**
54
• **comma-shaped gram-negative rods**
**• microaerophilic**
* positive oxidase and catalase tests
* grows well at 42°C on **Skirrow agar**
CAMPYLOBACTER JEJUNI
55
Optochin Sensitivity
**OV**E**RP**A**S**S
## Footnote
**Optochin**
**Viridans = Resistant**
**Pneumoniae = Sensitive**
56
drug of choice for all rickettsial infections
doxycycline
57
**Scalded Skin Syndrome (Ritter disease)**
S. aureus
* **exfoliatin** cleaves **desmoglein** in desmosomes
* separation of epidermis at **stratum granulosum**
* distinguish from TEN (Lyell disease) where separation occurs at **dermo-epidermal junction**
58
most common cause of CAP
S. pneumoniae
## Footnote
o Blood-tinged, pink, or rusty sputum
o Blood cultures often positive
59
DOC for mycoplasma pneumoniae
erythromycin or azithromycin
60
**• gram-negative "kidney-bean" diplococci**
* insignificant capsule
* oxidase-positive colonies on **Thayer-Martin medium**
**• ferment glucose only**
. NEISSERIA GONORRHOEAE
61
* facultative gram-negative rods with **large polysaccharide capsule**
* **extended spectrum beta-lactamase (ESBL)** activity in drug resistant strains
**• urease-positive**
KLEBSIELLA PNEUMONIAE
62
**• facultative gram-negative rods**
* **lactose-fermenting** colonies on EMB or MacConkey agar
* **green sheen on EMB agar; metallic sheen**
**• typing by O and H antigens**
ESCHERICHIA COLI
63
* fever, chills, intense headache
* **calf tenderness**
* due to **rapid multiplication of leptospires** in muscles with high oxygen tension
* **conjunctival suffusion**
* **due to damaged and leaky conjunctival vessels**
* painful and itchy but with **minimal tearing**
Acute Leptospiremic Phase
64
What virulence factor causes Typhoid Fever (S. typhi)?
Vi (virulence) capsular antigen
## Footnote
o organisms enter, multiply in **Peyer patches**, and then spread to reticulo-endothelial system
o predilection for invasion of the **gallbladder**, which can result in establishment of the **chronic carrier state**
65
LACTOSE FERMENTERS
**LaCtose is KEE. Grow in MacConKEE agar.**
Citrobacter
Klebsiella
Escherichia coli
Enterobacter
66
most important virulence factor of TB
**cord factor**
## Footnote
o inhibits WBC migration
o causes characteristic serpentine growth pattern
o induces TNF-α release
67
for detection of toxigenicity of C. diphtheriae
modified Elek test
68
Treatment of Cholera
* **Cholera**
* fluid and electrolyte replacement
* tetracycline or azithromycin shortens duration
* **V. parahaemolyticus, V. vulnificus Infectio**n
* minocycline plus fluoroquinolone or cefotaxime
69
* thin, coiled spirochetes
* hook at one or both pointed end**s (Shepherd’s crook)**
* **obligate aerobe**
* grown on **Ellinghausen-McCullough-Johnson-Harris (EMJH) medium or Fletcher medium**
LEPTOSPIRA INTERROGANS
70
all pregnant women should be screened for GBS colonization at what AOG
**35-37 weeks AOG**
71
• aerobic, acid-fast rods
**o Ziehl-Neelsen (or Kinyoun)**
• high lipid content
o mycolic acids and wax D
* produces catalase and niacin
* slow-growing on **Löwenstein-Jensen medium**
**• luciferase assay for** drug resistance
MYCOBACTERIUM TUBERCULOSIS
72
* infections commonly due to combinations of bacteria in **synergistic pathogenicity**
* LPS with **low endotoxic activity**
* capsule (antiphagocytic and anticomplement)
* **foul-smelling discharge** → because of short-chain fatty-acid products of fermentation
BACTEROIDES FRAGILIS
73
antibodies decrease efficacy of streptokinase in managing MI
anti-streptokinase
74
**Marantic endocarditis AKA nonbacterial thrombotic endocarditis (NBTE)** in patients with abdominal malignancy
Strep bovis
75
GRAM NEGATIVE RODS - GIT AND GUT
76
* anaerobic, gram-positive, spore-forming rods
* **double hemolysis** on blood agar
* growth on **egg-yolk agar** - nonmotile but with rapidly spreading growth on culture media
CLOSTRIDIUM PERFRINGENS
77
DOC for cutaneous anthrax
ciprofloxacin
78
NOVOBIOCIN SENSITIVITY
**NO StRES**
**NOvobiocin**
**Saprophyticus Resistant**
**Epidermidis Sensitive**
79
ANTIBIOTICS FOR ACTINOMYCETES
**S–N–A–P**
Sulfa for Nocardia; for Actinomyces, use Penicillin.
80
Which capsular type of Neisseria meningitidis lacks immunogenicity even with protein conjugation, hence, not included in the vaccine?
B
81
**• non-lactose-fermenting,** gram-negative rods
• produce no gas from the fermentation of glucose
**• do not produce H2S**
**• nonmotile**
* **have O antigens**
* cultured in **XLD medium**
SHIGELLA SPP.
82
cultured in **Eaton’s agent** - requires cholesterol and nucleic acids; penicillin is added to inhibit growth of contaminating bacteria; dome-shaped colonies with **“fried egg”** appearance or **“mulberry”** appearance (in the case of Mycoplasma pneumoniae)
Mycoplasma pneumoniae
83
DOC for Salmonella
Ceftriaxone
## Footnote
**Philippines: amoxicillin, chloramphenicol, co-trimoxazole**
84
TULAREMIA
FRANCISELLA TULARENSIS
## Footnote
* small gram-negative rods
* reservoir: rabbits, deer, and rodents
* transmission: ticks (e.g., **Dermacentor**), aerosols, contact, and ingestion
* treatment: streptomycin or gentamicin
85
• Pneumonia
o thick, bloody sputum **("currant-jelly" sputum)**
o usually nosocomial
**o most common cause in alcoholics**
Klebsiella pneumoniae
86
REITER SYNDROME
Triad of **urethritis, uveitis, and arthritis**
CAN’T PEE
CAN’T SEE
CAN’T CLIMB A TREE
87
**o clinically similar but milder than S. aureus TSS**
**o due to pyrogenic exotoxin A**
**o recognizable site of pyogenic inflammation**
**o blood cultures are often positive**
Streptococcal Toxic Shock Syndrome
88
* **ecthyma gangrenosum**
* hemorrhagic lesions
* **febrile neutropenia**
* leukemia or lymphoma post chemo- or radiation therapy
* severe burns
Pseudomonas
89
* aerobic, filamentous gram-positive rods with **aerial hyphae**
* weakly acid-fast **(Fite-Faraco)**
* transmission: inhalation of particles from soil
* manifests as **mycetomas** and lung and brain abscesses **(orange colonies)**
* treatment: TMP-SMX + drainage
**NOCARDIOSIS**
**(NOCARDIA ASTEROIDES)**
90
most common cause of urethritis
Gonococcal Urethritis
91
o post-impetigo (commonly the M12 type) **OR** postpharyngitic
o M protein incites immune complex deposition on the glomerular basement membrane
o ssx: hypertension, periorbital edema, **hematuria**
PSAGN
92
**o most common bacterial cause of sore throat**
o inflammation, exudate, fever, leukocytosis, and tender CLAD
o pyogenic complications: peritonsillar and retropharyngeal (Quincy) abscess, otitis, sinusitis, meningitis
**S. pyogenes (GAS)**
93
**Floppy Baby Syndrome**
* when babies ingest spores found in **household dust or honey**
* due to **absence of competitive bowel microbes**
Infant Botulism
94
most common cause of acute endocarditis
S. aureus
95
Virulence factors of Pseudomonas
* **endotoxin**
* **exotoxin A**
* tissue necrosis and inactivates EF-2
* **type III secretion system** facilitates exotoxin transfer
* **elastase** and **proteases**
* **pyocyanin** damages the cilia and mucosal cells
* **verdoglobin** from hemoglobin breakdown → any of several green compounds derived from hemoglobin or related compounds by cleavage of the porphyrin ring
96
Virulence factors of MYCOPLASMA PNEUMONIAE
* **toll-like receptor 2 protein (P1 adhesin)**
* attachment, inhibition of ciliary motion and necrosis
* **hydrogen peroxide**
* contributes to the damage to the respiratory tract cells
* autoantibodies against red cells **(cold agglutinins)** and brain, lung, and liver cells
97
FACULTATIVE INTRACELLULAR BACTERIA
**Some Bugs May Live FacultativeLY.**
Salmonella
Brucella
Mycobacterium
Listeria
Francisella
Legionella
Yersinia
98
• **IgA protease** for colonization
**• c-substance** reacts with CRP
S. pneumoniae
99
ABCDEFG of Diphtheria
ADP-ribosylation
Beta-prophage
Corynebacterium
Diphtheriae
Elongation Factor-2
Granules (metachromatic)
100
For N. gonorrhea, sterile clinical specimens (e.g. blood, synovial fluid, CSF) should be inoculated onto
**enriched chocolate agar**
101
**GRAM POSITIVE BACTERIA**
**MEMOOORRRIIIIZZZEEEE!!!!**
102
DOC for Shigella
ciprofloxacin
103
injection of diphtheria exotoxin into the skin, to determine whether a person is susceptible to infection by diphtheriae (not to be confused with Dick test in scarlet fever)
**Schick test**
104
Q fever
Coxiella burnetti
105
* anaerobic, gram-positive, spore-forming rods
* spore is at one end **(terminal spore)** so organism looks like a **tennis racket**
CLOSTRIDIUM TETANI
106
o triggers cell-mediated immunity in TB→ caseation and granulomas
o triggers delayed hypersensitivity reaction
o a surface protein
tuberculin surface protein
107
**• gram-negative "kidney-bean" diplococci**
* large polysaccharide capsule
* oxidase-positive colonies on chocolate agar
**• ferments maltose and glucose**
NEISSERIA MENINGITIDIS
108
FORMS OF CHLAMYDIA
Elementary body = Enfectious, Enters cell via Endocytosis
Reticulate body = Replicates in cell by fission
109
o within hours, enters lymphatics and multiplies
o local, nontender ulcer (**chancre**) usually forms in 2–10 weeks
o Highly infectious, heals spontaneously in 3-6 weeks
Primary Syphilis
110
DOC for S. pyogenes (GAS)
Penicillin G
111
Osteomyelitis in IV drug abusers
* Staphylococcus aureus
* Pseudomonas aeruginosa
112
C. difficile exotoxins A (enterotoxin) and B (cytotoxin) inhibit GTPases, leading to apoptosis and death of enterocytes leading to \_\_\_
pseudomembranes
113
* many years after inoculation
* clinical spectrum
* granulomas (**gummas**)
* **neurosyphilis**
* **tabes dorsalis**
* **Argyll-Robertson pupil / Prostitute’s pupil**
* **dementia paralytica**
* cardiovascular (aortitis)
* obliterative invasion of small blood vessels and vasa vasorum, causing **endarteritis**
Tertiary Syphilis
114
LYME DISEASE
**BAKE a Key LYME pie**
Bell Palsy
Arthritis
Kardiac block
Erythema chronicum migrans
115
Toxic Shock Syndrome
**S. aureus**
* due to **TSST-1**
* fever, hypotension, sloughing of the filiform papillae → **strawberry tongue, desquamating rash** and multi-organ involvement (\>3)
* **usually no site of pyogenic inflammation; blood CS negative**
* usual scenario: **tampon**-using menstruating women or in patients with **nasal packing** for epistaxis
116
Ehrlichiosis
Ehrlichia chaffeensis
117
o Non-bloody diarrhea associated with **pseudomembranes** (yellow-white plaques) on the colonic mucosa
o **toxic megacolon** can occur
Pseudomembranous Colitis
118
* C. trachomatis types L1–L3
* papule or vesicular which ulcerates and leads to suppurative inguinal lymphadenitis (**buboes**)
* positive **Frei test**
* intradermal injection of antigen
Lymphogranuloma Venereum
119
* aerobic, non-spore-forming, gram-positive rods
* arranged in V- or L-shape
**• tumbling motility**
• narrow zone of beta-hemolysis
**• cold enhancement:** paradoxical growth in cold temperature
LISTERIA MONOCYTOGENES
120
**Reddish metachromatic (Babes-Ernst / Volutin) granules** can be seen
C. diphtheriae
121
* aerobic, **gram-positive box-car like rods**
* nonmotile
* **spore-forming**
* **Medusa head** morphology - dry "ground glass" surface and projections along lines of inoculation
BACILLUS ANTHRACIS
122
2nd most common cause of UTIs in sexually active women
STAPHYLOCOCCUS SAPROPHYTICUS
123
* Seen in lepromatous form
* Tender red nodules or humps on both shins
* Signals acute flare-ups of disease
* Treated with **Thalidomide** → category X drug; associated with phocomelia if given during pregnancy
Erythema Nodosum Leprosum
124
* most common cause of crippling of the hand
* Damage in the following nerves is characteristic impairments in leprosy:
* Ulnar and median: clawed hand
* Posterior tibial: plantar insensitivity and clawed toes
* Common peroneal: foot drop
* Radial cutaneous, facial, and greater auricular nerves (may also be involved)
Leprosy / Hansen Disease
125
most commonly identified cause of GBS
Campylobacter infection
126
Thayer-Martin agar composition
Mueller-Hinton agar with 5% chocolate sheep blood plus the following antibiotics (VPN):
* **Vancomycin (inhibits gram-positive organisms)**
* **Polymyxin\* inhibits gram-negative organisms excluding Neisseria species)**
* **Nystatin (inhibits fungi)**
\*Alternatively, polymyxin can sometimes be replaced with **colistin** (hence, VCN) or **trimethoprim**.
127
Which of the following refers to an obsolete skin test for venereal lymphogranuloma that uses antigens prepared from chlamydia grown in the yolk sac of a chick embryo?
Frei test
128
* poorly gram-negative rods
* **visualize with silver stain**
* **facultative intracellular bacteria**
* culture on **charcoal yeast extract agar**
* increased amounts of iron and cysteine
* optimal between 28 and 40°C; organisms are dormant below 20°C and are killed at temperatures above 60°C
* **rapid urinary antigen test**
LEGIONELLA PNEUMOPHILA
129
Epidemic Typhus
Rickettsia prowazekii
130
o watery diarrhea in large volumes (**rice-water stools)**
o patients with severe hypovolemia may have sunken eyes, dry mouth, cold clammy skin, decreased skin turgor, or wrinkled hands and feet, aka ‘washerwoman's hands’
Cholera
131
* gram-positive cocci in chains
* catalase-negative
**• gamma hemolytic colonies**
**• Lancefield group D**
• bile and optochin-resistant
**• hydrolyzes esculin in bile-esculin agar (BEA)**
**• positive PYR test**
**• E. faecalis can grow in 6.5% NaCl while S. bovis cannot**
**GROUP D STREPTOCOCCI**
132
**bird fancier’s disease** - sudden onset pneumonia with malaise, fever, anorexia, sore throat, photophobia, and severe headache
CHLAMYDIA PSITTACI
133
**satellite phenomenon** around S. aureus colonies - hemolysis by S. aureus liberates factor V
H. influenzae
134
DOC for Pseudomembranous Colitis
**oral metronidazole or vancomycin** should be given and fluids replaced - oral vancomycin because it has poor intestinal absorption, hence, it ‘coats’ the lesions with antibiotic
135
* gram-positive cocci in clusters
* catalase-positive
**• coagulase-negative**
**• novobiocin-sensitive**
• whitish, non-hemolytic colonies on blood agar
STAPHYLOCOCCUS EPIDERMIDIS
136
Two genera of bacterial pathogens are known to produce **endospores**:
aerobic **Bacillus** and anaerobic **Clostridium**
137
**exotoxin** inhibits protein synthesis by adding ADP-ribose to **elongation factor-2 (EF-2)**
## Footnote
o subunit A, has ADP-ribosylating activity
o subunit B, binds the toxin to cell surface
o exotoxin encoded by b -prophage
C. diphtheriae
138
**GRAM NEGATIVE BACTERIA**
**MEMMMOOOORRRIIIZZZEEEE!!!**
139
o most severe form of meningococcemia
o high fever, shock, widespread purpura, disseminated intravascular coagulation, thrombocytopenia, and **adrenal insufficiency**
§ **bilateral hemorrhagic destruction of the adrenal glands**
Waterhouse-Friderichsen Syndrome
140
OSTEOMYELITIS in burns
Pseudomonas aeruginosa
141
* gram-positive cocci in chains
* Catalase-negative
**• Beta-hemolytic**
**• Bacitracin-resistant**
**• Lancefield group B**
* hydrolyze hippurate
* CAMP test–positive
* grow using Lim broth
**STREPTOCOCCUS AGALACTIAE**
**(GROUP B STREPTOCOCI)**
142
S. pyogenes preotein that prevents phagocytosis by binding to the Fc region of IgG
Protein A
143
o postpharyngitic
o cross-reacting antibodies to **M proteins** and antigens of joint, heart, and brain tissue
o Jones Criteria:
**§ migratory polyarthritis**
**§ pancarditis**
**§ erythema marginatum**
**§ Sydenham chorea**
**§ subcutaneous nodules**
**Acute Rheumatic Fever sec to S. pyogenes (GAS)**
144
* small gram-negative rod
* culture on chocolate agar with heme (factor X)
* PE: **painful** genital ulcer
CHANCROID
| (HAEMOPHILUS DUCREYI)
145
Pseudomonas susceptible drugs
**o antipseudomonal penicillins (ticarcillin, piperacillin)**
**o penicillin plus beta-lactamase inhibitor (ticarcillinclavulanate, piperacillin-tazobactam)**
**o third generation cephalosporins (ceftazidime)**
**o fourth generation cephalosporins (cefepime)**
**o monobactam (aztreonam)**
**o carbapenems (imipenem, meropenem)**
**o fluoroquinolones (ciprofloxacin)**
146
OBLIGATE INTRACELLULAR BACTERIA
Stay inside cells when it is **R**eally **C**old
## Footnote
**Ricketssia**
**Chlamydia**
147
blocks acetylcholine release causing **flaccid paralysis (descending pattern)**
botulinum toxin (heat-labile neurotoxin)
148
• culture on Bordet-Gengou agar or Regan-Lowe charcoal medium
BORDETELLA PERTUSSIS
149
**ABCDE of beta-prophage encoded toxins**
**ShigA-like toxin (EHEC)**
**Botulinum toxin**
**Cholera toxin**
**Diphtheria toxin**
**Erythrogenic toxin (S. pyogenes)**
150
o nosocomial pneumonia, VAP, necrotizing pneumonia, complicated by **empyema**, abscess or **pneumatocele**
o **post-viral pneumonia**
S. aureus
151
o bacteremia results in the seeding of many organs, with **osteomyelitis, pneumonia, and meningitis** as the most common sequelae
o commonly in patients with **sickle cell anemia** or cancer
Salmonella choleraesuis
152
**• smallest free-living organisms**
• not seen on Gram-stain
**o no cell wall**
**o only bacteria with sterol in cell membra**ne
MYCOPLASMA PNEUMONIAE
153
**Exotoxin A and B** - cause depolymerization of actin filaments in gastrointestinal mucosal cells, leading to mucosal cell death (i.e. pseudomembranes)
Clostridoides difficile
154
Cellulitis
**S. pyogenes and Staphyloco**
**§ deeper infection involving subcutaneous/dermal tissues**
**§ facilitated by hyaluronidase (spreading factor)**
155
VIRULENCE FACTORS OF S.PYOGENES / GROUP A STREP
156
* Osteomyelitis & Septic Arthritis
* from hematogenous spread or local introduction at wound site
* **Brodie abscess**
* sequestered focus of osteomyelitis arising in the metaphyseal area of a long bone
S. aureus
157
(woolsorter’s disease)
BACILLUS ANTHRACIS
158
method of determining s**usceptibility to scarlet fever** by injection into the skin of 0.1 cubic centimetre of scarlet fever toxin (do not consufe this with the Schick test for diphtheria susceptibility)
Dick test
159
treatment of erythema nodosum leprosum
thalidomide
160
Virulence factors of LISTERIA MONOCYTOGENES
**• internalin**: interacts with E-cadherin on the surface of cells
**• listeriolysin:** escape from phagosomes
**• actin rockets (actin polymers):** propels the bacteria through the membrane of one human cell and into another
161
cultured in mouse footpad or in the armadillo
MYCOBACTERIUM LEPRAE
162
DOC for pertussis
Erythromycin
163
UNDULATING FEVER
BRUCELLA ABORTUS
## Footnote
* transmission: contaminated dairy or direct contact
* treatment: doxycycline plus rifampin
164
Enterotoxin produced by B. cereus
**Heat-Labile Enterotoxin**
**o cholera-like enterotoxin** causes ADP-ribosylation, increasing cAMP
165
**o most severe form of leptospirosis**
**o triad: jaundice, bleeding, uremia**
**o orange cast skin** (severe jaundice)
o most common cause of death is r**espiratory failure due to massive pulmonary hemorrhage**
Weil Syndrome
166
Endemic typhus
Rickettsia typhi
167
* anaerobic, gram-positive, spore-forming rods
* exotoxin in stool detected by **cytopathic effect** (final phase by which viral cells infect cells) on cultured cells or ELISA
CLOSTRIDIUM DIFFICILE now CLOSTRIDIOIDES DIFFICILE
168
* Ubiquitous in man and **natural water environments**
* Freshwater amoebae appear to be the natural reservoir for the organisms.
* transmission via aerosol (**e.g. AC, cooling towers)**
* person-to-person transmission does not occur
LEGIONELLA PNEUMOPHILA
169
**• most virulent bacteria**
* small gram-negative rods with bipolar **(safety pin)** staining
* reservoir: wild rodents
* transmission: **flea** bite, inhalation
* PE: **buboes**, cutaneous hemorrhage
* treatment: streptomycin and tetracycline
* No vaccine available
YERSINIA PESTIS
170
antiphagocytic capsule of B. anthracis
poly-D-glutamate)
171
titers to document antecedent **skin infection**
anti-DNAse B
172
GRAM POSITIVE RODS
173
UREASE-POSITIVE BACTERIA
**Particular Kinds Have Urease.**
Proteus mirabilis
Klebsiella pneumoniae
Helicobacter pylori
Ureaplasma urealyticum
174
* most common type of atypical pneumonia **(walking pneumonia)**
* clinical findings not compatible with chest x-ray
**• extra-pulmonary manifestations:**
o hemolysis, Stevens-Johnson syndrome, Raynaud, GuillainBarre syndrome
MYCOPLASMA PNEUMONIAE
175
**BITES and OSTEOMYELITIS**
* short, encapsulated gram-negative rod that exhibits bipolar staining (‘**closed safety pin appearance’)**
* **buttery** colonies with **musty** odor due to indole production
* reservoir: cats and dogs
* transmission: **animal bites**
* treatment: penicillin G
PASTEURELLA MULTOCIDA
176
MCC of neonatal pneumonia, sepsis and meningitis
**STREPTOCOCCUS AGALACTIAE**
**(GROUP B STREPTOCOCI)**
177
• **urease** hydrolyzes the urea in urine to form **ammonia**
o raises pH producing alkaline urine
o encourages the formation of **struvite** stones, composed of **magnesium-ammonium-phosphate**
PROTEUS MIRABILIS
178
**ATYPICAL PNEUMONIA**
* pneumonia accompanied by confusion, non-bloody diarrhea, hyponatremia, proteinuria and hematuria
LEGIONELLA PNEUMOPHILA
179
NEONATAL MENINGITIS
**B–E–L**
B group streptococci (S. agalactiae)
Escherichia coli
Listeria monocytogenes
180
DOC of MRSA
Vancomycin
181
• facultative gram-negative rods
**• non-lactose-fermenting**
* produces **H2S**
* **Widal test** detects antibodies in patient's serum
* cultured in **XLD medium**
SALMONELLA SPP.
182
What is the vector of plague (Yersinia pestis)?
FLEA
183
**granulomatosis infantiseptica**
o transplacental transmission
o characterized by late miscarriage or birth complicated by sepsis, multiorgan abscesses, and disseminated granulomas
Early-Onset Neonatal Listeriosis
184
* facultative gram-negative rods
* non-lactose-fermenting
**• urease-positive**
**• swarming motility**
PROTEUS MIRABILIS
185
Drugs associated with Psudomembranous colitis secondary to C. difficile
**clindamycin, 2 nd & 3 rd gen cephalosporins, ampicillin**
186
* **tracheal cytotoxin**
* damages ciliated cells
* causes whooping
* **extracytplasmic (false) adenylate cyclase**
* ‘weakens’ neutrophils lymphocytes and monocytes
* inhibits phagocytosis
* **filamentous hemagglutinin**
* pili rod that extends from the surface of B. pertussis, enabling the bacteria to bind to ciliated epithelial cells of the bronchi
* mediates attachment
* **pertussis toxin**
* causes ADP-ribosylation
* activates G proteins that increases cAMP resulting in:
BORDETELLA PERTUSSIS
187
o central area of **Langhan giant cells** surrounded by a zone of e**pithelioid cells**
o **tubercle** is a granuloma surrounded by fibrous tissue that has undergone central caseation
Granulomatous Lesions in TB
188
* **may mimic ulcerative colitis**
* disease associations
* **Guillain-Barré syndrome**
* antigenic cross-reactivity between oligosaccharides in bacterial capsule and glycosphingolipids on surface of neural tissues
* **reactive arthritis (Reiter syndrome)**
CAMPYLOBACTER JEJUNI
189
Methicillin resistance in S aureus is mediated by what gene?
**mecA gene**
## Footnote
\* encodes for a novel penicillin-binding protein (PBP), **PBP2a**, with reduced binding affinity for antibiotic.
190
§ most severe form of bacillary dysentery
§ most common cause of epidemic dysentery
**Shigella dysenteriae type 1 – Shiga bacillus**
191
o **condyloma lata**, maculopapular rash, fever headache, malaise, anorexia, lymphadenopathy
o occurs after 1 to 3 months
Secondary Syphilis
192
gold standard for leptospirosis diagnosis
leptospire microscopic agglutination test (lepto MAT)
193
DOC for Tetanus
Metronidazole or penicillin - Metronidazole (400mg rectally or 500 mg IV every 6 h for 7 days) is the preferred antibiotic. An alternative is penicillin (100,000–200,000 IU/kg per day), although this drug theoretically may exacerbate spasms (Harrisons)
194
Necrotizing fasciitis AKA flesh-eating disease
**S. pyogenes (GAS)**
* rapidly progressive infection of deep subcutaneous tissues
* facilitated by **exotoxin B**
* **Fournier's gangrene**
* form of necrotizing fasciitis involving the male genital area and perineum; often caused by mixed organisms but can be caused by GABHS
195
STREPTOCOCCI - OVERVIEW
196
* encapsulated, pleomorphic gram-negative bacillus
* bipolar densities (**Donovan bodies**) look like **closed safety pins**
* small painless papule ulcerates to form **beefy red ulcer** with velvety surface
* **pseudobuboe formation** → lump in the groin similar in appearance to bubo (remember bubonic plague?); it is actually a granuloma and not an inflamed lymph node, hence, it is a ‘false’ bubo
* treatment: **azithromycin**
**GRANULOMA INGUINALE /DONOVANOSIS**
**(KLEBSIELLA GRANULOMATIS)**
197
NEISSERIA
**Neisseria MeninGitidis ferments Maltose and Glucose**
**Neisseria GOnorrhoeae ferments Glucose Only**
198
BUBONIC, PNEUMONIC and SEPTICEMIC PLAGUE
YERSINIA PESTIS
199
• ingestion of **unpasteurized milk products,** e.g., cheese
LISTERIA MONOCYTOGENES
200
Rockey mountain Spotted fever
Rickettsia rickettsii
201
ZOONOSES
**Bugs From Your Pets.**
Brucella abortus
Francisella tularensis
Yersinia pestis
Pasteurella multocida
202
TETANUS PROPHYLAXIS
203
DRUGS USED IN TB TREATMENT
204
DOC of VRSA
Linezolid
205
prevents phagosome-lysosomal fusion in TB
exported repetitive protein (sulfatides)
206
**• most common cause of**
**o prosthetic valve endocarditis**
**o septic arthritis in prosthetic joints**
**o ventriculoperitoneal shunt infections**
S. Epidermidis
207
protein complex responsible for the massive, watery diarrhea (e.g. rice water stools) characteristic of cholera infection
**Cholera toxin** (a.k.a. **choleragen**, sometimes abbreviated as CTX, Ctx or CT)
* CT acts by causing constitutive activation of adenylate cyclase, leading to elevated cAMP levels in intestinal epithelial cells. Cyclic AMP (cAMP) activates protein kinase A, which causes the opening of ion channels in the membrane, leading to chloride and bicarbonate secretion by intestinal crypt cells and disruption in absorption by villus cells.
208
Halberstaedter-Prowazek inclusions
C. trachomatis
209
LEPTOSPIROSIS PHASE?
* aseptic meningitis
* CSF pleocytosis with or without meningeal symptoms
* **coincides with appearance of antibody titers**
* pulmonary involvement
* **snow-flake lesions in CXR**
* hepatic necrosis
* glomerulonephritis
* **due to immune-complex deposition**
Immune Leptospiruric Phase
210
most common cause of bacillary dysentery
**Shigella sonnei – Duval’s bacillus**
211
**Neonatal Pneumonia**
* **types D–K**
* **late-onset** (2-4 weeks) o striking tachypnea, characteristic paroxysmal cough **(staccato cough**), absence of fever, and eosinophilia
C. trachomatis
212
The heat resistance of bacterial spores, such as those of B. anthracis, is due in part to their **dehydrated state** and in part to the presence of large amounts of which of the following?
**Calcium dipicolinate**
## Footnote
\* Dipicolinic acid forms a complex with calcium ions within the endospore core. This complex binds free water molecules, causing dehydration of the spore.
213
• looks like **Chinese characters**
## Footnote
**• metachromatic granules**
C. diphtheriae
214
* gram-negative rods
* **obligate aerobe**
**• non-lactose-fermentin**g
**• oxidase-positive**
**• pyocyanin (blue-green pigment)**
**• sweet grape-like odor**
• grown on **Cetrimide agar**
PSEUDOMONAS AERUGINOSA
215
VIRULENCE FACTORS OF VIBRIO
* **enterotoxin (choleragen)** acts by ADP ribosylation
* **mucinase** enhances attachment to the intestinal mucosa
* high infectious dose
* pandemics caused by **Vibrio cholerae O1 biotype El Tor (cholera El Tor)**
216
* glycocalyx adheres well to **foreign bodies and form biofilms**
* prosthetic heart valves
* prosthetic joints
* ventriculoperitoneal shunts
* indwelling catheters
STAPHYLOCOCCUS EPIDERMIDIS
217
tetanus toxin
**tetanospasmin**
o protease that cleaves proteins involved in the release of glycine from Renshaw cells in spinal cord
o Prevents release of GABA by cleaving of synaptobrevin 2
218
only bacteria with sterol in cell membrane
MYCOPLASMA PNEUMONIAE
219
TRACHOMA = TYPES A, B, C
ABC:
Africa
Blindness
Chronic infection
220
DOC of inhalational/gastrointestinal anthrax
DOC is **ciprofloxacin or doxycycline** with one or two additional antibiotics (rifampin, vancomycin, penicillin, imipenem, clindamycin, clarithromycin)
221
GROUP A STREP TOXINS
222
o alkaline **vegetables** such as green beans, peppers, and mushrooms
o smoked fish
o **canned goods (bulging)**
o **honey**
CLOSTRIDIUM BOTULINUM
223
cause pulmonary disease in immunocompromised hosts (AIDS patients with CD4 \<50)
MYCOBACTERIUM AVIUM-INTRACELLULARE COMPLEX (MAI, MAC)
224
* gram-positive cocci in clusters
* catalase-positive
**• coagulase-negative**
**• novobiocin-resistant**
* whitish, non-hemolytic colonies on blood agar
* Nitrite negative (unlike E. coli)
STAPHYLOCOCCUS SAPROPHYTICUS
225
titers to document antecedent pharyngitis
anti-streptolysin O (ASO)
226
direct epidermal contact with spores causes formation of a **malignant pustule** with subsequent eschar and central necrosis
Cutaneous Anthrax
227
most common cause of **subacute and native endocarditis**
**S. sanguis (VIridans Strep),** for subacute bacterial endocarditis (SBE)
228
most common cause of septic arthritis in sexually active adults
N. gonorrhea
229
• curved gram-negative rods
## Footnote
**• urease-positive**
**• microaerophilic**
HELICOBACTER PYLORI
230
MCC of death is **pulmonary hemorrhage** in the ff:
**• Anthrax (pulmonary) aka wool sorter’s disease**
**• Leptospirosis, severe (Weil’s syndrome)**
**• Congenital syphilis**
231
allows adherence of bacteria to the mucous membranes of the respiratory, genitourinary and gastrointestinal tracts
IgA protease
232
• Skin & Soft Tissue Infections
o bullous impetigo, folliculitis, furuncles, carbuncles, cellulitis, hidradenitis suppurativa, mastitis, surgical site infections
S. aureus
233
cause **culture negative subacute bacterial endocarditis i**n patients with preexisting heart disease
**HACEK ORGANISMS**
## Footnote
Haemophilus aphrophilus
Actinobacillus actinomycetemcomitans
Cardiobacterium hominis
Eikenella corrodens
Kingella kingae
234
o snuffles / saddle nose
o mulberry molars
o Hutchinson triad: Hutchinson teeth, deafness, keratitis
o saber shins
o rhagades (angle of mouth)
o Higoumenakis sign (clavicle) → unilateral enlargement of the sternoclavicular portion of the clavicle, leads to detachment
o Clutton’s joints (synovitis)
o pulmonary hemorrhage
Congenital Syphilis
235
Treatment of tuberculoid leprosy
dapsone and rifampin
236
o acute onset (4 hrs) of vomiting and diarrhea due to ingestion of **preformed heat-stable enterotoxin**
o source: **salad** made with **mayonnaise** (potato or tuna salad)
Gastroenteritis sec to S. aureus
237
ENTEROBACTERIACEAE
238
**• obligate intracellular** bacteria
**• energy parasites** that use host ATP
* cell wall **lacks muramic acid**
* grown in **cycloheximide** culture
**• cytoplasmic inclusions** in Giemsa
CHLAMYDIA TRACHOMATIS
239
**Erysipelas AKA St. Anthony's Fire**
**S. pyogenes (GAS)**
**superficial infection extending into dermal lymphatics**
240
Virulence factors of B. anthracis
241
Bacillary angiomatosis presents with cutaneous nodules very similar in appearance to those found in which disease?
Kaposi sarcoma
242
Shiga-like toxin (just like the real Shiga toxin produced by Shigella) inhibits ____ ribosomal subunits, resulting in decreased protein synthesis in gastrointestinal mucosal cells.
60S
243
* small **gram-negative (coccobacillary) rods**
* requires **factor X (hemin**) and **V (NAD)** for growth **(chocolate agar)**
HAEMOPHILUS INFLUENZAE
244
o dissemination of meningococci into the bloodstream
o multiorgan disease, consumptive coagulopathy, **petechial or purpuric rash (purpura fulminans)**
Meningococcemia
245
NONE of the cephalosporins are active against the following:
**• Enterococci**
**• Listeria monocytogenes**
**• MRSA**
