Micro - General lecture 1,2 Flashcards

1
Q

Folliculitis causative agent

A

Staph aureeus

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2
Q

Staphylococcus aureus lab tests

A

Gram + Cocci in grape like clusters
Catalase +
Coagulase +
Beta hemolytic

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3
Q

S. aureus protein A

A

Inhibits complement activation by binding to Fc portion of IgG

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4
Q

Honey Crusted lesions - starting around the mouth and nose

Patches of itchy, oozing vesicles

A

Impetigo - Staph aureus (also Strep pyogenes)

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5
Q

Large blisters over entire body - filled with clear fluid and no bacteria. Entire skin peels within 2 days - grows back in 7-10 days.

A

Staphylococcal Scaled Skin Syndrome/Ritter’s Disease - caused by S. aureus exfoliative toxin

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6
Q

Localized form of Staphylococcal Scalded Skin Syndrome

A

Bullous Impetigo

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7
Q

Fever, hypotension, diffuse, macular erythematous rash (Desquamation of the skin, including palms and soles).
Shock, multiple organ failure, death

A

Toxic Shock Syndrome - TSST1-superantigen of S. aureus

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8
Q

Streptococcus pyogenes lab tests

A

Group A Beta hemolytic strep growing in chians

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9
Q

Warm, erythematous, swollen lesions.
Acute spreading infection of subcutaneous tissue developing within a few hours-days.
Predisposed to trauma or skin lesion

A

Cellulitis
Strep pyogenes
also S aureus and anaerobes

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10
Q

Intense pain at site of infection - pain is disproportionate to appearance of infected area.
Rapidly progressive disease which destroys muscle, fat, and skin tissue

A

Necrotizing fasciitis - “Flesh eating disease”

Strep pyogenes

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11
Q

Different types of Necrotizing fasciitis

A

Type 1: Polymicrobial (at least 1 anaerobe with at least 2 faculatative bacteria)
Type 2: Strep pyogenes with or without S. auresus
Type 3: Gas gangrene: Clostridium perfringens

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12
Q

Sandpaper rash on trunk and inner arms and legs.

Desquamation occurs in about 5-7 days. Strawberry tounge

A

Scarlet fever.

Complication of strep throat - production of pyrogenic exotoxins (Strep pyogenes)

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13
Q

Bright red rash with RAISED boarders - butterfly pattern on face.

A

Erysipelas - infection spreads from skin to lymph nodes

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14
Q

Causative agent of Acne

A

Propionibacterium acnes

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15
Q

Propionibacterium acnes lab tests

A

Gram + rods

Metabolize sebum - produce propionic acid

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16
Q

Causative agent of Leprosy/Hansen’s disease

A

Mycobacterium leprae

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17
Q

Mycobacterium leprae lab tests

A

Acid-fast rod that does NOT gram stain well because of waxy, thick, mycolic acid (intracellular)

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18
Q

2 types (and etiology) of leprosy

A

Tuberculoid leprosy: Good CMI, less severe infection

Lepromatous leprosy: Poor CMI - severe infection

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19
Q

Dry, blotch, red lesions on the face and trunk and extremities.
Nerve damage results in LOSS OF FEELING (prone to trauma)

A

Tuberculoid leprosy

20
Q

Skin thickening and nodules
large # of bacteria
Thickening of nostrils, ears, and cheeks - eventually destroy septum of nose
“Leonine facial appearance”

A

Lepromatous leprosy

21
Q

Pseudomonas aeruginosa lab tests

A

Gram negative rod

Blue-green pigment - grape like smell

22
Q

Hot tub folliculitis (also swimming pool)

A

Pseudomonas aeruginosa

23
Q

Ecthyma gangrenosum

A

Characteristic lesion of bacteremia of Pseudomonas aeruginosa

24
Q

Gram + rod with endospores and a glutamic acid capsule
Train/box car arrangement
7-10 days later - develop painless BLACK ESCHAR

A

Bacillus anthracis - cutaneous anthrax

Wool sorters, cattle ranchers

25
Q

Differentiate between meningitides and gonorrhoeae

A

Meningitidis metabolizes maltose

Gonorrhoeae metabolizes glucose AND maltose

26
Q

Neisseria meningitdis lab tests

A
Gram negative diplococcic
Culture on THAYER-MARTIN agar
non-motile, fastidious
Capnophilic; 5% CO2
LOS: Lipooligosaccharide (No O antigen)
27
Q

N. meningitides major virulence factor for Meningococcemia

A

Capsule - antiphagocytic

28
Q

Fever, Arthralgia, Muscle pain, PETECHIAL rash

Growth on Thayer-martin agar

A

Meningococcemia - Neiseria

29
Q

Complication of Meningocooccemia

A

Waterhouse-Friderichsen Syndrome:
Bilateral hemorrhage of adrenal galndes
Coma
Death can occur in 6-8 hours

30
Q

Menomune

A

Meningococcemia vaccine - Meningococcal capsular polysaccharide vaccine
Does NOT work in children < 2 years old

31
Q

Menactra

A

Meningococcal conjugate vaccine recommended for college students, army recruits, splenectomy, and travelers

32
Q

Causative Agent o Syphilis

A

Treponema pallidum

33
Q

Treponema pallidum lab tests

A

Spirochete - usually NOT visible on gram stain

34
Q

Primary phase of Syphilis

A

Painless chancre (raised, red lesion) at site of infection

35
Q

Secondary phase of Syphilis

A

Flu like symptoms
Disseminated disease: COPPER COLORED rash over entire body and on PALMS and SOLES of the feet
Condyloma latum: Soft fleshy papules in genital region

36
Q

Late phase of Syphilis

A

Cardiovascular
Neurosyphilis
Benign tertiary: Gummas

37
Q

Gram negative aerobic rod that is an obligate intracellular bacteria. Lyses the phagosome before lysosome-phagosome fusion. Causes disease spread by the American dog tick.

A

Rickettsia rickettsii - Rocky Mountain spotted Fever

38
Q

A seasonal disease. Non-itchy rash that begins on the hands and feet and spreads inwards to trunk (centripetal spread).
Initial maculopapular rash but later stages becomes petechial and hemorrhagic

A

Rocky Mountain spotted Fever - Rickettsia rickettsii

39
Q

Centrifugal (trunk to extremities) spread of a maculopapular rash 2-3 days after onset of fever, chills, headache, myalgia, lymphadenopathy

A

Scrub Typhus - Orientia tsutsugamushi

NOT a tick - think traveler - transmitted by chiggers - mite larvae

40
Q

Clostridium perfringens lab tests

A

Gram + spore forming rods
Strict anaerobe. Spores.
alpha toxin, lecithinase: Breaks down lipids in cell membranes resulting in cell death
“Drum stick” Or “Tennis racket” appearance

41
Q

Severe pain that is disproportionate to physical findings.
Swelling with hemorrhagic bullae
Crepitation
May have brownish foul smelling discharge

A

Gas gangrene - C. perfringens

42
Q

Cause of an erysipeloid infection

A

Erysipelothrix rhusipathiae

Gram + rod in GI tract of animals

43
Q

Lab tests for Vibrio vulnificus

A

Gram negative, comma shaped

Halophile: wound exposed to salt water

44
Q

Causative agent of Cat scratch fever

A

Bartonella henselae

Gram negative, aerobic bacillus

45
Q

In AIDS patients - cutaneous papules/nodules that resembles Kaposi sarcoma. Patient has cats.

A

Bacillary Angiomatosis - B. henselae

46
Q

Animal bites:

A

Pasteurella multocida
Gram negative coccobacillus, oxidase - positive
Bipolar staining “Saftey pin”