Medical Microbiology Chapters 19, 20, 21

Front 1

What are the two major groups of Gram-positive pathogens?

What is this name based on?

Back 1

Low G + C Gram-positive bacteria and High G + C Gram-positive bacteria

It is based on the ration of guanine-cytosine nucleotide base pairs to adenine-thymine nucleotide base pairs in these organisms' DNA

Front 2

What three genera of pathogenic spherical cells are included in the Low G + C gram positive category?

Back 2

Staphylococcus, streptococcus, and Enterococcus

Front 3

What three genera of pathogenic rod-shaped cells are included in the Low G + C gram positive cateogory?

Back 3

Bacillius, Clostridium, and Listeria

Front 4

What rod shaped cells are included in the high G + C gram positive category?

Back 4

Corynebacterium, Mycobacterium, and Propionicbacterium

Front 5

What filamentus, fungus like cells are in the high G + C category?

Back 5

Norcardia, and Actinomyces

Front 6

Give the break down of Staphylococcus.

1. Category (genus)
2. Structure and Physiology
3. Pathogenicity
4. Epidemiology
5. Disease
6. Diagnosis, TX and prevention

Back 6

1. Low G + C gram positive bacteria
2. spherical clusters, anaerobic, (salt, radiation, dessication, heat tolerant)
3. Protein A (interferes with humoral immune response by halting opsonization and the complement cascade), outer surface has bound coagulase (causes fibrin clots that "hide" the bacteria), Slime layers, enzymes, toxins
4. Direct contact and fomites
5. Noninvasive (food poisoning), cutaneous (scaleded skin syndrome, impetigo, and folliculitis), systemic diseases (TSS, bacteremia, endocarditis, pneumonida and empyema, osteomyelitis)
6. resistant to many antibiotics
methicillin and vancomycin are drugs of last resort
MRSA and VRSA are of extreme public health concern

Front 7

What two species are commonly associated with staphylococcal diseases in humans?

Back 7

1. Staphylococcus aureus
2. Staphylococcus epidermidis

Front 8

What does staphylococcus synthesize that other G + C Gram positive cocci do not?

Back 8

Catalase

Front 9

What toxins do staphylococci produce to contribute to their survival and pathogenicity?

Back 9

Cell-free coagulase, hyalouronidase, staphylokinase, lipases, and b-Lactamase

Front 10

True or False

Only S.aureus produces cell-free coagulase

Back 10

True

Front 11

True or False

All staphylococci produce lipases

Back 11

True

Front 12

What is the function of staphylokinase

Back 12

To break down fibrin clots

Front 13

What is the function of B-lactamase

Back 13

To break down penicillion

Front 14

List the Toxins associated with staphylococcus

Back 14

Cytolytic toxins, exfoliative toxins, toxic shock syndrome toxin, and entereotoxins

Front 15

______ is one of the more common causes of food poisoning

Back 15

s.aureus

Front 16

True or False

Food contaminated with s.aureus generally tastes bitter and sour.

Back 16

False- it usually does not appear or taste unusual

Front 17

S.aureus causes localized ______ lesions.

Back 17

Pyogenic

Front 18

Whats the difference between impetigo and scalded skin syndrome?

Back 18

Impetigo’s patches are filled with bacteria, sss’s patches aren’t

Front 19

When the pneumonia occurs and the fluid that fills the lungs is pus, the condition is then known as ____.

Back 19

Empyema

Front 20

If staphylococcal samples are able to clot blood then they are coagulase positive ______. If they aren’t, then they are coagulase negative _____.

Back 20

S.aureaus and S.epidermidis, respectively

Front 21

What is generally used to treat MRSA infections?

Back 21

Vancomycin

Front 22

What does MRSA stand for?

Back 22

Methicillin-resistant staphylococcus aureus

Front 23

Give the break down of Staphylococcus Group A.

1. Category (genus)
2. Structure and Physiology
3. Pathogenicity
4. Epidemiology
5. Disease
6. Diagnosis, TX and prevention

Back 23

1. Low G + C gram positive bacteria – aka s.pyogens
2. Facultatively anaerobic, spherical cells, usually forms a large zone of beta hemolysis and capsules
3. Protein M (destabilizes complement therefore interferes with opsonization and lysis), and hyaluromic acid (acts as camoflauge since HA is normally found in the body), streptokinases, deoxyribonucleases, C5a peptidase and streptolysins. Toxins include pyrogenic toxins
4. Respiratory droplets in crowded conditions
5. Pharyngitis, scarlet fever, pyoderma and erysipelas, streptococcal toxic shock syndrome, necrotizing fascitis, rheumatic fever, glomerulonephritis
6. antibiotic sensitive, so serious forms of disease are rare. (penicillin, cepahlosporins, topical antimicrobials like bacitracon)

Front 24

True or False

Streptococcus is catalase positive

Back 24

False- only staphylococcus is catalase positive

Front 25

A ___ is a confined, pis-producing lesion that usually occurs on the exposed skin of the face, arms, or legs.

Back 25

Pyoderma

Front 26

When a streptococcal infection involves the lymph nodes, the condition is known as __.

Back 26

erysipelas