Skin wounds

Question 1

What gram positive cocci cause skin & tissue illnesses?

Answer 1

Staphylococcus aureus
Staphylococcus epidermis
Streptococcus pyogenes, group A
Viridans Strep
Enterococcus Faecalis

Question 2

Which bacteria that causes skin and wound infections that is Gram positive cocci in clusters?

Answer 2

Staphylococcus aureus

Staphylococcus epidermis

Question 3

Which gram positive cocci in cluster bacteria is more likely to cause a skin infection and is organized in large Yellow Beta hemolytic colonies?

Answer 3

Staphylococcus aureus

Question 4

What bacteria is gram positive cocci in chains?

Answer 4

Streptococcus pyogenes, group A
Viridans Strep
Enterococcus Faecalis

Question 5

Which gram positive in chains bacteria can be alpha hemolytic or non-hemolytic?

Answer 5

Viridans Strep

Question 6

of the gram positive in cocci in chains is also beta hemolytic?

Answer 6

Streptococcus pyogenes, group A

Question 7

What Gram positive Bacilli causes tissue necrosis and what are its other morphological characteristics?

Answer 7

Clostridium Perfringens

it is also anaerobic & spore forming

Question 8

What are the gram negative Bacilli that can cause skin and tissue illnesses?

Answer 8

Vibrio Vulnificus
E. Coli
Proteus spp
Providencia spp.
Aermonas spp.
Plesiomonas shigelloides
Pseudomonas aeruginosa
Acinetobacter baumannii
Bacteroides Fragilis

Question 9

What are the 2 different Gram positive Bacilli that cause skin/tissue infections & what differentiates them?

Answer 9

Clostridium Perfringens- anaerobic

Bacillus Antracis- aerobic

Question 10

What is known for causing Impetigo, Folliculitis, Furuncles. & Abscess

Answer 10

Staphylococcus aureus

Question 11

Staphylococcus aureus is also known for cuasing Scaled skin syndrome, which is also known as Toxic Epidermal Necrolysis (TEN) in childern under 5 what is this disease process characterized by?

Answer 11

initially localized red rash following conjunctivitis or URI; then Large Flaccid Bullae rupture & sheets of epidermis peel/reveal moist, red, scaled dermis

Question 12

A female patient presents with an acute illness accompanied by a high fever, diffuse rash, hypotension.. Upon physical exam it is noted that patient has been using absorbent tampons, what is the possible disease process & the causing bacterial agent?

Answer 12

Toxic shock syndrome-

due to Toxic shock syndrome Toxin (TSST) of Staphylococcus aureus

Question 13

a patient presents with Superficial skin infection characterized by small “blisters”/pustules followed by thin crust over area, which is also been accompanied by a scarlett fever, what bacterial agent & virulence factor are causing this illness?

Answer 13

Streptococcus pyogenes, group A

erythrogenic toxin

Question 14

what are the virulence factors of Staphylococcus aureus?

Answer 14

• Coagulase, fibrinolysin, lipase, & various proteases
• Adhesive matrix (biofilm)
• Quorum-sensing
• (many have) superantigens
• pathogenicity largely due to Plasmids
• (85% produce) beta-lactamase resistant to most penicillin’s / cephalosporins
• (30% MRSA) Methicillin Resistant to all beta-lactam antibiotics

Question 15

What 2 bacteria cause 90% of all skin infections?

Answer 15

Staphylococcus aureus

Streptococcus pyogenes, group A

Question 16

A patient present with a large diffuse red rash, that is warm to the touch and the area is swallon. What skin infection is this likely, and what bacteria may be causing/ what virulence factor should be tested to differentiate it?

Answer 16

Cellulitis

Staphylococcus aureus
Streptococcus pyogenes, group A

Coagulase- Group A Strep doesn’t produce and cellulitis is the halmark of Group A strep.

Question 17

This is characterized by the rapid destruction of muscle & fat tissue /high fever & pain is considered invasive & life threatening? what causes it & treatment?

Answer 17

Streptococcal Toxic Shock Syndrome/Necrotizing Fascitis/ strep gangrene, invasive cellulitis/ “flesh eating bacteria”

Group A Strep

Tx: agressive antimicrobic & surgical intervention

Question 18

What are the virulence factors of Streptococcal pyogenes, group A?

Answer 18

’s envasive enzymes & toxins

Hyloronic capsule-appears as “self” Ag to host slows Ab response

“M” Protein, antiphagocystic

Erythrogenic toxin causes scarlet fever rash

Streptolysin O&S—cytotoxic; & base for ASO titer

Question 19

A Patient developed an abcess after a traumatic accident in Afghanistan, if this particularbacteria is expected it will grow on McConkey media?

Answer 19

Acinetobacter baumannii

Question 20

Apatient presents with an skin infection after visiting an area w/ warm costal sea water. Upon the infection had hemorrhagic bullae & necrotizing fasciitis. what bacterial agent is suspected & what is it morphological presentation?

Answer 20

Vibrio Vulnificus

GN Bacillus, curved