Skin Infections 2

Question 1

Pyogenic bacteria

Answer 1

Staph, strep, Trueperella, corynebacterium

Question 2

Classical granulomatous inflammation

Answer 2

Central necrosis surrounded by giant epithelioid cells, macrophages, lymphocytes, granulocytes surrounded by thick fibrous capsule

Question 3

Difficulty w granulomatous inflammation

Answer 3

Classic lesions are caused by mycobacteria
Difficult to get rid of
Associated w chronic pyo to Gran inflammation

Question 4

Diseases caused by mycobacterium

Answer 4

Tuberculosis
Johne’s
Feline leprosy
Canine leproid granuloma
Panniculitis syndrome

Question 5

What type of bacteria is mycobacteria

Answer 5

Gram positive rods
Stict aerobes
Lipid rich cell wall -
Acid facts - Ziehl Nielsen stain
Resistant!! To disinfectants, antibodies, acid and desiccation
Survive intracellularly in mononuclear phagocytes

Question 6

Classification of mycobacteria

Answer 6

Obligate parasites - do not multiple outside host
Saprophytic mycobacteria - live in environment

Question 7

How do mycobacteria cause disease

Answer 7

Cord factor - inhibits chemotaxis and are leukotoxic
Can survive intracellularly and replicate in macrophages
- glycolipids
- sulfatides
- sulfolipids
Superoxide dismutase - higher amt in virulent strains
Mycobactins & exochalins - iron acquisition

Question 8

Glycolipids prevent

Answer 8

Macrophage activation by INFgamma

Question 9

Sulfatides (glycolipids) prevent

Answer 9

Phagolysozome formation by macrophages

Question 10

Sulfolipids prevent

Answer 10

Phagosomal lysosomal fusion

Question 11

Canine leproid granuloma syndrome

Answer 11

Spread by biting insects - short coats (boxer) predisposed
Lesions can be single /multiple nodules

Question 12

lesions of CLGS

Answer 12

Predominantly on head and ears - bite zone
Painless, sometime pruritic - doesn’t spread internally

Question 13

DX of CLGS

Answer 13

On cytology, histology or PCR
Cant culture organism in VITRO

Question 14

TX of CLGS

Answer 14

Lesions typically self resolve
Respond to rifampicin & clarithromycin - enter and treat intracellular organisms

Question 15

Feline leprosy syndrome

Answer 15

Group of diseases that present similarly
- non culturally mycobacteria
- tuberculosis bacteria (m bovis)
- m. Avium complex (MAC)

Question 16

Transmission and lesions of FLS

Answer 16

Transmitted through active wounds
Can be cutaneous, subcutaneous granulomas
- focal - head, face, limb, trunk
- peripheral lymphadenopathy
- can be widespread and ulcerated

Question 17

DX and TX for FLS

Answer 17

DX
- FNA & cytology
- biopsy & Histopathology
- PCR
TX
- difficult
- surgery on lesions
- appropriate drugs

Question 18

Panniculitis syndrome in cats (& dogs)

Answer 18

Due to rapidly growing mycobacteria
More common in cats than dogs
Common in geographical areas - Australia, UK or US
Follows trauma that penetrates fatty tissues where dirty contaminates wounds
Commonly seen in inguial fat pad in cats

Question 19

Infection of PSC

Answer 19

Mycobacteria is introduced to fat by trauma
Survive in macrophages in fat - down regulate MHC expression
Fat provides triglycerides for growth & promotes them from host immune response

Question 20

Tx for superficial pyoderma

Answer 20

creams, gels, ointments, shampoos) should be
used as sole on-animal antibacterial treatment for surface and superficial infections whenever a pet and owner can be expected to be compliant!

Question 21

Systemic treatment for systemic superficial pyoderma

Answer 21

cephalosporins, pot ampicillin, lincosamides, macrolides
Empirical therapy usually effective

Question 22

Treating surface pyoderma

Answer 22

Topical - shampoo is common

Question 23

Treating deep pyoderma

Answer 23

Systemic antibiotics is often needed
Susceptibility testing ** if suspect mixed infection

Question 24

Problems w treating staph

Answer 24

Facultative intracellular parasites
Antimicrobials resistance
Biofilm production
Non responsive therapy - perform susceptibility test

Question 25

Which lesions almost NEVER self cure?

Answer 25

Panniculitis syndrome in cats