13. MSK infection-4 Flashcards
A 33 year old woman comes in for breast enlargement surgery. A month goes by and she comes back an now has a non/healing ulcerative skin lesion at the surgical skin. She also presents with flu like symptoms and occur issues. The ulcer is swabbed for a sample and doesn’t gram stain and is found to be an acid fast bacteria . Given the patients history and symptoms what is the most likely casual agent?
A. Mycobacetrium chelonae B.Mycobacterium marinum C. Mycobacterium fortuitum D. Mycobacterium ulcerans E. Mycobacterium leprae
RFA
Ans. C. Mycobacterium fortuitum- Found in water and dirt and usually caused by wound and surgical site infection. Symptoms local cutaneous disease, osteomyelitis joint infection, ocular diseases. Causes non heal ulcerative skin lesion.
A. Mycobacetrium chelonae- found in water. Symptoms lung disease joint infection and other organ infection. Non-healing wound.
B.Mycobacterium marinum- know as fish tank granulomas, found in fish handlers and swimmer. Single lump or pustle. mostly in elvow knees, feet and knuckeles or finger. May cause lung disease
D. Mycobacterium ulcerans- Found in central and west Africa in swamps , painless lesion that grows slowly and itches, after Week infection breaks skin after month shallow ulcer. May destroy blood vessels, nerves and invade bone
E.Mycobacterium leprae- infects skin and peripheral nerves
A 42 year old Indian man has diffuse skin hypo-pigmentation with thickening and plaques. He says has lost sensation to extremities and has very poor eye site. Lab are done finding a acid fast bacteria with a non reactive lepromin skin test. What cell does this infection replicate in?
A. Astrocytes B. Oligodedrocytes C. Erthrocytes D. Schwann cells E. Chrondroblast
RFA
Ans. D-Swchann cells, The man has Mycobacterium leprae more specially the Lepromatous form( the more severe and infections) as noted by the no reaction Lepromin skin test, Tuberculoid form would be positive. The bacteria also infects and replicates in macrophages.
