Micro Flashcards
What is positive Nikolsky sign?
When do you see it?
fragile blisters that rupture with pressure
present in staph scalded skin syndrome, toxic epidermal necrolysis, and pemphigus vulgaris.
Transposons play what important role in bacterial evolution?
sharing Multi-drug resistance
Asplenic patients have increased susceptibility to capsular infections, WHY? be specific
One of the functions of the normal spleen is to process bacteria and produce opsonizing ANTIBODY
The most common cause of meningitis in AIDS patients?
Best way to dx this bug?
Cryptococcus neoformans
It is usually diagnosed with latex particle agglutination; India ink detects only 50% of cases.
Vaginal exam negative for bacterial showing thin-frothy yellow green smelly discharge. What is it?
Trichomonas vaginalis sexually transmitted protozoan causing trichomoniasis
Reiter syndrome (reactive arthritis): triad of what symptoms and caused by what bugs?
arthritis, urethritis, conjunctivitis
autoimmune reaction to a previous infection with one of the following organisms: Shigella, Salmonella, Yersinia, Campylobacter, Chlamydia
Up to 75% of patients are HLA-B27-positive.
Spinal pain in low back is common
Pt from Mississippi or Ohio with calcifying lung lesions makes you think of what bugs?
describe microscopic findings of each
Histoplasma or blastomycoses
Histo: small intracellular yeasts in macrophages and grow in culture as small (2 to 5 µm) yeasts with no true capsule
Blasto: broad based budding yeast (vs cryptococcus which is most prominent in immunocomprimised and is seen as broad prominent capsule!)
formation of syncytia and Cowdry type A inclusion bodies in the nucleus of infected cell-what type of infection is this?
Genital herpes (HSV2)
Describe the different characteristics between coccidioidomycosis and paracoccidioidomycosis
coccidio: Southwest US, spherule filled with endospores
para: Latin America, “captains wheel” spherical yeast cells with multiple peripheral buds encircling the central cell
he organism most commonly responsible for pseudoappendicitis in the United States is ?
Yersinia enterocolitica, which is transmitted via contaminated pork or milk.
It is a gram-negative, oxidase-negative bacillus belonging to the family Enterobacteriaceae.
cough, coryza (rhinorrhea), and conjunctivitis.
The rash is characteristically an erythematous exanthem that starts at the head/face and moves caudally.
What is it?
Measles!
The presence of microglial nodules and multinucleated giant cells in the brain tissue of an HIV pt indicates what type of disease causing brain atrophy?
HIV encephalopathy
Cerebral involvement is frequent and leads to cortical atrophy, dementia, and other neurologic abnormalities.
Associated with low CD4 count and high viral load
Immunohistochemical stain shows positive HIV p24 antigen within affected microglial and multinucleated cells.
One of the virulence factors of S. aureus is Protein A. What is it’s function and where is it found?
In the peptidoglycan cell wall. It binds the Fc portion of IgG leading to impaired complement activation, opsonization, and phagocytosis.
Infection with what virus can cause arthralgia with or without rash in adults? (hint also associated with hydrops fetalis)
Parvovirus B19 (non enveloped ssDNA)
hydrops fetalis = severe anemia, heart failure, pleural effusions, pericardial effusions, and ascites
Hib vaccination is polysachh conjugated with protein toxoid from diptheria or tetanus. vaccination greatly reduces incidence of which diseases caused by Hib?
meningitis, pneumonia, bacteremia, and epiglotitis
