Micro Flashcards
how do ongoing STIs facilitate the transmission of HIV?
create small mucosal lesions where CD4 T cells and macrophages are so it gets easy access
which cause of vaginal discharge is strictly STI?
protozoal, the other two can also be from overgrowth of normal microbiota
what is the cause of bacterial vaginosis?
decreased lactobacilli
overgrowth of gardnerella vaginalis
what is seen on wet prep for bacterial vaginosis?
clue cell
what are the criteria for diagnosis for bacterial vaginosis?
pH >4.5 thin white (milky) discharge fishy odor with "whiff test"
Discuss gardnerella vaginalis?
Gr + rod non motile, non encapsulated beta hemolytic creates biofilms -> vaginosis resistant to lactic acid h2O2
risk factors for fungal vulvovaginitis
diabetes
antibiotics
pregnancy
inc. exposure to moisture
what are the criteria for dx of fungal vulvovaginitis
pH
Discuss candida albicans
dimorphic fungus ubiquitous pseudohyphae in vivo true hypae in environment dx with germ tube test
risk factors for candida albicans infection
antibiotics, dec. CMI, diabetes, elderly, catheter
what are the criteria for diagnosis of trichomoniasis
pH >4.5 yellow greeen frothy discharge fishy odor on "whiff test" microscopy: trichomonads, >10 WBCs per high powered field strawberry cervix
Discuss trichomonas vaginalis
flagellated protozoan motile trophozoite (no cyst) facultative anaerobe proteases, toxins-VF dx with NAAT and other molecular tests
what are the trichomonas 5 Fs?
flagella frothy discharge fishy odor fornication flagyl (metronidazole)
Discuss lactobacillus
Gr + rod
non endospore forming
acidophilic (produces lactic acid)
makes hydrogen peroxide
Discuss mycoplasma
prokaryotes
CM contains sterols
pleopmorphic-> lacks cw
tiny fried egg colonies
discuss strep. agalactiae (GBS)
Gr + coccus, chains sialic acid capsule leading cause of meningitis in kids beta hemolytic bacitracin resistant catalase - \+ CAMP and hippurate hydrolysis
what is the main cause of NGU urethritis?
chlamydia trachomatis
what are the characteristics of NGU discharge vs gonococcal discharge?
NGU- clear and serous
GU- purulent
general characteristics of Neisseria gonorrhoeae
gr - diplococcus kidney beans human reservoir LOS oxidizes glucose oxidase + catalase + chocolate/thayer martin agar`\
what can infections from childbirth manifest as?
conjunctivitis, pharyngitis, arthritis, sepsis, meningitis
what are the virulence factors for Neisseria gonorrhoeae
opa pilli IgA1 protease facultative intracellular LOS bind host sialic acid outer membrane blebbing
general characteristics of chlamydia trachomatis
gr - obligate intracellular lack peptidoglycan human reservoir elementary body in environment reticulate body (actively replicating)
what can infections during childbirth cause?
inclusion conjunctivitis, pneumonia