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
what are the signs of a disseminated gonococcal infection?
migratory polyarthralgia
septic arthritis
petechial skin lesions
what do you see on gram stain for gonorrhea?
PMNs with intracellular gram - diplococci in the cells
what is reiter syndrome in associate with chlamydia?
urethritis, arthritis, conjunctivitis, mucocutaneous lesions
the most frequent cause of bacterial STI in the US is?
chlamydia
actinomyces israelii PID is associated with waht?
IUDs
the causes and effects of PID CAN be EPIC
Chlamydia actinomyces Neisseria Ectopic Pregnancy Infertility Chronic pain
what is the cardinal presenting symptom of PID
lower abdominal pain
what causes the complication Fitz hugh curtis syndrome
PID due to chlamydia and neisseria
adhesions similar to violin strings found between abd wall and liver
what is seen with PID on pelvic exam?
CMT
purulent endocervical discharge
tender adnexal mass
how should PID be treated
treated as a mixed infection
Discuss actinomyces israelii
gr + filamentous bacillus
human reservoir
non acid fast
characteristic sulfur granules
describe HPV
naked
dsDNA, circular
replicates in nucleus
what types of HPV cause genital warts and laryngeal papillomas
types 6 and 11
what is condylomata acuminata
genital warts
what type of HPV is most common in malignancy and can spontaneously regress?
type 16
what are the two types of HPV that can cause malignancy?
type 16 and 18
16 most common
what early HPV gene products are implicated in malignancy
E6 and E7
interact with pRB (tumor suppressor)
degradation of p53 (tumore suppressor protein)
which genital ulcers are painful?
genital herpes
chancroid ulcers
which genital ulcers are painless?
syphilitic
lymphogranuloma venereum
granuloma inguinale
characteristics of genital herpes
enveloped dsDNA nucleus HSV2 mc recurrent painful vesicular lesions
where does herpes lay dormant?
sacral ganglia
what test do you use to test for genital herpes?
tzanch test showing multinucleate giant cells
what does haemophilus ducreyi cause?
chancroid ulcers
characteristics of haemophilus ducreyi
gr - coccobacillus strictly human pathogen facultative anaerobe chocolate agar cytotoxin, pili, LOS lymphadenopathy with bubos
what is seen on gram stain with chancroid ulcers?
school of fish
gr - coccobacillus
what does treponema pallidum cause?
syphillis
characteristics of treponema pallidum?
gr - spiral human reservoir extremely labile very motile (axial filaments) penicillin sensitive
characteristics of primary syphillis
highly infectious
hard chancre
painless
characteristics of secondary syphillis
high infectious
rash on skin
may see condyloma lata
characteristics of tertiary syphillis
noncontagious
gummatous
cardiovascular
neurosyphilis
what are the 2 serological tests for syphilis?
treponemal tests
use pallidum as antigen
nontreponemal tests (VDRL and RPR)
what causes lymphogranuloma venereum
chlamydia trachomatis
invades lymphatic tissue
what are the signs of lymphogranuloma venereum
tropical bubo
groove sign
what causes granuloma inguinale
klebsiella granulomatis (gr - rod, capsule, nonmotile) donovan bodies subcutaneous nodules
what is a normal microscopic test on syphilis?
dark field microscopy
