Microbiology - Greenblatt - Syphilis, Pediculosis and Gonorrhea, Chlamydia Flashcards
(26 cards)
Why are pubic lice called crabs?
Their body shape is longer than body and head lice. Presence of pubic lice warrants screening for all STIs
How do you stain for treponema?
Darkfield, no gram staining in the “poorly staining bacteria” category cannot be cultured they are too small to be seen by standard light microscopy
What is the result of immune evasion with treponema?
Low virulence but persisting symptoms that worsen over time Humans raise mostly useless antibodies against the infection T pallidum enters lymphatics ans bloodstream immediately and does not need to build up numbers for symptoms to begin
What is the infection caused by treponema palladum?
Syphilis, transmitted sexually and congenitally
What is the Argyll-Robertson pupil?
The prostitute will accomodate but not react… tertiary (neuro) syphilis
What are the stages of syphilis?
- primary chancre, 2. secondary body-wide rashes, condylomata lata (Reddish-brown papular lesions on the penis or anogenital area) and patchy alopecia, 3. latent period - 2/3 patients progress only to here 4. tertiary gummas, neurosyphilis, cardiac involvement - 1/3 of patients progress to tertiary syphilis
Neurosyphilis may includes what sequelae?
meningitis, tabes dorsalis (damage to spinal cord → impaired sensation, wide-based gait), general paresis, check for Argyll-Robertson pupil
Why is congenital syphilis dangerous?
kills 50% fetus/newborn, survivors are infected, bone deformities, interstitial keratitis, progress rapidly to symptoms of secondary&tertiary syphilis if untreated
Why are body lice (pediculus humanus) dangerous?
Can transmit typhus and relapsing fever, trench fever
What is the relationship between syphilis and HIV?
Ulcerations of syphilis facilitate HIV infection HIV immunosuppression accelerates syphilis course, and reduces efficacy of treatment
What is the treatment for syphilis?
Penicillin G IV (same for yaws and pinta which are also treponema)
How do you test for syphilis?
Syphilis serology for reagin (VDRL, RPR) is best test for disease-in-progress and for efficacy of treatment; confirm exposure with tests for treponeme-specific antibodies; histo of lesions shows infiltrate rich in plasma cells
What kind of organism is Neisseria gonorrhea?
Gram (-) diplococci oxidase + catalase +
How does gonorrhea present in males, females and neonates?
Males - urethritis Females - asymptomatic or cervicitis or PID Neonates - purulent conjunctivitis - can treat with prophylactic eye ointment
T/F: Gonorrheal infection is a marker for sexual abuse in children.
True
What are virulence factors for gonorrhea?
IgA protease - clears IgA from mucosal surfaces to facilitate colonization Pili LOS (less immunogenic than LPS) - local inflammation Opa - opacity-associated proteins enhance binding
Arthritis/dermatitis can be signs of what disseminated infection?
N. gonorrhea Other complications are DGI, meningitis, endocarditis
What is the best way to test for gonorrhea?
Nucleic acid amplification tests (NAAT) - same for chlamydia gram stain (-) organism is delicate culture on Thayer-Martin (chocolate agar)
What are important similarities between N. meningitides and N. gonorrhea?
Culture on Thayer-Martin Septic arthritis as a complication IgA protease as a virulence factor
What are the treatment options for gonorrhea?
Ceftriaxone Cefotaxime
What are the treatment options for C. trachomatis?
Doxycyline (or azithromycin) unless pregnant, then use erythromycin these drugs must penetrate cell membrane bc chlamydia is intracellular
What is the known virulence factor for chlamydia that is involved in inclusion body formation?
T3SS Reticulate bodies form intracellular inclusions that are visible on microscopy; within the inclusions they multiply by binary fission, forming new reticulate bodies and later new elementary bodies.
What are the symptoms of chlamydia in women?
May be asymptomatic Easily induced endocervical bleeding Mucopurulent endocervical discharge Intermenstrual bleeding Dysuria Abdominal pain can cause PID Men: can be asymptomatic reservoirs Urethral discharge Urinary frequency and/or urgency Dysuria Scrotal pain/tenderness Perineal fullness
What causes reactive arthritis?
Defined as Conjunctivitis + Urethritis + Arthritis From chlamydia infection - aka Reiter’s syndrome
