Repro- Bacteria and antibiotics Flashcards
Syphilis- real name
Treponema pallidum
Syphilis- morphology
spirochete
Syphilis- diagnosis
Serology:
- Non-treponemal (VDRL, RPR) tests for signs of active infection, but may not detect syphilis in early chancre stage or in late (tertiary) stage
- Treponemal (FTA-ABS) tests for antibodies to syphilis directly. Will always be positive.
Darkfield microscopy needed for direct visualization.
Reasons for false positive in non-Treponemal test for syphilis
Mononucleosis, RF, SLE, leprosy, IV drug use
Primary syphilis presentation
Painless genital chancre a few weeks after inoculation, due to local invasion of blood vessels and subsequent ischemic necrosis. Nerve damage makes it painless. Heals in 3-6 weeks.
Secondary syphilis- presentation
Systemic disease with maculopapular rash all over (weeks to months after infection), but affects hands and soles of feet (this is uncommon for many other rashes). “Condyloma lata.”
Tertiary syphilis- presentation
Gummas (soft growths with firm necrotic center), which can occur anywhere in the body (skin, organs, bone, etc.); aortitis, especially in ascendng thoracic aorta, which may cause an aneurysm with a “tree-barking” appearance due to vasa vasorum damage; tabes dorsalis (demyelination of the dorsal columns of spinal cord); Argyll-Robertson pupils that accommodate but do not react
Congenital syphilis- presentation
Saber shins (anterior bowing of tibia); saddle-shaped nose; Hutchinson’s teeth (notched incisors); Mulberry molars (enamel outgrowths); congenital deafness
Gonorrhea- full name
Neisseria gonorrhoeae
Gonorrhea- morphology
Gram-negative diplococci; facultative intracellular (PMNs); not encapsulated
Gonorrhea- presentation (male)
Males: urethritis, which may lead to prostatitis or orchitis; white, purulent discharge; gonococcal arthritis
Gonorrhea- treatment
Ceftriaxone for gonorrhea, plus azithromycin/doxycycline for chlamydia coinfection and multi-drug resistance
Gonorrhea- presentation (female)
Pelvic inflammatory disease (PID); Fitz Hugh Curtis syndrome (PID, spread to peritoneum with “violin string” adhesions on liver capsule)
Gonorrhea- presentation (congenital)
Purulent conjunctivitis within first 5 days of life
Chlamydia- morphology
Obligate intracellular (no Gram stain), appearing as inclusion bodies on microscopy.
Why is chlamydia an obligate intracellular species?
Cannot make its own ATP
Why can’t you use penicillins for chlamydia?
Lacks muramic acid in cell wall
Chlamydia- lifecycle
Elementary bodies enter cell and become reticulate bodies (the active form that can multiply). When they are released from cell, they are in elementary form.
Chlamydia- diagnosis
Nucleic acid amplification test (NAAT); visualized by Giemsa stain
Chlamydia trachomatis- presentation (A-C)
Trachoma; blindness
Chlamydia trachomatis- presentation (D-K)
STI; watery discharge, pelvic inflammatory disease (PID),
Most common bacterial STI in the US
Chlamydia trachomatis (D-K)
Chlamydia trachomatis- presentation (D-K; congenital)
Conjunctivitis (1-2 weeks after birth); pneumonia with staccato cough; Reiter syndrome
Chlamydia trachomatis- presentation (L1-L3)
Lymphogranuloma venereum; infection of lymphatics (inguinal), beginning as a painless genital ulcer, presenting weeks later with tender lymphadenopathy
Leading cause of blindness, worldwide
Trachoma (Chlamydia trachomatis, A-C)
Chlamydia trachomatis- transmission (A-C)
Hand-to-eye contact or fomites
Chlamydophila pneumoniae- presentation
Atypical pneumonia in the elderly
Reiter syndrome- triad
Uveitis, reactive arthritis, urethritis
Reiter syndrome- associated infections
Chlamydia trachomatis, Campylobacter, Shigella, Salmonella
Chlamydophila psittaci- transmission
Bird droppings (often parrots, “pet store”)
Chlamydia species- treatment
Macrolides (azithromycin), tetracyclines (doxycycline). Oral form needed for conjunctivitis. For STI, also give ceftriaxone empirically for gonorrhea.
Most likely cause of PID with white, purulent discharge
Neisseria gonorrhoeae
Most likely cause of PID with watery discharge
Chlamydia trachomatis (D-K)
Neonatal conjunctivitis during the first week of life
Neisseria gonorrheae
Neonatal conjunctivitis during the second week of life
Chlamydia trachomatis (D-K)
Listeria monocytogenes- morphology
Gram-positive rod; beta-hemolytic; facultative intracellular
Listeria monocytogenes- motility
Flagella outside of cell; actin rockets from cell to cell
Which foodborne illness thrives in freezing temperatures?
Listeria monocytogenes
Listeria monocytogenes- consequences in pregnancy
Early: early termination
Late: disease in newborn (e.g. meningitis)
Causes of meningitis in the newborn
1) Group B strep
2) E. coli
3) Listeria monocytogenes
Listeria monocytogenes- presentation (elderly)
Meningitis
Empiric treatment for meningitis
Vancomycin and ceftriaxone, plus ampicillin in the elderly
Why is ampicillin included in empiric treatment for meningitis in the elderly?
Common cause of meningitis in adults >60
What is the Thayer-Martin stain?
It is chocolate agar with antibiotics that only grows Neisseria species
Gardnerella vaginalis- morphology
Gram-variable rod;
Gardnerella vaginalis- presentation
Thin, grayish-white, “fishy” discharge.
Gardnerella vaginalis- predisposing factors
Overgrowth of anaerobic bacteria causes a decrease in lactobacilli.
Gardnerella vaginalis- diagnosis
pH above 4.5. Positive “whiff test” after treating discharge with 10% KOH prep. Wet mount shows “Clue cells,” which are epithelial cells coated with bacteria.
