L41- Urogenital Infections III Flashcards
Treponema pallidum, briefly describe the progression of disease
(syphilis)
Primary (weeks after): chancre on genitals
Secondary (wks - mos): flu-like syndrome + copper rash + condylomata lata
Tertiary (15-20yrs): diffuse chronic inflammation, CNS, CVS involvement
describe the relationship between T. pallidum and pregnancy
(congenital syphilis)
-crosses uterine/placental membranes
- MOST cases –> spontaneous, septic abortion
- occasional live-birth –> infants with active infection, usually teratogenic effects seen
list three distinguishing features of late-stage congenital syphilis
- Stromal Haze due to interstitial keratitis
- Saddle Nose
- Hutchinson’s teeth
Syphilis pathogenesis:
- (1) is usually required first, then (2) can occur
- (3) can precipitate perivascular infiltration (‘spreading factor’)
- coating of (4) protects T. pallidum from phagocytosis
1- adherence via outer membrane proteins
2- tissue destruction / lesions => immune response
3- hyaluronidase
4- fibronectin
Primary Syphilis:
- (1) route of entry
- (2) replication occurs
- (3) results and (4) is the final stage
1- enters subepithelial tissues via skin breach (sexual transmission)
2- slow / fastidious: doesn’t tolerate wide-range of environmental conditions
3- endarteritis, granulomas
4- lesions heal –> bacterial dissemination via LNs, blood (latency is poorly understood)
(1) occurs before the beginning of secondary syphilis, and then (2) may be trigger symptoms. Tertiary syphilis involves (3) to occur.
1- immune system evasion (poorly understood)
2- inflammatory response
3- diffuse chronic inflammation, damage to CNS
________ is the main definitive diagnosis of early syphilis
(direct microsopy) dark-field examination of exudate from skin lesions (primary)
Hemophilus ducreyi key microbial features
- Gram- anaerobic rod (maybe coccobacilli)
- fastidious
- pleomorphic shape
-obligate human pathogen
Hemophilus ducreyi:
- (1) is main presentation
- (2) predominant geographic areas
- (3) risk is increased
1- chancroid: painful soft ulcer
2- tropics (Africa, Asia, Latin America — sporadic in N. America)
3- HIV transmission
list some signs and symptoms of Hemophilus ducreyi infections
- painful genital ulcer / penile chancre
- (men) inguinal bubo (LN enlargement) along w/ penile ulceration
-(women) chancroid ulcer on posterior vaginal wall –> spontaneous rupture of L inguinal bubo in 25% cases
describe the key factors of Hemophilus ducreyi pathogenesis
-extracellular pathogen resisting phagocytosis
Virulence factors:
- outer membrane serum resistance protein
- Toxins: i) CDT (cytolethal distending toxin) + ii) hemolysin => tissue destruction
describe the difficulty of diagnosing H. ducreyi
Other DDx: syphilis, HSV1/2 (frequently co-infections); 30-50% cases, Dx is based on ulcer appearance
- culture requires special usually unavailable agars and not 100% sensitive:
- Gonococcal agar case w/ 2% bovine Hb + 5% fetal calf serum
- Mueller Hinton agar (heated horse blood)
-Ag detection, serology, amplification (PCR, ect) is not easily available and accurate
Chancroid:
- (soft/hard) chancre, (mildly/firmly) indurated, (mild/moderate) erythema
- pain-(less/ful)
- (5) on microscopic observation
- (6) required for Dx
1- soft 2- mildly indurated 3- moderate erythema 4- very painful (+/- superinfection) 5- Gram stain 6- culture
Syphilus:
- (soft/hard) chancre, (mildly/firmly) indurated, (mild/moderate) erythema
- (pain/-less)
- (5) on microscopic observation
- (6) required for Dx
1- hard 2- firmly indurated 3- mild erythema 4- painless (unless secondary infection) 5/6- darkfield examination
______ are considered the less common STI pathogens
- mycoplasma genitalium
- Klebsiella granulomatis
Mycoplasma, Ureaplasma:
- (1) key microbial traits
- (2) general Sxs
1- very small free living bacteria, lack cell wall, obligate intracellular
2:
- symptomless
- Sxs: discharge, dysuria/burning, frequency, urgency, pain
Mycoplasma genitalium infects (1) to cause (2)
1- GUT
2- non-gonococcal urethritis
Ureaplasma urealyticum infects (1) to cause (2)
1:
- respiratory tract
- GUT
2:
- non-gonococcal urethritis
- pyelonephritis
- spontaneous abortion
- premature birth
Mycoplasma genitalium mainly cause NGU:
- (1) number of species
- (2) is main feature, causing bacteria to have (3) shape
- (4) describe outer membrane
1- >16
2- mollicutes (soft skin) = lack of cell wall
3- pleomorphic
4- triple layer w/ sterol (external membrane) –> serum/cholesterol must be added to growth media
Klebsiella granulomatis = _____:
- family
- main characteristic
- main microbial features
= granuloma inguinale
-Enterobacteria family
-**Donovan bodies = intracellular inclusions in macrophages
- encapsulated
- Gram-
- pleomorphic / ‘safety-pin’ appearance
- fastidious (difficult to culture on standard media)
Klebsiella granulomatis:
- (1) main geographic area
- (2) Sxs
1- Tropics, Subtropics
2- painless, expanding, supporative lesion —- tend to bleed easily = ‘beefy red’
describe the spectrum of HPV infections
low risk HPV = Condyloma Acuminata
high risk HPV = cervical dysplasia or cervical cancer
sites of HPV infections (descending order)
cervix anus vagina penis vulva oropharynx oral cavity
Both low risk and high risk HPV infections often present with (1). (2) is the other presentation with a (3) long incubation period. (4) is the result if (2) remains untreated.
1- asymptomatic
2- anogenital warts
3- wks to mos to yrs
4- regression of wart size and number
genital warts = _______
condylomata acuminata
Anogenital warts:
- (1) are the most common causes
- (2) are the most affected groups (men and women)
1- HPV6, HPV11 (90% of anogenital warts)
2:
Women: 20-24 y/o
Men: 25-29 y/o
in addition to anus and genitals, HPV can infect (1) and eventually can (2); note- (3) is the most common type
1- throat (oropharynx + oral cavity; oral sex transmission)`
2- throaat cancer (higher risk than smoking or alcohol)
3- HPV16 (72% cancers)
HPV:
- (1) genome
- infects (2) cells
- low risk HPV => (3)
- high-risk HPV => (4)
1- circular dsDNA (8kB)
2- epithelial cells
3- genital warts
4- premalignant lesions = CIN / cancer
HPV infections cause (1) of viral genome and the overexpression of (2) and (3), include targets. (4) are the HPV capsid proteins.
1- episomal / integration of viral DNA
2- E6 –> p53
3- E7 –> RB
4- L1, L2
describe HPV Dx
1) genital warts –> dx by visual inspection
2) cervical cell changes –> routine PAPs or HPV testing/typing
list the main HPV strains with vaccine and age group given to
(Gardasil)
HPV- 16, 18 (high risk) + 6, 11 (low-risk)
-now added HPV- 31, 33, 45, 52, 58
Given to ages 9-26 y/o (for test, but actually up to 45 y/o)
describe the additional testing for Syphilis Dx
1st: Non-treponemal screening test
- beef heart / bovine Cardiolipin: reactive, weak reactive, minimally weak reactive, non-reactive
- RPR (rapid plasma reagin) test
2nd (if pos): treponemal test = TP-particle agglutination (TP-PA)
