STIs I Flashcards
What are the most common STIs, in order?
Chlamydia
Gonorrhea
What is trachoma? What is this caused by?
chronic, inflammatory granulomatous process of eye surface, leading to corneal ulceration, scarring, pannus formation and blindness. Caused by C. Trachomatis
What is adult inclusion conjunctivitis? What is this caused by?
acute process with mucopurulent discharge, dermatitis, corneal infiltrates, and corneal vascularization in chronic disease. Caused by C. Trachomatis
What is neonatal conjunctivitis?
acute process characterized by a mucopurulent discharge. Caused by C. Trachomatis
What is infant pneumonia caused by? Symptoms? What is this caused by?
C. Trachomatis
after a 2- to 3- week incubation period, the infant develops rhinitis, followed by bronchitis with characteristic dry cough.
What are the 5 major symptoms of cystitis caused by chlamydia?
- Cloudy or bloody urine, which may have a foul or strong odor
- Low fever (not everyone will have a fever)
- Dysuria
- Pressure/cramping in the lower abdomen
- Polyuria
True or false: most people with chlamydia infections are asymptomatic
true
What does chlamydia stain with? Why?
Nothing-lack a cell wall (peptidoglycan)
Why is chlamydia an obligate intracellular parasite (what does it need from the host)?
Cannot make their own ATP
What is the gram stain and morphology of chlamydia? Does it have LPS?
Gram - Cocci without a peptidoglycan layer
Has LPS, but weak
What are the two forms that chlamydia takes? Which is infectious?
Elementary body = infectious
Reticulate body
Which has a rigid cell wall: the elementary bodies or the reticulate bodies of chlamydia?
Elementary body
What are the inclusions of a cell infected with chlamydia made of?
Reticulate bodies
What are the 3 clinically important species of chlamydia?
Trachomatis
Pneumonia
Psittaci
What is the route of transmission for chlamydia?
Sexually (no other)
What is the only host for C. trachomatis?
Humans
What are the two biovars of C. trachomatis? Which is more invasive?
Trachoma
LGV -more invasive
What are the serovars of chlamydia based on?
Major outer membrane proteins (MOMP)
What is the tropism for C. trachomatis?
Nonciliated columnar/cuboidal/transitional cells of urethra, eyes, respiratory tract etc
How does C. trachomatis cause disease?
Destruction of epithelial cells and proinflammatory response
What is the major consequence of untreated chlamydia?
Fibrosis and inflammation, leading to infertility
What is the most invasive form of chlamydia? What do they cause? Why?
L types b/c they replicate in mononuclear phagocytes
Lymphogranuloma venereum
How is chronic conjunctivitis caused by chlamydia transmitted?
Transmitted by droplets, flies.
What are the symptoms of acute conjunctivitis caused by chlamydia?
Mucopurulent discharge, keratitis, corneal vascularization
Why do we use erythromycin in the eyes of newborns?
Prevent neonatal conjunctivitis
Are men and women equally symptomatic with chlamydia?
No- men symptomatic
Women not
What are the symptoms of urogential infections with chlamydia in men?
Urethritis Conjunctivitis Urethral **mucopurulent** discharge Dysuria Polyarthritis (reitrs syndrome)
What are the symptoms of urogential infextions with chlamydia in women? (3)
Mucopurulent discharge
PID
Cervical motion tenderness
What is the major consequence of untreated C. trach infx in the urogenital tract?
Infertility
Fibrosis
Where is LGV usually found?
In africa, asia, and south america
What are the major symptoms of LGV infx? (3)
Inguinal lymph node swelling
Painless lesion at the site of infection
Proctitis
How do you diagnose C.trach? (3) What is needed in a culture?
- Staining with iodine to id the RBs
- ELISA
- NAAT from urine or urethral discharge
Need live cells for culture
What is necessary to get a sample of chlamydia infex for diagnosis?
Scrapings of epithelial cells
What is the treatment for C. trach? What does this depend on?
Doxy or macrolides
Depends on pregnancy, age etc
Do you generate a secondary immune response to chlamydia?
No
What is the prevention technique for chlamydia?
Safe sex practices
Why isn’t chlamydia susceptible to beta lactams?
No cell wall
What is the gram stain, morphology, and aerobic/anerobic properties of neisseria gonorrhea? How about N.Meningitidis?
Gram negative diplococci
How do you differentiate N. Gonorrhea vs meningitits?
Maltose fermentation
What are the vectors for N. Gonorrhea?
None-Humans only
What are the virulence factors for N. Gonorrhea? (7)
- Pilin
- Por protein
- LOS
- OPA protein
- IgA protease
- B-lactamase
7 .outer membrane Blebs
(P.P. Bilbo)
What is the function of the pilin virulence factor on Gonorrhea?
Attachment, antiphagocytic
What is the function of the por protein (porin) on N.Gonorrhea?
Promotes intracellular survivial
What is the function of LOS that N. Gonorrhea?
Endotoxin
What is the function of Opa protein on N. Gonorrhea?
Attachment to eukaryotic cells
Are men or women usually symptomatic with N.Gonorrhea?
Men
How is N. Gonorrhea transmitted?
Sexually
N. Gonorrhea is susceptible to what?
C5b -C9b attack complex generated by complement
What are the three places that N. Gonorrhea infections take place?
Mouth
Eye
Dodads
How does N.Gonorrhea infect cells? What part of the bacteria generates the inflammatory response
Pass through cells to subepithelial space
LOS stimulates inflammation via chemokines (TNF-alpha)
Does N.Gonorrhea have a capsule? What is the consequence of this?
No, thus can by uptaken by macrophages much more readily. Not cause systemic disease readily.
What are the symptoms of N.Gonorrhea?
Mucopurulent discharge
Dysuria
What are the complications of untreated Gonorrhea?
Epidiymitis/prostatitis
Salpingitis
PID
What is associated with sepsis caused by Gonorrhea?
Infection of the skin and joints (suppurative arthritis)
Diffuse pustular rash
What are the pharyngitis infections symptoms of gonorrhea?
Mild to asymptomatic
Accompanied by genital infections
How do you diagnose Gonorrhea? How is this different in men vs women?
Gram stain/culture from urethral scrapings
NAAT
Men much more accurate than females
What is the agar needed for N.Gonorrhea?
Chocolate agar
What is the treatment for N.Gonorrhea?
Ceftriaxone + Doxy or az to treat chlamydia
How do you prevent infections of N.Gonorrhea?
Pt edu
Condoms
What is the prophylaxis for neonates?
Erythromycin in eyes
Why can you not grow Chlamydia in a broth culture?
Need cells–they are intracellular parasites
Which serovars of Chlamydia cause trachoma?
A, B, Ba, C
Which serovars of Chlamydia cause urogenital tract disease?
D-K
Which serovars of Chlamydia cause lymphogranuloma venerum (LGV)?
L1, L2, L2a, L2b, L3
What is Reiter syndrome that is caused by C. trach infections in men?
Urethritis
Conjunctivitis
Polyarthritis
(Can’t see, can’t pee, can’t climb a tree)
How long does it take for chlamydia to replicate?
72 hours
What type of discharge is seen with C.trachomatis infections?
Thin, mucopurulent
What is the MOA of macrolides?
Binds to 50s ribosome, preventing protein synthesis
Which four of the seven virulence factors for N.Gonorrhoeae undergo antigenic variation?
Pilin
Porin
Opa
LOS
What is the function of the outermembrane blebs of N. Gonorrhea?
Enhance toxicity and shield the bacteria from antibodies
Which bacteria has LOS in its cell wall? What effect does this have on the immune response?
N.Gonorrhoeae
Antigenic variation prevents immune resposnes
Why is it significant that N.Gonorrhea has IgA protease?
It is found in mucosal sites
People who lack the C5b-9 complement proteins (that form the attack complex) are susceptible to which infection?
N.Gonorrhoeae
The discharge associated with N.Gonorrhea has what cells? What is inside them?
PMNs with gram negative diplococci
Which has a capsule, N. Gonorrhea or N. Meningiditis? What is the function of this?
N.Meningiditis
Prevents phagocytosis and allows it to spread
What does N.Gonorrhoeae associated with?
Chlamydia infectons
What is Lymphogranuloma venereum?
a painless ulcer develops at the site of infection that spontaneously heals, followed by inflammation and swelling of lymph nodes draining the area, then progression to systemic symptoms.
Caused by C. Trachomatis
What is the most common cause of preventable blindness?
C. Trachomatis infection
Why is it that in diagnosing C.trachomatis you should take a sample from the cervix, and not the vagina?
Chlamydia infects columnar cells, NOT squamous
Are Neisseria species oxidase positive? Catalase?
Both positive