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Flashcards in GU Infections Deck (55)
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1
Q

How to epithelial cells in the female GU tract serve as a defense mechanism?

A
  • Provide a mechanical barrier
  • Produce and secrete antimicrobial molecules
  • Transport IgA
  • Process and present antigen
  • Communicate with underlying immune cells
2
Q

How does the normal microbial flora of the female GU tract act as a defense mechanism?

A

Lactobacillus lowers the vaginal pH to 4.2-5.0

3
Q

What are the defense mechanisms of the male GU tract?

A
  • Epithelial cells
  • Normal flora
  • Urethral length
  • Urine flow
  • Circumcision (possibly)
4
Q

Evaluation, treatment, and counseling should be provided for sex partners of persons who are infected with an STI within the previous _____ days

A

Evaluation, treatment, and counseling should be provided for sex partners of persons who are infected with an STI within the previous **60 **days

5
Q

What are some prevention methods for STI transmission?

A
  • Abstinence
  • Reduction of number of sex partners
  • Pre-exposure vaccines
  • Condoms
6
Q

What are special populations to be considered in STI evaluation?

A
  • Pregnant women
  • Adolescents
  • Children
  • Persons in correction facilities
  • Men who have sex with men
  • Women who have sex with women
7
Q

What are the 5 Ps of a sexual history?

A
  • Partners
  • Prevention of Pregnancy
  • Protection from STIs
  • Practices
  • Past history of STIs
8
Q

What are the two forms of Chlamydia trachomatis?

What is the replication potential for each?

A
  • Elementary body - Metabolically inactive; cannot replicate
  • Initial body/Reticulate bodies - Intracellular inclusions that can divide
9
Q

Which form of chlamydia is infectious? What types of cells does it infect?

A

Elementary bodies: infects non ciliated epithelial cells of the mucosa

10
Q

Chlamydia trachomatis is hard to see on gram stain because it lacks…(2)

A

Peptidoglycan layer and muramic acid

11
Q

What is the most common bacterial STD in the US?

What else can it cause besides GU infection?

A

Chlamydia trachomatis

Can also cause pneumonia and conjunctivitis

12
Q

How is Chlamydia treated?

A

Azithromycin and Doxycycline

(Abx that target peptidoglycan wall are not effective)

13
Q

How is Trichomonas Vaginalis highly motile?

A

Four flagella and undulating membrane (fin-like extension of membrane)

14
Q

How is Trichomonas vaginalis diagnosed?

What is the treatment?

A

Diagnosed by direct microscopic examination of discharge

Metronidazole is the treatment of choice

15
Q

What is the smallest free living bacteria?

Why are gram stain and ß-antibiotics useless against it?

A

Ureaplasma urealyticum

Has no cell walls

16
Q

What is the rate of growth of Ureaplasma urealyticum?

How does it produce its “diagnostic” smell?

A

Very slow rate of growth - takes a long time to detect

Produces urease to break down urine into ammonia

17
Q

How is Ureaplasma Urealyticum diagnosed?

How is it treated?

A

Diagnosed with culture (takes a long time) or PCR

Treatment of choice is erythromycin or doxycycline

18
Q

Neisseria gonorrhea is a gram ______ and catalse ______ diplococci

A

Neisseria gonorrhea is a gram **negative **and catalse **positive **diplococci

19
Q

What are the virulence factors for Neisseria gonorrhea?

How does the bacteria prevent lasting immunity?

A
  • Virulence factors: pili, porins, and opaque proteins (Opa)
  • Bacteria can switch surface antigens to prevent lasting immunity – reinfection is always possible (no vaccine)
20
Q

How is Neisseria gonorrhea diagnosed?

How is it treated?

A

Culture was routine (chocoalte agar or Thayer Martin agar) but now PCR is routinely used

Ceftriaxone is treatment of choice (many strains are highly resistant to penicillin)

21
Q

What diseases are associated with Neisseria gonorrhea in…

  • Males:
  • Females:
  • Both sexes:
A
  • Males: urethritis with painful urination and purulent discharge, epididymitis, prostatitis, urethral strictures
  • Females: urethritis, endocervicitis, can progress to PID
  • Both sexes: Bacteremia and Septic Arthritis
22
Q

Chlamydia replicates ________ and Neisseria gonorrhea replicates _________

A

Chlamydia replicates **Intracellularly **and Neisseria gonorrhea replicates Extracellularly

23
Q

What causes painful genital lesions?

What causes non-painful genital lesions?

A
  • Painful: Herpes, Chancroid, Lymphogranuloma venereum
  • Non-painful: Syphilis, Molluscum, Genital wart
24
Q

What are the two lifecycles of the Herpes simplex virus?

What are the locations and symptoms of each?

A
  • Latent infection (quiescent) – limited to neurons (sacral ganglion) – not associated with symptoms
  • Lytic replication – active; produces infectious viruses at mucosa/skin at site of initial inoculation
25
Q

Describe the structure of HSV

A

Double stranded DNA virus

DNA is encased into a capsid, which is further wrapped in a lipid bilayer (envelope)

26
Q

What is the term describing the switch of HSV from a latent to lytic lifecycle?

A

Reactivation

27
Q

How long is an HSV infection?

What is the treatment for each lifecycle?

A

Infection is life long - no vaccine

  • Lytic: Antivirals such as acyclovir are nucleotide analogs that specifically target viral DNA polymerase and inhibit replication
  • Latent: No treatment for latent infection
28
Q

How is HSV diagnosed?

A

Clinical presentation (vesicles), detection of virus in the lesions (culture, IFA, PCR), or detection of HSV-1 or HSV-2 specific antibodies

29
Q

What disease is associated with Haemophilus ducreyi?

A

Chancroid - tender papule with an erythematous base that progresses to painful ulceration with associated lymphadenopathy

30
Q

How is Haemophilus Ducreyi diagnosed?

What is the treatment?

A
  • Diagnosis: Culture or PCR of ulcer or lymph node aspirates
  • Treatment: Azithromycin, ceftriaxone, ciprofloxacin
31
Q

What type of organism is Trepona Pallidum?

What disesase is it is associated with?

A

Gram negative spirochete bacteria

Causative agent of Syphilis

32
Q

Describe the primary and secondary stage of Syphilis?

A
  • Primary stage: painless chancre at inoculation site – highly infectious
  • Secondary: systemic spread to multiple organs and CNS – systemic (fever and rash) and local (condyloma latum) symptoms
33
Q

Describe the latent and tertiary stages of Syphillis

A
  • Latent: Asymptomatic and noninfectious (except during pregnancy) – can relapse back to secondary
  • Tertiary: due to immune system driven damage to multiple organs (skin, bones, vessels, nerves)
34
Q

What is the rate of growth of Trepona Pallidum?

What type of infection is associated with a high mortality rate?

A

Very slow growth compared to other bacteria

Congenital infection is associated with high mortality rates

35
Q

How is Syphilis diagnosed?

How is it treated?

A

Diagnosed with darkfield microscopy, serology, PCR

Treated with benthazine penicillin (modified penicillin that is slowly absorbed) - antibiotics not effective against tertiary stage

36
Q

What are the types of tertiary syphilis?

A
  • Gummatous syphilis: localized granulomatous lesions within skin or bones, non-infectious.
  • Cardiovascular syphilis: aneurysm in the ascending aorta or aortic arch – due to destruction of small arterioles supplying the aorta.
  • Neurosyphilis: can be asymptomatic, subacute or meningiovascular
37
Q

Antibiotics given within the first __ months of pregnancy can prevent congenital syphilis

A

Antibiotics given within the first 4 months of pregnancy can prevent congenital syphilis

38
Q

What is the Jarisch-Herxheimer Phenomenon of Syphilis?

A

Acute worsening of symptoms immediately after start of antibiotics – due to pyrogen released by killed organism

39
Q

Is there a vaccine for syphilis?

A

No (immunity is not protective)

40
Q

To what family does Molluscum Contagiosum belong?

What type of virus is it?

A

Poxvirus family

Large double stranded DNA virus

41
Q

Where does Molluscum contagiosum replicate?

What is seen on histology of lesions?

A

Replicates exclusively in the cytoplasm of the infected cell (unique feature for a DNA virus)

Histology: Molluscum bodies (large eosinophlic inclusion in the cytoplasm)

42
Q

Describe the appearance of the Molluscum Contagiosum virion

Describe the appearance of the disease

A

Virion: ovoid to brick shaped; complex structure with several membranes

Disease: Nodular to wart-like skin lesions, begin as papules and become umbilicated with central caseous plug; occur in cluster of 5-20 nodules

43
Q

How is Molluscum Contagiosum diagnosed?

How is it treated?

A
  • Diagnosis: Based on the presentation of lesions
  • Treatment: Nodules can be removed by scraping, application of liquid nitrogen, or iodine treatment. More severe disease can be treated with ritonavir or cidofovir; No vaccine is available
44
Q

What type of virus is HPV? To which family does it belong?

A

Small, double stranded DNA virus from the Papovavirus family

45
Q

How does HPV replicate and lead to infection?

A
  • Initial infection requires access to basal epithelial layer (skin damage)
  • Active replication is mostly in the upper epithelium layers to escape immune system
  • Virus DNA has to be maintained as an episome for productive replication
46
Q

Occasionally HPV DNA is accidentally integrated into the host genome. What are the two outcomes of this?

A
  • In most cases this leads to abortive infection, as the virus cannot use integrated DNA to replicate
  • In other cases, integration leads to cancer
47
Q

What is the mechanism of HPV integration and induction of cancer?

A

Viral DNA integration disrupts the expression of viral E2 genes which are a negative regulator of viral E6 and E7 oncogenes

48
Q

What is the vaccine against high risk strains of HPV?

A

Gardasil

49
Q

What is Amsel’s criteria in diagnosing bacterial vaginosis?

How is diagnosis done currently?

A
  • Amsel’s criteria – old technique but still used (highly specific and highly sensitive)
    • Vaginal pH greater than 4.5
    • Presence of clues in vaginal fluid
    • Milky, homogenous vaginal discharge
    • Fishy (amine) odor after addition of 10% KOH to vaginal fluid
  • Current diagnosis is done with PCR
50
Q

How does Gardernella vaginalis (type of BV) cause disease?

What normally prevents overgrowth of this bacteria?

A

Part of normal vaginal flora; disturbance of normal flora leads to outgrowth, causing disease (Abx treatment)

Vaginal lactobactillus keeps G. vaginalis in check

51
Q

How is Gardernella Vaginalis treated?

A

Nitroimidazoles (Metronidazole or Tinidazole) or Clindamycin

52
Q

What is the disease appearance of gardernella vaginalis?

A

Vaginitis, pruritis, dysuria, foul smelling copious vaginal discharge with a fishy odor.

53
Q

When does Candida cause disease?

A

When Candida is allowed to expand and outgrow normal microbial community (this can happen following Abx, oral contraceptives, menses, pregnancy, diabetes, or use of corticosteroids)

54
Q

How is Candida diagnosed? Why is culture not useful?

What is the treatment for Candida?

A

Diagnosed by microscopic - abnormally high presence of candida

Culture is not very useful because yeast is a part of the normal flora

Treatment: Imidazole vaginal suppositories or a single dose of fluconazole

55
Q

What are GU tract consequences of STIs?

A
  • Spontaneous abortion
  • PID; Ectopic pregnancy
  • Infertility in women
  • Urethral strictures in men
  • Cervical penile carcinoma
  • Death