Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MS2 - Infectious Disease > Bacterial STDs > Flashcards

Bacterial STDs Flashcards

1
Q

What is the etymology of the term “clap”?

A

It comes from a French word for brothel.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List the prevalence of STDs in the U.S.?

A

Chlamydia: 1,500,000
Gonorrhea: 400,000
Syphilis: 24,000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

______________ is a facultative intracellular pathogen.

A

Neisseria gonorrhoeae

Remember the red cushions on the white chairs in the Sketchy scene.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

If you have high specificity, then you have low ___________.

A

false positives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

With low sensitivity, what will you have a lot of?

A

False negatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

____________ describes what percent of people without the disease will test negative.

A

Specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Oropharyngeal samples might test positive (falsely) for ______________.

A

Neisseria, because there are commensal bacteria that are intracellular Gram-negative diplococci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Gram stains for Neisseria gonorrhoeae have low _____________.

A

sensitivity (meaning high rate of false negatives)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which strains of Neisseria are encapsulated?

A

N. meningitidis

(In the Sketchy scenes, the evidence in the college dorms is covered with glass domes, while in the nightclub scene the glass is broken on the floor!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What virulence factor causes inflammation in Neisseria meningitidis?

A

Lipooligosaccharide (remember the LOS envelopes that are burning in the Sketchy college student’s dorm); these are the same as LPS but without the O sidechain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Neisseria require ___________ to grow.

A

5% CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Colonies turn ____________ in positive oxidase tests.

A

black

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Both strains of Neisseria can ferment __________.

A

glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What two things are generally needed for a diagnosis of gonorrhea?

A
  • Either mucopurulent cervical discharge or exposure to an infected person
  • Growth on susceptible agar, PCR, or Gram stain showing Gram-negative diplococci
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or false: more men than women are asymptomatic carriers of gonorrhea.

A

False. Many more women are asymptomatic carriers (about 50%).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

PID occurs in about _______ percent of female gonorrhea infections.

A

10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Untreated, gonorrheal conjunctivitis can cause __________.

A

corneal perforations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What age group has the highest incidence of gonorrhea?

A

15 - 24 (over 50%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What mechanism allows Neisseria to escape the immune system?

A
  • Antigenic variation from amino acid switching in pili (can make up to 1,000,000 different forms)
  • Phase variation (on-off switching for expression of genes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

In the 1970s, Neisseria gonorrhea became resistant to _________________.

A

penicillins (due to expression of beta-lactamases)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

______________ are no longer recommended for treatment of Neisseria gonorrhoeae due to widespread resistance.

A

Fluoroquinolones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

_______________ is the only recommended therapy for gonorrhea.

A

Ceftriaxone and azithromycin

The macrolide can cover Chlamydia, but tetracycline can be substituted.

23
Q

Chlamydia are much _________ than Streptococcus.

A

smaller

24
Q

Which strains of Chlamydia are specific to humans?

A

C. trochomatis and C. pneumoniae

25
Q

How does Chlamydia survive inside cells?

A

It inhibits phagolysosome formation (meaning it is non-fusogenic).

26
Q

Most people infected with Chlamydia are ____________.

A

asymptomatic

27
Q

_____________ reproduce via transverse fusion.

A

Spirochetes

28
Q

________________ cannot be cultured in vitro.

A

Treponema pallidum

29
Q

Tertiary syphilis is ____________ transmissible.

A

not

30
Q

Syphilis initially travels by _____________.

A

lymphatics

31
Q

Describe the timeline of syphilis.

A 
Infection
Incubation period: 3 weeks
Primary syphilis: 2-6 weeks
Asymptomatic period: 2-24 weeks
Secondary syphilis: 2-6 weeks
Latent syphilis: 3-30 years
Tertiary syphilis
32
Q

What percent of people recover from syphilis infection?

A

~25%

33
Q

Describe the symptoms of each stage of syphilis.

A

Primary: painless chancre at site of lesion (usually as macule to papule to ulcer) and lymphadenopathy

Secondary: maculopapular rash, lymphadenopathy, alopecia, condyloma lata

34
Q

If you suspect syphilis but a person has a painful chancre, what organism might have caused this?

A

Haemophilus ducreyi

35
Q

The only sign or symptom of latent syphilis is _____________.

A

positive serologic testing

36
Q

What microscopy technique is needed to identify Treponema pallidum?

A

Darkfield microscopy

37
Q

____________ is more common in females and ___________ is more common in males.

A

Chlamydia; syphilis

Rates of gonorrhea are about the same between genders.

38
Q

Neisseria undergo rapid autolysis at ____________.

A

25º C or alkaline pH

39
Q

The best screening test for Chlamydia and N. gonorrhoeae is ____________.

A

NAAT (basically PCR)

40
Q

In someone with gonorrhea, it is important to contact and treat those who’ve had sex with that person in the past __________.

A

60 days

41
Q

How should gonorrhea be treated?

A

With intramuscular ceftriaxone and oral azithromycin (the latter for Chlamydial coinfection)

42
Q

Which stain helps identify Chlamydia?

A

Giemsa (like the GEMS from the Sketchy scene)

43
Q

How does Chlamydia cause conjunctivitis?

A

It causes the eyelids to turn inward, thereby scraping the eye continually and leading to conjunctivitis.

44
Q

Lymphogranuloma venereum can mimic ____________.

A

ulcerative colitis (because it can spread through the peritoneum)

45
Q

What is unique about Treponemal growth?

A

They divide by transverse fission.

46
Q

Can treponema persist in the environment?

A

Mostly no. They of course had to come from somewhere, but infection by fomites has not been documented.

47
Q

Which of the bacterial STDs is on the rise?

A

Syphilis

The incidence in 2015 was three times the incidence in 2005.

48
Q

Leptospirosis presents with damage to what organs?

A

Liver and kidney

49
Q

Which are larger, reticulate bodies or elementary bodies?

A

Reticulate

50
Q

What percent of untreated patients will develop tertiary syphilis?

A

30%

Note: this is now rare because antibiotics during the primary or secondary phase prevent this complication.

51
Q

Other than presence of pain, how can you distinguish H. ducreyi from syphilis?

A

H. ducreyi present with multiple ulcers while syphilis presents with a single indurated ulcer.

52
Q

Which immune pathway is responsible for the elimination of syphilis?

A

T-cells

53
Q

The Jarisch-Herxheimer reaction occurs in the ____________ stages of syphilis.

A

first and second

54
Q

Neisseria obtained a beta-lactamase from _________.

A

E. coli

MS2 - Infectious Disease (57 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions