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Flashcards in Microbiology 2 Deck (43):
1

Candida albicans
C. glabrata
Gardnerella vaginalis MICRO
Mobiluncus spp.

-opportunistic microorganisms
-not normally sexually transmitted
-normally present in low and harmless numbers (intestinal flora)
-have virulence factors that allow them to over-colonize female genital tract and cause disease

2

Key factor in candida/BV overgrowth is?

-disturbance of normal flora (esp. by gram + lactobacilli)
-other normal flora maintain low pH & make hydrogen peroxide

3

What things may alter normal bacterial flora?

-antibiotics
-sexual activity
-douching
-initial use of IUD
-menstrual cycle
-pregnancy
-tight undergarment

4

Trichomonas vaginalis

-causes vaginitis (trichomoniasis)
-single cell protozoan
-frank pathogen, not normal, sexually transmitted
-non-gonorrheal urethritis (10%) in males

5

Bacterial Vaginosis (BV): causative agent

-NOT caused by SINGLE agent
-combo of anaerobes normally present in GI & low #'s in vagina
-Gardnerella vaginalis, Mobiluncus, anaerobes, mycoplasmas

6

Candidiasis: causative agent

-candida albicans: most common
-c. glabrata (fungi not bacteria)

7

Trichomoniasis: causative agent

-trichomonas vaginalis - a protozoan

8

Vulvovaginal Candidiasis: Symptoms

-abnormal vaginal discharge
-external dysuria
-vulvar itching/pain/irritation
-scant, white, clumped discharge with adherent plaques
-no fishy oder with KOH

9

Vulvovaginal Candidiasis: Inflammation?

-vulvar erythema, edema, or fissure
-erythema of vaginal epithelium,
-introitus

10

Vulvovaginal Candidiasis: Viginal pH

= 4.5

11

Vulvovaginal Candidiasis: Microscopy

-leukocytes
-epithelial cells
-mycelia or pseudomycelia (50-85%)

12

Trichomonal Vaginitis: Symptoms

-profuse yellow vaginal discharge
-extreme dysuria
-vulvar itching
-homogeneous or frothy discharge
-may be FISHY with KOH

13

Trichomonal Vaginitis: Inflammation?

-erythema of vaginal and vulvar epithelium
-colpitis macularis

14

Trichomonal Vaginitis: pH?

>4.5

15

Trichomonal Vaginitis: Microscopy?

-leukocytes
-trichomonads (50-70% of culture +)

16

Bacterial Vaginosis: Symptoms?

-increased, abnromal, or malodorous vaginal discharge
-grey or white, adherent, homogenous discharge that uniformly coats vagina
-may be FISHY with KOH

17

Bacterial Vaginosis: Inflammation?

none

18

Bacterial Vaginosis: pH?

>4.5

19

Bacterial Vaginosis: Microscopy

clue cells (81-94%)
-few leukocytes
-lactobacilli outnumbered by mixed flora

20

Cystitis is characterized by?

-dysuria
-suprapubic pain (mild)
-leukocytes (polys) in urine
-sig.# or bacteria in urine (>10^5)
-insig. fever

21

Pyelonephritis is characterized by?

-same as cystitis plus:
-sig. fever
-flank/back pain ~ waist high
-WBC & RBC casts in urine

22

Cervicitis is characterized by?

-dysuria
-mucopurulent discharge (cervix)
-maybe fever
-maybe lower abdominal pain
-maybe pruritis
-inapparent, subclinical infections are common

23

Transmission of BV & Candidiasis?

-sexually
-generally supra-infections of normal flora

24

Transmission of T. vaginalis

-sexually
-may be #1 STD

25

Bacterial Vaginosis: Diagnosis

-foul odor (fishy: amines after KOH) WHIFF TEST
-discharge of dirty white/grey that homogeneously coats vaginal wall
-pH>4.5
-clue cells (vaginal epithelial cells w/adherent bacteria in wet mounts or gram stain)
-dysuria & vaginal discomfort typically absent
-little or no signs of inflammation (overgrowth of stinky bugs)

26

Candidiasis: Diagnosis

-vaginal itching, extreme
-discharge: patchy white clumps (cottage cheese)
-pungent odor (not foul)
-pH 4.5
-yeasts & branching hyphae seen on wet mount treated with KOH
-dysuria

27

Trichomonas: Diagnosis

-yellow(green), homogenous (copious/frothy) discharge
-malodorous (whiff test +)
-pH >4.5
-dysuria
-itching, punctate erythema seen by colposcopy
-wet mount: trichomonads with twitching motility, PMNs present

28

Treatment of Trichmonas

-oral Metronidazole

29

Treatment of Candidiasis

-topical and oral azoles (antifungals)

30

Agent of Syphilis

-spirochete
-Treponema pallidum
-can be grown in laboratory, but in rabbit testes (the source of antigen for treponeme-specific serological tests)

31

Syphilis Microbiology

-helical/spiral-shaped bacterium
-to thin to be seen by standard direct light transmission microscopy (no gram stain)
-can be seen by darkfield microscopy: useful Dx method early in disease process before abs
-culture plays no role in Dx

32

Syphilis Immune Response

-rigorous humoral & cellular response that does not eliminate infection
-Host's cellular immune response probably controls infection but also responsible for the pathology (esp. tertiary S)
-unknown mech: have latent phase that can last for years

33

Syphilis Untreated

-infection can continue for life, and latent infection can progress to tertiary stage

34

Primary Syphilis

2-3 week incubation
symptoms resolve in 3-6 weeks
-painless ulcer (chancre) at site of entry (1-2cm)
-indurated ridges (hard chancre; compare to soft chancre)

35

Secondary Syphilis

1 or 2 months after infection, symptoms resolve in a month or so without treatment
-disseminated infection (bone & lymph), many tissues/organs infected
-hyperpigmented maculopapular rash over entire body that with time extends to palms & soles
-mucous membrane patches in mouth and genitals and sometimes on tongue "snail track lesions"
-condylomata lata (wart) may occur in moist skin folds in perineum & anal regions
-sick, fever, headache, diffuse lymphadenopathy (nodes are non-tender)
-patchy baldness, thinning at eyebrow edges (alopecia), may be CNS (mild meningitis)
-liver involvement

36

Early latent syphilis

1-2 year period after resolution of secondary syphilis
-no symptoms, positive serology, may be relapse to secondary syphilis
-pregnant women may pass infection in utero

37

Late latent syphilis

begins 1-2 years post infection, may lat a lifetime, may progress to tertiary syphilis, infection may resolve spontaneously
-no symptoms, positive serology, may be relapse to secondary syphilis
-not infectious (even to fetus)

38

Tertiary syphilis

-almost any organ-system can be affected
-heart, CNS, skin, bone
-progressive, inflammatory (takes years to develop)
-endarteritis
-few spirochetes in lesions (not infectious)
-Gummas: characteristic skin & bone lesions

39

Congenital syphilis

-may or may not be symptoms at birth
-stigmata may develop 2 yrs or more after birth
-still birth/spon abortion
-disseminated infection transmitted transplacentally after first trimeter via blood (no chancre

40

Late congential syphilis

-stigmata develop over years

41

Transmission of syphilis

-STD
-biting or crack in skin

42

Diagnosis of Syphilis

1. Serology: non-treponemal serologic tests
(Ag is not T. pallidum but beef heart)
A. Rapid Plasma Reagin (RPR) test
B. Venereal Disease Research Lab (VDRL) test
-cheap, sensitive, false positive
2. Treponemal Tests: antigen is pathogenic T. pallidum
A. Fluorescent Treponemal Antigen-Absorbed test (FTA-ABS)
-titers remain months/years after pt is cured

43

Treatment of Syphilis

-large, single IM dose of PenG