Microbiology 2 Flashcards
1
Q
Candida albicans
C. glabrata
Gardnerella vaginalis MICRO
Mobiluncus spp.
A
- 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
Q
Key factor in candida/BV overgrowth is?
A
- disturbance of normal flora (esp. by gram + lactobacilli)
- other normal flora maintain low pH & make hydrogen peroxide
3
Q
What things may alter normal bacterial flora?
A
- antibiotics
- sexual activity
- douching
- initial use of IUD
- menstrual cycle
- pregnancy
- tight undergarment
4
Q
Trichomonas vaginalis
A
- causes vaginitis (trichomoniasis)
- single cell protozoan
- frank pathogen, not normal, sexually transmitted
- non-gonorrheal urethritis (10%) in males
5
Q
Bacterial Vaginosis (BV): causative agent
A
- NOT caused by SINGLE agent
- combo of anaerobes normally present in GI & low #’s in vagina
- Gardnerella vaginalis, Mobiluncus, anaerobes, mycoplasmas
6
Q
Candidiasis: causative agent
A
- candida albicans: most common
- c. glabrata (fungi not bacteria)
7
Q
Trichomoniasis: causative agent
A
-trichomonas vaginalis - a protozoan
8
Q
Vulvovaginal Candidiasis: Symptoms
A
- abnormal vaginal discharge
- external dysuria
- vulvar itching/pain/irritation
- scant, white, clumped discharge with adherent plaques
- no fishy oder with KOH
9
Q
Vulvovaginal Candidiasis: Inflammation?
A
- vulvar erythema, edema, or fissure
- erythema of vaginal epithelium,
- introitus
10
Q
Vulvovaginal Candidiasis: Viginal pH
A
= 4.5
11
Q
Vulvovaginal Candidiasis: Microscopy
A
- leukocytes
- epithelial cells
- mycelia or pseudomycelia (50-85%)
12
Q
Trichomonal Vaginitis: Symptoms
A
- profuse yellow vaginal discharge
- extreme dysuria
- vulvar itching
- homogeneous or frothy discharge
- may be FISHY with KOH
13
Q
Trichomonal Vaginitis: Inflammation?
A
- erythema of vaginal and vulvar epithelium
- colpitis macularis
14
Q
Trichomonal Vaginitis: pH?
A
> 4.5
15
Q
Trichomonal Vaginitis: Microscopy?
A
- leukocytes
- trichomonads (50-70% of culture +)
16
Q
Bacterial Vaginosis: Symptoms?
A
- increased, abnromal, or malodorous vaginal discharge
- grey or white, adherent, homogenous discharge that uniformly coats vagina
- may be FISHY with KOH
17
Q
Bacterial Vaginosis: Inflammation?
A
none
18
Q
Bacterial Vaginosis: pH?
A
> 4.5
19
Q
Bacterial Vaginosis: Microscopy
A
clue cells (81-94%)
- few leukocytes
- lactobacilli outnumbered by mixed flora
20
Q
Cystitis is characterized by?
A
- dysuria
- suprapubic pain (mild)
- leukocytes (polys) in urine
- sig.# or bacteria in urine (>10^5)
- insig. fever
21
Q
Pyelonephritis is characterized by?
A
- same as cystitis plus:
- sig. fever
- flank/back pain ~ waist high
- WBC & RBC casts in urine
22
Q
Cervicitis is characterized by?
A
- dysuria
- mucopurulent discharge (cervix)
- maybe fever
- maybe lower abdominal pain
- maybe pruritis
- inapparent, subclinical infections are common
23
Q
Transmission of BV & Candidiasis?
A
- sexually
- generally supra-infections of normal flora
24
Q
Transmission of T. vaginalis
A
- 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
