UTIs/STIs - Mclean

Question 1

Mycoplasma

Answer 1

Lack rigid cell wall

Very small
pleomorphic
require cholesterol
fried egg appearance

Question 2

Chlamydia

Answer 2

thot to be viruses
very little peptidoglycan, have 2 lipid bilayers.

Question 3

Life cycle of chlamydia.

Answer 3

elementary body will infect cell (EB)
will convert to reticulate body (RB) - metabolic active. This is what divides.
eventually convert back to EB -> release from cell, infect others.

Question 4

How to differentiate between chlamydia trachomatis and other chlamydia

Answer 4

inclusions contain glycogen.

Question 5

Chlamydia trachomatis:

serotypes ABC affect:
DK affect:
L1 L2 L3 affect:

Important slide

Answer 5

eyes (disease known as Trachoma)
genitals (STI’s)
genitals (STI’s)

Question 6

Chlamydia trachomatis:

serotype D-K facts

Answer 6

most common bacterial STD in USA

males: inflammation of urethra, anal , rectal
females: cervix can be inflammed, maybe in fallopian tube too.

Symptoms: Chlamydia: more clear discharge than gonorrhea.
Gonorrhea: more pus-like discharge.

Eyes: Inclusion conjunctivitis. Conjunctiva of eyes are affected. Mucous / pus coming from eyes. (acute)

Question 7

QUESTIONS ON MIDTERM REVOLVE AROUND DIAGNOSIS AND TREATMENT.

Question 8

Chlamydia trachomatis:

Serotypes L1, L2, L3 facts

Answer 8

Cause Lymphogranuloma Venereum (LGV)
more rare. More invasive than D-K.

Primary stage: local infection. can be transffered skin to skin
Secondary stage: dissemination. swelling of inguinal / perirectal lymph nodes
tertiary stage: progressive tissue damage. Ulcers, fistulas, more.

Question 9

Chlamydia trachomatis

Serotpes A, B, C facts

Answer 9

major cause of blindness in asia africa
more chronic
causes Trachoma
scarring of cornea
repeated infections: eyelids being turned inwards. scratches surface of eye.

Question 10

Diagnosis of chlamydia trachomatis:

Treatment:

important slide

Answer 10

Diagnosis: NAAT (nucleic acid amplification test)
Microscopy using direct fluorescent antibody staining

Treatment: doxycycline. It is a tetracycline antibiotic, targets protein synthesis.
Erythromycin / azithromycin for small children. Don’t want to use tetracycline bc it binds to ca2+ in teeth, which becomes yellow.
Azithromycin for pregnant.

Question 11

Neisseria: meningitidis, gonorrhoeae.

Morphology:

Answer 11

Morphology: gram negative diplococci

Meningitidis is the one with a capsule***
Gonorrhoeae is the one without.

There is a vaccine for meningitidis but not gonorrhea. Vaccine is against capsule.

Question 12

Cultivation of meningitidis / gonorrhea

Answer 12

Meningitidis: use on chocolate agar bc its non selective
Gonorrhea: use on thayer-martin agar bc its more selective.

Question 13

Plasmids / B-lactamase production in Neisseria gonorrhea / miningitidis

Answer 13

gonorrhea: commonly have plasmids, commonly have B-lactamase production

Meningitidis: few plasmids, no b-lactamase production

bc gonorrhea have common of those two, they are becoming highly resistant to antibiotics.

Question 14

6 important virulence factors with meningitis / gonorrhea

Answer 14

1.) capsule (meninigitis)
2.) Pili: attachment
3.) lipo-oligosaccharide (LOS). (shorter / more branching than LPS)
4.) Opacity proteins: prevent phagocytosis
5.) Porin (protein 1): associated with attachment.
6.) IgA protease: cleaving IgA

IgA is the antibody that protects mucosal surfaces. So if u can cleave it, theres less protection.

Question 15

Treatment of gonorrhea:

Answer 15

1% silver nitrate, erythromycin

gonorrhea is pus-like, burning during urination (urinating razorblades)

Question 16

Diagnosis of gonorrhea:

Treatment:

Answer 16

NAAT.
Culture on Thayer Martin agar
Gram stain: Gram negative organism. look for diplococci

Ceftriaxone injection is first choice
Doxycycline is added if coinfection with chlamydia trachomatis not ruled out

Question 17

Spirochetes

general characteristcs

Answer 17

possess endoflagella for motility
gram negative, spiral shaped

treponema: regular coils, tight.

Question 18

Spirochetes: signs symptoms:

T. pertenue:
T. carateum
T. denticola
T. pallidum:

Answer 18

T. pertenue: yaws in tropics. infection of skin bones joints
T. carateum: pinta. skin disease
T. denticola: present in mouth, implicated in gingivitis, acute necrotizing ulcerative gingivitis
T. pallidum: cause syphilis ***

Question 19

T. pallidum: syphilis

different stages

Answer 19

primary stage: non-tender, indurated ulcer. (sore)
Secondary stage: rashes all over
Latent syphilis: can last 30 years
Tertiary phase: no organ of body is immune. gummatous disease, nervous system affected.

Question 20

T. pallidum: syphilis

diagnosis:

Answer 20

darkfield microscopy can see spiral organisms
direct fluorescent antibody test: find antigen
blood tests: anti-treponemal antibody test: look for antibodies specific to antigen
non-treponemal antibody test (reagin): look for antibodies of damaged cells. Not as accurate. VDR test: use microscope. RPR test: agglutination. no microscope.

Question 21

Treatment of syphilis

Answer 21

Benzathine penicillin G

Question 22

Trichomoniasis:

caused by trichomonas vaginalis:

Answer 22

Most prevalent non viral STI

treatment: metronidazole

Question 23

Bacterial Vaginosis (BV)

Answer 23

not an STI. disruption of normal flora.

treatment: metronidazole