218b microbio part I

Question 1

neisseria gonorrhoeae stain

Answer 1

gram - diplococci

grow on Thayer-martin media and Nucleic acid amplifacation tests on first void urine samples

Question 2

neisseria gonorrhoeae - pathogenicitiy

Answer 2

pili w/ antigenic variation –I phagocytosis and adheres to epithelial cells

Opa (opacity associated) proteins –I anchors the bacteria to host cell and leads to internalization

IgA protease - cleaves IgA in mucosa

Endotoxin - b/c gram -

Question 3

neisseria gonorrhoeae - clinical disease

Answer 3

1) urethritis - inflammation of urethrea, discharge, freq and urgent urination, w/ dysuria

differentiate from UTI (e coli is gram - rod)

2) disseminated gonococcal disease –> fever, arthritis, rash (STD = synovitis, tenosynovitis, d?
3) women - PID - ascending infection of uterusu, tubes, periotenal cavity –> infertility, ectopic pregnancy, Cervical motion tenderness
4) men - epididymitis and prostatisis
5) gonococcal ophthalmia – infection of the conjunctiva in neonates from infected mother (Rx - antimicrobial eye drops)

Question 4

neisseria gonorrhoeae - rx

Answer 4

Ceftriaxone (1/3 are penicillin resistant) - 3rd generation cephalosporin

must treat partners too (antigenic variation leads to reinfection) AND fro chlamydia

notify public health departmnet

Question 5

Chlamydia trachomatis - gram stain and environment

Answer 5

too small to stain

obligate intracellular

Question 6

Chlamydia trachomatis - seovars

Answer 6

A, B, C - endemic trachoma
D-K STD
L1,2,3 lymphogranuloma venerum (LGV)

Question 7

Chlamydia trachomatis - pathogenicity

Answer 7

1) EB and RB

elementary body - inert spherical extracellular spore –> binds receptors which leads to endocytosis

reticulate body –> active form, replicates, forms inclusion body, converts back to EB and lysis cell for futrhter infection

2) Type III secretion system

Question 8

Chlamydia trachomatis - clinical disease

Answer 8

1) urethritis - aka nongonococcal crethritis b/c doesn’t take up gram stain; may be asymptomatic (less severe than gonorrhea) –> epididymitis, prostatitis, PID
2) inclusion conjuctivits in new born
3) Lymphogranuloma venereum (LGV) –> ulcers to fever and swollen lymph nodes
4) trachoma (not an STD) - chlamydia infection of the eye –> blindness via scarring of conjegtive; eye lashes turn inward –> scarring of cornea

Question 9

Chlamydia trachomatis - dx lab

Answer 9

McCoy cells in lab

DNA/RNA amp tests

Question 10

Chlamydia trachomatis - rx

Answer 10

azithroymycin or doxycycline

Question 11

lesions of the genetialia

Answer 11

treponema pallidum

Question 12

treponema pallidum

Answer 12

stain: spirochete, very tiny, IF w/ flagella

Question 13

treponema pallidum - pathogenicity

Answer 13

flagella and motile in periplasm (not external surface)

few proteins on exposed surface –> evades detection –> chronic detection

Chancre develops

humoral immune response develops leads to resolution of sore, but still have bug

disseminates –> secondary sphyilis with widespread lesions

tertiary - years later, neuro findings

Question 14

treponema pallidum - clinical disease

Answer 14

1 - nontender chancre 2-10 weeks post infection that heals in 1 month

2 - generalized rash on soles and palms w/ nontender enlarged lymph nodes, resolves

3- neuro - general paresis (personality changes), tabes dorsalis in spinal column (changes in gait, bladder control), CV (enlarges aorta), gummas (granulamatous lesions in any organ)

congenital symphilis - stillbirth, premature, hydrops fetalis (edema,fluid), etc

Question 15

treponema pallidum - dx lab

Answer 15

dark field microscopy

VDRL/RPR -

can’t be cultured

Question 16

treponema pallidum - rx

Answer 16

penicilin G (killing bacteria can cause Jarish-Herxheimer –> fever, headache, muscle aches)

treat sex partners and test for HIV

Question 17

haemophilus ducreyi

Answer 17

chancroid - tender chancre unlike syphilis + tender adenopathy

like syphilis presentation but very tender

Question 18

HSV

Answer 18

I and II

Rx - acyclovir

Question 19

HPV

Answer 19

causes warts

high risk - 16, 18, 31, 33

rx - cryotherapy but has recurrences

Question 20

HPV vaccines

Answer 20

–I L1 capsid protein
prevents cervical cancer

bivalent 16, 18
gardasil 6, 11, 16, 18

females 11-12 + gardasil for males

Question 21

trichomonas vaginalis

Answer 21

protoza - pear shaped causing vaginal symptoms

flagella – motile

vaginitis - bad odor, yellow green discharge, ithcing, pain with intercourse (dyspareunia)

males are asymptomatic

rx - oral metronidazole

Question 22

bacterial vaginosis (not -itis so no inflammation/PMNs)

Answer 22

symptoms from a change of population of bacteria living in vagina –> fishy smell, white discharge, irritation

displace lactobacillus (normal flora of vagina)

Question 23

bacterial vaginosis - dx

Answer 23

clue cells - epi cells from vagina that are coated with bacteria

pH > 4.5

Question 24

bacterial vaginosis - rx

Answer 24

metronidazole

Question 25

yeast vaginitis

Answer 25

candida albicans is common –> cheesy discharge

follows antibiotics