218b microbio part I Flashcards
neisseria gonorrhoeae stain
gram - diplococci
grow on Thayer-martin media and Nucleic acid amplifacation tests on first void urine samples
neisseria gonorrhoeae - pathogenicitiy
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 -
neisseria gonorrhoeae - clinical disease
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)
neisseria gonorrhoeae - rx
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
Chlamydia trachomatis - gram stain and environment
too small to stain
obligate intracellular
Chlamydia trachomatis - seovars
A, B, C - endemic trachoma
D-K STD
L1,2,3 lymphogranuloma venerum (LGV)
Chlamydia trachomatis - pathogenicity
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
Chlamydia trachomatis - clinical disease
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
Chlamydia trachomatis - dx lab
McCoy cells in lab
DNA/RNA amp tests
Chlamydia trachomatis - rx
azithroymycin or doxycycline
lesions of the genetialia
treponema pallidum
treponema pallidum
stain: spirochete, very tiny, IF w/ flagella
treponema pallidum - pathogenicity
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
treponema pallidum - clinical disease
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
treponema pallidum - dx lab
dark field microscopy
VDRL/RPR -
can’t be cultured
