Glossary of MID 14 - STDs Gonorrhea

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Gonorrhea is caused by what microbe?
Neisseria gonorrhoeae
What is the epidemiology of Gonorrhea
2nd most common STD. Greatest risk in 15-24 yr olds. Incubation of 1-14 days. Transmission male->female 50-70%, female->male 20%. Asymptomatic carriage major issue. PID and increased HIV transmission also public health issues
What are the pertinent microbio characteristics of N. gonorrhoeae?
aerobic non-motile, gram (-), kidney bean shaped diplococci, forms oxidase + colonies, ferments glu not malt, need complex media, CO2 enriched atmosphere.
Describe the pathogenesis of N. Gonorrhoeae.
Infects columnar or cuboidal epithelium, penetrates cells and multiplies, infection occurs in subepithelial space. Pilin, Porin, Opa mediated attachment and penetration. gonococcal-LOS causes inflammatory response (TNF-alpha), PMNs cause microabscesses and pus.
Name the major virulence factors of N. gonorrhoeae.
Pili, Porin, Opacity proteins (OPA), LOS, Transferrin-binding proteins, B-lactamase
What is the role of the pili in the pathogenesis of gonorrhea?
extend through peptidoglycan and outer mem. Cause tight binding to mucosa, inhibit phagocytosis by PMNs, essential for virulence
What is the role of the porin in the pathogenesis of gonorrhea?
major outer membran protein in N. gonorrhoeae, necessary for organisms survival, forms pores for nutrients and waste, intereferes with degranulation of PMNs and phagolysosomal fusion, impt. for invasion into epithelial cells and resistance to complement-mediated serum killing
What is the role of the Opa in the pathogenesis of gonorrhea?
Adhesin molecule that mediates tight binding to epithelial cells and is important for cell-to-cell signalling.
What is the role of the LOS in the pathogenesis of gonorrhea?
lipooligosacharide is similar to LPS, important cell wall component and is also an endotoxin
What is the role of the transferrin binding proteins in the pathogenesis of gonorrhea?
mediate acquistion of iron for bacterial metabolism by competeing with their human hosts for iron.
How do most other bacteria scavenge iron?
Via the synthesis of siderophores
What is the role of the Betalactamase in the pathogenesis of gonorrhea?
B-lactamase degrades penicillin which leads to resistance
What are the main features of N. gonorrhoeae that facilitate immune evasion?
Antigenic variation - frequent changes in the antigenic forms of pili and Opa proteins due to multiple copies. Phase variation - ability to turn pilin and Opa proteins on and off. IgA protease - cleaves and inactivates IgA1 heavy chain.
What are the clinical features of N. gonorrhoeae infection in men?
30% co-infection with chlamydia trachomatis, anterior urethritis, purulent urethral discharge and dysuria, erythema of urethral meatus, prostatitis, epididymitis (unilateral), DGI, proctitis, pharyngeal infection
What are the clinical features of N. gonorrhoeae infection in women?
30% co-infection with chlamydia trachomatis, majority are asymptomatic, cervicitis, urethritis, PID, bartholin's glands abscess, perihepatitis, proctitis, DGI
What is Fitz-Hugh-Curtis syndrome?
Perihepatitis involving RUQ abdominal pain/tendernes with elevated liver enzymes, Due to direct extension of gonorrhea or chlmydia from fallopian tube to the liver capsule and overlying peritoneum
Is rectal infection with gonorrhea symptomatic or asymptomatic?
many times it is asymptomatic.
What is PID? How do you treat it?
infection of the endometrium, fallopian tubes, and/or the surrounding peritoneum which occurs as a complication of cervicitis due to ascending infection. Tubal scarring can lead to ectopic pregnancy and infertility. Treated with coverage for N. gonorrhoeae, C. trachomatis, anaerobes, Gram (-) rods, and streptococci
Signs and symptoms of PID
10-20% of gonorrhea patients get PID. Lower ab pain, pain during sex, vaginal bleeding, endocervical discharge, cervical motion tenderness, uterine tenderness, fever, elevated WBC, ESR, CRP.
What is DGI?
disseminated gonoccocal infection, bacteremia occuring in 1-3% of patients. Symptoms: fever, skin lesions on extremities, tenosynovitis, oligoarthritis, migratory polyarthralgias. if untreated : septic arthritis, hepatitis, endocarditis, meningitis
Is there any risk to newborns from Gonorrhea infection of the mother?
neonatal development of gonococcal conjunctivitis (opthalmia neonaturm). Bilateral conjunctival inflammation. 1% Ag nitrate, 2% tetracycline, or .5% erythromycin protects.
What are the means to diagnose gonorrhea infection?
Gram stain of urethral discharge. highly sensistive and specific. In asymptomatic individulas use nuelic amplification or cultures on modified Thayer-Martin medium and non-selective chocolate blood agar
What is the treatment for gonorrhea infection?
Third generation cephalosporins (ceftriaxone injection, cefixime orally) or a quinolone like ciproloxacin. Treat for chlamydia concurrently with azithromycin or 1-wk of doxycycline). Evaluate and treat partners as well.

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