Neisseria gonorrhoeae Flashcards
what is the biology of Neisseria gonorrhoeae?
Gram negative diplococcus (kidney-shaped cocci) *
Oxidase +
catalase + *
Breaks down only Glucose (Gonococcus) *
where do we find a reservoir of N. gonorrhoeae in the body?
Human genital tract (asymptomatic infected individuals)*
how does it spread?
Sexual contact
Neonates – during birth
what disease does neisseria gonorrhoeae cause?
- Causes Gonorrhoea – a sexually transmitted disease (STD)
- Rectal infections *
- Pharyngitis *
- Ophthalmia neonatorum *(neonatal conjunctivitis)
- Disseminated infection
- Septic arthritis *
what are Gonococcus’s Virulence factors *?
Pili
Outer membrane proteins
IgA protease
Lipooligosaccharide (LOS) *
Antigenic and Phase variation *
what will the pili help do?
adherence and colonization *
besides the pili, what other virulence factor is important for colonization?
IgA protease
what is Antigenic and Phase variation *?
- antigenic variation = the ability to express numerous different pili
- The aminoacid sequences of the pili vary, therefore the pili are antigenically distinct
- During an infection Gonococcus can evade detection by the hosts’ immune system by changing the pili it expresses
- phase variation = turning on or off the production of pili
Antigenic variation occurs with what virulence factors?
Pili
Outer membrane proteins
LOS (Lipooligosaccharide)
Antigenic variation accounts for what?
chronicity of infections *
lack of protection against subsequent gonococcal infections
what is gonorrhea?
- mucous membrane infection
- the site of infection is dependent on type of sexual contact & sexual practices
who transmits the disease?
Both asymptomatic and symptomatic persons
what will untreated and repeated infections cause?
- cause scarring
- May lead to infertility in both sexes
- may predispose women to ectopic pregnancy
what Genito-urinary tract infection will be caused in men?
Urethritis in men
Epididymitis
Prostatitis
what is urethritis?
- yellow purulent exudate (gram stain shows numerous PMNs +GN diplococci)
- Frequent, painful urination
Gonococcus will lead to what Genito-urinary tract inf. in women?
Endocervicitis (Urethritis in females)
what is Endocervicitis?
Purulent discharge (examine cervix)
Frequent, painful urination, lower abdominal pain
Approx. 50% cases go undetected
what complicatins can happen with endocervicitis?
Complications include salpinigitis, Pelvic inflammatory disease (PID) and sterility
rectal infections iw th neisseria gonorrhoea occur more frequently in whom?
in homosexual men
Pharyngitis due to neisseria gonorrhea occurs due to what? what is seen?
Due to oral-genital contact
Purulent exudate is seen
neisseria gonorrhea pharingitis will resemble what?
Resembles “Strep” throat
what is Ophthalmia neonatorum?
what is another name for this?
what happens if not treated early?
- Redness, swelling of eye, purulent discharge, contracted by newborns during delivery
- Neonatal conjunctivitis
- Rapidly leads to blindness if not immediately treated
treatment for Ophthalmia neonatorum?
1% silver nitrate, 1% tetracycline, or 0.5% erythromycin
what are the most common STDs that cause septic neonatal conjunctivitis*?
Chlamydia and N.gonorrhea
what is Gonococcemia?
Disseminated infection - untreated infection which has invaded bloodstream that will Also produces necrotic skin lesions on a erythematous base
Gonococcemia Most commonly results in what?
septic arthritis *
what is Septic Arthritis?
Arthritis is inflammation of the joint
what is the most common cause of septic arthritis in the sexually active age group?
Gonococcus
what is the most common cause of septic arthritis in children and adults over 50yrs?
Staph. aureus
how is Gonococcus diagnosed?
Gram stain: (only in male patients *)
- In males: urethral discharge
Culture:
Thayer Martin media (chocolate agar with antibiotics to supress other bacteria – normal flora) *
Provide 5-10% CO2 *
Patients with gonorrhea should be tested for what else?
Chlamydia trachomatis infection also (concurrent infection) *
what is the Gonococcus – Treatment* * for resistnat to penicillin N.gonorrhea? what is its mechanism of resistance?
how do you treat Due to the many cases of co-existing infection with C. trachomatis ?
- Third generation cephalosporins - Ceftriaxone *
- Changes in penicillin-binding proteins
- Doxycycline is added to treatment regime *
