Neisseria gonorrhoeae Flashcards
Neisseria gonorrhoeae
Neisseria gonorrhoeae
- _Gram negative diplococcus (kidney-shaped cocci) *_
- _Oxidase +, catalase + *_
- _Breaks down only Glucose (Gonococcus) *_
- Reservoir:
- _Human genital tract (asymptomatic infected individuals) *_
- Transmission:
- Sexual contact
- Neonates – during birth
- Causes Gonorrhoea – a sexually transmitted disease (STD)
Gonococcus – Virulence factors *
(Neisseria Gram negative cocci)
Gonococcus – Virulence factors *
- Pili – adherence and colonization *
-
Outer membrane proteins (OMP)
- Opa and Porin proteins
- adherence
- IgA protease – imp. for colonization
- Lipooligosaccharide (LOS) *
- _Antigenic and Phase variation *_
Antigenic and Phase variation of Gonococcus *
(Neisseria Gram negative cocci)
Antigenic and Phase variation of Gonococcus *
- Antigenic and Phase variation *
- Each bacterium has the ability to express numerous different pili, it can change the pili at any time
- The aminoacid sequences of the pili vary, therefore the pili are antigenically distinct
- Each different pilus elicits a different antibody
- During an infection Gonococcus can evade detection by the hosts’ immune system by changing the pili it expresses
- it can also turn on or off the production of pili (phase variation)
- Antigenic variation occurs with pili, OMP (outer membrane protein) and LOS (Lipooligosaccharide)
Antigenic variation of Gonococcus accounts for?
(Neisseria Gram negative cocci)
Antigenic variation of Gonococcus accounts for:
- ** chronicity of infections ***
- ** lack of protection against subsequent gonococcal infections**
- Reason why both partners must be treated at the same time
Gonococcus – Disease spectrum
(Neisseria Gram negative cocci)
Gonococcus – Disease spectrum
- Gonorrhoea – genito-urinary tract infection
- In men:
- _Urethritis *_
- Epididymitis
- Prostatitis
- In women:
- Urethritis
- Endocervicitis *
- Pelvic inflammatory disease (PID)
- Rectal infections *
- Pharyngitis *
- Ophthalmia neonatorum *(neonatal conjunctivitis)
- Disseminated infection
- Septic arthritis *
Gonorrhoea – genito-urinary tract infection in men
(Neisseria Gram negative cocci)
Gonorrhoea – genito-urinary tract infection in men
- _Urethritis *_
- Epididymitis
- Prostatitis
Gonorrhoea – genito-urinary tract infection in females
(Neisseria Gram negative cocci)
Gonorrhoea – genito-urinary tract infection
- Urethritis
- Endocervicitis *
- Pelvic inflammatory disease (PID)
Gonorrhoea – genito-urinary tract infection in neonates
(Neisseria Gram negative cocci)
Gonorrhoea – genito-urinary tract infection in neonates
Ophthalmia neonatorum *(neonatal conjunctivitis)
Gonococcus - Urethritis in men
(Neisseria Gram negative cocci)
Gonococcus - Urethritis in men
- Thick, yellow purulent exudate
- (gram stain shows numerous PMNs (polymorphonuclear leukocytes) +GN diplococci)
- Frequent, painful urination
- Complications include epidydimitis and prostatitis
Gonococcus – Endocervicitis, Urethritis in females
(Neisseria Gram negative cocci)
Gonococcus – Genito-urinary tract infection in females with Endocervicitis, Urethritis in females
- Purulent discharge (examine cervix)
- Frequent, painful urination, lower abdominal pain
- Approx. 50% cases go undetected
- Complications include salpinigitis(infection and inflammation in the fallopian tubes. used synonymously with pelvic inflammatory disease (PID)) , Pelvic inflammatory disease (PID) and sterility
Rectal infections caused by Gonorrhoea
(Neisseria Gram negative cocci)
Rectal infections caused by Gonorrhoea
- Prevalent in men who have sex with men (MSM)
- painful defecation, discharge, constipation, proctitis (Inflammation of the anus and lining of the rectum)
Pharyngitis caused by Gonorrhoea
(Neisseria Gram negative cocci)
Pharyngitis caused by Gonorrhoea
- Due to oral-genital contact
- Mild to severe infection
- Purulent exudate
- Resembles “Strep” throat
Ophthalmia neonatorum
(Neisseria Gram negative cocci)
Ophthalmia neonatorum - cause by Gonorrhoea
- Also known as Neonatal conjunctivitis (inflammation of the surface or covering of the eye).
- Contracted by newborns during delivery
- Redness, swelling of eye, purulent discharge
- Rapidly leads to blindness if not immediately treated
- Standard procedure in hospitals → administer antibiotic drops/ointment after delivery → Helps prevent eye infection (even if the mother shows no symptoms of infection)
- _Chlamydia and N.gonorrhea are the most common STDs that cause septic neonatal conjunctivitis******_
The hell this baby got? What it’s caused by?
Ophthalmia neonatorum, caused by that younge Gonococcus (Gonorrhoea).
(Neisseria Gram negative cocci)
Gonococcemia
(Neisseria Gram negative cocci)
Gonococcemia
- Disseminated infection - untreated infection which has invaded bloodstream
- Rarely occurs (as most strains do not multiply in blood)
- Also produces necrotic skin lesions on a erythematous base
- Most commonly results in _septic arthritis *_
Septic Arthritis
Septic Arthritis (possible component in gonorrhoea infection)
- Arthritis is inflammation of the joint
- If caused by a pathogen → septic /infectious arthritis
- When pathogen is bacterial→ bacterial/suppurative arthritis
- Could result from hematogenous spread from another site of infection or
- Direct infection of the joint (wound/penetrating injury)
- Gonococcus is the most common cause of septic arthritis in the sexually active age group
- Staph. aureus is the most common cause overall (in adults and children over 2 yrs)
(Neisseria Gram negative cocci)
Gonococcus – Diagnosis
(Neisseria Gram negative cocci)
Gonococcus – Diagnosis
- Genital disease
- In males: urethral discharge
- In females: endocervical swab
- Gram stain
- Of diagnostic value only in male patients *
- Not useful for endocervial, throat and other specimens * (because some species of Neisseria are normal flora in the oro- and nasopharynx)
- Culture
- All specimens must be cultured to establish diagnosis
- Thayer Martin media (chocolate agar with antibiotics to supress other bacteria – normal flora) *
- Provide 5-10% CO2 *
- Gene probes and PCR also available
- _Patients with gonorrhea should be tested for Chlamydia trachomatis infection also (concurrent infection) *_
Gonococcus – Treatment* *
(Neisseria Gram negative cocci)
Gonococcus – Treatment* *
- 20% gonococcal isolates → resistant to penicillin, PPNG (penicillinase-producing N.gonorrhea) *
- Beta-lactamase production
- Changes in penicillin-binding proteins
- Common resistance also to:
- Tetracyclines, erythromycin and fluoroquinolones
- Drugs of choice now:
- Third generation cephalosporins - Ceftriaxone *
- Due to the many cases of **co-existing infection with C. trachomatis **
- Doxycycline is added to treatment regime *
