Chapter 1.8 Neisseria Flashcards
What is the only pathogenic gram-negative cocci?
Neisseria
What is the shape of Neisseria?
Diplococci and each coccus is shaped like a kidney bean with their concave sides facing each other
What are the 2 species of Neisseria that cause disease in humans?
Neisseria meningitidis and Neisseria gonorrhoeae
What type of meningitis is associated with Neisseria meningitidis?
Central nervous system irritation-meningitis (meningocococcus)
What dose Neisseria gonorrhoeae cause?
Sexually transmitted disease (STD) gonorrhea
What disease other then meningitis does Neisseria meningitidis cause?
Life threatening sepsis (meningococemia)
What are the virulence factors of Neisseria meningitidis?
Polysaccharide capsule, endotoxin (LPS), IgA1 protease, iron extraction from transferrin
What is the function of endotoxin (LPS) in Neisseria meningitidis?
Cause blood vessel destruction (hemorrhage) to look like petechiae and sepsis
What makes someone a carrier of Neiserria meningitidis?
When the Neisseria becomes part of the normal flora of the nasopharynx and they are asymptomatic
What are the high risk groups for Neisseria meningitidis?
Infants from 6 months to 2 years and army recruits
Why are infants from 6 mo. - 2 years susceptible to meningococcal infections?
Up until then they were protected by mothers antibodies and haven’t made their own yet
Why are army recruits susceptible to invasive meningococcal invasion from Neisseria?
Since they are in such close quarters, each army recruit an be a carrier of a certain strain of meningococcus that the other army recruit’ immune system has never encountered
How does Neisseria meningitidis spread?
Via respiratory secretions and lives asymptomatic ally in the nasopharynx
What is the classic clue to an invasive meningococcal infection?
Appearance of petechial rash from release of endotoxin and vascular necrosis of skin
What is meningooccemia?
Intravascular invasion of Neisseria meningitidis in the bloodstream
What is the clinical presentation of meningococcemia?
Spiking fevers, chills, arthralgia, muscle pains, and petechial rash
What is arthralgia?
Joint pain
What is fulminant meningococcemia?
septic shock from bilateral hemorrhage into the adrenal glands that causes adrenal insufficency
*also called Waterhouse-Friderichsen syndrome
What is the clinical presentation of fulminant meningococcemia?
Abrupt onset of hypotension and tachycardia
Rapidly enlarging petechial skin lesion
DIC and coma may occur
Death occurs in 6-8 hours
What is the most common form of meningocococcal disease?
Meningitis in infants
What is the clinical presentation of an infant with meningitis?
Nonspecific findings of infection- fever, visiting, irritability, and lethargy
Anterior Fontainebleau may be present
What is the clinical presentation of a slightly older child with meningitis?
Stiff neck and positive Kernig’s and Brudzinski’s sign
What tests are done to diagnose meningitis?
Gram stain
Culture from blood, CSF, or petechial scraping
What agar does Neisseria grow best?
Chocolate agar- blood agar that has been heated
What is the classic medium for culturing Neisseria?
Thayer-Martin VCN media- chocolate agar with antibiotics
*Neisseria is the only bacteria that can grow in this
V- vancomycin
C- colistin
N- nystatin
What an kill all gram-positive organisms?
Vancomycin
What can kill all gram-negative organisms except Neisseria?
Colistin (polymyxin)
What can eliminate fungi?
Nystatin
How to culturally differentiate between the 2 Neisseria strains?
Neisseria meningitidis can produce acid from metabolism while Neisseria gonorrhoeae cannot
What is another name for Neisseria gonorrhoeae?
Gonococcus
What is the first sexually transmitted disease? What is the second?
- Chlamydia
2. Gonorrhoeae
What are the virulence factors of Neisseria gonorrhoeae?
Pili, protein II
What is the function of pili in Neisseria gonorrhoeae?
Protect bacteria from antibodies
Adhere to host cell allowing disease to occur
Prevent phagocytosis
How does Neisseria gonorrhoeae occur in men?
Men who have unprotected sex with an infected person
What is the mechanism of Neisseria gonorrhoeae in men?
Neisseria penetrates mucous membrane or urethra, causing inflammation (urethritis)
What is the clinical presentation of a man with Neisseria gonorrhoeae?
Painful urination
Purulent urethral dish argue (pus from tip of penis)
How is Neisseria gonorrhoeae occur in women?
Sexual transmission from infected person
What is the clinical presentation of a woman with Neisseria gonorrhoeae?
Painful burning on urination Purulent discharge from urethra Dyspareunia- pain with intercourse Lower abdominal discomfort *more likely asymptomatic
What is the clinical presentation of the cervix in a woman with Neisseria gonorrhoeae?
Reddened and friable with purulent exudate
What can a gonococcal infection of the cervix progress to?
Pelvic inflammatory disease (PID)
What is pelvic inflammatory disease?
Infection of the uterus (endometritis) , Fallopian tubes (salpingitis), and or/ovaries (oophoritis)
What is the clinical presentation of a woman with PID?
Fever, lower abdominal pain, abnormal menstrual bleeding, and cervical motion tenderness
What is the significance of an intrauterine device (IUD) in gonococcal infection?
Increases the risk of a cervical gonococcal infection that can progress to PID
What are the complications of PID from gonorrhoeae?
Sterility- increased risk from scarring of Fallopian tubes preventing sperm from reaching egg
Ectopic pregnancy- increased risk from scarring of fallopian tube and inflammation
Abscesses- can develop in Fallopian tube, ovaries, or peritoneum
Peritonitis- bacterial spread from ovaries and Fallopian tube and infect peritoneal fluid
Peri-hepatitis- infection of the capsule around the liver
What is the patient presentation of peri-hepatitis caused from Neisseria gonorrhoeae?
Right upper quadrant pain and tenderness
*also called Fitz-Hugh-Curtis syndrome
What are 2 gonococcal diseases that can occur in both men and women?
Gonococcal bacteremia and septic arthritis
What causes gonococcal bacteremia?
When Neisseria gonorrhoeae invades the bloodstream
What is the clinical presentation of gonococcal bacteremia?
Fever, joint pains, skin lesions
What is the clinical presentation of septic arthritis from Neisseria gonorrhoeae?
Acute onset of fever
Pain and swelling of 1 or 2 joints
Progressive destruction of joint
What tests are done for septic arthritis from Neisseria gonorrhoeae?
Synovial fluid exam- high WBCs
Gram stain and culture of synovial fluid- gram-negative diplococci within the WBCs
What is the most common kind of septic arthritis in young, sexually active individuals?
Gonococcal arthritis
How is Neisseria gonorrhoeae transmitted in infants?
From pregnant woman to her child during deliver
What is the clinical presentation of an infant who got Neisseria gonorrhoeae from delivery?
Ophthalmia neonatorum- eye infection that occurs on 1st or 2nd day of life
Damages cornea- causing blindness
What is the best way to diagnose Neiserria gonorrhoeae?
Gram stain and culture on Thyer-Martin VCN medium
Gram stain will show diplococci within WBCs
What disease can be caused by branhamella catarrhalis?
Otitis media, sinusitis, bronchitis, and pneumonia
What are the characteristics of branhamella catarrhalis?
Formerly called Neisseria catarrhalis
Is part of the normal respiratory flora
