Flashcards in Chapter 8: Neisseria Deck (35):
Only pathogenic gram-negative cocci
Pairs = diplococci
What does Neisseria meningitidis cause?
Life-threatening sepsis (meningococcemia)
What are the virulence factors of the meningococcus?
Capsule: A, B, C
IgA1 protease: Exclusive to Neisseria, cleaves IgA in half
and Pili : attachment
What does Endotoxin LPS from meningococcus cause?
Blood vessel destruction (hemorrhage) and sepsis
Can damage adrenal glands
What are the high risk groups for infection by Neisseria meningitidis (meningococcus)
Infants aged 6 months to 2 years
How does Neisseria meningitidis spread?
via respiratory secretions and usually lives asymptomatically in the nasopharynx
What is the major clue to for invasive meningococcal infection?
What is Meningococcemia
Intravascular infection of Neisseria meningitidis
Abrupt onset of spiking fevers, chills, arthralgia (joint pains) and muscle pains, and petechial rash
What is Fulminant meningococcemia?
It is the waterhouse-friederichsen syndrome
Bilateral hemorrhage into the adrenal glands ->adrenal insufficiency
Hypotension and tachycardia abruptly occurs
Rapily enlarging petechial skin lesions
What is the most common form of meningococcal disease?
Meningitis: striking infants less than a year of age
Fever, vomiting, irritability and/or lethargy
Bulging open anterior fontanelle
Slightly older infants may develop stiff neck and positive Kernig's and Brudzinski's signs
What does Neisseria gonorrhoeae/gonococcus cause?
The SECOND most common sexually transmitted disease, gonorrhea
What are the Virulence factors of gonococcus?
Pili, outer membrane protein porins
What virulence factor of gonococcus protects the bacteria from our Abs, vaccines, and also serves to prevent phagocytosis?
Hypervariable amino acid sequences
Pili also possibly hold the bacteria so close to host cells that Mo or neurtrophils are unable to attack
What is the role of outer membrane protein porins of gonoccucus?
PorA and PorB appear to promote invasion into epithelial cells
What are opa proteins?
class of outer membrane proteins that promote adherence and invasion into epithelial cells; expression results in opaque colonies
What do pili, porins and opa proteins allow gonoccoci to do overall?
bind to fallopian tube non-ciliated eipthelial cells where LPS can destroy cells
Gonococcal disease in men
Organisms penetrates the mucous membranes of the urethra, causing inflammation (urethritis), dysuria, and purulent discharge from the penis. Both symptomatic and asymptomatic men pass the disease
Epididymitis, prostatitis, and urethral strictures
MSM: rectal gonococcal infection
What are the symptoms of Gonococcal disease in men?
Painful urination along with a purulent urethral discharge (pus expressed from tip of penis)
Gonococcal disease in women
More likely to be asymptomatic with minimal urethral discharge
Infects columnar epithelium of the cervix - reddened, friable, purulent exudate
Both symptomatic and asymptomatic women can transmit the disease
What are the symptoms of Gonococcal disease in women?
If symptoms do develop, the women may complain of lower abdominal discomfort pain with sexual intercourse
Purulent vaginal discharge
What can gonococcal infection of the cervix progress to?
PID - pelvic inflammatory disease
Infection of the uterus (endometritis), fallopian tubes (salpinitis), and/or ovaries (oophoritis)
Low fever, lower abdominal pain, abnormal menstrual bleeding, cervical m otion tenderness
Menstruation allows bacteria to spread
What can increase the risk of cervical gonococcal infection progressing to PID?
What is the major cause of PID?
What are the complications of PID?
Ectopic pregnancy: salpingitis and scaring
Abscesses: in fallopian tubes, ovaries, or peritoneum
Peritonitis: infected peritoneal fluid
Peri-hepatitis: capsule around liver
What is Fitz-Hugh-Curtis syndrome?
Infection of Neisseria gonorrhoeae of the capsule that surrounds the liver
RUQ pain and tenderness
Also PID by chlamydia
Rarely Neisseria gonorrhoeae can invade the bloodstream
Men and women
Fever, joint pain, skin lesions on extremities
Pericarditis, endocarditis, and meningitis rare complications
Gonococcal septic arthritis
Acute onset of fever along with pain and swelling of 1 or 2 joints
Pregressive destruction of joint
Synovial fluid reveals increased WBCs
Gram stain and culture of fluid
diplococci within WBC
What is the most common kind of septic arthritis in young, sexually active individuals?
Gonococcal disease in infants
Transmitted during delivery
Results in opthalmia neonatorum - eye infection that can cause blindness (can also occur in adults)
What does Moraxella (Branhamella) catarrhalis cause?
Otitis media and URI in pts with COPD or emphysema or in the elderly
Pneumonia in the elderly
What group commonly has otitis media?
80% of all children by 3 years of age
What is otitis media mainly cuased by?
Strep penumoniae, Haemophilus influenzae and Moraxella catarrhalis (decreasing order)
Worsening of wheezing, shortness of breath and cough - COPD exacerbations are often associated with what?
acquisition of a new strain of nontypeable Haemophilus influenzae or infection with Moraxella catarrhalis
frequently colonizes the throats of young children and can cause septic arthritis and osteomyelitis in children
Can cause endocarditis of native and prosthetic vavles in adults and children