Chapter 8: Neisseria Flashcards Preview

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Flashcards in Chapter 8: Neisseria Deck (35):
1

Neisseria

Only pathogenic gram-negative cocci
Pairs = diplococci

2

What does Neisseria meningitidis cause?

Meningitis
Life-threatening sepsis (meningococcemia)

3

What are the virulence factors of the meningococcus?

Capsule: A, B, C
Endotoxin (LPS)
IgA1 protease: Exclusive to Neisseria, cleaves IgA in half
and Pili : attachment

4

What does Endotoxin LPS from meningococcus cause?

Blood vessel destruction (hemorrhage) and sepsis
Petechiae
Can damage adrenal glands

5

What are the high risk groups for infection by Neisseria meningitidis (meningococcus)

Infants aged 6 months to 2 years
Army recruits
College freshmen

6

How does Neisseria meningitidis spread?

via respiratory secretions and usually lives asymptomatically in the nasopharynx

7

What is the major clue to for invasive meningococcal infection?

petechial rash

8

What is Meningococcemia

Intravascular infection of Neisseria meningitidis
Abrupt onset of spiking fevers, chills, arthralgia (joint pains) and muscle pains, and petechial rash

9

What is Fulminant meningococcemia?

It is the waterhouse-friederichsen syndrome
Septic shock
Bilateral hemorrhage into the adrenal glands ->adrenal insufficiency
Hypotension and tachycardia abruptly occurs
Rapily enlarging petechial skin lesions
DIC, coma

10

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

11

What does Neisseria gonorrhoeae/gonococcus cause?

The SECOND most common sexually transmitted disease, gonorrhea

12

What are the Virulence factors of gonococcus?

Pili, outer membrane protein porins
Opa proteins

13

What virulence factor of gonococcus protects the bacteria from our Abs, vaccines, and also serves to prevent phagocytosis?

Pili
Hypervariable amino acid sequences
Pili also possibly hold the bacteria so close to host cells that Mo or neurtrophils are unable to attack

14

What is the role of outer membrane protein porins of gonoccucus?

PorA and PorB appear to promote invasion into epithelial cells

15

What are opa proteins?

class of outer membrane proteins that promote adherence and invasion into epithelial cells; expression results in opaque colonies

16

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

17

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

18

What are the symptoms of Gonococcal disease in men?

Painful urination along with a purulent urethral discharge (pus expressed from tip of penis)

19

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

20

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

21

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

22

What can increase the risk of cervical gonococcal infection progressing to PID?

IUD

23

What is the major cause of PID?

Chlamydia trachomatis

24

What are the complications of PID?

Sterility: scarring
Ectopic pregnancy: salpingitis and scaring
Abscesses: in fallopian tubes, ovaries, or peritoneum
Peritonitis: infected peritoneal fluid
Peri-hepatitis: capsule around liver

25

What is Fitz-Hugh-Curtis syndrome?

Peri-hepatitis
Infection of Neisseria gonorrhoeae of the capsule that surrounds the liver
RUQ pain and tenderness
Follows PID
Also PID by chlamydia

26

Gonococcal bacteremia

Rarely Neisseria gonorrhoeae can invade the bloodstream
Men and women
Fever, joint pain, skin lesions on extremities
Pericarditis, endocarditis, and meningitis rare complications

27

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

28

What is the most common kind of septic arthritis in young, sexually active individuals?

Gonococcal arthritis

29

Gonococcal disease in infants

Transmitted during delivery
Results in opthalmia neonatorum - eye infection that can cause blindness (can also occur in adults)

30

What does Moraxella (Branhamella) catarrhalis cause?

Otitis media and URI in pts with COPD or emphysema or in the elderly

Pneumonia in the elderly

31

What group commonly has otitis media?

80% of all children by 3 years of age

32

What is otitis media mainly cuased by?

Strep penumoniae, Haemophilus influenzae and Moraxella catarrhalis (decreasing order)

33

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

34

Kingella kingae

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

35

What are the slow growing gram negative pathogens known to cause endocarditis?

HACEK group
Haemophilus species
Actinobacillus species
Cardiobacterium species
Eikenella species
Kingella species