03 - Gram Negative Cocci - Microbes 28 through 30

Question 1

List all of the gram negative cocci

Answer 1

Neisseria
Moraxella (elongated)

Question 2

a. Gram-negative cocci in pairs (some slightly elongated)
b. Medical Significance
(1) Causes upper respiratory tract infections, especially including otitis media and sinusitis in children (3rd most common cause)
(2) Causes bronchitis or pneumonia in children and adults (in the top 3-4 of causes).
c. Virulence factors: endotoxins, resistance to complement, beta-lactamase production (about 20% of strains)
d. Laboratory diagnosis by routine culture and biochemical tests

Answer 2

Moraxella catarrhalis (formerly Branhamella catarrhalis)

Question 3

3rd most common cause of URI (especially otitis media and sinusitis in children)

top 3-4 causes of bronchitis or pneumonia

gram negative cocci

Answer 3

Moraxella catarrhalis (formerly Branhamella catarrhalis)

Question 4

Moraxella catarrhalis (formerly Branhamella catarrhalis)

Virulence factors?

Answer 4

endotoxins, resistance to complement

beta-lactamase production (about 20% of strains)

Question 5

Major cause (#2) of meningitis

Answer 5

Neisseria meningitidis

Question 6

a. Gram-negative cocci in pairs

b. Disease
1) Major cause (#2) of meningitis
(2) Often causes secondary tissue necrosis (invasive

Answer 6

Neisseria meningitidis

Question 7

Epidemiology

(1) Antigenic groups A, B, C, W, & Y (B, C, & Y problematic)
(2) Predominates (#1) in school-age children and college students; some epidemics in schools and day care centers
(3) Sub-Saharan Africa noted for noted for thousands of cases each year

Answer 7

Neisseria meningitidis

Question 8

d. Virulence factors
(1) Polysaccharide capsule - antiphagocytic
(2) Pili – tissue attachment & help resist phagocytosis
(3) Porin proteins – resist phagocytosis
(4) Lipooligosaccharide w/ Lipid A (i.e. endotoxin)
(5) IgA protease
(6) Disseminiated Intravascular Coagulation (DIC)

Answer 8

Neisseria meningitidis

Question 9

Disseminiated Intravascular Coagulation (DIC) = which microbe?

Answer 9

Neisseria meningitidis

Question 10

e. Vaccine
(1) Meningococcal conjugate vaccine (groups ACWY)
(2) Group B meningococcal vaccine

f. Laboratory diagnosis
(1) Culture and biochemical tests
(2) Antigenic identification from CSF

Answer 10

Neisseria meningitidis

Question 11

a. Gram-negative cocci in pairs (may be intra- or extra cellular regarding phagocytes)
b. Gonorrhea (genital, sexually transmitted infection, #2 cause)
(1) Male – urethritis
(2) Female – endocervix and/or Pelvic Inflammatory Disease
(3) Sometimes asymptomatic
(4) Symptoms usually within 2 to 5 days
(5) Often co-infects along with Chlamydia

Answer 11

Neisseria gonorrhoeae

Question 12

2 cause of STD/ STI

Answer 12

Neisseria gonorrhoeae

Question 13

Causes the following:

Gonorrhea

Pharyngitis and rectal infection

Septic arthritis

Answer 13

Neisseria gonorrhoeae

Question 14

Virulence factors

(1) Beta lactamase
(2) Pili – tissue attachment & help resist phagocytosis
(3) Porin proteins – resist phagocytosis
(4) Lipooligosaccharide w/ Lipid A (i.e. endotoxin)

Hint: Gram Negative Cocci

Answer 14

Neisseria gonorrhoeae

Question 15

Laboratory diagnosis

(1) Requires enriched media (e.g. selective Supplemented Chocolate Agar) and CO2
(2) Do not chill or refrigerate
(3) Beta-lactamase test needed – certain regions have high penicillin resistance (PPNG)

Hint: Gram Negative Cocci

Answer 15

Neisseria gonorrhoeae

Question 16

Lab Dx of Neisseria gonorrhoeae

Answer 16

(1) Requires enriched media (e.g. selective Supplemented Chocolate Agar) and CO2
(2) Do not chill or refrigerate
(3) Beta-lactamase test needed – certain regions have high penicillin resistance (PPNG)