Bacteria: Gram-Negative Cocci

Question 1

What is the gram negative cocci

Answer 1

1. Neisseria meningitidis

2. Neisseria Gonorrhoeae

Question 2

Neisseria meningitidis and gonorrhoeae bacteria are

Answer 2

1. gram-negative
2. diplococci
3. oxidase positive

Question 3

chocolate agar (heated blood agar) is required for growth of

Answer 3

Neisseria meningitidis and gonorrhoeae

Question 4

the antimicrobials vancomycin, polymyxin (colistin), and nystatin (VPN) are included in

Answer 4

Thayer-Martin agar

Question 5

Thayer-Martin agar

Answer 5

encourages the growth of Neisseria meningitidis and gonorrhoeae while inhibiting the growth of other microorganisms

Question 6

Thayer-Martin agar is comprised of

Answer 6

the antimicrobials vancomycin, polymyxin (colistin), and nystatin (VPN), which encourage the growth of Neisseria meningitidis and gonorrhoeae while inhibiting the growth of other microorganisms

Question 7

Deficiency in the terminal complement components C5-C9 (which form the membrane attack complex (MAC)) results in increased susceptibility to

Answer 7

Neisseria meningitidis and gonorrhoeae infection

Question 8

The pili of Neisseria meningitidis and gonorrhoeae bacteria display

Answer 8

antigenic variation (due to frequent genetic rearrangement)

Question 9

The IgA protease of Neisseria meningitidis and gonorrhoeae bacteria

Answer 9

cleaves secretory IgA (found on mucosal surfaces) at the hinge region

Question 10

Neisseria meningitidis is easily

Answer 10

spread in close quarters, such as college dorms

Question 11

Important characteristics of Neisseria meningitidis bacteria include:

Answer 11

1. gram-negative
2. diplococci morphology
3. oxidase-positive
4. growth on chocolate agar
5. growth on Thayer-Martin (VPN) agar
6. higher infection rates in patients with C5-C9 complement deficiency (absence of MAC)
7. production of an IgA protease, and fimbriae/pili that demonstrate antigenic variation
8. encapsulated

Question 12

Neisseria meningitidis bacteria are able to

Answer 12

ferment both glucose and maltose (in contrast to Neisseria gonorrhoeae, which can only ferment glucose)

Question 13

Neisseria meningitidis is transmitted via

Answer 13

respiratory droplets (typically from nasopharyngeal colonization of asymptomatic carriers)

Question 14

Meningococcal vaccines include

Answer 14

antigens contained in the polysaccharide capsule of Neisseria meningitidis (the polysaccharide quadrivalent or conjugate vaccine)

Question 15

Neisseria meningitidis subtype B causes

Answer 15

⅓ of meningococcal disease in the US because vaccines against subtype B have only recently become available

Question 16

Sickle cell patients are more susceptible to infections from

Answer 16

encapsulated bacteria, such as Neisseria meningitidis

Question 17

The outer membrane lipooligosaccharide (LOS) of Neisseria meningitidis causes

Answer 17

sepsis by generating a severe inflammatory response

Question 18

The inflammatory response caused by the Neisseria meningitidis endotoxins (LOS glycolipids)

Answer 18

The inflammatory response caused by the Neisseria meningitidis endotoxins (LOS glycolipids) → increased capillary permeability

Question 19

Hemorrhagic skin lesions (e.g. petechiae, purpura) often present in

Answer 19

fulminant meningococcemia

Question 20

The inflammatory response caused by the Neisseria meningitidis endotoxins (LOS glycolipids)

Answer 20

the inflammatory response caused by the Neisseria meningitidis endotoxins (LOS glycolipids) → increased capillary permeability → hypovolemia → septic shock

Question 21

Waterhouse-Friderichsen syndrome (also known as fulminant meningococcemia) is a

Answer 21

serious complication of meningococcemia characterized by bilateral adrenal hemorrhage → adrenal insufficiency

Question 22

_____ is effective against Neisseria meningitidis

Answer 22

ceftriaxone

Question 23

______ should be administered prophylactically to close contacts of patients with meningococcal infection

Answer 23

rifampin

Question 24

Important characteristics of Neisseria gonorrhoeae bacteria include:

Answer 24

1. gram-negative
2. diplococci morphology
3. oxidase-positive
4. growth on chocolate agar
5. growth on Thayer-Martin (VPN) agar
6. higher infection rates in patients with C5-C9 complement deficiency (absence of MAC)
7. production of an IgA protease, and fimbriae/pili that demonstrate antigenic variation

Question 25

gonorrhea is a ________ transmitted disease

Answer 25

sexually transmitted disease

Question 26

Neisseria gonorrhoeae bacteria are

Answer 26

1. gram-negative diplococci that are facultatively intracellular within polymorphonuclear leukocytes (often neutrophils) 2. non-encapsulated (in contrast to Neisseria meningitidis, which has a polysaccharide capsule)

Question 27

Neisseria gonorrhoeae infections can progress to

Answer 27

pelvic inflammatory disease in women

Question 28

A characteristic white, mucopurulent urethral discharge (in both men and women) or vaginal discharge can present in

Answer 28

Neisseria gonorrhoeae infection

Question 29

Fitz-Hugh Curtis syndrome is

Answer 29

a rare complication of pelvic inflammatory disease (commonly caused by Neisseria gonorrhoeae) characterized by inflammation of the peritoneum and/or diaphragm and the capsule of the liver, leading to the development of adhesions between these structures known as “violin string” adhesions

Question 30

“Violin string” adhesions

Answer 30

can develop between the peritoneum and/or diaphragm and the capsule of the liver in Fitz-Hugh Curtis syndrome (commonly caused by gonococcal PID)

Question 31

Disseminated gonococcal infection can cause

Answer 31

septic arthritis or polyarthralgias (typically asymmetrical and of the knee)

Question 32

Passage of newborns through a birth canal colonized with Neisseria gonorrhoeae can cause

Answer 32

an infection of the conjunctivae (gonococcal ophthalmia neonatorum), which results in blindness if left untreated

Question 33

Treatment for gonorrhea

Answer 33

ceftriaxone (given as a single intramuscular injection) is effective against gonorrhea

Question 34

The standard treatment for suspected gonococcal infection

Answer 34

presumes a Neisseria gonorrhoeae and Chlamydia trachomatis co-infection; azithromycin or doxycycline should be administered in addition to ceftriaxone (effective against Chlamydia trachomatis and Neisseria gonorrhoeae, respectively)