Bacteria: Gram-Negative Cocci Flashcards

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1
Q

What is the gram negative cocci

A
  1. Neisseria meningitidis

2. Neisseria Gonorrhoeae

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2
Q

Neisseria meningitidis and gonorrhoeae bacteria are

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

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

A

Neisseria meningitidis and gonorrhoeae

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4
Q

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

A

Thayer-Martin agar

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5
Q

Thayer-Martin agar

A

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

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6
Q

Thayer-Martin agar is comprised of

A

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

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7
Q

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

A

Neisseria meningitidis and gonorrhoeae infection

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8
Q

The pili of Neisseria meningitidis and gonorrhoeae bacteria display

A

antigenic variation (due to frequent genetic rearrangement)

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9
Q

The IgA protease of Neisseria meningitidis and gonorrhoeae bacteria

A

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

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10
Q

Neisseria meningitidis is easily

A

spread in close quarters, such as college dorms

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11
Q

Important characteristics of Neisseria meningitidis bacteria include:

A
  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
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12
Q

Neisseria meningitidis bacteria are able to

A

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

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13
Q

Neisseria meningitidis is transmitted via

A

respiratory droplets (typically from nasopharyngeal colonization of asymptomatic carriers)

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14
Q

Meningococcal vaccines include

A

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

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15
Q

Neisseria meningitidis subtype B causes

A

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

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16
Q

Sickle cell patients are more susceptible to infections from

A

encapsulated bacteria, such as Neisseria meningitidis

17
Q

The outer membrane lipooligosaccharide (LOS) of Neisseria meningitidis causes

A

sepsis by generating a severe inflammatory response

18
Q

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

A

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

19
Q

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

A

fulminant meningococcemia

20
Q

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

A

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

21
Q

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

A

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

22
Q

_____ is effective against Neisseria meningitidis

A

ceftriaxone

23
Q

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

A

rifampin

24
Q

Important characteristics of Neisseria gonorrhoeae bacteria include:

A
  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
25
Q

gonorrhea is a ________ transmitted disease

A

sexually transmitted disease

26
Q

Neisseria gonorrhoeae bacteria are

A
  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)
27
Q

Neisseria gonorrhoeae infections can progress to

A

pelvic inflammatory disease in women

28
Q

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

A

Neisseria gonorrhoeae infection

29
Q

Fitz-Hugh Curtis syndrome is

A

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

30
Q

“Violin string” adhesions

A

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

31
Q

Disseminated gonococcal infection can cause

A

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

32
Q

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

A

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

33
Q

Treatment for gonorrhea

A

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

34
Q

The standard treatment for suspected gonococcal infection

A

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)