Micro 6 - Intro To Gram Negative Bacteria

Question 1

Which G(-) cocci is a maltose fermenter?

Answer 1

N.meningitids.

Question 2

Which G(-) cocci is a maltose nonfermenter?

Answer 2

N.gonorrhoeae.

Question 3

What are 4 important Coccoid Rods?

Answer 3

H.influenzae, B.pertussis, Pasteurella, Brucella.

Question 4

Which three G(-) rods are fast lactose fermenters?

Answer 4

Klebsiella, E.coli, Enterobacter.

Question 5

Which two G(-) rods are lactose slow fermenter?

Answer 5

Citrobacter, Serratia, Others.

Question 6

Which three G(-) rods are lactose nonfermenter and oxidase negative?

Answer 6

Shigella, Salmonella, Proteus.

Question 7

Which G(-) rod is a lactose nonfermenter and oxidase positive?

Answer 7

Pseudomonas.

Question 8

Which G(-) bacteria that is oxidase positive has a curved shape grows in 42C?

Answer 8

Campylobacter jejuni (helical or Z shaped).

Question 9

Which G(-) bacteria that is oxidase positive has a curved shape and grows in alkaline media?

Answer 9

Vibrio cholerae (comma-shaped).

Question 10

What are three important G(-) Cocci?

Answer 10

N.meningitidis, N.gonorrhoeae, Moraxella catarrhalis.

Question 11

What are three descriptions of Neisseria species?

Answer 11

G(-) diplococci, ferment glucose, IgA protease.

Question 12

What can Neisseria Gonococci cause?

Answer 12

Urethritis, PID, STI, Septic arthritis, conjunctivitis (newborns thru the birth canal).

Question 13

What are two descriptions of Neiseeria Gonococci?

Answer 13

Maltose non-fermenter, No polysaccharide capsule.

Question 14

What is the first line treatment for Neisseria Gonococci? Second line?

Answer 14

First line is Ceftriaxone. Second line is Azithromycin.

Question 15

What is the mode of transmission of Neisseria meningococci that Neisseria gonococci does not have?

Answer 15

N.meningococci can be transmitted by respiratory secretions. N.gonococci is transmitted sexually or by birth canal.

Question 16

What syndrome can N.meningococci cause?

Answer 16

Waterhouse-Friderichsen syndrome (adrenal hemorrhage).

Question 17

What is the treatment for Neisseria Meningococci?

Answer 17

Ceftriaxone. Penicllin G only if it is confirmed by culture and sensitivity confirmation that it is going to work.

Question 18

What is the prophylaxis treatment for Neisseria Meningococci?

Answer 18

Rifampin, ciprofloxacin, or ceftriaxone. You do not wait for culture results.

Question 19

What type of bacteria is Haemophilus influenzae?

Answer 19

G(-) coccoid rod or coccobacilli.

Question 20

What disease can Haemophilus influenzae cause?

Answer 20

Epiglottitis (in children, it can cause the “sniffing dog” position, because they are trying to open their airway to breath better, “thumbs up” on Xray), meningitis, otitis media, sinusitis, pneumonia.

Question 21

How can we culture Haemophilus Influenzae?

Answer 21

Chocolate agar with factor V and X.

Question 22

What is the treatment for Haemophilus influenzae?

Answer 22

Ceftriaxone.

Question 23

What is the prophylaxis treatment for Haemophilus influenzae?

Answer 23

Rifampin.

Question 24

What does Haemophilus ducreyi cause?

Answer 24

Causes a chancroid, a genital ulcer that is painful and solitary.

Question 25

What type of bacteria is Legionella pneumophila?

Answer 25

G(-) rod but stains very poorly so a silver stain is needed.

Question 26

What is needed to culture Legionella pneumophila?

Answer 26

You need a charcoal and yeast extract with iron and cystine. [French Legionare with a silver helmet, with a charcoal fire, has an iron dagger and he is no sissy].

Question 27

What is the treatment for Legionella pneumophila?

Answer 27

Erythromycin or other macrolides.

Question 28

What disease does Legionella pneumophila cause?

Answer 28

Legionnaires' disease, a severe pneumonia with fever. Or it can cause Pontiac fever, a flu-like disease.

Question 29

What is the infection route of Legionella pneumophila?

Answer 29

It is transmitted in aerosol transmission from a body of water (airconditioner infected in an old barracks). There is no person-to-person transmission.

Question 30

How can we diagnose Legionella pneumophila?

Answer 30

Presence of antigen in the urine.

Question 31

What are four descriptions of Pseudomonas aeruginosa?

Answer 31

G(-) rod, oxidase positive and lactose non-fermenter. Causes a blue-green pigment.

Question 32

What type of environment does pseudomonas aeruginosa love?

Answer 32

Moist environments (Hot tub folliculitis). Contaminates medical equipment and catheters and burn victims.

Question 33

What diseases does Pseudomonas aeruginosa cause?

Answer 33

Pneumonia (cystic fibrosis), otitis externa, UTIs, Osteomyelitis (diabetics), sepsis.

Question 34

What toxin does Pseudomonas aeruginosa produce and what is it's mechanism?

Answer 34

Exotoxin-A and it inactivates EF-2 causing cell necrosis.

Question 35

What is the treatment for Pseudomonas aeruginosa?

Answer 35

It depends on the site of infection. Since it is a dangerous bacteria it needs to antibiotics: piperacillin and ticarcillin; cefepime and ceftazidime; imipenem, meropenem, fluoroquinolones.

Question 36

What is the cause of more than 90% of duodenal ulcers?

Answer 36

Helicobacter pylori.

Question 37

What are three descriptions of Helicobater pylori?

Answer 37

G(-) rod, Urease positive, has a helical or Z shape.

Question 38

How can we diagnose Helicobater pylori?

Answer 38

Urea breath test, stool antigens and serology studies.

Question 39

What is the treatment for Helicobacter pylori?

Answer 39

Triple therapy: PPI, clarithromycin, and amoxicillin or metronidazole (If someone is penicillin allergic). Quadruple therapy: Bismuth, metronidazole, PPI, Tetracycline.

Question 40

A culture reveals a G(-), oxidase (+), diplococci. What bacteria might you suspect?

Answer 40

Neisseria gonorrhoeae or Neisseria meningitidis.

Question 41

A 22yo medical student has burning feeling in his abdomen after a meals and EGD is performed and biopsy reveals spiral shaped G(-) bacteria. What is the diagnosis?

Answer 41

Helicobacter pylori.

Question 42

A 50yo smoker presents with a new cough and flu like symptoms. Gram stain of the sputum reveals shows no organisms but silver stain shows rods. What is the disease and bacteria that is causing this?

Answer 42

Pontiac fever by Legionella pneumophila.

Question 43

What G(-) causes sepsis, DIC, and adrenal hemorrhage?

Answer 43

It is Waterhouse-Friderichsen syndrome caused by N.meningitids.

Question 44

What G(-) causes a 5yo w/ pharyngitis, drooling, and X-ray reveals thumb sign?

Answer 44

Epiglotittis caused by Haemophilus Influenza type B.

Question 45

What G(-) would cause a burn wound infection?

Answer 45

Pseudomonas.

Question 46

What G(-) causes life-threatning meningitis + purpura?

Answer 46

Neisseria meningitidis.

Question 47

What G(-) would cause septic arthritis in young, sexually active patients?

Answer 47

Neisseria gonorrhoeae.