Gram - Part 3

Question 1

Has multiple flagella at one pole and is actively motile.

Answer 1

Helicobacter pylori

Question 2

Grows in 3–6 days when incubated at 37°C in a microaero-

philic environment

Answer 2

H pylori

Question 3

Media for primary isolation of H pylori

Answer 3

• Skirrow’s medium with
vancomycin, polymyxin B
• trimethoprim, chocolate medium

Question 4

Translucent colonies

Answer 4

H pylori

Question 5

• oxidase positive
• catalase positive
• motile
• a strong producer of urease.

Answer 5

H pylori

Question 6

Optimal pH H pylori grows.

Answer 6

6.0-7.0 pH

Not grows at the pH within the gastric lumen

Question 7

H pylori is found:

Answer 7

Deep in the mucous layer near epithelial surface where physiologic pH is present

Question 8

Produces protease that modifies the gastric mucus and reduces the ability of acid to diffuse through the mucus

Answer 8

H pylori

Question 9

Organism that yelds in the production of ammonia and buffering of acid

Answer 9

H pylori

Question 10

Acute symptoms of infection of H pylori may last for

Answer 10

1-2 weeks

Question 11

H pylori is also a risk factor for

Answer 11

Gastric carcinoma and lymphoma

Question 12

Determination of serum antibodies in H pylori infection

Answer 12

Blood

Question 13

Gastric biopsy specimens can be used for histologic examination or
minced in saline and used for culture.

Answer 13

H pylori

Question 14

May be collected for H pylori antigen detection

Answer 14

Stool samples

Question 15

Required for diagnosis of H pylori infection

Answer 15

Gastroscopy

Question 16

Demonstrates in routine stains of H pylori infection

Answer 16

Gastritis

Question 17

can show the curved or spiral-shaped organisms

Answer 17

Giemsa or special silver

stains H pylori

Question 18

performed when patients are not responding to treatment,

and there is a need to assess susceptibility patterns.

Answer 18

Culture for H pylori

Question 19

Persist even if the H pylori infection is

eradicated, and the role of this in diagnosing active infection or after therapy is therefore limited.

Answer 19

Serum antibodies

Question 20

Used to detect urease activity are widely used for presumptive identification of H pylori in specimens.

Answer 20

Rapid tests

Question 21

Test that will result if H pylori is present, the urease activity generates labeled CO2 that can be detected in the patient’s exhaled breath.

Answer 21

Urea breath tests

Question 22

Appropriate as a test of

cure for patients with known H pylori infection who have been treated.

Answer 22

Stool specimen

Question 23

Eradicates H pylori infection in 70–95% of patients

Answer 23

Triple therapy with metronidazole and either bismuth subsalicylate or bismuth subcitrate plus either amoxicillin or tetracycline for 14 days

Question 24

enhances ulcer

healing in H pylori infection

Answer 24

Acid-suppressing agent given for 4–6 weeks

Question 25

Directly inhibit H pylori and appear to | be potent urease inhibitors.

Answer 25

Proton pump inhibitors (PPIs)

Question 26

The preferred initial therapy of H pylori infection

Answer 26

7–10 days of a PPI plus amoxicillin and | clarithromycin or a quadruple regimen of a PPI metronidazole, tetracycline, and bismuth for 10 days

Question 27

At 6–8 hours in rich medium, the small coccobacillary forms predominate. • Later, there are longer rods and very pleomorphic forms.

Answer 27

Haemophilus influenza

Question 28

Used for the capsule of Haemophilus influenza

Answer 28

Typing H influenza

Question 29

Culture demonstrate flat, grayish, translucent colonies with diameters of 1–2 mm are present after 24 hours of incubation of Haemophilus influenza

Answer 29

Chocolate agar

Question 30

Does not grow on sheep blood agar except around colonies of staphylococci (“satellite phenomenon”)

Answer 30

H influenzae

Question 31

Identification of organisms of the Haemophilus group depends partly on demonstrating the need for certain growth factors called

Answer 31

X and V

Question 32

Acts physiologically as hemin

Answer 32

Factor X

Question 33

Factor that can be replaced by nicotinamide adenine dinucleotide (NAD) or other coenzymes

Answer 33

Factor V

Question 34

Contains capsular polysaccharides of one of six types (a–f)

Answer 34

Encapsulated H influenza

Question 35

A type of capsular antigen is a polyribitol ribose phosphate (PRP).

Answer 35

Type B

Question 36

Can be typed by slide agglutination, | coagglutination with staphylococci, or agglutination of latex particles coated with type-specific antibodies

Answer 36

Encapsulated H influenzae

Question 37

Normal microbiota of the upper respiratory tract are not encapsulated and are referred to as nontypeable (NTHi).

Answer 37

Most H influenzae

Question 38

The somatic antigens of H influenzae consist of

Answer 38

outer membrane proteins

Question 39

Produces no exotoxin

Answer 39

H influenzae

Question 40

The major virulence factor of H influenzae

Answer 40

Polyribose phosphate capsule of type b

Question 41

Most common etiologic agents of bacterial otitis media and acute sinusitis.

Answer 41

H influenzae, mostly nontypeable, and pneumococci

Question 42

Before the use of the conjugate vaccine, it was the most common cause of bacterial meningitis in children aged 5 months to 5 years in the United States.

Answer 42

H influenzae type B

Question 43

Available for immunologic detection of H | influenzae antigens in spinal fluid

Answer 43

Commercial kits

Question 44

Specimens of H influenzae are grown on

Answer 44

IsoVitaleX-enriched chocolate agar

Question 45

H influenzae is differentiated from related gram-negative bacilli by

Answer 45

its requirements for X and V factors and by its lack of hemolysis on blood agar

Question 46

The Haemophilus species that require this grow around paper strips or disks containing V factor placed on the surface of agar that has been autoclaved before the blood was added

Answer 46

V factor (heat liable)

Question 47

A strip containing this can be placed in parallel with one containing V factor on agar deficient in these nutrients

Answer 47

X factor

Question 48

Susceptible to ampicillin, but up to 25% produce a β-lactamase under control of a transmissible plasmid and are resistant.

Answer 48

Many strains of H influenzae type B

Question 49

All strains of H influenzae is susceptible to

Answer 49

third-generation cephalosporins and carbapenems

Question 50

Treatment for H influenzae that is given intravenously

Answer 50

Cefotaxime