Deck 39: Neisseria and Moraxella Catarrhalis

Question 1

Using charcoal-treated nontoxic swabs and immediate inoculation to appropriate medium and a carbon dioxide-enriched atmosphere describe specimen collection and handling requirements for which organism?

A)Moraxella catarrhalis
B)Neisseria meningitidis
C)Neisseria gonorrhoeae
D)All of the above are correct.

Answer 1

C
Neisseria gonorrhoeae is very sensitive to drying. Calcium alginate, rayon- or charcoal-treated cotton swabs are acceptable for N. gonorrhoeae if the specimen will be plated within 6 hours. The best method for culture and transport of N. gonorrhoeae is to inoculate the agar immediately after specimen collection and then place the medium in an atmosphere of increased carbon dioxide (CO₂) for transport.

Question 2

Presumptive identification of an oxidase-positive, gram-negative diplococcus on Thayer-Martin medium from genital sites of a 6-year-old female as Neisseria gonorrhoeae

A)provides the physician with quick and reliable results at minimal cost.
B)should be confirmed with a repeat culture.
C)may sometimes be incorrect and should not be reported.
D)should only be done when venereal disease is suspected.

Answer 2

C
An isolate from a child or a case of sexual abuse must be identified unequivocally, because of the medicolegal ramifications of these results. It is recommended that these organisms be identified using at least two different types of tests, that is, biochemical, immunologic, enzymatic, or the nonamplified DNA probe.

Question 3

Choose the genus that is best described as oxidase-positive, gram-negative cocci that are normal flora of the respiratory and other mucosal surfaces, and that often form diplococci.

A)Haemophilus
B)Stomatococcus
C)Staphylococcus
D)Neisseria

Answer 3

D
Species of the genus Neisseria discussed in Chapter 42 are all oxidase-positive, gram-negative diplococci. Except for Neisseria gonorrhoeae, the organisms are normal inhabitants of the upper respiratory tract of humans.

Question 4

M.catarrhalis may be differentiated from the gonococci and meningococci based on

A)its growth on blood agar at 35° C.
B)its growth on nutrient agar at 22° C.
C)the reduction of nitrite to nitrate.
D)its production of DNase.
E)All of the above

Question 5

Not only normal flora of humans and animals, this genus of bacteria contains agents of important diseases such as gonorrhea, meningitis, and septicemia.

A)Staphylococcus
B)Streptococcus
C)Neisseria
D)Micrococcus

Question 6

The bacterial species that can be described as oxidase-positive, glucose-positive, maltose-positive, sucrose-negative, lactose-negative, and a major cause of bacterial meningitis is

A)Neisseria meningitidis.
B)Streptococcus pneumoniae.
C)Streptococcus pyogenes.
D)Streptococcus agalactiae.
E)Viridans streptococcus.

Question 7

Glucose, maltose, sucrose, and lactose are tests most likely performed on a/an

A)oxidase-positive, gram-negative coccus.
B)alpha-hemolytic streptococcus.
C)oxidase-negative, gram-negative coccus.
D)nonhemolytic streptococcus.

Question 8

Moraxella catarrhalis may be described as

A)oxidase-positive.
B)a glucose utilizer.
C)a major cause of venereal disease.
D)often carrying an antiphagocytic capsule.
E)All of the above are true.

Question 9

Differentiation of the similar Moraxella catarrhalis and Neisseria can be best accomplished by

A)examination of Gram stain of colony.
B)vancomycin susceptibility testing.
C)the oxidase test.
D)glucose utilization testing.

Question 10

Generally speaking, Neisseria require what ingredient found in some conventional culture media?

A)Vitamin B6
B)Nalidixic acid and its components
C)Vitamin B12
D)Blood or blood products

Question 11

Neisseria meningitidis can be described as

A)oxidase-positive.
B)a maltose utilizer.
C)a major cause of bacterial meningitis.
D)often carrying an antiphagocytic capsule.
E)All of the above are true.

Question 12

Collection and handling of specimens for the detection of Neisseria gonorrhoeae should optimally include

A)charcoal-treated nontoxic swabs.
B)immediate inoculation to appropriate medium.
C)carbon dioxide-enriched atmosphere.
D)All of the above are correct.

Question 13

Organisms belonging to the genus Neisseria are

A)gram-positive diplococci.
B)gram-negative diplococci.
C)gram-negative coccobacilli.
D)gram-negative bacilli.

Question 14

Moraxella catarrhalis can be described as a

A)gram-positive diplococcus.
B)gram-negative diplococcus.
C)gram-negative coccobacillus.
D)gram-negative bacillus.

Question 15

Thayer-Martin, Martin-Lewis, and New York City media were all developed for the selective isolation of which organism?

A)Moraxella catarrhalis
B)Neisseria meningitidis
C)Neisseria gonorrhoeae
D)All of the above are correct.

Question 16

The gram-negative coccus that can be described as oxidase-positive, glucose-negative, maltose-negative, sucrose-negative, lactose-negative, and DNAse-positive is

A)Neisseria meningitidis.
B)Moraxella catarrhalis.
C)Neisseria cinerea.
D)Neisseria gonorrhoeae.

Question 17

Presumptive identification of a gram-negative diplococcus on chocolate agar from eye or ear cultures that is oxidase-positive and that hydrolyzes tributyrin can be made as

A)Neisseria meningitidis.
B)Neisseria cinerea.
C)Moraxella catarrhalis.
D)Neisseria gonorrhoeae.

Question 18

The bacterial species that can be described as oxidase-positive, glucose-positive, maltose-negative, sucrose-negative, lactose-negative, and a major cause of venereal disease is

A)Neisseria meningitidis.
B)Neisseria gonorrhoeae.
C)Streptococcus pyogenes.
D)Streptococcus agalactiae.
E)Viridans streptococcus.

Question 19

Neisseria gonorrhoeae can be described as

A)oxidase positive.
B)a glucose utilizer.
C)a major cause of venereal disease.
D)a producer of penicillin-inactivating beta-lactamase enzyme.
E)All of the above are true.

Question 20

Gonococci require for growth which of the following nutrients?

A)Arginine
B)Hypoxanthine
C)Uracil
D)IsoVitaleX

Question 21

An advantage of all molecular assays is

A)the ability to test for Chlamydia trachomatis from the same specimen at the same time.
B)the ability to use them for assessing successfulness of treatment.
C)their role as evidence in medicolegal cases.
D)All of the above are true.

Question 22

Determination of carbohydrate utilization patterns for differentiation of Neisseria spp.and M.catarrhalis is best done by

A)48- to 72-hour incubation of inoculated cystine trypticase soy agar (CTA) with 1% dextrose, maltose, lactose, and sucrose.
B)oxidative-fermentative (OF) medium with dextrose, maltose, lactose, and sucrose.
C)heavy inoculation of buffered, low-peptone substrate with dextrose, maltose, lactose, and sucrose.
D)carbohydrate testing strips.

Question 23

Which statement is true regarding the pathogenesis of N.gonorrhoeae?

A)Infections caused by N.gonorrhoeae usually are localized to the area of initial exposure.
B)Localized infections can be acute with a pronounced purulent response.
C)Localized infections may be asymptomatic.
D)Dissemination from the initial infection site can lead to severe disseminated disease.
E)All of the above are true.

Question 24

Blood cultures collected for the recovery of N.gonorrhoeae or N.meningitidis require

A)no special methods.
B)more than 0.025% sodium polyanetholsulfonate (SPS).
C)transfer from Vacutainer tubes to culture broth within 1 hour of collection.
D)less than 0.025% SPS.

Question 25

Which statement is true regarding the pathogenesis of N.cinerea?

A)N.cinerea is a leading cause of fatal bacterial meningitis.
B)Virulence factors include pili, capsule formation, and endotoxin.
C)Disseminated intravascular coagulation (DIC) and thrombocytopenia are complications of infection.
D)N.cinerea is commonly encountered as a contaminant in clinical specimens.
E)All of the above are true.

Question 26

Which statement is true regarding the pathogenesis of N.meningitidis?

A)N.meningitidis is a leading cause of fatal bacterial meningitis.
B)Virulence factors include pili, capsule formation, and endotoxin.
C)Disseminated intravascular coagulation (DIC) and thrombocytopenia are complications of infection.
D)Petechiae (rash) may be associated with meningitis and bacteremia.
E)All of the above are true.

Question 27

M.catarrhalis may be differentiated from the gonococci and meningococci based on

A)its growth on blood agar at 22° C.
B)its growth on nutrient agar at 35° C.
C)the reduction of nitrate to nitrite.
D)its production of DNAse.
E)All of the above.

Question 28

Which type of test has the advantage of being able to test for Chlamydia trachomatis and Neisseria gonorrhoeae from the same specimen at the same time?

A)Culture
B)Molecular assays
C)Enzyme-linked immunosorbent assay (ELISA)
D)All of the above are true.

Question 29

True or False? Amplified molecular assays should be used to assess the successfulness of treatment of infections caused by Neisseria gonorrhoeae.

A)True
B)False