LAB EXAM 1

Question 1

What are the reagents used for acid-fast staining?

Answer 1

-Kinyoun carbol-fuchsin
-acid alcohol
-Methylene blue counterstain

Question 2

Why are mycobacteria difficult to stain?

Answer 2

-lipophilic
-cell-wall-bound mycolic acids

Question 3

What is the reverse CAMP test used to differentiate?

Answer 3

Clostridium perfringens from other Clostridium sp.

Question 4

Reverse CAMP test:

Colostridium perfringens is streaked at right angles to _______________

Answer 4

Streptococcus agalactiae (group B)

Question 5

what is the E-test used to determine?

Answer 5

the MIC

Question 6

What is needed to perform the E-test?

Answer 6

-Muller Hinton Agar
-bacterial suspension
-0.5 McFarland standard
-E-test strip

Question 7

Two spore-forming anaerobes?

Answer 7

-Clostridium perfringes and botulism and Teni
-bacillus

Question 8

a genus of Gram-negative, obligate anaerobic bacteria, non-endospore-forming bacilli

Answer 8

Bacteroides

Question 9

What is the morphology of Clostridium tetani?

Answer 9

drumstick or tennis racket GPR

Question 10

Gram stain shows “box car” shaped spores

Answer 10

Clostridium perfringens

Question 11

Clostridium ___________ shows a double zone of hemolysis

Answer 11

perfringens

Question 12

Morphology of fusobacterium?

Answer 12

gram stain will look slender, spindle shape GNR with tapered ends

To make one end gradually smaller then the other

Question 13

examples of three types of mircosporum?

Answer 13

-Mircosporum canis
-Mircosporum gyseum
-Mircosporum nanum

Question 14

Macroconidium vs Microcondiida?

Answer 14

Microconidia: Small, unicellular conidia that are round, elliptical, or pyriform (pear-shaped).
Macroconidia: Large, multi-septate conidia that are club- or spindle-shaped

Question 15

Answer 15

Fusarium

Question 16

Answer 16

Bipolaris

Question 17

Answer 17

Mucor

Question 18

Answer 18

Histoplasma capsulatam

Question 19

Answer 19

Blastomyces dermatitidis

Question 20

Answer 20

Blastomyces dermatitidis

(look for broad base)

Question 21

What aspergillus species appears green macroscopically?

What appears blue

Answer 21

Aspergillus fumigatus

-Aspergillus flavus (more of a bluish appearance?)

Question 22

Answer 22

Alternaria

Question 23

Answer 23

Trichophyton (mentagrophytes) and rubrum

Question 24

Answer 24

Microsporum canis

Question 25

Answer 25

Microsporum gyseum

Question 26

Answer 26

Microsporum nanum

Question 27

Answer 27

B. dermatitidis

Question 28

Answer 28

Coccidioides immitis

Question 29

Answer 29

Coccidioides spherule (spherule containing endospores)

Question 30

Answer 30

Paracoccidioides brasiliensis (wheel like structure)

Question 31

Direct detection?

Answer 31

-Calcofluor white -KOH -Histology stains

Question 32

An asexual conidium that forms by a blowing out or budding process

Answer 32

Blastoconidia

Question 33

What are structures seen in yeast? What is most common in Candida albicans

Answer 33

-Blastoconidia -Chlamydospores and pseudohyphae are most common in Candida albicans

Question 34

Buds elongate, fail to dissociate, and form subsequent buds – they have cell wall constrictions rather than true septa

Answer 34

Pseudohyphae

Question 35

Answer 35

candida

Question 36

What does MBC stand for?

Answer 36

Minimum bactericidal concentration- lowest concentration of antibacterial agent required to kill a bacteria.

Question 37

What does MIC stand for?

Answer 37

Minimum inhibitory concentration- lowest concentration of an antibiotic at which bacterial growth is completly inhibited

Question 38

Answer 38

-

Question 39

Anaerobic growth chamber indicators: The pink tablet will turn what color if anaerobic?

Answer 39

remain pink

Question 40

Anaerobic growth chamber indicators: Blue strip will change to _______ if anaerobic conditions are maintained.

Answer 40

white

Question 41

a physical property that gives a bacterium the ability to resist decolorization by acids during staining procedures. This means that once the bacterium is stained, it cannot be decolorized using acids routinely used in the process.

Answer 41

Acid fastness

Question 42

How is Mucor, Rhizopus, and Absidia differentiated?

Answer 42

-Mucor: without root -Rhizopus: with root -Absidia: roots are not directly under sporangiophore (alternating in between)

Question 43

four dermatophytes...

Answer 43

canis, gypseum, nanum, and Trichophyton mentagrophytes

Question 44

no root...

Answer 44

mucor

Question 45

root directly underneath sporangiophore

Answer 45

rhizopus

Question 46

roots are not directly under sporangiophore (alternating in between)

Answer 46

Absidia

Question 47

What are two examples of acid fast bacteria?

Answer 47

-Mycobacterium tuberculosis -Nocardia (weak)

Question 48

Acid fast positive

Answer 48

Pink or red

Question 49

Acid fast negative

Answer 49

Blue or green