Gram Positive Bacilli, non- encapsulated, non-motile, non-spore forming

Question 1

Majority of the species are found as indigenous microbiota on the skin and mucous membranes
of humans and animals

Answer 1

Corynebacterium

Question 2

corynebacterium species are glucose and maltose fermenters except

Answer 2

C. urealyticum and C.
pseudodiphtheriticum

Question 3

Slightly curved, gram-positive rods with unparallel sides and slightly wider ends that
produce a ―club-like shape

Answer 3

Corynebacterium

Question 4

BAP-colonies have a small zone of Beta hemolysis, although some strains nonhemolytic

Answer 4

Corynebacterium

Question 5

The members of this group are fastidious corynebacteria that require 48 hours of
incubation before any growth can be observed
 The addition of lipids in the culture medium can enhance the bacterial growth

Answer 5

. Lypophilic corynebacteria

Question 6

Examples of lipophilic corynebacteria

Answer 6

Corynebacterium jeikeium and C. urealyticum

Question 7

The members of this group exhibit fermentative or oxidative metabolism

Answer 7

. Non-lipophilic corynebacteria

Question 8

examples of non-lipophilic corynebacteria

Answer 8

: C. diphtheria, C.pseudodiphtheriticum, C. pseudotuberculosis,C.
ulcerans

Question 9

o Corynebacterium species that are associated with human infections and diseases.

Answer 9

: C. diphtheria, C. jeikenum, C. pseudotuberculosis,
C.pseudodiphtheriticum, and C. urealyticum

Question 10

It is also known as the diphtheria bacillus or Kleb-Loffler bacillus

Answer 10

Corynebacterium diphtheria

Question 11

It is a non-lypophilic, facultative anaerobe but grows best under aerobic conditions
 It is not part of the indigenous microbiota of the respiratory tract, and only inhabits the human
nasopharynx in a carrier state

Answer 11

Corynebacterium diphtheria

Question 12

 It is acquired through inhalations of contaminated respiratory droplets or direct contact with
infected cutaneous lesion

Answer 12

Corynebacterium diphtheria

Question 13

it rarely enters the bloodstream

Answer 13

Corynebacterium diphtheria

Question 14

 It is a glucose and maltose fermenter

Answer 14

Corynebacterium diphtheria

Question 15

Its cells have rounded ends and ―club-shaped sweiings‖
o Its highly pleomorphic cells are arranged in pairs and create X, V, Y and L formations
that closely resembles Chinese letters

Answer 15

Corynebacterium diphtheria

Question 16

Corynebacterium diphtheria biochemical test

Answer 16

(-) Urease (+)nitrate reduction

Question 17

Three biotypes of Corynebacterium diphteriae:
very small, flat, dry, and grayish-black colonies; non-hemolytic

Answer 17

Intermedius

Question 18

Three biotypes of Corynebacterium diphteriae:
small, black, and covex colonies that have a ―”fried-egg” appearance; hemolytic

Answer 18

mitis

Question 19

Three biotypes of Corynebacterium diphteriae:
large, flat, and dark gray colonies that have a ―”daisy-head” appearance; nonhemolytic

Answer 19

Gravis

Question 20

o It is a heat-labile polypeptide
o It is produced by strains with a lysogenic beta-phage that carries the TOX gene

Answer 20

Diphtheria Toxin

Question 21

It causes tissue necrosis and exudate formations over the tonsils, larynx and pharynx

Answer 21

Diphtheria Toxin

Question 22

It favors an alkaline pH (7.8-8.0), an aerobic environment, and sufficient amount of iron
in the medium consumed

Answer 22

Diphtheria Toxin

Question 23

the toxin is absorbed systemically but is less severe

Answer 23

. Cutaneous or skin diphtheria (Veldt sore)- C. diptheria

Question 24

It is one of the most frequently isolated and most clinically significant Corynebacteria species

Answer 24

Corynebacterium urealyticum

Question 25

It is a urinary pathogen, a strict aerobe, and lipophilic

Answer 25

Corynebacterium urealyticum

Question 26

It does not ferment glucose and maltose

Answer 26

Corynebacterium urealyticum

Question 27

Arranged in V-shaped forms and palisades

Answer 27

Corynebacterium urealyticum

Question 28

: BAP- Colonies are pinpoint, white, smooth, and are non-hemolytic

Answer 28

Corynebacterium urealyticum

Question 29

Biochemical test: Rapid urease producer

Answer 29

Corynebacterium urealyticum

Question 30

(Hoffman bacillus)

Answer 30

Corynebacterium pseudodiptheriticum

Question 31

It is an indigenous microbiota of the human nasopharynx

Answer 31

Corynebacterium pseudodiptheriticum

Question 32

 It causes respiratory infection, UTI, and cutaneous wound infections in immunocompromised patient, such as those who have AIDS

Answer 32

Corynebacterium pseudodiptheriticum

Question 33

Cells are arranged in parallel rows or palisades and do not exhibit any other characteristic ―pleomorphism‖ that is similar to other corynebacteria

Answer 33

Corynebacterium pseudodiptheriticum (Hoffman bacillus)

Question 34

(+) Urease and nitrate production

Answer 34

Corynebacterium pseudodiptheriticum (Hoffman bacillus)

Question 35

It is a skin microbiota that is found in inguinal, axillary, and rectal sites

Answer 35

Corynebacterium jeikenum

Question 36

It is an obligate aerobe and a multi-antibiotic resistant bacterium

Answer 36

Corynebacterium jeikenum

Question 37

It is isolated from immunocompromised individuals

Answer 37

Corynebacterium jeikenum

Question 38

It is a coomon cause of diphtheroid prosthetic valve endocarditis in adults

Answer 38

Corynebacterium jeikenum

Question 39

Microscopy: Pleopmorphic, club-shaped, and arranged in V-shaped forms

Answer 39

Corynebacterium jeikenum

Question 40

BAP- Colonies appear large when added with 1% Tween 80

Answer 40

Corynebacterium jeikeium

Question 41

(-) Urease and nitrate reduction.

Answer 41

Corynebacterium jeikenum

Question 42

It is acquired through animal contact or ingestion of unpasteurized dairy products  It is also isolated from skin ulcers and exudative pharyngitis

Answer 42

Corynebacterium ulcerans

Question 43

It is associated with diphtheria-like sore throats

Answer 43

Corynebacterium ulcerans

Question 44

CTBA- Colonies have a surrounding brown halo

Answer 44

Corynebacterium ulcerans

Question 45

BAP- Colonies have a narrow zone of Beta hemolysi

Answer 45

Corynebacterium ulcerans

Question 46

Loeffler‘s serum agar- Colonies exhibit growth

Answer 46

Corynebacterium ulcerans

Question 47

(+) Urease and gelatinases, (-) nitrate reduction

Answer 47

Corynebacterium ulcerans

Question 48

It is an animal pathogen that humans can contract through direct contact with infected animals

Answer 48

Corynebacterium pseudotuberculosis

Question 49

It produces a dermonecrotic toxin that causes death of various cell types  It can also produce diphtheria toxin

Answer 49

Corynebacterium pseudotuberculosis

Question 50

CTBA- Colonies exhibit a black color and are surrounded with a brown halo

Answer 50

Corynebacterium pseudotuberculosis

Question 51

BAP-Colonies are small and yellowish-white

Answer 51

Corynebacterium pseudotuberculosis

Question 52

(+) Urease (-) gelatinase

Answer 52

Corynebacterium pseudotuberculosis

Question 53

best specimens for isolation of C. diptheriae

Answer 53

Nasopharyngeal and throat swabs

Question 54

Swab preferred for collection

Answer 54

calcium alginate swab

Question 55

: Bacterial cells exhibit a beaded formation

Answer 55

Methylene blue statining

Question 56

used for staining metachromatic granule

Answer 56

Neisser‘s and Albert‘s stains

Question 57

Neisser‘s staining method is composed mainly of either

Answer 57

r methylene blue or crystal violet

Question 58

the components of Albert‘s stain.

Answer 58

Malachite green and toluidine

Question 59

CTBA and Tinsdale agar should be incubated for at least

Answer 59

48 hours at 35C

Question 60

The multiplication of corynebacteria occurs within the range of

Answer 60

15C to 40C

Question 61

 It is the preferred medium for the isolation and identification of corynebacteria

Answer 61

Cytine tellutite blood agar (CTBA)

Question 62

It is a modification of Tinsdale agar  It is both a selective and differential medium

Answer 62

Cytine tellutite blood agar (CTBA)

Question 63

It contains sheep blood, bovine serum, cysteine, and potassium tellurite

Answer 63

Cytine tellutite blood agar (CTBA)

Question 64

Colonies of corynebacteria exhibit a black or brown color after 48 hrs of incubation

Answer 64

Cytine tellutite blood agar (CTBA)

Question 65

(+) Black or brown colonies surrounded by a brown halo

Answer 65

CTBA: C. diphtheria, C. ulcerans, and C. pseudotuberculosis

Question 66

(+) Result: Colonies exhibit a black colorand are surrounded by abrown halo

Answer 66

Tinsdale agar

Question 67

It is useful for observing the microscopic morphology and metachromatic granules of C. diphteriae

Answer 67

Loeffler‘s serum agar

Question 68

(+) Result: C. diphteriae colonies exhibit a ―"poached-egg" appearance

Answer 68

Loeffler‘s serum agar

Question 69

The metachromatic granules of C. diptheriae are called

Answer 69

―Babes-Ernst bodies

Question 70

This is used to observe the urease production of C. uralyticum

Answer 70

Christensen urea slant

Question 71

it is a skin test used to determine the susceptibility of a person to diphtheria

Answer 71

. Schick test

Question 72

The procedure involves the intradermal introduction of a small amount of diphtheria toxin into the arm of the individual who is suspected to be harboring the disease o (+) Result: Redness and Swelling around the site

Answer 72

Schick test

Question 73

 It produces a dermonecrotic toxin that causes death of various cell types

Answer 73

Corynebacterium pseudotuberculosis