Non-spore-forming Gram-positive Bacilli

Question 1

an acute disease caused by toxigenic (toxin-producing) strains of C. diphtheriae.

Answer 1

Diphtheria

Question 2

The incubation period for diphtheria is [?], with a range of 1 to 10 days.

Answer 2

2 to 5 days

Question 3

The most common sites of diphtheria infection are the pharynx and the tonsils.

Answer 3

Respiratory diphtheria (pharyngeal, tonsillar, laryngeal, nasal)

Question 4

Characterized by gradual onset of pharyngitis; early symptoms include sore throat with low-grade fever and dyspnea.

Answer 4

Respiratory diphtheria (pharyngeal, tonsillar, laryngeal, nasal)

Question 5

Localized manifestations:

[?] forms in the throat (i.e., gray-white patches composed of fibrin, necrotic host cells and bacteria) over the pharynx, tonsils, uvula, and palate.

The membrane is firmly adherent to the tissue, and forcible attempts to remove it cause [?]

Answer 5

Pseudomembrane

bleeding

Question 6

In severe disease, marked edema of the submandibular areas and the anterior neck along with lymphadenopathy giving a characteristic [?] appearance is usually present.

Answer 6

“bull neck”

Question 7

Systemic manifestations:

Major complications include

Answer 7

myocarditis
polyneuritis
nephritis
thrombocytopenia

Question 8

Paralysis of [?] can occur after the fifth week.

Answer 8

eye muscles, limbs, and the diaphragm

Question 9

Secondary pneumonia and respiratory

failure may result from [?].

Answer 9

diaphragmatic paralysis

Question 10

Damage to the heart causes [?], which is the most common cause of mortality in diphtheria.

Answer 10

heart failure

Question 11

Death occurs in [?].

Answer 11

5-10%

Question 12

Cutaneous diphtheria (wound diphtheria)

• Presents as [?] which lack a characteristic appearance; a membrane forms on the infected wound that fails to heal.

Answer 12

infected skin lesions

Question 13

Cutaneous diphtheria (wound diphtheria)

May be associated with [?] strains of C. diphtheriae

Answer 13

non-toxigenic

Question 14

Appears to result less frequently in [?] complications

Answer 14

systemic

Question 15

[?] and [?] are closely related to C. diphtheriae and may carry the diphtheria tox gene.

Both are zoonotic organisms. Whereas the toxigenic C. ulcerans can cause disease similar to clinical diphtheria, C. pseudotuberculosis rarely causes disease in humans.

Answer 15

Corynebacterium ulcerans and Corynebacterium pseudotuberculosis

Question 16

Produced by lysogenized strains of C. diphtheriae infected by [?] that carry the tox gene; all strains produce the same antigenic type of toxin.

Answer 16

β-prophages (corynebacteriophages)

Question 17

Absorption of toxins through the mucous membranes and into the blood circulation causes local tissue destruction damage to the peripheral nervous system, heart, and other organs of the body.

Answer 17

Diphtheria exotoxin (Diphtherotoxin)

Question 18

Diphtheria toxin consists of two polypeptide fragments:

Answer 18

Fragment A

Fragment B

Question 19

interacts metabolically with factors in the cytoplasm and stops protein synthesis by inhibiting polypeptide chain elongation. It is assumed that the abrupt arrest of protein synthesis is responsible for the necrotizing and neurotoxic effects of diphtheria toxin

Answer 19

Fragment A

Question 20

binds to and facilitates the entry of the toxin into the cytoplasm of the cells of the heart and nervous system through receptor-mediated endocytosis.

Answer 20

Fragment B

Question 21

a modified diphtheria toxin that induces protective antitoxin antibodies

Answer 21

diphtheria toxoid

Question 22

is grown in liquid media and the toxin is converted to the inactive toxoid by treatment with formalin

Answer 22

Toxin-producing C. diphtheriae

Question 23

It is usually given as part of a vaccine

against tetanus and pertussis called the

Answer 23

DPT (diphtheria, pertussis, tetanus) vaccine.

Question 24

Three vaccinations are recommended, starting at

Answer 24

• 6-8 weeks of age
• 15 months
• school age

Question 25

(with Hep B, Hib, or IPV --- respectively, Hepatitis B vaccine, Haemophilus influenzae type B vaccine, or inactivated poliovirus vaccine) are increasingly being used.

Answer 25

DPT-containing multi-antigen vaccines

Question 26

Persons with suspected respiratory diphtheria should be promptly given [?], produced in horses, in adequate dosage, without waiting for laboratory confirmation.

Answer 26

diphtheria antitoxin

Question 27

will neutralize circulating toxin and prevent progression of disease, but does not neutralize toxin that is already fixed to tissues,

Answer 27

Diphtheria antitoxin

Question 28

Diphtheria infections are also managed by [?], i.e., patients are treated with antibiotics.

Answer 28

chemotherapy

Question 29

The disease is usually no longer contagious [?] after antibiotics have been given.

Answer 29

48 hours

Question 30

[?] should not be relied alone. This must be done in addition to antitoxin therapy,

Answer 30

Antibiotic therapy

Question 31

Schick test is performed to determine the following: • [?] (due to lack of antitoxins), or [?] (due to presence of circulating antitoxins) of an individual against diphtheria. • [?] to diphtheria toxin or other proteins of the diphtheria cell.

Answer 31

susceptibility immunity hypersensitivity

Question 32

This serves as a basis whether a person may receive vaccination against diphtheria or not. Individuals who are [?] to diphtheria are to be vaccinated, and if they are [?], they should be vaccinated with caution --- the doses of the vaccine shall be reduced with increased number of [?]. It should also be performed first before[?] since antitoxin is normally of horse origin, which may cause hypersensitivity.

Answer 32

susceptible hypersensitive injections antitoxin therapy

Question 33

The procedure involves injection of [?] on the test arm (TA) and [?] (vaccine preparation or heat-inactivated toxin --- whose toxicity is destroyed but retains capacity to elicit allergic reactions) on the control arm (CA)

Answer 33

0. 1 mL of diphtheria toxin | 0. 1 mL of diphtheria toxoid

Question 34

• The injection site (TA and CA) is inspected daily up to the 6th day for [?] which consists of a positive reaction.

Answer 34

erythema, induration or necrosis

Question 35

Results interpretation are as follows: (1) POSITIVE REACTION: TA – CA –

Answer 35

reaction persists until the 6th day no reaction

Question 36

``` Results interpretation are as follows: (2) NEGATIVE REACTION: TA – CA – *Immuned; Not hypersensitive ```

Answer 36

no reaction no reaction

Question 37

``` Results interpretation are as follows: (3) COMBINED REACTION: TA – CA – *Susceptible and hypersensitive ```

Answer 37

reaction persists until the 6th day reaction peaks at about 48 hours and subsides by day 5

Question 38

``` Results interpretation are as follows: PSEUDOREACTION: TA – CA – *Immuned and hypersensitive ```

Answer 38

reaction subsides by day 5 reaction subsides by day 5

Question 39

Disease for Listeria monocytogenes is known as

Answer 39

listeriosis

Question 40

Are [?] intracellular pathogens, within phagocytes and non-phagocytic cells

Answer 40

facultative

Question 41

the organisms can penetrate the epithelial cells of the gastrointestinal (GI) tract and grow within [?]

Answer 41

hepatic and splenic macrophages

Question 42

from there, the organism can spread to the [?] or the [?].

Answer 42

CNS | pregnant uterus

Question 43

it is often a mild or subclinical infection with non specific symptoms of fever, diarrhea, and sore throat

Answer 43

In normal adults

Question 44

listeriosis usually presents as meningitis and septicemia

Answer 44

In children and immunocompromised adults, esp. renal transplant patients and cancer patients, and the elderly

Question 45

most common in the third trimester, listeriosis presents as mild flu-like illness without meningitis Bacteremia occurs concomitantly, during which time the uterine contents are infected Progression to amnionitis may lead to abortion, stillbirth, or delivery of an acutely ill infant

Answer 45

In pregnant women

Question 46

listeriosis may have an early or late onset

Answer 46

In neonates

Question 47

is the result of infection in utero and is a disseminated form of the disease characterized by neonatal sepsis, pustular lesions, and granulomas containing L monocytogenes in multiple organs. Death may occur before or after delivery.

Answer 47

Early-onset syndrome (granulomatosis infantiseptica)

Question 48

causes the development of meningitis between birth and the third week of life; it is often caused by serotype 4b and has a significant mortality rate

Answer 48

The late-onset syndrome

Question 49

which facilitate bacterial binding to the host cells.

Answer 49

Adhesin proteins (Ami, Fbp A, and flagellin)

Question 50

are cell wall surface proteins that interact with E-cadherin, a receptor on epithelial cells, promoting phagocytosis of L. monocytogenes cells into the epithelial cells.

Answer 50

Internalins (A and B)

Question 51

is an enzyme produced by the bacterium at low pH. It lyses the phagolysosome membrane allowing the listeriae to escape into the cytoplasm of the epithelial cell.

Answer 51

Listeriolysin O

Question 52

another listerial surface protein, induces host cell actin polymerization, which propels the listeriae to the cell membrane of the host’s epithelial cells and permits it to move from cell to cell without being exposed to antibodies, complement, or polymorphonuclear cells.

Answer 52

Act A

Question 53

Prevention of L. monocytogenes can be improved by: - avoidance of - adequate pasteurization temperatures and thorough cooking foods that are suspected of being contaminated with [?]

Answer 53

- unpasteurized dairy products | - animal manure or sewage

Question 54

Unlike [?], there is no vaccine available to prevent listeriosis.

Answer 54

diphtheria

Question 55

Cold storage is not an effective control \ measure because the microbe can grow at most

Answer 55

refrigeration temperature

Question 56

is most commonly isolated from acutely ill or immunocompromised patients.

Answer 56

Corynebacterium jeikeium

Question 57

It produces infections, including bacteremia that have a high mortality rate and is resistant to many commonly used antimicrobial drugs.

Answer 57

Corynebacterium jeikeium

Question 58

is a normal inhabitant of the human nasopharynx, can colonize natural and artificial heart valves.

Answer 58

Corynebacterium pseudodiphtheriticum

Question 59

It has been associated with respiratory tract infections.

Answer 59

Corynebacterium pseudodiphtheriticum

Question 60

normally lives in the eye, skin, and mucous membranes and is an occasional opportunist in eye and postoperative infections.

Answer 60

Corynebacterium xerosis

Question 61

is the causative agent of erythrasma, a superficial skin infection characterized by small, brown-red macular areas, commonly of the axillary and inguinal skin, and also between the toes and finger, axilla.

Answer 61

Corynebacterium minutissimum

Question 62

gives a coral (brick red) fluorescence when exposed to Wood’s light (long-wave UV radiation, also called black light) due to porphyrin

Answer 62

Corynebacterium minutissimum

Question 63

has been associated with hospital-acquired respiratory tract and other infections.

Answer 63

Corynebacterium striatum

Question 64

is a slowly growing species that is multiply resistant to antibiotics. It has been associated with acute or chronic encrusted urinary tract infections manifested by alkaline urine pH and crystal formation.

Answer 64

Corynebacterium urealyticum

Question 65

is most commonly isolated species in the clinical laboratory and may represent a skin contaminant or a significant agent of infection

Answer 65

Corynebacterium amycolatum

Question 66

• Gram-positive, nonmotile bacilli that are arranged singly, in short chains, or in long non-branching filaments. It sometimes look gram-negative since it decolorizes easily.

Answer 66

Erysipelothrix rhusiopathiae

Question 67

Forms small, transparent, and glistening colonies that may be alpha-hemolytic or gamma-hemolytic on blood agar medium.

Answer 67

Erysipelothrix rhusiopathiae

Question 68

Catalase(-), oxidase (-)

Answer 68

Erysipelothrix rhusiopathiae

Question 69

Erysipelothrix rhusiopathiae exhibits a [?] growth in gelatin stab culture

Answer 69

“test tube brush-like” or "pipe cleaner"

Question 70

is distributed in land and sea animals worldwide, including a variety of vertebrates and invertebrates. It causes disease in domestic swine, turkeys, ducks, and sheep.

Answer 70

Erysipelothrix rhusiopathiae

Question 71

The most important impact is in swine, in which it causes [?].

Answer 71

erysipelas

Question 72

Humans, acquire E. rhusiopathiae infection by [?] from animals or animal products.

Answer 72

direct inoculation

Question 73

Persons at greatest risk are fishermen, fish handlers, abattoir workers, butchers, and others who have [?] with animal products.

Answer 73

contact

Question 74

most common E. rhusiopathiae infection in humans

Answer 74

erysipeloid

Question 75

a nodular type of cellulitis

Answer 75

erysipeloid

Question 76

erysipeloid usually occurs on the fingers by direct inoculation at the site of a cut or abrasion, and has been called

Answer 76

“seal finger” and “whale finger”

Question 77

Additional clinical forms of infection (both rare) are a [?] form and [?] with or without endocarditis. [?] has also been reported.

Answer 77

diffuse cutaneous bacteremia Septic arthritis

Question 78

Swine erysipelas can be prevented by [?], but the vaccine is not protective for humans.

Answer 78

vaccinating pigs

Question 79

Animal handlers can lower their risk by

Answer 79

wearing protective gloves

Question 80

gram-positive bacilli within square ends; arranged in pairs and in chains. They are anaerobes that can be aerotolerant and α-hemolytic; nonmotile, catalase (-); and majority are vancomycin resistant.

Answer 80

lactobacilli

Question 81

are major members of the normal microbiota of the human vagina, gastrointestinal tract, and oropharynx.

Answer 81

Lactobacillus species

Question 82

Glycogen deposited in vaginal epithelial cells under the influence of [?] is metabolized by lactobacilli to lactic acid.

Answer 82

estrogenic hormones

Question 83

The [?] product of their metabolism helps maintain the low pH (pH 4 to 5) of the normal adult female genital tract which is optimal for growth and survival of the lactobacilli, but inhibits many other organisms.

Answer 83

lactic acid

Question 84

They rarely cause disease, and if present, they may be found occasionally in

Answer 84

deep-seated infections