MICROBIOLOGY-NON BRANCHING, CATALASE POSITIVE, GRAM-POSITIVE BACILLI (BACILLUS AND SIMILAR ORGANISMS)

Question 1

o Aerobic
o Facultative or strictly anaerobic
o Gram-positive
o Spore-forming rods

Answer 1

Bacillus

Question 2

What are the characteristics of Bacillus anthracis?

Answer 2

• Aerobic
• Gram-positive box
  car-like rods
• Nonmotile
• Spore-forming
  (endospores)
• Nonhemolytic ”comet
  tail or Medusa head”
  or ground glass
  colonies on 5% sheep
  blood agar
• Rarely found

Question 3

HABITAT ni Bacillus anthracis

Answer 3

In soil, contracted by various herbivores

Question 4

MODE OF TRANSMISSION ni Bacillus anthracis

Answer 4

• Direct contact: animal tissue or
  products such as wool or hair
• Traumatic or insect bites: organisms
  or spores
• Injection: contaminated drugs
• Ingestion: contaminated meat
• Inhalation: spores; during exposure
  to animal products (wool sorter’s
  disease)
• Person-to-person transmission (rare)

Question 5

Virulence Factor ni Bacillus Anthracis

Answer 5

Lethal toxin and Edema Toxin

Question 6

It is primarily responsible for death.

Answer 6

lethal toxin (LT)

Question 7

It facilitates the transport of other proteins into the cell.

Answer 7

protective antigen (PA)

Question 8

It is responsible for edema.

Answer 8

edema toxin (ET)

Question 9

Name the functional enzymes involved in virulence factors.

Answer 9

Lethal factor (LF) and Edema factor (EF).

Question 10

What type of anthrax accounts for most human infections?

Answer 10

Cutaneous anthrax.

Question 11

How is cutaneous anthrax contracted?

Answer 11

Through contact with infected animal products and inoculation of endospores through a break in the skin.

Question 12

What are the symptoms of cutaneous anthrax?

Answer 12

Papule ring of vesicles leading to ulceration (eschar).

Question 13

How is cutaneous anthrax treated?

Answer 13

it is effectively treated with antibiotics.

Question 14

How is gastrointestinal anthrax contracted?

Answer 14

By ingestion of endospores.

Question 15

What are the two forms of gastrointestinal anthrax?

Answer 15

Oral or oropharyngeal (buccal cavity or tongue, tonsils, or pharyngeal mucosa) and gastrointestinal (mucosa of the terminal ileum).

Question 16

What was inhalation anthrax previously referred to as?

Answer 16

Pulmonary anthrax.

Question 17

How is inhalation anthrax contracted?

Answer 17

By inhalation of endospores.

Question 18

What are the initial symptoms of inhalation anthrax?

Answer 18

Flu-like symptoms: fever, chills, fatigue, nonproductive cough, nausea, and vomiting.

Question 19

What are the advanced symptoms of inhalation anthrax?

Answer 19

Respiratory distress, edema, cyanosis, shock, and death.

Question 20

What are the common name for inhalation anthrax?

Answer 20

Woolsorters’ disease and ragpickers’ disease.

Question 21

What are the chest X-ray findings in inhalation anthrax?

Answer 21

Pleural effusion, infiltrates, and mediastinal widening.

Question 22

How is injectional anthrax contracted?

Answer 22

Through contaminated drugs of abuse (heroin).

Question 23

What are the symptoms of injectional anthrax?

Answer 23

Severe soft tissue infection and dissemination leading to septic shock.

Question 23

How should specimens be collected for laboratory diagnosis of anthrax?

Answer 23

Specimens should be collected in leak-proof containers and placed in a secondary container.

Question 24

Where should samples be taken from for cutaneous anthrax diagnosis?

Answer 24

Samples should be taken from underneath the eschar.

Question 24

What type of testing is used for cutaneous anthrax?

Answer 24

Histochemical testing with a punch biopsy in 10% formalin.

Question 25

What specimens are collected for inhalation anthrax diagnosis?

Answer 25

Blood cultures, pleural fluid, and serum for serology.

Question 26

What tissues are biopsied for inhalation anthrax?

Answer 26

Bronchial tissue or pleural tissue.

Question 27

What specimens are collected for gastrointestinal anthrax diagnosis?

Answer 27

Blood cultures, ascites fluid, material from any lesions, and serum for serology.

Question 28

What are the direct detection methods for anthrax?

Answer 28

Detection of large, gram-positive rods in singles, pairs, or serpentine chains.

Question 29

What is the width of vegetative cells of B. anthracis?

Answer 29

The vegetative cell width is usually greater than 1µm, and the endospores do not cause swelling of the cell.

Question 30

It is used for the selection and isolation of B. anthracis from contaminated species.

Answer 30

Polymyxin-lysozyme-EDTA-thallous acetate (PLET)

Question 30

What media are used for the cultivation of B. anthracis?

Answer 30

5% sheep blood agar, chocolate agar, routine blood culture media, and nutrient broths.

Question 31

Medium-large, gray, flat irregular with swirling projections (Medusa head or comet tail) or ground glass appearance, nonhemolytic.

Answer 31

B. anthracis

Question 32

it induces B. anthracis capsule formation, resulting in large and mucoid colonies.

Answer 32

bicarbonate agar

Question 33

purpose of heat shock treatment in the cultivation of B. anthracis?

Answer 33

-is used for the growth and enhancement of endospores from clinical specimens -typically at 62-65°C for 15-20 minutes.

Question 34

What serodiagnostic methods are used to detect antibodies to B. anthracis?

Answer 34

Indirect hemagglutination and ELISA.

Question 34

What antigens or proteins are typically detected in serodiagnosis of B. anthracis?

Answer 34

PA antigen, toxin protein, LF, and EF.

Question 35

What is the treatment for severe anthrax?

Answer 35

IV ciprofloxacin (7-10 days) plus one aminoglycoside or two additional drugs.

Question 36

What genetic analysis methods are used for B. anthracis?

Answer 36

Multilocus sequence typing (MLST) and multiple-locus variable-number tandem-repeat analysis.

Question 37

What is the treatment for cutaneous or uncomplicated anthrax?

Answer 37

Oral ciprofloxacin or doxycycline for 7-10 days.

Question 38

What are the prevention methods for anthrax?

Answer 38

-Cell-free inactivated vaccine -chemoprophylaxis with ciprofloxacin or doxycycline after aerosol exposure to B. anthracis.

Question 39

IDENTIFY is crystal-forming and cold-tolerant.

Answer 39

Bacillus thuringiensis

Question 40

is known for being heat-tolerant?

Answer 40

Bacillus weihenstephanensis

Question 41

is known for being a probiotic.

Answer 41

Bacillus cytotoxicus

Question 42

Name three other species in the Bacillus cereus group

Answer 42

Bacillus toyonensis,Bacillus mycoides and B. pseudomycoides

Question 43

HABITAT sa Bacillus cereus group

Answer 43

* Soil * Widely distributed in nature * Vegetative cells and spores ubiquitous in nature; may transiently colonize skin or GIT or respiratory tracts

Question 44

MODE OF TRANSMISSION sa (Bacillus cereus group)

Answer 44

* Trauma * Associated with immunocompromised patients * Predominantly ingestion of food (rice) contaminated with B. cereus-type species or toxins formed by this organism

Question 45

IDENTIFY THE TOXINS Diarrheal symptoms.

Answer 45

Hemolysin BL (HBL)

Question 46

How do Hemolysin BL (HBL) and Nonhemolytic enterotoxin (Nhe) act?

Answer 46

They act synergistically.

Question 47

Which toxin is responsible for the major symptoms in diarrheal presentation?

Answer 47

Nonhemolytic enterotoxin (Nhe).

Question 48

What is another name for Cytotoxin K?

Answer 48

Hemolysin IV.

Question 49

Which toxin is a heat-stable, proteolysis, and acid-resistant toxin.

Answer 49

Cereulide

Question 50

What form does Cereulide cause?

Answer 50

Emetic form.

Question 51

What systemic conditions can Bacillus species cause

Answer 51

Bacteremia, endocarditis, and septicemia.

Question 52

What are some health-care associated infections caused by Bacillus species?

Answer 52

Contaminated gowns, gloves, linens, dressings, and medical devices (ventilators, catheters, and bronchoscopy equipment).

Question 53

What toxin does B. thuringiensis harbor?

Answer 53

Cereulide toxin.

Question 54

What are the two types of symptoms of food poisoning caused by Bacillus species?

Answer 54

Diarrhea and abdominal pain within 8-16 hours, and nausea and vomiting (emetic food poisoning) within 1-5 hours.

Question 55

What is the commercial use of B. thuringiensis toxins?

Answer 55

They are used for the control of insects that cause agricultural damage (moths, beetles, flies, and parasitic worms).

Question 56

Large gram-positive rods in singles, pairs, or serpentine chains, and endospores that may appear as gram variable.

Answer 56

Bacillus cereus group

Question 57

What media are used for the cultivation of Bacillus species?

Answer 57

-5% sheep blood agar, -chocolate agar, -routine blood culture media, -nutrient broths, - specific Bacillus cereus media like MEYP, PEMBA, and BCM.

Question 58

What is the purpose of heat shock treatment in Bacillus species?

Answer 58

To kill vegetative cells and retain spores, effective at 70°C for 30 minutes or 80°C for 10 minutes.

Question 59

What serodiagnostic methods are used for detecting B. cereus toxin in food and feces?

Answer 59

Oxoid BCET-RPLA and TECRA VIA.