BACILLUS

Bacillus anthracis

A 53-year-old Sheep farmer presents with a 2-week history of a 4.5 cm circular skin lesion of black eschar surrounded by vesicles and edema.Culture and gram stain shows gram positive bacilliin chains.

What is the organism most likely causing the disease?

C. Bacillus cereus

The health department is notified of a small outbreak of patients who sought medical help afteran episode of abdominal cramps, nausea, and vomiting in 6 members of a party of 20 who ateat a restaurant 4 hours before. The food was served family style with the 'usual fixings',including sauteed chicken, eggrolls, fried noodles and fried rice. What is the most likely causative agent?

A. Clostridium perfringens
B. Clostridium botulinum
C. Bacillus cereus
D. Bacillus anthracis
E. Staphylococcus aureus
F. I don't know

C. Inhibition of acetylcholine release

A 42-year-old woman is brought to the ED with rapid onset of ptosis (droopy eyelids), double vision, slurred speech, and difficulty swallowing or speaking, as well as difficulty breathing and onset paralysis on both sides of the body, starting at the neck. On questioning about her last food items, she reports drinking home-made carrot-juice about 24 hours ago. Which of the following best describes the mechanism of action ofthe offending Toxin?

A. Inhibition of GABA release
B. Destruction of membranes by lecithinase
C. Inhibition of acetylcholinerelease
D. Polyclonal activation of T cells by superantigen
E. Blockage of proteintranslation via EF2
F. I don't know

1. Staph aureus

2. C. perfringens

3. C. difficile

4. B. cereus

Main cause of GI symptoms

T

Bacillus are Aerobic spore formers (t/f)

Anthrax

Bacillus anthracis causes

1. Bacillus spp.

2. Clostridium spp.

   BC

Spore forming

1. Erysipelothrix spp.

2. Listeria spp.

3. Corynebacterium spp.

   ELC

Non-spore forming

1. Rhodococcus spp.

2. Actinomyces spp.

3. Nocardia spp.

RAN

Branching

Bacillus is SPORE FORMING

Bacillus is non-spore forming (t/f)

T

Bacillus are rod-shaped organisms; can be isolated from soil (t/f)

F

Bacillus are aerobic / Facultative anaerobes (t/f)

Bacillus are aerobic / Facultative aerobes (t/f)

T

Bacillus produces spores aerobically & anaerobically (t/f)

PERITRICHOUS FLAGELLA

Bacillus are motile with -

Bacillus anthracis & Bacillus mycoides

Bacillus are motile with PERITRICHOUS FLAGELLA except for

Catalase +

Ferments Glucose

Biochemical test for Bacillus:

Catalase :

Ferments :

-5°C

Bacillus can survive in temp as low as

75°C (heat stable)

Bacillus can survive in temp as high as

Bacillus cereus

what is the most clinically significant Bacillus group

1. B. anthracis

2. B. cytotoxicus - heat-tolerant, a probiotic

3. B. weihenstephanensis - cold-tolerant

4. B. thuringiensis - crystal-forming

5. B. mycoides

6. B. pseudomycoides

7. B. toyonensis & morphologic variants,

Bacillus cereus group is the most clinically significant species:

Halophilic 7% NaCl

Bacillus anthracis is Halophilic (-)

Agent of Bioterrorism

Bacillus anthracis is famously known as

Fried rice Bacillus

Bacillus cereus is famously known as

Hay Bacillus

Bacillus subtilis is famously known as

• Flat sour spoilage

• Biological indicator of autoclave

Bacillus stearothermophilus is famously known as

Insect pathogen

Bacillus thuringiensis is famously known as

Glucose, maltose, sucrose B

GSM

Bacillus anthracis produces acid from

T

Bacillus anthracis is non-motile (t/f)

oval centrally located spores

Bacillus anthracis’ spores are

Malachite green

Bacillus anthracis’ oval centrally located spores is visualized using

• Boxcar / DIsjointed Bamboo morphology

• Fishing rod / Serpentine appearance

Morphology and Colonial Characteristics

Bacillus anthracis on Gram stain

opaque zone around the colonies

Morphology and Colonial Characteristics

Bacillus anthracis on Lecithinase test/ Egg Yolk Agar + result

Comet tail /Medusa head / Ground glass colonies

Morphology and Colonial Characteristics

Bacillus anthracis on 5% SBA (non-hemolytic) colonies

string of pearls

Morphology and Colonial Characteristics

Bacillus anthracis on Mueller-Hinton agar and a 10 U penicillin disk

Virulence Factor

Bacillus anthracis has a D-glutamase capsule which is not a polysaccharide unlike other

Virulence Factor

Bacillus anthracis has a D-glutamase capsule which is a polysaccharide unlike other (t/f)

M’ Fadyean Capsular Stain / McFadyean stain

Virulence Factor

Bacillus anthracis has a D-glutamase capsule which is not a polysaccharide unlike other which is visualized using

1. Protective Antigen (PA)

2. Edema Factor (EF)

3. Lethal Factor (LF)

   LEP

Virulence Factor

Bacillus anthracis has exotoxin with 3 components

PROTECTIVE ANTIGEN + LETHAL FACTOR= DEATH (Necrosis)

PLDn

Virulence Factor

Bacillus anthracis

PROTECTIVE ANTIGEN + LETHAL FACTOR=

PROTECTIVE ANTIGEN + EDEMA FACTOR= EDEMA (swell)

PEEs

Virulence Factor

Bacillus anthracis

PROTECTIVE ANTIGEN + EDEMA FACTOR=

1. Cutaneous Anthrax

2. Pulmonary / Inhalation (Woolsorter’s / Ragpickers’ Dx) Anthrax

3. Gastrointestinal Anthrax

4. Injectional Anthrax

Diseases Associated in Bacillus anthracis

Cutaneous Anthrax

Diseases Associated with Bacillus anthracis

MOST COMMON, LEAST SEVERE

Cutaneous Anthrax

Diseases Associated with Bacillus anthracis

May develop BLACK ESCHAR at the site of entry

Cutaneous Anthrax

Diseases Associated with Bacillus anthracis

The organisms enter through skin penetration (cut, open wound, etc.)

Black eschar

Diseases Associated with Bacillus anthracis

black necrotic central area or malignant pustule and it is PAINLESS and does not produce pus

Pulmonary / Inhalation (Woolsorter’s / Ragpickers’ Dx) Anthrax

Diseases Associated with Bacillus anthracis

acquired through inhalation of spores during shearing or sorting of animal hair

Gastrointestinal Anthrax

Diseases Associated with Bacillus anthracis

MOST SEVERE FORM; LEAST COMMON

Gastrointestinal Anthrax

Diseases Associated with Bacillus anthracis

Ora/ oropharyngeal or gastrointestinal

Gastrointestinal Anthrax

Diseases Associated with Bacillus anthracis

Ingestion of improperly cooked, infected meats and ingestion of spores

Gastrointestinal Anthrax

Diseases Associated with Bacillus anthracis

o Bloody diarrhea and hematemesis

Injectional Anthrax

Diseases Associated with Bacillus anthracis

injection of contaminated drugs of abuse, frequently heroin

Injectional Anthrax

Diseases Associated with Bacillus anthracis

characteristic lesion or eschar is absent

Bacillus cereus

Motile on BAP and beta-hemolytic

Bacillus cereus

- blood bag contaminant at RT

F

Bacillus cereus produce acid from glucose, maltose, salicin

Bacillus cereus produce acid from glucose, maltose, sucrose (t/f)

Lecithinase +

Bacillus cereus is Lecithinase + or – ?

1. hemolysin BL (HBL),

2. nonhemolytic enterotoxin (Nhe),

3. cytotoxin K (CytK) / Hemolysin IV

Virulence Factor

Bacillus cereus’ Toxin production are

Bacillus cereus

Commonly associated with food poisoning in rice, cereal, vegetables, and milk

1. Emetic Form (Rice)

2. Diarrheal Form ( Meat & Vegetables)

Diseases Associated with Bacillus cereus

Forms of Infection:

Emetic Form (Rice)

Diseases Associated with Bacillus cereus

caused by the production of HEAT-STABLE EMETIC TOXIN (Cerrulide Toxin)

Cerrulide Toxin

Diseases Associated with Bacillus cereus

Emetic Form (Rice) is caused by the production of HEAT-STABLE EMETIC TOXIN (-)

1-6 HOURS

6 hrs

Diseases Associated with Bacillus cereus

Emetic form (Rice) : SHORT INCUBATION (-); vomiting occurs within - hours after ingestion of contaminated food

Diarrheal Form (Meat & Vegetables)

Diseases Associated with Bacillus cereus

caused by the production of a HEAT-LABILE ENTEROTOXIN

8-16 HOURS

Diseases Associated with Bacillus cereus

Diarrheal Form (Meat & Vegetables) is LONG INCUBATION PERIOD (-)

Diarrheal Form (Meat & Vegetables)

Diseases Associated with Bacillus cereus

toxin is produced when foods are left at RT

1. Septicemia

2. pneumonia

3. meningitis

4. peritonitis

5. Eye infections associated with trauma

Diseases Associated with Bacillus cereus

Diarrheal Form (Meat and Vegetables) is commonly associated with what diseases

F

B. anthracis & B. mycoides is the non-motile,

B. anthracis is the only motile, Beta hemolytic on BAP (t/f)

T

Bacillus subtilis is motile & beta-hemolytic on BAP (t/f)

F

Bacillus subtilis is known to be an opportunistic pathogen

Bacillus subtilis is known to be an non-opportunistic pathogen (t/f)

T

Bacillus subtilis is Halophilic (7% NaCl) (t/f)

T

Bacillus subtilis is G+ rod in chains (t/f)

central spore

Bacillus subtilis spores

Bacillus subtilis

Common laboratory contaminant

Bacillus subtilis

Quality control for sterilization

Bacillus subtilis

CAUSES EYE INFECTION IN HEROIN ADDICT

Penicillin RESISTANT

Bacillus subtilis Penicillin R or S

Guthrie Test

Bacillus subtilis is used in what test which is a microbiological test for

phenylketonuria

phenylketonuria

Guthrie Test is a microbiological test for

Mannitol Egg Yolk Polymyxin B Agar

Bacillus subtilis selective media for isolation is

FLAT SOUR SPOILAGE

Bacillus stearothermophilus is famously known as

AUTOCLAVE (no gas but with acid)

Bacillus stearothermophilus is a biological indicator of

Bacillus stearothermophilus

- FLAT SOUR SPOILAGE in canned goods

Bacillus stearothermophilus

-biological indicator of AUTOCLAVE; no gas but with acid

Bacillus thuringiensis

- pesticides and insecticides, wound, burn, and pulmonary disease

- an insect pathogen