7/29/2019 Gram Positive Spore Forming Bacilli

1/52

Gram-positive spore-

forming bacilliBacillusand Clostridiumspecies

7/29/2019 Gram Positive Spore Forming Bacilli

2/52

gram-positive spore-forming

bacilli

Bacillus

Clostridium

7/29/2019 Gram Positive Spore Forming Bacilli

3/52

BacillusSpecies

Aerobic

gram-positive rods occurring in

chains saprophytic organisms

7/29/2019 Gram Positive Spore Forming Bacilli

4/52

Morphology &

Identification

Typical Organisms

7/29/2019 Gram Positive Spore Forming Bacilli

5/52

Culture

7/29/2019 Gram Positive Spore Forming Bacilli

6/52

Bacillus anthracis

Pathogenesis

Anthrax

-in humans:a. entry of spores through injured skin

b. mucous membranes

c. inhalation of spores into the lung

7/29/2019 Gram Positive Spore Forming Bacilli

7/52

Anthrax toxin

a. protective antigen (PA)

b. edema factor (EF)c. lethal factor (LF).

7/29/2019 Gram Positive Spore Forming Bacilli

8/52

Types of Anthrax

inhalation anthrax ("woolsorter'sdisease")

-spores from the dust of wool, hair, orhides are inhaled

- hemorrhagic mediastinitis and

sepsis

7/29/2019 Gram Positive Spore Forming Bacilli

9/52

Cutaneousanthrax"malignant

pustule (alsocalled black

escher)

- on exposed

surfaces of the

arms or hands

- pruritic papule

7/29/2019 Gram Positive Spore Forming Bacilli

10/52

gastrointestinal anthrax

- Ingestion of contaminated raw meat

-extremely uncommon- Abdominal pain, vomiting, and

bloody diarrhea

7/29/2019 Gram Positive Spore Forming Bacilli

11/52

Diagnostic Laboratory

Tests

Specimens:fluid or pus

Blood agar plates:

7/29/2019 Gram Positive Spore Forming Bacilli

12/52

7/29/2019 Gram Positive Spore Forming Bacilli

13/52

Media:

PEA (Phenylethyl alcohol agar)

Special Media: PLET (polymyxin-lysozyme-EDTA-

thallous acetate)

Bicarbonate agar

7/29/2019 Gram Positive Spore Forming Bacilli

14/52

Other test

Ascoli test

Salicin Fermentation test

7/29/2019 Gram Positive Spore Forming Bacilli

15/52

Characteristics B. anthracis B.cereus

Hemolysis onBAP

= +

Catalase + +

Motility = +

String of pearls + =

Growth on PEA = +

Gelatin hydrolysis = +

Susceptibility toPenicillin (10U/ml)

Susceptible Resistant

7/29/2019 Gram Positive Spore Forming Bacilli

16/52

7/29/2019 Gram Positive Spore Forming Bacilli

17/52

Treatment

Ciprofloxacin

penicillin G, along with gentamicin or

streptomycin

7/29/2019 Gram Positive Spore Forming Bacilli

18/52

Epidemiology,

Prevention, & ControlControl measures:

(1) disposal of animal carcasses by burning or by

deep burial in lime pits,

(2) decontamination (usually by autoclaving) ofanimal products,

(3) protective clothing and gloves for handling

potentially infected materials

(4) active immunization of domestic animals withlive attenuated vaccines

7/29/2019 Gram Positive Spore Forming Bacilli

19/52

Bacillus cereus

fried rice bacilli

Caused food poisoning

two distinct forms:a. emetic type

b. diarrheal type

7/29/2019 Gram Positive Spore Forming Bacilli

20/52

Egg yolk agar

7/29/2019 Gram Positive Spore Forming Bacilli

21/52

Pathogenesis

eye infections,

-severe keratitis,

- endophthalmitis- panophthalmitis

7/29/2019 Gram Positive Spore Forming Bacilli

22/52

ClostridiumSpecies

Large, anaerobic

gram-positive

motile rods Soil or intestinal tract

7/29/2019 Gram Positive Spore Forming Bacilli

23/52

Morphology &

Identification

Typical Organisms

7/29/2019 Gram Positive Spore Forming Bacilli

24/52

Culture

7/29/2019 Gram Positive Spore Forming Bacilli

25/52

Clostridium botulinum

Canned bacillus

causes botulism

found in soil and occasionally inanimal feces.

7/29/2019 Gram Positive Spore Forming Bacilli

26/52

Toxin

Botulinum toxin

toxin (AG) are known

7/29/2019 Gram Positive Spore Forming Bacilli

27/52

Pathogenesis

Intoxication from ingestion of food

with toxin

Clinical Findings visual disturbances, inability to

swallow, and speech difficulty

bulbar paralysis respiratory paralysis or cardiac

arrest

7/29/2019 Gram Positive Spore Forming Bacilli

28/52

infant botulism

infants ingest food contaminated

with Clostridium botulinumspores

7/29/2019 Gram Positive Spore Forming Bacilli

29/52

Treatment

trivalent (A, B, E) antitoxin

7/29/2019 Gram Positive Spore Forming Bacilli

30/52

Clostridium tetani

causes tetanus

soil and in the feces of horses and

other animals

7/29/2019 Gram Positive Spore Forming Bacilli

31/52

Toxin

tetanospasmin

-causes a sustained contraction of

skeletal muscles called tetany

7/29/2019 Gram Positive Spore Forming Bacilli

32/52

7/29/2019 Gram Positive Spore Forming Bacilli

33/52

Pathogenesis

toxin are aided by:

(1)necrotic tissue

(2)calcium salts(3) associated pyogenic infections

7/29/2019 Gram Positive Spore Forming Bacilli

34/52

Prevention & Treatment

(1)active immunization with toxoids

(2)proper care of wounds

contaminated with soil(3) prophylactic use of antitoxin

(4) administration of penicillin.

CONTROL:immunization with tetanus toxoid

7/29/2019 Gram Positive Spore Forming Bacilli

35/52

Clostridium perfringens

myonecrosis and gas gangrene

food poisoning.

7/29/2019 Gram Positive Spore Forming Bacilli

36/52

Toxins

alpha toxin ofC perfringenstype A

theta toxin

DNase and hyaluronidase enterotoxin

7/29/2019 Gram Positive Spore Forming Bacilli

37/52

Pathogenesis

PORTAL of entry:

intestinal tract

Traumatized tissue

7/29/2019 Gram Positive Spore Forming Bacilli

38/52

gas gangrene

7/29/2019 Gram Positive Spore Forming Bacilli

39/52

Treatment

early surgery

antibiotic administration

Hyperbaric oxygen Antitoxins

7/29/2019 Gram Positive Spore Forming Bacilli

40/52

Diagnostic Laboratory

Tests for clostridium

Specimens: wounds, pus, and

tissue

Culture:chopped meat-glucose medium

thioglycolate medium

blood agar plates

7/29/2019 Gram Positive Spore Forming Bacilli

41/52

Double zone of

hemolysis

7/29/2019 Gram Positive Spore Forming Bacilli

42/52

Reverse CAMP test

7/29/2019 Gram Positive Spore Forming Bacilli

43/52

7/29/2019 Gram Positive Spore Forming Bacilli

44/52

Cycloserine Cefoxitin

Fructose Agar (CCFA)

7/29/2019 Gram Positive Spore Forming Bacilli

45/52

Thioglycollate Broth

7/29/2019 Gram Positive Spore Forming Bacilli

46/52

PRAS medium

7/29/2019 Gram Positive Spore Forming Bacilli

47/52

7/29/2019 Gram Positive Spore Forming Bacilli

48/52

7/29/2019 Gram Positive Spore Forming Bacilli

49/52

Litmus Milk Reactions

7/29/2019 Gram Positive Spore Forming Bacilli

50/52

Clostridium difficile

Cause Pseudomembranous Colitis

Toxins:Toxin A

Toxin B

7/29/2019 Gram Positive Spore Forming Bacilli

51/52

gas-liquid

chromatography (GLC)

Detects isocaproic acid

Toxin producing C. difficile

7/29/2019 Gram Positive Spore Forming Bacilli

52/52