Clostridium Perfringens

Life-threatening intravascular hemolysis, due to a toxin with lecithinase activity, occurs with Clostridium perfringens sepsis.

Ans. is ‘b’ i.e., Lecithinase 

.  Lecithinase (phospholipase) in the presence of Ca’ and Mg” ions, splits lecithin into phosphorylcholine and diacylglycerol. This reaction is seen as an opalescence in serum or egg yolk media.

Ans. is ‘d’ i.e., It is a gram negative rod that does not ferment lactose

Clostridium perfringens is gram positive bacteria that ferments lactose.

Infections caused by cl.perfringens

.    Clostridium perfringens produces the following human infections :

i)         Gas gangrene

– Type A is the predominant organism

ii)       Food poisoning

.            Mainly by Type A strain.

.            The food sources primarily involved are meat, meat products and poultry.

.            Incubation period is 8 -24 hrs.

.            Nausea, diarrhea and epigastric pain are the usual symptoms. Fever and vomiting are uncommon.

iii) Necrotizing enteritis (enteritis necroticans or pigbel)

.    Caused by (3 toxin produced by type ‘c ‘strain ofC perfringens following high protein meal in conjuction with trypsin inhibitors (e.g. is sweet potatoes).

iv) Gangrenous appendicitis

.            Caused by Type A (and occasinally Type D)

v)       Neutropenic enterocolitis (Typhlitis)

vi)     Biliary tract infection

.            Acute emphysematous cholecystitis and post cholecystectomy septicemia.

vii) Endogenous gas gangrene of intra abdominal origin

.            As a complication of abdominal surgery.

viii)  Brain abscess and meningitis

ix)     Panophthalmitis

x)       Thoracic infections : empyema

xi)     Urogenital infections

.            following nephrectomy

.    associated with septic abortion

xii) Bacteremia and clostridial sepsis Also Remember

.   C. perfringens is the most common of the Clostridial species isolated from tissue infections and bacteremia.

.   An association has been made between malignancy of GI. tract (colon) and the isolation of C. septicum.

Ans. is ‘d’ i.e., Clostridium Perfringens

Ans. is ‘a’ i.e. Staphylococcus 

Ans. is ‘c’ i.e., Clostridium perfringens 

Coliform organism – Most commonly used bacteriological indicator

Faecal streptococci – Recent faecal pollution of water

Spores of Cl. perfringens -Remote faecal contamination of water.

Ans. C i.e. Clostridium perfringenes

Clostridium perfringens

• Gram-positive, spore-forming, non-motile, strictly anaerobic rods that reduce sulphite to H2S, but also ferment lactose, sucrose and inositol with the production of gas, produce a stormy clot fermentation with milk, reduce nitrate, hydrolyse gelatin and produce lecithinase and acid phosphatase.
• Bonde (1963) suggested that not all SRC (sulphite reducing clostridia) in receiving waters are indicators of faecal pollution, hence C. perfringens is the appropriate indicator.

Ans. is ‘a’ i.e., Cl perfringens

Ans. is ‘c’ i.e., Clostridium perfringens

Two important characteristic feature of Cl. perfringens are:‑

1. Target hemolysis (double zone hemolysis) on blood agar. It is a narrow zone of complete hemolysis by theta toxin which is surrounded by wider incomplete hemolysis by alpha-toxin.
2. Naegler’s reaction detects alpha-toxin (phospholipase or lecithinase C). When CL. perfringens is grown on a medium with the antitoxin spread on one half of the plate, colonies on the other half without the antitoxin will be surrounded by a zone of opacity. There will be no opacity around the colonies on the half of the plate with the antitoxin, due to the specific neutralisation of the alpha-toxin.

Ans. is ‘c’ i.e., Between middle and pole of cells

• Clostridium perfringens (C. perfringens) is a spore-forming gram-positive bacterium that is found in many environmental sources as well as in the intestines of humans and animals. C. perfringens is commonly found on raw meat and poultry

Spores of clostridium may be:‑

1. Terminal: Located at poles.

2. Central: Located in the middle of the cells.

3. Subterminal: Between the middle of the cell and pole of the cells.