Clostridium perfringens

91,041views

00:00 / 00:00

High Yield Notes

9 pages

Flashcards

Clostridium perfringens

of complete

Questions

USMLE® Step 1 style questions USMLE

of complete

A 30-year-old man is brought to the emergency department with pain and discoloration of the right thigh. A week ago the patient was involved in a motor vehicle accident and suffered deep lacerations over the same region. The patient was evaluated at an urgent care facility afterward and a piece of scrap metal was removed from the right thigh. Currently, temperature is 38.9°C (102.0°F), pulse is 108/min, respirations are 14/min, blood pressure is 70/44 mmHg and SpO2 is 93% of room air. The appearance of the right thigh is shown below. On palpation of the right thigh, there is tenderness and crepitus. Which of the following toxins is most likely responsible for this patient’s presentation?
 
 Reproduced from ">Wikimedia Commons  

External References

First Aid

2024

2023

2022

2021

Clostridium perfringens p. , 136

clindamycin p. 189

exotoxin production p. 131

food poisoning p. 175

spore-formation p. 129

traumatic open wound p. 183

watery diarrhea p. 176

Gas gangrene

Clostridium perfringens p. , 131, 136, 176

Hemolysis

Clostridium perfringens as cause p. 136

External Links

Transcript

Watch video only

Clostridium perfringens is from the family of Clostridia, and as a family, they’re obligate anaerobes, meaning they don’t require oxygen to thrive, in fact, they’re better off without it.

Anaerobes, clostridia included, tend to lack the enzymes catalase or superoxide dismutase, so oxygen is actually toxic to them.

In nature, they thrive in deep, compact soil, and when they feel the stress of fresh oxygenated air, they often produce spores, which are extremely resilient to the environment, and can even survive cooking.

When conditions improve, for example, when food is slowly cooled or stored, the spores can sprout into full-fledged Clostridia.

In fact, at an optimum temperature, Clostridium perfringens has one of the fastest growing rates of any bacterium! In the lab, when doing a gram stain, Clostridium perfringens is Gram-positive, or purple when Gram stained, and look like big cylinders or rods, also called bacilli.

Clostridium perfringens is a common cause of food poisoning, in fact, it’s sometimes called “the cafeteria germ”.

That’s because it typically infects food that’s prepared in large quantities, and then kept warm for prolonged periods, such as in cafeterias or buffets.

Clostridium perfringens are found in the environment and they can accidentally contaminate food when it’s been left out for a while.

If a person eats food contaminated with C. perfringens, the bacteria will soon colonize the gut.

Within 24 hours, the bacteria starts to make clostridium perfringens enterotoxin, or CPE.

The CPE specifically targets the tight junctions that connect epithelial cells lining the intestines to one another.

When the tight junctions get destroyed, it causes inflammation and compromises the structural integrity of the intestinal wall.

Fortunately, CPE is heat labile, so prolonged cooking at 72°C or above will inactivate it.

And that’s one reason why freshly cooked food is best to eat - the other reason is that it’s simply tastier that way!

But uncooked food - like salads, or reheated food - like leftovers, can be a good home to Clostridium perfringens.

The symptoms of Clostridium perfringens enteritis include abdominal cramping, watery diarrhea, and vomiting.

Fortunately, most of these improve over the course of a day, as the bacteria makes its way through the intestines.

In terms of treatment, antibiotics aren’t needed, and instead the goal is to keep the individual well hydrated.

Summary

Clostridium perfringens is a spore-forming, gram-positive obligate anaerobe bacterium that can cause food poisoning. The most common symptoms of Clostridium perfringens food poisoning are abdominal cramps and diarrhea, and vomiting. Clostridium perfringens also causes myonecrosis or gas gangrene once it gets into a wound. It can be deadly unless urgent surgical debridement and antibiotic therapy are initiated rapidly.

Elsevier

Copyright © 2024 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.

RELX