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Bacterial structure and functions
Bacillus anthracis (Anthrax)
Bacillus cereus (Food poisoning)
Corynebacterium diphtheriae (Diphtheria)
Clostridium botulinum (Botulism)
Clostridium difficile (Pseudomembranous colitis)
Clostridium tetani (Tetanus)
Streptococcus agalactiae (Group B Strep)
Streptococcus pyogenes (Group A Strep)
Bartonella henselae (Cat-scratch disease and Bacillary angiomatosis)
Legionella pneumophila (Legionnaires disease and Pontiac fever)
Salmonella typhi (typhoid fever)
Yersinia pestis (Plague)
Vibrio cholerae (Cholera)
Bordetella pertussis (Pertussis/Whooping cough)
Francisella tularensis (Tularemia)
Haemophilus ducreyi (Chancroid)
Gardnerella vaginalis (Bacterial vaginosis)
Coxiella burnetii (Q fever)
Ehrlichia and Anaplasma
Rickettsia rickettsii (Rocky Mountain spotted fever) and other Rickettsia species
Borrelia burgdorferi (Lyme disease)
Borrelia species (Relapsing fever)
Treponema pallidum (Syphilis)
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clindamycin p. 189
exotoxin production p. 131
food poisoning p. 175
spore-formation p. 129
traumatic open wound p. 183
watery diarrhea p. 176
Clostridium perfringens p. , 131, 136, 176
Clostridium perfringens as cause p. 136
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.
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.
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.
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