Campylobacter jejuni

Definitions & Key takeaways

Campylobacter jejuni is a comma-shaped gram-negative, oxidase-positive bacteria commonly found in poultry and other animals. It can cause a foodborne illness called campylobacteriosis, which is characterized by diarrhea, abdominal pain, and fever. In severe cases, the infection can spread to the bloodstream and cause life-threatening complications like sepsis. Campylobacter jejuni is most commonly spread through the feco-oral route, usually by ingesting contaminated food or water. Treatment for campylobacteriosis includes antibiotics and supportive care. Prevention of this infection includes proper hand hygiene and safe food preparation practices.

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With Campylobacter jejuni, “campylo” means curved, “bacter” means rod, while “jejuni” refers to the jejunum, which is a segment of the small intestines found between the duodenum and the ileum.
So, Campylobacter jejuni is a comma-shaped bacteria, and it’s one of the most common causes of bacterial gastroenteritis worldwide.
It's commonly found in foods like poultry, and unpasteurized milk.Now, let’s talk microbe anatomy and physiology. Campylobacter jejuni is a comma-shaped bacteria that has a thin peptidoglycan cell wall, which doesn’t take in the purple dye when Gram stained, and instead appears pink or red – which makes it a gram-negative bacteria.
It also has a flagellum at one end which it uses to get around, so it’s a motile bacteria. In addition to this, it’s oxidase-positive, meaning that it can use oxygen to create stored energy or ATP.
Lastly, Campylobacter jejuni is a microaerophile that loves warmth, so it grows best in low-oxygen environments, at 42 degrees Celsius, on blood agar varieties like Skirrow, Butzler, and Campy-BAP.Alright, Campylobacter jejuni is usually transmitted from animals to humans, via the fecal-oral route.
In other words, you catch it by ingesting stool particles containing the bacteria. Campylobacter jejuni usually resides in the gastrointestinal tract of birds.
So, when people eat raw and undercooked poultry, there's a possibility of infection. Similarly, cows are common carriers, so people that drink unpasteurized milk can also risk infection.
There’s also direct contact with infected pets, notably puppies which excrete the bacteria in their stool. Kids are the most susceptible to getting infected after playing with an infected pet.
Lastly, infected stool can end up in sources of freshwater, like rivers, and cause infection. Once inside our body, Campylobacter jejuni has a number of virulence factors that it can use to attach to host cells and cause disease.
First, it has fimbriae-like filaments and cell surface proteins like PEB1 and CadF that help it attach to the mucosa of the small intestine and colon.There, Campylobacter jejuni uses its spiral shape and long flagella to ‘drill' into the mucosa where they release toxins called cytolethal distending toxins.
These toxins damage nearby intestinal epithelium cells, further worsening the inflammation.When the inflammation and damage becomes pretty extensive the colon might dilate, resulting in toxic megacolon.
The bacteria can also keep ‘drilling’ until they reach the bloodstream, causing bacteremia.The immune system may react to the presence of bacteria in the blood by making antiganglioside antibodies which attack the peripheral nerves, causing Guillain–Barré syndrome, a type of paralysis.In the same vein, the infection can also cause an autoimmune inflammatory reaction where immune cells attack the joints in condition called reactive arthritis.Symptoms usually show up after a 1 to 7 days incubation period.
Typically, people have symptoms like fever, muscle pain, malaise and headache, which are followed by crampy abdominal pain, diarrhea that is watery and ill-smelling at first, and then turns bloody.
Bloody diarrhea is more commonly seen in children. Additional symptoms may appear with complications.
With toxic megacolon, there’s bloating, tachycardia, and possible loss of bowel sounds on physical examination. With Guillain–Barré syndrome, there's ascending paralysis, meaning it starts at the feet and then extends to the upper body.Campylobacter jejuni infection is actually one of the most common bacterial causes of Guillain–Barré syndrome.
Lastly, with reactive arthritis, there’s pain in large joints.Campylobacter jejuni infection is diagnosed based on clinical manifestations, plus direct examination of a stool sample which shows gram negative comma-shaped bacteria, and also white and red blood cells in the stool, or by isolating the bacteria on cultures.Now, since the infection usually resolves on its own, treatment usually relies on hydration and correcting any electrolyte imbalances that may occur as a result of diarrhea and vomiting.With severe infection, antibiotics like erythromycin can be used.Finally, a means of preventing transmission in humans is hand washing, thoroughly cooking meat, especially poultry.
Keeping raw meat, specifically poultry, separate from other foods, and lastly, don't drink raw or unpasteurized milk.##SummaryAlright, as a quick recap, Campylobacter jejuni is a comma-shaped, gram-negative, oxidase-positive bacteria found mostly in poultry, and unpasteurized milk.
It grows best on Skirrow, Butzler, and Campy-BAP blood agars, at 42 degrees, in low oxygen environments.And it’s responsible for causing gastroenteritis and symptoms include bloody diarrhea, fever, crampy abdominal pain, and vomiting.
Some worthy complications to mention are toxic megacolon,