Campylobacter jejuni

Tiny germs live in chicken.

These germs can make you sick. They often live in animal waste. They can get into your food. This happens if meat is not cooked well.

You might get a bad tummy ache. You might also have a fever. Most people feel better in a week. It is smart to wash your hands. This helps you stay healthy.

Campylobacter jejuni is a type of germ called a bacterium. Its name means "curved rod" because of its shape.

These germs are very common. They often live in poultry, like chicken. They can also be found in animal waste.

People usually get sick from eating undercooked meat. You can also get sick by touching raw chicken. This is a zoonotic disease. That means it spreads from animals to people. In the US, many people get sick from it every year.

When these germs enter your body, they cause enteritis. This is a word for inflammation, or swelling, in the small intestine.

It can cause a bad stomach ache, fever, and diarrhea. Most people feel better in about one week.

Sometimes, the illness can lead to other problems. One is called Guillain–Barré syndrome. This affects the body for a few weeks after the sickness. Another is reactive arthritis, which is swelling in the joints. Most people recover well with rest or medicine.

Campylobacter jejuni is a type of bacterium that causes food poisoning. Its name comes from Greek words meaning "curved rod."

This microbe is a very common cause of stomach sickness in people. It is often found in poultry, like chickens, and in animal waste. Most people get sick through a zoonotic path. This means the germ moves from animals to humans. Many people in the US and Europe get sick from it every year. In the US, the CDC thinks 1.5 million people get infected annually.

This bacterium has a very specific way it works to stay alive. It is a microaerophile, which means it needs a little bit of oxygen to grow. It has a single tail called a flagellum to help it move. Instead of eating sugar, it uses amino acids for energy. It likes to use serine, aspartate, asparagine, and glutamate to grow. These are tiny building blocks found in many living things. If these run out, it can use other things like acetate or lactate. It is very good at changing its way of living to survive.

Scientists have studied this germ for a long time. It was originally named Vibrio jejuni because it looked similar to other microbes. In 1963, researchers proposed the new name Campylobacter. The first major record of this infection happened in 1938. During that time, 355 people in Illinois got sick from milk. Later, in the 1970s, scientists found it in human intestines. By 1996, the CDC and other groups found it caused over 40% of bacterial stomach sickness in labs.

When the bacteria enter the body, they cause a hard job for the gut. They use special proteins to break through the walls of the small intestine. This leads to enteritis, which is a swelling of the intestine.

This causes pain, fever, and diarrhea. Most people feel better after about seven days. However, some people might face more serious problems. One is Guillain–Barré syndrome, which happens to 0.3 per 1000 infected people. Another is reactive arthritis, which affects the joints.

Understanding this germ helps us stay healthy every day. We can prevent it by handling raw chicken very carefully. It is important to cook meat well so the heat kills the bacteria. You should also wash your hands after touching animals or raw poultry. This helps stop the germs from moving from the food to your mouth. Knowing how these tiny microbes live helps us make safer food for everyone. By being careful, we can avoid the sickness they cause.

Campylobacter jejuni is a highly significant species of pathogenic bacteria. It is a major cause of bacterial gastroenteritis, which is inflammation of the stomach and intestines, across the entire world. The name comes from the Greek words "kampylos," meaning curved, and "baktron," meaning rod.

This microbe is particularly important to public health because of how often it infects humans. It is commonly associated with poultry and is frequently found in animal feces. Because it is a zoonotic disease, it spreads from animals to people more often than between humans.

To understand how this bacterium survives, we must look at its unique biology. C. jejuni is a Gram-negative, helical-shaped bacterium. It is also microaerophilic, meaning it requires small amounts of oxygen to grow. It possesses a single flagellum, or whip-like tail, at one or both poles to help it move. If it is exposed to too much atmospheric oxygen, the bacterium can change into a coccal form. This flexibility helps it navigate different environments. It grows best at temperatures between 37 and 42 degrees Celsius.

The metabolism of C. jejuni is quite specialized. Unlike many other microbes, it cannot use sugars as a carbon source. This is because it lacks the necessary enzymes, specifically glucokinase and 6-phosphofructokinase, to use the EMP pathway. Instead, it relies on amino acids for growth. Its preferred amino acids are serine, aspartate, asparagine, and glutamate. Serine is the most vital for its growth. It enters the cell through SdaC transport proteins and is broken down into pyruvate by the SdaA dehydratase. This pyruvate then enters the TCA cycle to help the bacterium create energy and carbohydrates.

If these preferred amino acids are unavailable, C. jejuni is highly adaptable. It can use proline, acetate, or lactate to survive. It can even take advantage of products from other microbes in the gut, such as hydrogen or formate. To manage energy, it uses terminal oxidases to accept electrons. While it primarily uses oxygen, it can also use nitrate, nitrite, or sulfur oxides to survive in oxygen-limited conditions. To protect itself from the dangerous reactive oxygen species created by oxygen, it carries specific enzymes like catalase and superoxide dismutase.

When C. jejuni enters a human host, it begins a complex process of pathogenesis. It must first penetrate the enterocytes, which are the cells lining the gut. The bacterium uses proteases, specifically one called HtrA, to disrupt the junctions between cells. It also uses a protein called fibronectin as a binding site to help it move through the cell layer. Once inside, it can hide within Clathrin-coated vesicles for up to 72 hours to avoid being destroyed by the cell's digestive systems. As it colonizes the intestines, it releases toxins that contribute to the severity of the infection.

The resulting illness is known as campylobacteriosis. Most symptoms, such as abdominal pain, fever, and bloody diarrhea, develop within two to five days of exposure. The acute phase usually lasts about seven days, though pain can persist for weeks. While most cases are self-limiting, some people experience serious complications. Guillain–Barré syndrome is a rare neurological complication that develops in about 0.3 per 1000 infections. Another complication is reactive arthritis, which is strongly linked to individuals with the HLA-B27 genetic marker.

History shows how our understanding of this bacterium has evolved. It was originally named Vibrio jejuni because it looked similar to the Vibrio genus. In 1963, researchers proposed the new genus name, Campylobacter, based on its specific growth requirements and metabolism. The first well-recorded incident occurred in 1938, when 355 inmates in Illinois became ill from contaminated milk. By 1996, the CDC and other agencies identified C. jejuni as the cause of over 40% of bacterial gastroenteritis cases in laboratories.

Today, the scale of infection is massive. In the United States, the CDC estimates there are 1.5 million infections every year. The FoodNet surveillance network reports about 20 cases per 100,000 people annually, though many cases go unreported. In the European Union, the European Food Safety Authority estimated nine million cases of campylobacteriosis in 2018 alone. Because the bacteria are often found in ice, water, and raw poultry, careful food handling remains the best way to prevent these widespread infections.