Salmonella

Tiny germs called Salmonella live in many places.

They can live in animals like reptiles. Some germs can get into our food or water. This often happens if they touch waste.

These germs can move around. They have tiny parts that help them swim. They can live in dry places for a long time. They can even live in a bathroom for weeks.

These germs do not like heat. Cooking food well helps to kill them. You can also use bright light to stop them.

Eating bad food can make you sick. It can make your tummy hurt.

We can stay safe by being careful with food. Do you wash your hands after touching animals?

Salmonella are tiny germs called bacteria. They are shaped like rods. They have many small parts called flagella. These parts help them swim around.

There are two main types of Salmonella. One is called Salmonella enterica. The other is called Salmonella bongori. Some types can live in animals. For example, they live in reptiles. People can get sick if they touch these animals.

Salmonella can get into our food or water. This often happens through waste. These germs are very tough. They can live in dry places for years. They can even stay in a bathroom for weeks. They do not die in the freezer.

Heat is the best way to stop them. Cooking food to the right temperature kills the germs. They also die from bright UV light. If you eat food with these germs, you might get sick. This can cause a tummy ache. Some types can cause a fever. Scientists study these germs to keep us safe.

Salmonella is a group of tiny living things called bacteria. These germs are shaped like small rods. They belong to a large family of bacteria called Enterobacteriaceae. There are two main species in this group. One is named Salmonella enterica and the other is Salmonella bongori. The Salmonella enterica species is very large and diverse. It is divided into six subspecies. These groups include more than 2,650 different types called serotypes.

These bacteria have a very clever way of moving and eating. They have tiny parts called flagella that stick out all around their bodies. These flagella act like little motors to help them swim. They are also very good at making their own energy. They get energy from chemical reactions using organic sources. They are called facultative anaerobes. This means they can use oxygen to make energy when it is around. If there is no oxygen, they use a process called fermentation instead.

Scientists have been studying these germs for a long time. A man named Karl Eberth first saw them in 1880. He looked at the bodies of people with typhoid fever. Later, Georg Theodor Gaffky grew them in a pure culture in 1884. The group was named after Daniel Elmer Salmon. He was an American veterinary surgeon. A scientist named Joseph Leon Lignières suggested the name Salmonella in 1900. He chose it to honor Salmon's work.

Salmonella can be found in many different places. They live in the digestive tracts of humans and animals. You can often find them in reptiles. Some types can cause a sickness called salmonellosis. Other types cause more serious illnesses like typhoid fever. These germs are incredibly tough and can survive in dry places for years. They do not die in a freezer. They can even live in a bathroom for weeks.

We can protect ourselves by using heat to kill these germs. Heating food to the right internal temperature is the best way to stay safe. Most Salmonella will die if they are heated to 165°F for 12 minutes. They can also be destroyed by bright UV light. Scientists use special tests to find them in food. They can look at the DNA of the bacteria to see exactly which type it is. This helps them find where the germs came from.

Salmonella is a genus of rod-shaped bacteria known as bacilli. These organisms belong to the family Enterobacteriaceae. They are classified as Gram-negative, which describes their cell structure. Salmonella is a significant subject in microbiology because it includes many different types. Some of these types cause illness in humans and animals. Understanding these bacteria helps scientists prevent foodborne diseases and manage public health.

These bacteria have unique ways of moving and surviving. They possess peritrichous flagella, which are hair-like structures located all around the cell body. These flagella allow the bacteria to swim through different environments. Salmonella are also chemotrophs, meaning they get energy from oxidation and reduction reactions. They use organic sources to fuel these processes. Additionally, they are facultative anaerobes. This means they can produce adenosine triphosphate (ATP) using oxygen when it is available. If oxygen is missing, they use fermentation or other electron acceptors to generate energy.

The genus is divided into two primary species: Salmonella enterica and Salmonella bongori. Salmonella enterica is the type species and is highly diverse. It contains six subspecies, which include S. e. enterica, S. e. salamae, S. e. arizonae, S. e. diarizonae, S. e. houtenae, and S. e. indica. These subspecies are further divided into over 2,650 serotypes. Serotypes are specific varieties defined by their somatic O and flagellar H antigens. Scientists use the Kauffmann–White classification to organize these many different types.

History shows how our understanding of these bacteria grew over time. Karl Eberth first visualized Salmonella in 1880 within the spleens of typhoid patients. Four years later, Georg Theodor Gaffky successfully grew the pathogen in a pure culture. In 1885, Theobald Smith discovered Salmonella enterica while working for the United States Department of Agriculture. At that time, he worked under Daniel Elmer Salmon, a veterinary pathologist. The name Salmonella was proposed in 1900 by Joseph Leon Lignières to honor Salmon. Later, in the 1930s, Australian bacteriologist Nancy Atkinson established a specialized typing laboratory.

Salmonella causes different types of illness depending on the serotype. Nontyphoidal Salmonella are zoonotic, meaning they can move between animals and humans. They usually invade the gastrointestinal tract and cause salmonellosis. While these symptoms often resolve without antibiotics, they can be invasive in sub-Saharan Africa. Typhoidal Salmonella serotypes are different because they only transfer between humans. These can cause typhoid and paratyphoid fever by invading the bloodstream and organs. This can lead to serious conditions like septic shock or hypovolemic shock. Such cases require intensive care and antibiotics to treat.

These bacteria are remarkably resilient in many environments. They can survive desiccation, which is the process of drying out. This allows them to persist in dry foods and environments for years. Salmonella are not destroyed by freezing temperatures. However, they can be killed by heat or UV light. Most die after being heated to 165°F for 12 minutes. If they are in high-fat foods like peanut butter, they can survive up to 165°F for 30 minutes. To stay safe, it is recommended to heat food to an internal temperature of 165°F.

Modern science uses advanced tools to study and identify these bacteria. Scientists perform serotyping by mixing cells with antibodies for specific antigens. They also use molecular biology techniques like whole genome sequencing. Other methods include pulsed-field gel electrophoresis and real-time PCR. These DNA-based methods can be faster than traditional antibody reactions. Identifying the exact serotype helps investigators find the source of contamination. It also helps doctors choose the right antibiotics based on known resistance. This connection between genetics and medicine is vital for controlling outbreaks.